tools/debugserver/source/RNBRemote.cpp

//===-- RNBRemote.cpp -------------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  Created by Greg Clayton on 12/12/07.
//
//===----------------------------------------------------------------------===//

#include "RNBRemote.h"

#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include <mach/exception_types.h>
#include <sys/sysctl.h>

#include "DNB.h"
#include "DNBLog.h"
#include "DNBThreadResumeActions.h"
#include "RNBContext.h"
#include "RNBServices.h"
#include "RNBSocket.h"
#include "StringExtractor.h"

#include <iomanip>
#include <sstream>

#include <TargetConditionals.h> // for endianness predefines

//----------------------------------------------------------------------
// std::iostream formatting macros
//----------------------------------------------------------------------
#define RAW_HEXBASE     std::setfill('0') << std::hex << std::right
#define HEXBASE         '0' << 'x' << RAW_HEXBASE
#define RAWHEX8(x)      RAW_HEXBASE << std::setw(2) << ((uint32_t)((uint8_t)x))
#define RAWHEX16        RAW_HEXBASE << std::setw(4)
#define RAWHEX32        RAW_HEXBASE << std::setw(8)
#define RAWHEX64        RAW_HEXBASE << std::setw(16)
#define HEX8(x)         HEXBASE << std::setw(2) << ((uint32_t)(x))
#define HEX16           HEXBASE << std::setw(4)
#define HEX32           HEXBASE << std::setw(8)
#define HEX64           HEXBASE << std::setw(16)
#define RAW_HEX(x)      RAW_HEXBASE << std::setw(sizeof(x)*2) << (x)
#define HEX(x)          HEXBASE << std::setw(sizeof(x)*2) << (x)
#define RAWHEX_SIZE(x, sz)  RAW_HEXBASE << std::setw((sz)) << (x)
#define HEX_SIZE(x, sz) HEXBASE << std::setw((sz)) << (x)
#define STRING_WIDTH(w) std::setfill(' ') << std::setw(w)
#define LEFT_STRING_WIDTH(s, w) std::left << std::setfill(' ') << std::setw(w) << (s) << std::right
#define DECIMAL         std::dec << std::setfill(' ')
#define DECIMAL_WIDTH(w) DECIMAL << std::setw(w)
#define FLOAT(n, d)     std::setfill(' ') << std::setw((n)+(d)+1) << std::setprecision(d) << std::showpoint << std::fixed
#define INDENT_WITH_SPACES(iword_idx)   std::setfill(' ') << std::setw((iword_idx)) << ""
#define INDENT_WITH_TABS(iword_idx)     std::setfill('\t') << std::setw((iword_idx)) << ""
// Class to handle communications via gdb remote protocol.

extern void ASLLogCallback(void *baton, uint32_t flags, const char *format, va_list args);

RNBRemote::RNBRemote (bool use_native_regs) :
    m_ctx(),
    m_comm(),
    m_extended_mode(false),
    m_noack_mode(false),
    m_continue_thread(-1),
    m_thread(-1),
    m_mutex(),
    m_packets_recvd(0),
    m_packets(),
    m_rx_packets(),
    m_rx_partial_data(),
    m_rx_pthread(0),
    m_breakpoints(),
    m_max_payload_size(DEFAULT_GDB_REMOTE_PROTOCOL_BUFSIZE - 4),
    m_use_native_regs (use_native_regs)
{
    DNBLogThreadedIf (LOG_RNB_REMOTE, "%s", __PRETTY_FUNCTION__);
    CreatePacketTable ();
}


RNBRemote::~RNBRemote()
{
    DNBLogThreadedIf (LOG_RNB_REMOTE, "%s", __PRETTY_FUNCTION__);
    StopReadRemoteDataThread();
}

void
RNBRemote::CreatePacketTable  ()
{
    // Step required to add new packets:
    // 1 - Add new enumeration to RNBRemote::PacketEnum
    // 2 - Create a the RNBRemote::HandlePacket_ function if a new function is needed
    // 3 - Register the Packet definition with any needed callbacks in this fucntion
    //          - If no response is needed for a command, then use NULL for the normal callback
    //          - If the packet is not supported while the target is running, use NULL for the async callback
    // 4 - If the packet is a standard packet (starts with a '$' character
    //      followed by the payload and then '#' and checksum, then you are done
    //      else go on to step 5
    // 5 - if the packet is a fixed length packet:
    //      - modify the switch statement for the first character in the payload
    //        in RNBRemote::CommDataReceived so it doesn't reject the new packet
    //        type as invalid
    //      - modify the switch statement for the first character in the payload
    //        in RNBRemote::GetPacketPayload and make sure the payload of the packet
    //        is returned correctly

    std::vector <Packet> &t = m_packets;
    t.push_back (Packet (ack,                           NULL,                                   NULL, "+", "ACK"));
    t.push_back (Packet (nack,                          NULL,                                   NULL, "-", "!ACK"));
    t.push_back (Packet (read_memory,                   &RNBRemote::HandlePacket_m,             NULL, "m", "Read memory"));
    t.push_back (Packet (read_register,                 &RNBRemote::HandlePacket_p,             NULL, "p", "Read one register"));
    t.push_back (Packet (read_general_regs,             &RNBRemote::HandlePacket_g,             NULL, "g", "Read registers"));
    t.push_back (Packet (write_memory,                  &RNBRemote::HandlePacket_M,             NULL, "M", "Write memory"));
    t.push_back (Packet (write_register,                &RNBRemote::HandlePacket_P,             NULL, "P", "Write one register"));
    t.push_back (Packet (write_general_regs,            &RNBRemote::HandlePacket_G,             NULL, "G", "Write registers"));
    t.push_back (Packet (insert_mem_bp,                 &RNBRemote::HandlePacket_z,             NULL, "Z0", "Insert memory breakpoint"));
    t.push_back (Packet (remove_mem_bp,                 &RNBRemote::HandlePacket_z,             NULL, "z0", "Remove memory breakpoint"));
    t.push_back (Packet (single_step,                   &RNBRemote::HandlePacket_s,             NULL, "s", "Single step"));
    t.push_back (Packet (cont,                          &RNBRemote::HandlePacket_c,             NULL, "c", "continue"));
    t.push_back (Packet (single_step_with_sig,          &RNBRemote::HandlePacket_S,             NULL, "S", "Single step with signal"));
    t.push_back (Packet (set_thread,                    &RNBRemote::HandlePacket_H,             NULL, "H", "Set thread"));
    t.push_back (Packet (halt,                          &RNBRemote::HandlePacket_last_signal,   &RNBRemote::HandlePacket_stop_process, "\x03", "^C"));
//  t.push_back (Packet (use_extended_mode,             &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "!", "Use extended mode"));
    t.push_back (Packet (why_halted,                    &RNBRemote::HandlePacket_last_signal,   NULL, "?", "Why did target halt"));
    t.push_back (Packet (set_argv,                      &RNBRemote::HandlePacket_A,             NULL, "A", "Set argv"));
//  t.push_back (Packet (set_bp,                        &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "B", "Set/clear breakpoint"));
    t.push_back (Packet (continue_with_sig,             &RNBRemote::HandlePacket_C,             NULL, "C", "Continue with signal"));
    t.push_back (Packet (detach,                        &RNBRemote::HandlePacket_D,             NULL, "D", "Detach gdb from remote system"));
//  t.push_back (Packet (step_inferior_one_cycle,       &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "i", "Step inferior by one clock cycle"));
//  t.push_back (Packet (signal_and_step_inf_one_cycle, &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "I", "Signal inferior, then step one clock cyle"));
    t.push_back (Packet (kill,                          &RNBRemote::HandlePacket_k,             NULL, "k", "Kill"));
//  t.push_back (Packet (restart,                       &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "R", "Restart inferior"));
//  t.push_back (Packet (search_mem_backwards,          &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "t", "Search memory backwards"));
    t.push_back (Packet (thread_alive_p,                &RNBRemote::HandlePacket_T,             NULL, "T", "Is thread alive"));
    t.push_back (Packet (vattach,                       &RNBRemote::HandlePacket_v,             NULL, "vAttach", "Attach to a new process"));
    t.push_back (Packet (vattachwait,                   &RNBRemote::HandlePacket_v,             NULL, "vAttachWait", "Wait for a process to start up then attach to it"));
    t.push_back (Packet (vcont_list_actions,            &RNBRemote::HandlePacket_v,             NULL, "vCont;", "Verbose resume with thread actions"));
    t.push_back (Packet (vcont_list_actions,            &RNBRemote::HandlePacket_v,             NULL, "vCont?", "List valid continue-with-thread-actions actions"));
    // The X packet doesn't currently work. If/when it does, remove the line above and uncomment out the line below
//  t.push_back (Packet (write_data_to_memory,          &RNBRemote::HandlePacket_X,             NULL, "X", "Write data to memory"));
//  t.push_back (Packet (insert_hardware_bp,            &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "Z1", "Insert hardware breakpoint"));
//  t.push_back (Packet (remove_hardware_bp,            &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "z1", "Remove hardware breakpoint"));
//  t.push_back (Packet (insert_write_watch_bp,         &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "Z2", "Insert write watchpoint"));
//  t.push_back (Packet (remove_write_watch_bp,         &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "z2", "Remove write watchpoint"));
//  t.push_back (Packet (insert_read_watch_bp,          &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "Z3", "Insert read watchpoint"));
//  t.push_back (Packet (remove_read_watch_bp,          &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "z3", "Remove read watchpoint"));
//  t.push_back (Packet (insert_access_watch_bp,        &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "Z4", "Insert access watchpoint"));
//  t.push_back (Packet (remove_access_watch_bp,        &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "z4", "Remove access watchpoint"));
    t.push_back (Packet (query_current_thread_id,       &RNBRemote::HandlePacket_qC,            NULL, "qC", "Query current thread ID"));
//  t.push_back (Packet (query_memory_crc,              &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "qCRC:", "Compute CRC of memory region"));
    t.push_back (Packet (query_thread_ids_first,        &RNBRemote::HandlePacket_qThreadInfo,   NULL, "qfThreadInfo", "Get list of active threads (first req)"));
    t.push_back (Packet (query_thread_ids_subsequent,   &RNBRemote::HandlePacket_qThreadInfo,   NULL, "qsThreadInfo", "Get list of active threads (subsequent req)"));
    // APPLE LOCAL: qThreadStopInfo
    // syntax: qThreadStopInfoTTTT
    //  TTTT is hex thread ID
    t.push_back (Packet (query_thread_stop_info,        &RNBRemote::HandlePacket_qThreadStopInfo,   NULL, "qThreadStopInfo", "Get detailed info on why the specified thread stopped"));
    t.push_back (Packet (query_thread_extra_info,       &RNBRemote::HandlePacket_qThreadExtraInfo,NULL, "qThreadExtraInfo", "Get printable status of a thread"));
//  t.push_back (Packet (query_image_offsets,           &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "qOffsets", "Report offset of loaded program"));
    t.push_back (Packet (query_launch_success,          &RNBRemote::HandlePacket_qLaunchSuccess,NULL, "qLaunchSuccess", "Report the success or failure of the launch attempt"));
    t.push_back (Packet (query_register_info,           &RNBRemote::HandlePacket_qRegisterInfo, NULL, "qRegisterInfo", "Dynamically discover remote register context information."));
    t.push_back (Packet (query_shlib_notify_info_addr,  &RNBRemote::HandlePacket_qShlibInfoAddr,NULL, "qShlibInfoAddr", "Returns the address that contains info needed for getting shared library notifications"));
    t.push_back (Packet (query_step_packet_supported,   &RNBRemote::HandlePacket_qStepPacketSupported,NULL, "qStepPacketSupported", "Replys with OK if the 's' packet is supported."));
    t.push_back (Packet (query_host_info,               &RNBRemote::HandlePacket_qHostInfo,     NULL, "qHostInfo", "Replies with multiple 'key:value;' tuples appended to each other."));
//  t.push_back (Packet (query_symbol_lookup,           &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "qSymbol", "Notify that host debugger is ready to do symbol lookups"));
    t.push_back (Packet (start_noack_mode,              &RNBRemote::HandlePacket_Q            , NULL, "QStartNoAckMode", "Request that " DEBUGSERVER_PROGRAM_NAME " stop acking remote protocol packets"));
    t.push_back (Packet (set_logging_mode,              &RNBRemote::HandlePacket_Q            , NULL, "QSetLogging:", "Request that the " DEBUGSERVER_PROGRAM_NAME " set its logging mode bits"));
    t.push_back (Packet (set_max_packet_size,           &RNBRemote::HandlePacket_Q            , NULL, "QSetMaxPacketSize:", "Tell " DEBUGSERVER_PROGRAM_NAME " the max sized packet gdb can handle"));
    t.push_back (Packet (set_max_payload_size,          &RNBRemote::HandlePacket_Q            , NULL, "QSetMaxPayloadSize:", "Tell " DEBUGSERVER_PROGRAM_NAME " the max sized payload gdb can handle"));
    t.push_back (Packet (set_environment_variable,      &RNBRemote::HandlePacket_Q            , NULL, "QEnvironment:", "Add an environment variable to the inferior's environment"));
//  t.push_back (Packet (pass_signals_to_inferior,      &RNBRemote::HandlePacket_UNIMPLEMENTED, NULL, "QPassSignals:", "Specify which signals are passed to the inferior"));
    t.push_back (Packet (allocate_memory,               &RNBRemote::HandlePacket_AllocateMemory, NULL, "_M", "Allocate memory in the inferior process."));
    t.push_back (Packet (deallocate_memory,             &RNBRemote::HandlePacket_DeallocateMemory, NULL, "_m", "Deallocate memory in the inferior process."));
}


void
RNBRemote::FlushSTDIO ()
{
    if (m_ctx.HasValidProcessID())
    {
        nub_process_t pid = m_ctx.ProcessID();
        char buf[256];
        nub_size_t count;
        do
        {
            count = DNBProcessGetAvailableSTDOUT(pid, buf, sizeof(buf));
            if (count > 0)
            {
                SendSTDOUTPacket (buf, count);
            }
        } while (count > 0);

        do
        {
            count = DNBProcessGetAvailableSTDERR(pid, buf, sizeof(buf));
            if (count > 0)
            {
                SendSTDERRPacket (buf, count);
            }
        } while (count > 0);
    }
}

rnb_err_t
RNBRemote::SendHexEncodedBytePacket (const char *header, const void *buf, size_t buf_len, const char *footer)
{
    std::ostringstream packet_sstrm;
    // Append the header cstr if there was one
    if (header && header[0])
        packet_sstrm << header;
    nub_size_t i;
    const uint8_t *ubuf8 = (const uint8_t *)buf;
    for (i=0; i<buf_len; i++)
    {
        packet_sstrm << RAWHEX8(ubuf8[i]);
    }
    // Append the footer cstr if there was one
    if (footer && footer[0])
        packet_sstrm << footer;

    return SendPacket(packet_sstrm.str());
}

rnb_err_t
RNBRemote::SendSTDOUTPacket (char *buf, nub_size_t buf_size)
{
    if (buf_size == 0)
        return rnb_success;
    return SendHexEncodedBytePacket("O", buf, buf_size, NULL);
}

rnb_err_t
RNBRemote::SendSTDERRPacket (char *buf, nub_size_t buf_size)
{
    if (buf_size == 0)
        return rnb_success;
    return SendHexEncodedBytePacket("O", buf, buf_size, NULL);
}

rnb_err_t
RNBRemote::SendPacket (const std::string &s)
{
    DNBLogThreadedIf (LOG_RNB_MAX, "%8d RNBRemote::%s (%s) called", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__, s.c_str());
    std::string sendpacket = "$" + s + "#";
    int cksum = 0;
    char hexbuf[5];

    if (m_noack_mode)
    {
        sendpacket += "00";
    }
    else
    {
        for (int i = 0; i != s.size(); ++i)
            cksum += s[i];
        snprintf (hexbuf, sizeof hexbuf, "%02x", cksum & 0xff);
        sendpacket += hexbuf;
    }

    rnb_err_t err = m_comm.Write (sendpacket.c_str(), sendpacket.size());
    if (err != rnb_success)
        return err;

    if (m_noack_mode)
        return rnb_success;

    std::string reply;
    RNBRemote::Packet packet;
    err = GetPacket (reply, packet, true);

    if (err != rnb_success)
    {
        DNBLogThreadedIf (LOG_RNB_REMOTE, "%8d RNBRemote::%s (%s) got error trying to get reply...", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__, sendpacket.c_str());
        return err;
    }

    DNBLogThreadedIf (LOG_RNB_MAX, "%8d RNBRemote::%s (%s) got reply: '%s'", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__, sendpacket.c_str(), reply.c_str());

    if (packet.type == ack)
        return rnb_success;

    // Should we try to resend the packet at this layer?
    //  if (packet.command == nack)
    return rnb_err;
}

/* Get a packet via gdb remote protocol.
 Strip off the prefix/suffix, verify the checksum to make sure
 a valid packet was received, send an ACK if they match.  */

rnb_err_t
RNBRemote::GetPacketPayload (std::string &return_packet)
{
    //DNBLogThreadedIf (LOG_RNB_MAX, "%8u RNBRemote::%s called", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__);

    PThreadMutex::Locker locker(m_mutex);
    if (m_rx_packets.empty())
    {
        // Only reset the remote command available event if we have no more packets
        m_ctx.Events().ResetEvents ( RNBContext::event_read_packet_available );
        //DNBLogThreadedIf (LOG_RNB_MAX, "%8u RNBRemote::%s error: no packets available...", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__);
        return rnb_err;
    }

    //DNBLogThreadedIf (LOG_RNB_MAX, "%8u RNBRemote::%s has %u queued packets", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__, m_rx_packets.size());
    return_packet.swap(m_rx_packets.front());
    m_rx_packets.pop_front();
    locker.Reset(); // Release our lock on the mutex

    if (m_rx_packets.empty())
    {
        // Reset the remote command available event if we have no more packets
        m_ctx.Events().ResetEvents ( RNBContext::event_read_packet_available );
    }

    //DNBLogThreadedIf (LOG_RNB_MEDIUM, "%8u RNBRemote::%s: '%s'", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__, return_packet.c_str());

    switch (return_packet[0])
    {
        case '+':
        case '-':
        case '\x03':
            break;

        case '$':
        {
            int packet_checksum = 0;
            if (!m_noack_mode)
            {
                for (int i = return_packet.size() - 2; i < return_packet.size(); ++i)
                {
                    char checksum_char = tolower (return_packet[i]);
                    if (!isxdigit (checksum_char))
                    {
                        m_comm.Write ("-", 1);
                        DNBLogThreadedIf (LOG_RNB_REMOTE, "%8u RNBRemote::%s error: packet with invalid checksum characters: %s", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__, return_packet.c_str());
                        return rnb_err;
                    }
                }
                packet_checksum = strtol (&return_packet[return_packet.size() - 2], NULL, 16);
            }

            return_packet.erase(0,1);           // Strip the leading '$'
            return_packet.erase(return_packet.size() - 3);// Strip the #XX checksum

            if (!m_noack_mode)
            {
                // Compute the checksum
                int computed_checksum = 0;
                for (std::string::iterator it = return_packet.begin ();
                     it != return_packet.end ();
                     ++it)
                {
                    computed_checksum += *it;
                }

                if (packet_checksum == (computed_checksum & 0xff))
                {
                    //DNBLogThreadedIf (LOG_RNB_MEDIUM, "%8u RNBRemote::%s sending ACK for '%s'", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__, return_packet.c_str());
                    m_comm.Write ("+", 1);
                }
                else
                {
                    DNBLogThreadedIf (LOG_RNB_MEDIUM, "%8u RNBRemote::%s sending ACK for '%s' (error: packet checksum mismatch  (0x%2.2x != 0x%2.2x))",
                                      (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true),
                                      __FUNCTION__,
                                      return_packet.c_str(),
                                      packet_checksum,
                                      computed_checksum);
                    m_comm.Write ("-", 1);
                    return rnb_err;
                }
            }
        }
            break;

        default:
            DNBLogThreadedIf (LOG_RNB_REMOTE, "%8u RNBRemote::%s tossing unexpected packet???? %s", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__, return_packet.c_str());
            if (!m_noack_mode)
                m_comm.Write ("-", 1);
            return rnb_err;
    }

    return rnb_success;
}

rnb_err_t
RNBRemote::HandlePacket_UNIMPLEMENTED (const char* p)
{
    DNBLogThreadedIf (LOG_RNB_MAX, "%8u RNBRemote::%s(\"%s\")", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__, p ? p : "NULL");
    return SendPacket ("");
}

rnb_err_t
RNBRemote::HandlePacket_ILLFORMED (const char *description)
{
    DNBLogThreadedIf (LOG_RNB_MAX, "%8u RNBRemote::%s sending ILLFORMED", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__);
    return SendPacket ("E03");
}

rnb_err_t
RNBRemote::GetPacket (std::string &packet_payload, RNBRemote::Packet& packet_info, bool wait)
{
    std::string payload;
    rnb_err_t err = GetPacketPayload (payload);
    if (err != rnb_success)
    {
        PThreadEvent& events = m_ctx.Events();
        nub_event_t set_events = events.GetEventBits();
        // TODO: add timeout version of GetPacket?? We would then need to pass
        // that timeout value along to DNBProcessTimedWaitForEvent.
        if (!wait || ((set_events & RNBContext::event_read_thread_running) == 0))
            return err;

        const nub_event_t events_to_wait_for = RNBContext::event_read_packet_available | RNBContext::event_read_thread_exiting;
        set_events = 0;

        while ((set_events = events.WaitForSetEvents(events_to_wait_for)) != 0)
        {
            if (set_events & RNBContext::event_read_packet_available)
            {
                // Try the queue again now that we got an event
                err = GetPacketPayload (payload);
                if (err == rnb_success)
                    break;
            }

            if (set_events & RNBContext::event_read_thread_exiting)
                err = rnb_not_connected;

            if (err == rnb_not_connected)
                return err;

        } while (err == rnb_err);

        if (set_events == 0)
            err = rnb_not_connected;
    }

    if (err == rnb_success)
    {
        Packet::iterator it;
        for (it = m_packets.begin (); it != m_packets.end (); ++it)
        {
            if (payload.compare (0, it->abbrev.size(), it->abbrev) == 0)
                break;
        }

        // A packet we don't have an entry for. This can happen when we
        // get a packet that we don't know about or support. We just reply
        // accordingly and go on.
        if (it == m_packets.end ())
        {
            DNBLogThreadedIf (LOG_RNB_PACKETS, "unimplemented packet: '%s'", payload.c_str());
            HandlePacket_UNIMPLEMENTED(payload.c_str());
            return rnb_err;
        }
        else
        {
            packet_info = *it;
            packet_payload = payload;
        }
    }
    return err;
}

rnb_err_t
RNBRemote::HandleAsyncPacket(PacketEnum *type)
{
    DNBLogThreadedIf (LOG_RNB_REMOTE, "%8u RNBRemote::%s", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__);
    static DNBTimer g_packetTimer(true);
    rnb_err_t err = rnb_err;
    std::string packet_data;
    RNBRemote::Packet packet_info;
    err = GetPacket (packet_data, packet_info, false);

    if (err == rnb_success)
    {
        if (!packet_data.empty() && isprint(packet_data[0]))
            DNBLogThreadedIf (LOG_RNB_REMOTE | LOG_RNB_PACKETS, "HandleAsyncPacket (\"%s\");", packet_data.c_str());
        else
            DNBLogThreadedIf (LOG_RNB_REMOTE | LOG_RNB_PACKETS, "HandleAsyncPacket (%s);", packet_info.printable_name.c_str());

        HandlePacketCallback packet_callback = packet_info.async;
        if (packet_callback != NULL)
        {
            if (type != NULL)
                *type = packet_info.type;
            return (this->*packet_callback)(packet_data.c_str());
        }
    }

    return err;
}

rnb_err_t
RNBRemote::HandleReceivedPacket(PacketEnum *type)
{
    static DNBTimer g_packetTimer(true);

    //  DNBLogThreadedIf (LOG_RNB_REMOTE, "%8u RNBRemote::%s", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__);
    rnb_err_t err = rnb_err;
    std::string packet_data;
    RNBRemote::Packet packet_info;
    err = GetPacket (packet_data, packet_info, false);

    if (err == rnb_success)
    {
        DNBLogThreadedIf (LOG_RNB_REMOTE, "HandleReceivedPacket (\"%s\");", packet_data.c_str());
        HandlePacketCallback packet_callback = packet_info.normal;
        if (packet_callback != NULL)
        {
            if (type != NULL)
                *type = packet_info.type;
            return (this->*packet_callback)(packet_data.c_str());
        }
        else
        {
            // Do not fall through to end of this function, if we have valid
            // packet_info and it has a NULL callback, then we need to respect
            // that it may not want any response or anything to be done.
            return err;
        }
    }
    return rnb_err;
}

void
RNBRemote::CommDataReceived(const std::string& new_data)
{
    //  DNBLogThreadedIf (LOG_RNB_REMOTE, "%8d RNBRemote::%s called", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__);
    {
        // Put the packet data into the buffer in a thread safe fashion
        PThreadMutex::Locker locker(m_mutex);

        std::string data;
        // See if we have any left over data from a previous call to this
        // function?
        if (!m_rx_partial_data.empty())
        {
            // We do, so lets start with that data
            data.swap(m_rx_partial_data);
        }
        // Append the new incoming data
        data += new_data;

        // Parse up the packets into gdb remote packets
        uint32_t idx = 0;
        const size_t data_size = data.size();

        while (idx < data_size)
        {
            // end_idx must be one past the last valid packet byte. Start
            // it off with an invalid value that is the same as the current
            // index.
            size_t end_idx = idx;

            switch (data[idx])
            {
                case '+':       // Look for ack
                case '-':       // Look for cancel
                case '\x03':    // ^C to halt target
                    end_idx = idx + 1;  // The command is one byte long...
                    break;

                case '$':
                    // Look for a standard gdb packet?
                    end_idx = data.find('#',  idx + 1);
                    if (end_idx == std::string::npos || end_idx + 2 > data_size)
                    {
                        end_idx = std::string::npos;
                    }
                    else
                    {
                        // Add two for the checksum bytes
                        end_idx += 4;
                    }
                    break;

                default:
                    break;
            }

            if (end_idx == std::string::npos)
            {
                // Not all data may be here for the packet yet, save it for
                // next time through this function.
                m_rx_partial_data += data.substr(idx);
                //DNBLogThreadedIf (LOG_RNB_MAX, "%8d RNBRemote::%s saving data for later[%u, npos): '%s'",(uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__, idx, m_rx_partial_data.c_str());
                idx = end_idx;
            }
            else
                if (idx < end_idx)
                {
                    m_packets_recvd++;
                    // Hack to get rid of initial '+' ACK???
                    if (m_packets_recvd == 1 && (end_idx == idx + 1) && data[idx] == '+')
                    {
                        //DNBLogThreadedIf (LOG_RNB_REMOTE, "%8d RNBRemote::%s throwing first ACK away....[%u, npos): '+'",(uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__, idx);
                    }
                    else
                    {
                        // We have a valid packet...
                        m_rx_packets.push_back(data.substr(idx, end_idx - idx));
                        DNBLogThreadedIf (LOG_RNB_PACKETS, "getpkt: %s", m_rx_packets.back().c_str());
                    }
                    idx = end_idx;
                }
                else
                {
                    DNBLogThreadedIf (LOG_RNB_MAX, "%8d RNBRemote::%s tossing junk byte at %c",(uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__, data[idx]);
                    idx = idx + 1;
                }
        }
    }

    if (!m_rx_packets.empty())
    {
        // Let the main thread know we have received a packet

        //DNBLogThreadedIf (LOG_RNB_EVENTS, "%8d RNBRemote::%s   called events.SetEvent(RNBContext::event_read_packet_available)", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__);
        PThreadEvent& events = m_ctx.Events();
        events.SetEvents (RNBContext::event_read_packet_available);
    }
}

rnb_err_t
RNBRemote::GetCommData ()
{
    //  DNBLogThreadedIf (LOG_RNB_REMOTE, "%8d RNBRemote::%s called", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__);
    std::string comm_data;
    rnb_err_t err = m_comm.Read (comm_data);
    if (err == rnb_success)
    {
        if (!comm_data.empty())
            CommDataReceived (comm_data);
    }
    return err;
}

void
RNBRemote::StartReadRemoteDataThread()
{
    DNBLogThreadedIf (LOG_RNB_REMOTE, "%8u RNBRemote::%s called", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__);
    PThreadEvent& events = m_ctx.Events();
    if ((events.GetEventBits() & RNBContext::event_read_thread_running) == 0)
    {
        events.ResetEvents (RNBContext::event_read_thread_exiting);
        int err = ::pthread_create (&m_rx_pthread, NULL, ThreadFunctionReadRemoteData, this);
        if (err == 0)
        {
            // Our thread was successfully kicked off, wait for it to
            // set the started event so we can safely continue
            events.WaitForSetEvents (RNBContext::event_read_thread_running);
        }
        else
        {
            events.ResetEvents (RNBContext::event_read_thread_running);
            events.SetEvents (RNBContext::event_read_thread_exiting);
        }
    }
}

void
RNBRemote::StopReadRemoteDataThread()
{
    DNBLogThreadedIf (LOG_RNB_REMOTE, "%8u RNBRemote::%s called", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__);
    PThreadEvent& events = m_ctx.Events();
    if ((events.GetEventBits() & RNBContext::event_read_thread_running) == RNBContext::event_read_thread_running)
    {
        m_comm.Disconnect(true);
        struct timespec timeout_abstime;
        DNBTimer::OffsetTimeOfDay(&timeout_abstime, 2, 0);

        // Wait for 2 seconds for the remote data thread to exit
        if (events.WaitForSetEvents(RNBContext::event_read_thread_exiting, &timeout_abstime) == 0)
        {
            // Kill the remote data thread???
        }
    }
}


void*
RNBRemote::ThreadFunctionReadRemoteData(void *arg)
{
    // Keep a shared pointer reference so this doesn't go away on us before the thread is killed.
    DNBLogThreadedIf(LOG_RNB_REMOTE, "RNBRemote::%s (%p): thread starting...", __FUNCTION__, arg);
    RNBRemoteSP remoteSP(g_remoteSP);
    if (remoteSP.get() != NULL)
    {
        RNBRemote* remote = remoteSP.get();
        PThreadEvent& events = remote->Context().Events();
        events.SetEvents (RNBContext::event_read_thread_running);
        // START: main receive remote command thread loop
        bool done = false;
        while (!done)
        {
            rnb_err_t err = remote->GetCommData();

            switch (err)
            {
                case rnb_success:
                    break;

                default:
                case rnb_err:
                    DNBLogThreadedIf (LOG_RNB_REMOTE, "RNBSocket::GetCommData returned error %u", err);
                    done = true;
                    break;

                case rnb_not_connected:
                    DNBLogThreadedIf (LOG_RNB_REMOTE, "RNBSocket::GetCommData returned not connected...");
                    done = true;
                    break;
            }
        }
        // START: main receive remote command thread loop
        events.ResetEvents (RNBContext::event_read_thread_running);
        events.SetEvents (RNBContext::event_read_thread_exiting);
    }
    DNBLogThreadedIf(LOG_RNB_REMOTE, "RNBRemote::%s (%p): thread exiting...", __FUNCTION__, arg);
    return NULL;
}



/* Read the bytes in STR which are GDB Remote Protocol binary encoded bytes
 (8-bit bytes).
 This encoding uses 0x7d ('}') as an escape character for 0x7d ('}'),
 0x23 ('#'), and 0x24 ('$').
 LEN is the number of bytes to be processed.  If a character is escaped,
 it is 2 characters for LEN.  A LEN of -1 means encode-until-nul-byte
 (end of string).  */

std::vector<uint8_t>
decode_binary_data (const char *str, int len)
{
    std::vector<uint8_t> bytes;
    if (len == 0)
    {
        return bytes;
    }
    if (len == -1)
        len = strlen (str);

    while (len--)
    {
        unsigned char c = *str;
        if (c == 0x7d && len > 0)
        {
            len--;
            str++;
            c ^= 0x20;
        }
        bytes.push_back (c);
    }
    return bytes;
}

typedef struct register_map_entry
{
    uint32_t        gdb_regnum; // gdb register number
    uint32_t        gdb_size;   // gdb register size in bytes (can be greater than or less than to debugnub size...)
    const char *    gdb_name;   // gdb register name
    DNBRegisterInfo nub_info;   // debugnub register info
    const uint8_t*  fail_value; // Value to print if case we fail to reg this register (if this is NULL, we will return an error)
    int             expedite;   // expedite delivery of this register in last stop reply packets
} register_map_entry_t;



// If the notion of registers differs from what is handed out by the
// architecture, then flavors can be defined here.

static const uint32_t MAX_REGISTER_BYTE_SIZE = 16;
static const uint8_t k_zero_bytes[MAX_REGISTER_BYTE_SIZE] = {0};
static std::vector<register_map_entry_t> g_dynamic_register_map;
static register_map_entry_t *g_reg_entries = NULL;
static size_t g_num_reg_entries = 0;

static void
RegisterEntryNotAvailable (register_map_entry_t *reg_entry)
{
    reg_entry->fail_value = k_zero_bytes;
    reg_entry->nub_info.set = INVALID_NUB_REGNUM;
    reg_entry->nub_info.reg = INVALID_NUB_REGNUM;
    reg_entry->nub_info.name = NULL;
    reg_entry->nub_info.alt = NULL;
    reg_entry->nub_info.type = InvalidRegType;
    reg_entry->nub_info.format = InvalidRegFormat;
    reg_entry->nub_info.size = 0;
    reg_entry->nub_info.offset = 0;
    reg_entry->nub_info.reg_gcc = INVALID_NUB_REGNUM;
    reg_entry->nub_info.reg_dwarf = INVALID_NUB_REGNUM;
    reg_entry->nub_info.reg_generic = INVALID_NUB_REGNUM;
    reg_entry->nub_info.reg_gdb = INVALID_NUB_REGNUM;
}

#if defined (__arm__)

//----------------------------------------------------------------------
// ARM regiseter sets as gdb knows them
//----------------------------------------------------------------------

register_map_entry_t
g_gdb_register_map_arm[] =
{
    {  0,  4,  "r0",    {0}, NULL, 1},
    {  1,  4,  "r1",    {0}, NULL, 1},
    {  2,  4,  "r2",    {0}, NULL, 1},
    {  3,  4,  "r3",    {0}, NULL, 1},
    {  4,  4,  "r4",    {0}, NULL, 1},
    {  5,  4,  "r5",    {0}, NULL, 1},
    {  6,  4,  "r6",    {0}, NULL, 1},
    {  7,  4,  "r7",    {0}, NULL, 1},
    {  8,  4,  "r8",    {0}, NULL, 1},
    {  9,  4,  "r9",    {0}, NULL, 1},
    { 10,  4, "r10",    {0}, NULL, 1},
    { 11,  4, "r11",    {0}, NULL, 1},
    { 12,  4, "r12",    {0}, NULL, 1},
    { 13,  4,  "sp",    {0}, NULL, 1},
    { 14,  4,  "lr",    {0}, NULL, 1},
    { 15,  4,  "pc",    {0}, NULL, 1},
    { 16, 12,  "f0",    NULL, k_zero_bytes, 0},
    { 17, 12,  "f1",    NULL, k_zero_bytes, 0},
    { 18, 12,  "f2",    NULL, k_zero_bytes, 0},
    { 19, 12,  "f3",    NULL, k_zero_bytes, 0},
    { 20, 12,  "f4",    NULL, k_zero_bytes, 0},
    { 21, 12,  "f5",    NULL, k_zero_bytes, 0},
    { 22, 12,  "f6",    NULL, k_zero_bytes, 0},
    { 23, 12,  "f7",    NULL, k_zero_bytes, 0},
    { 24,  4, "fps",    {0}, NULL, 0},
    { 25,  4,"cpsr",    {0}, NULL, 1},
    { 26,  4,  "s0",    {0}, NULL, 0},
    { 27,  4,  "s1",    {0}, NULL, 0},
    { 28,  4,  "s2",    {0}, NULL, 0},
    { 29,  4,  "s3",    {0}, NULL, 0},
    { 30,  4,  "s4",    {0}, NULL, 0},
    { 31,  4,  "s5",    {0}, NULL, 0},
    { 32,  4,  "s6",    {0}, NULL, 0},
    { 33,  4,  "s7",    {0}, NULL, 0},
    { 34,  4,  "s8",    {0}, NULL, 0},
    { 35,  4,  "s9",    {0}, NULL, 0},
    { 36,  4, "s10",    {0}, NULL, 0},
    { 37,  4, "s11",    {0}, NULL, 0},
    { 38,  4, "s12",    {0}, NULL, 0},
    { 39,  4, "s13",    {0}, NULL, 0},
    { 40,  4, "s14",    {0}, NULL, 0},
    { 41,  4, "s15",    {0}, NULL, 0},
    { 42,  4, "s16",    {0}, NULL, 0},
    { 43,  4, "s17",    {0}, NULL, 0},
    { 44,  4, "s18",    {0}, NULL, 0},
    { 45,  4, "s19",    {0}, NULL, 0},
    { 46,  4, "s20",    {0}, NULL, 0},
    { 47,  4, "s21",    {0}, NULL, 0},
    { 48,  4, "s22",    {0}, NULL, 0},
    { 49,  4, "s23",    {0}, NULL, 0},
    { 50,  4, "s24",    {0}, NULL, 0},
    { 51,  4, "s25",    {0}, NULL, 0},
    { 52,  4, "s26",    {0}, NULL, 0},
    { 53,  4, "s27",    {0}, NULL, 0},
    { 54,  4, "s28",    {0}, NULL, 0},
    { 55,  4, "s29",    {0}, NULL, 0},
    { 56,  4, "s30",    {0}, NULL, 0},
    { 57,  4, "s31",    {0}, NULL, 0},
    { 58,  4, "fpscr",  {0}, NULL, 0}
};

void
RNBRemote::InitializeRegisters (int use_native_registers)
{
    if (use_native_registers)
    {
        RNBRemote::InitializeNativeRegisters();
    }
    else
    {
        const size_t num_regs = sizeof (g_gdb_register_map_arm) / sizeof (register_map_entry_t);
        for (uint32_t i=0; i<num_regs; ++i)
        {
            if (!DNBGetRegisterInfoByName (g_gdb_register_map_arm[i].gdb_name, &g_gdb_register_map_arm[i].nub_info))
            {
                RegisterEntryNotAvailable (&g_gdb_register_map_arm[i]);
                assert (g_gdb_register_map_arm[i].gdb_size <= MAX_REGISTER_BYTE_SIZE);
            }
        }
        g_reg_entries = g_gdb_register_map_arm;
        g_num_reg_entries = sizeof (g_gdb_register_map_arm) / sizeof (register_map_entry_t);
    }
}


#elif defined (__i386__)

register_map_entry_t
g_gdb_register_map_i386[] =
{
    {  0,   4, "eax"    , {0}, NULL, 0 },
    {  1,   4, "ecx"    , {0}, NULL, 0 },
    {  2,   4, "edx"    , {0}, NULL, 0 },
    {  3,   4, "ebx"    , {0}, NULL, 0 },
    {  4,   4, "esp"    , {0}, NULL, 1 },
    {  5,   4, "ebp"    , {0}, NULL, 1 },
    {  6,   4, "esi"    , {0}, NULL, 0 },
    {  7,   4, "edi"    , {0}, NULL, 0 },
    {  8,   4, "eip"    , {0}, NULL, 1 },
    {  9,   4, "eflags" , {0}, NULL, 0 },
    { 10,   4, "cs"     , {0}, NULL, 0 },
    { 11,   4, "ss"     , {0}, NULL, 0 },
    { 12,   4, "ds"     , {0}, NULL, 0 },
    { 13,   4, "es"     , {0}, NULL, 0 },
    { 14,   4, "fs"     , {0}, NULL, 0 },
    { 15,   4, "gs"     , {0}, NULL, 0 },
    { 16,  10, "stmm0"  , {0}, NULL, 0 },
    { 17,  10, "stmm1"  , {0}, NULL, 0 },
    { 18,  10, "stmm2"  , {0}, NULL, 0 },
    { 19,  10, "stmm3"  , {0}, NULL, 0 },
    { 20,  10, "stmm4"  , {0}, NULL, 0 },
    { 21,  10, "stmm5"  , {0}, NULL, 0 },
    { 22,  10, "stmm6"  , {0}, NULL, 0 },
    { 23,  10, "stmm7"  , {0}, NULL, 0 },
    { 24,   4, "fctrl"  , {0}, NULL, 0 },
    { 25,   4, "fstat"  , {0}, NULL, 0 },
    { 26,   4, "ftag"   , {0}, NULL, 0 },
    { 27,   4, "fiseg"  , {0}, NULL, 0 },
    { 28,   4, "fioff"  , {0}, NULL, 0 },
    { 29,   4, "foseg"  , {0}, NULL, 0 },
    { 30,   4, "fooff"  , {0}, NULL, 0 },
    { 31,   4, "fop"    , {0}, NULL, 0 },
    { 32,  16, "xmm0"   , {0}, NULL, 0 },
    { 33,  16, "xmm1"   , {0}, NULL, 0 },
    { 34,  16, "xmm2"   , {0}, NULL, 0 },
    { 35,  16, "xmm3"   , {0}, NULL, 0 },
    { 36,  16, "xmm4"   , {0}, NULL, 0 },
    { 37,  16, "xmm5"   , {0}, NULL, 0 },
    { 38,  16, "xmm6"   , {0}, NULL, 0 },
    { 39,  16, "xmm7"   , {0}, NULL, 0 },
    { 40,   4, "mxcsr"  , {0}, NULL, 0 },
};

void
RNBRemote::InitializeRegisters (int use_native_registers)
{
    if (use_native_registers)
    {
        RNBRemote::InitializeNativeRegisters();
    }
    else
    {
        const size_t num_regs = sizeof (g_gdb_register_map_i386) / sizeof (register_map_entry_t);
        for (uint32_t i=0; i<num_regs; ++i)
        {
            if (!DNBGetRegisterInfoByName (g_gdb_register_map_i386[i].gdb_name, &g_gdb_register_map_i386[i].nub_info))
            {
                RegisterEntryNotAvailable (&g_gdb_register_map_i386[i]);
                assert (g_gdb_register_map_i386[i].gdb_size <= MAX_REGISTER_BYTE_SIZE);
            }
        }
        g_reg_entries = g_gdb_register_map_i386;
        g_num_reg_entries = sizeof (g_gdb_register_map_i386) / sizeof (register_map_entry_t);
    }
}


#elif defined (__x86_64__)

register_map_entry_t
g_gdb_register_map_x86_64[] =
{
    {  0,   8, "rax"   , {0}, NULL, 0 },
    {  1,   8, "rbx"   , {0}, NULL, 0 },
    {  2,   8, "rcx"   , {0}, NULL, 0 },
    {  3,   8, "rdx"   , {0}, NULL, 0 },
    {  4,   8, "rsi"   , {0}, NULL, 0 },
    {  5,   8, "rdi"   , {0}, NULL, 0 },
    {  6,   8, "rbp"   , {0}, NULL, 1 },
    {  7,   8, "rsp"   , {0}, NULL, 1 },
    {  8,   8, "r8"    , {0}, NULL, 0 },
    {  9,   8, "r9"    , {0}, NULL, 0 },
    { 10,   8, "r10"   , {0}, NULL, 0 },
    { 11,   8, "r11"   , {0}, NULL, 0 },
    { 12,   8, "r12"   , {0}, NULL, 0 },
    { 13,   8, "r13"   , {0}, NULL, 0 },
    { 14,   8, "r14"   , {0}, NULL, 0 },
    { 15,   8, "r15"   , {0}, NULL, 0 },
    { 16,   8, "rip"   , {0}, NULL, 1 },
    { 17,   4, "rflags", {0}, NULL, 0 },
    { 18,   4, "cs"    , {0}, NULL, 0 },
    { 19,   4, "ss"    , {0}, NULL, 0 },
    { 20,   4, "ds"    , {0}, NULL, 0 },
    { 21,   4, "es"    , {0}, NULL, 0 },
    { 22,   4, "fs"    , {0}, NULL, 0 },
    { 23,   4, "gs"    , {0}, NULL, 0 },
    { 24,  10, "stmm0" , {0}, NULL, 0 },
    { 25,  10, "stmm1" , {0}, NULL, 0 },
    { 26,  10, "stmm2" , {0}, NULL, 0 },
    { 27,  10, "stmm3" , {0}, NULL, 0 },
    { 28,  10, "stmm4" , {0}, NULL, 0 },
    { 29,  10, "stmm5" , {0}, NULL, 0 },
    { 30,  10, "stmm6" , {0}, NULL, 0 },
    { 31,  10, "stmm7" , {0}, NULL, 0 },
    { 32,   4, "fctrl" , {0}, NULL, 0 },
    { 33,   4, "fstat" , {0}, NULL, 0 },
    { 34,   4, "ftag"  , {0}, NULL, 0 },
    { 35,   4, "fiseg" , {0}, NULL, 0 },
    { 36,   4, "fioff" , {0}, NULL, 0 },
    { 37,   4, "foseg" , {0}, NULL, 0 },
    { 38,   4, "fooff" , {0}, NULL, 0 },
    { 39,   4, "fop"   , {0}, NULL, 0 },
    { 40,  16, "xmm0"  , {0}, NULL, 0 },
    { 41,  16, "xmm1"  , {0}, NULL, 0 },
    { 42,  16, "xmm2"  , {0}, NULL, 0 },
    { 43,  16, "xmm3"  , {0}, NULL, 0 },
    { 44,  16, "xmm4"  , {0}, NULL, 0 },
    { 45,  16, "xmm5"  , {0}, NULL, 0 },
    { 46,  16, "xmm6"  , {0}, NULL, 0 },
    { 47,  16, "xmm7"  , {0}, NULL, 0 },
    { 48,  16, "xmm8"  , {0}, NULL, 0 },
    { 49,  16, "xmm9"  , {0}, NULL, 0 },
    { 50,  16, "xmm10" , {0}, NULL, 0 },
    { 51,  16, "xmm11" , {0}, NULL, 0 },
    { 52,  16, "xmm12" , {0}, NULL, 0 },
    { 53,  16, "xmm13" , {0}, NULL, 0 },
    { 54,  16, "xmm14" , {0}, NULL, 0 },
    { 55,  16, "xmm15" , {0}, NULL, 0 },
    { 56,   4, "mxcsr" , {0}, NULL, 0 }
};

void
RNBRemote::InitializeRegisters (int use_native_registers)
{
    if (use_native_registers)
    {
        RNBRemote::InitializeNativeRegisters();
    }
    else
    {
        const size_t num_regs = sizeof (g_gdb_register_map_x86_64) / sizeof (register_map_entry_t);
        for (uint32_t i=0; i<num_regs; ++i)
        {
            if (!DNBGetRegisterInfoByName (g_gdb_register_map_x86_64[i].gdb_name, &g_gdb_register_map_x86_64[i].nub_info))
            {
                RegisterEntryNotAvailable (&g_gdb_register_map_x86_64[i]);
                assert (g_gdb_register_map_x86_64[i].gdb_size < MAX_REGISTER_BYTE_SIZE);
            }
        }
        g_reg_entries = g_gdb_register_map_x86_64;
        g_num_reg_entries = sizeof (g_gdb_register_map_x86_64) / sizeof (register_map_entry_t);
    }
}


#else

void
RNBRemote::InitializeRegisters (int use_native_registers)
{
    // No choice, we don't have a GDB register definition for this arch.
    RNBRemote::InitializeNativeRegisters();
}

#endif


void
RNBRemote::InitializeNativeRegisters()
{
    if (g_dynamic_register_map.empty())
    {
        nub_size_t num_reg_sets = 0;
        const DNBRegisterSetInfo *reg_sets = DNBGetRegisterSetInfo (&num_reg_sets);

        assert (num_reg_sets > 0 && reg_sets != NULL);

        uint32_t regnum = 0;
        for (nub_size_t set = 0; set < num_reg_sets; ++set)
        {
            if (reg_sets[set].registers == NULL)
                continue;

            for (uint32_t reg=0; reg < reg_sets[set].num_registers; ++reg)
            {
                register_map_entry_t reg_entry = {
                    regnum++,                           // register number starts at zero and goes up with no gaps
                    reg_sets[set].registers[reg].size,  // register size in bytes
                    reg_sets[set].registers[reg].name,  // register name
                    reg_sets[set].registers[reg],       // DNBRegisterInfo
                    NULL,                               // Value to print if case we fail to reg this register (if this is NULL, we will return an error)
                    reg_sets[set].registers[reg].reg_generic != INVALID_NUB_REGNUM};

                g_dynamic_register_map.push_back (reg_entry);
            }
        }
        g_reg_entries = g_dynamic_register_map.data();
        g_num_reg_entries = g_dynamic_register_map.size();
    }
}


const register_map_entry_t *
register_mapping_by_regname (const char *n)
{
    for (uint32_t reg = 0; reg < g_num_reg_entries; reg++)
    {
        if (strcmp (g_reg_entries[reg].gdb_name, n) == 0)
            return &g_reg_entries[reg];
    }
    return NULL;
}

/* The inferior has stopped executing; send a packet
 to gdb to let it know.  */

void
RNBRemote::NotifyThatProcessStopped (void)
{
    RNBRemote::HandlePacket_last_signal ("");
    return;
}


/* `A arglen,argnum,arg,...'
 Update the inferior context CTX with the program name and arg
 list.
 The documentation for this packet is underwhelming but my best reading
 of this is that it is a series of (len, position #, arg)'s, one for
 each argument with "arg" ``hex encoded'' (two 0-9a-f chars?).
 Why we need BOTH a "len" and a hex encoded "arg" is beyond me - either
 is sufficient to get around the "," position separator escape issue.

 e.g. our best guess for a valid 'A' packet for "gdb -q a.out" is

 6,0,676462,4,1,2d71,10,2,612e6f7574

 Note that "argnum" and "arglen" are numbers in base 10.  Again, that's
 not documented either way but I'm assuming it's so.  */

rnb_err_t
RNBRemote::HandlePacket_A (const char *p)
{
    if (p == NULL || *p == '\0')
    {
        return HandlePacket_ILLFORMED ("Null packet for 'A' pkt");
    }
    p++;
    if (p == '\0' || !isdigit (*p))
    {
        return HandlePacket_ILLFORMED ("arglen not specified on 'A' pkt");
    }

    /* I promise I don't modify it anywhere in this function.  strtoul()'s
     2nd arg has to be non-const which makes it problematic to step
     through the string easily.  */
    char *buf = const_cast<char *>(p);

    RNBContext& ctx = Context();

    while (*buf != '\0')
    {
        int arglen, argnum;
        std::string arg;
        char *c;

        errno = 0;
        arglen = strtoul (buf, &c, 10);
        if (errno != 0 && arglen == 0)
        {
            return HandlePacket_ILLFORMED ("arglen not a number on 'A' pkt");
        }
        if (*c != ',')
        {
            return HandlePacket_ILLFORMED ("arglen not followed by comma on 'A' pkt");
        }
        buf = c + 1;

        errno = 0;
        argnum = strtoul (buf, &c, 10);
        if (errno != 0 && argnum == 0)
        {
            return HandlePacket_ILLFORMED ("argnum not a number on 'A' pkt");
        }
        if (*c != ',')
        {
            return HandlePacket_ILLFORMED ("arglen not followed by comma on 'A' pkt");
        }
        buf = c + 1;

        c = buf;
        buf = buf + arglen;
        while (c < buf && *c != '\0' && c + 1 < buf && *(c + 1) != '\0')
        {
            char smallbuf[3];
            smallbuf[0] = *c;
            smallbuf[1] = *(c + 1);
            smallbuf[2] = '\0';

            errno = 0;
            int ch = strtoul (smallbuf, NULL, 16);
            if (errno != 0 && ch == 0)
            {
                return HandlePacket_ILLFORMED ("non-hex char in arg on 'A' pkt");
            }

            arg.push_back(ch);
            c += 2;
        }

        ctx.PushArgument (arg.c_str());
        if (*buf == ',')
            buf++;
    }
    SendPacket ("OK");

    return rnb_success;
}

/* `H c t'
 Set the thread for subsequent actions; 'c' for step/continue ops,
 'g' for other ops.  -1 means all threads, 0 means any thread.  */

rnb_err_t
RNBRemote::HandlePacket_H (const char *p)
{
    p++;  // skip 'H'
    if (*p != 'c' && *p != 'g')
    {
        return HandlePacket_ILLFORMED ("Missing 'c' or 'g' type in H packet");
    }

    if (!m_ctx.HasValidProcessID())
    {
        // We allow gdb to connect to a server that hasn't started running
        // the target yet.  gdb still wants to ask questions about it and
        // freaks out if it gets an error.  So just return OK here.
    }

    errno = 0;
    nub_thread_t tid = strtoul (p + 1, NULL, 16);
    if (errno != 0 && tid == 0)
    {
        return HandlePacket_ILLFORMED ("Invalid thread number in H packet");
    }
    if (*p == 'c')
        SetContinueThread (tid);
    if (*p == 'g')
        SetCurrentThread (tid);

    return SendPacket ("OK");
}


rnb_err_t
RNBRemote::HandlePacket_qLaunchSuccess (const char *p)
{
    if (m_ctx.HasValidProcessID() || m_ctx.LaunchStatus().Error() == 0)
        return SendPacket("OK");
    std::ostringstream ret_str;
    std::string status_str;
    ret_str << "E" << m_ctx.LaunchStatusAsString(status_str);

    return SendPacket (ret_str.str());
}

rnb_err_t
RNBRemote::HandlePacket_qShlibInfoAddr (const char *p)
{
    if (m_ctx.HasValidProcessID())
    {
        nub_addr_t shlib_info_addr = DNBProcessGetSharedLibraryInfoAddress(m_ctx.ProcessID());
        if (shlib_info_addr != INVALID_NUB_ADDRESS)
        {
            std::ostringstream ostrm;
            ostrm << RAW_HEXBASE << shlib_info_addr;
            return SendPacket (ostrm.str ());
        }
    }
    return SendPacket ("E44");
}

rnb_err_t
RNBRemote::HandlePacket_qStepPacketSupported (const char *p)
{
    // Normally the "s" packet is mandatory, yet in gdb when using ARM, they
    // get around the need for this packet by implementing software single
    // stepping from gdb. Current versions of debugserver do support the "s"
    // packet, yet some older versions do not. We need a way to tell if this
    // packet is supported so we can disable software single stepping in gdb
    // for remote targets (so the "s" packet will get used).
    return SendPacket("OK");
}

rnb_err_t
RNBRemote::HandlePacket_qThreadStopInfo (const char *p)
{
    p += strlen ("qThreadStopInfo");
    nub_thread_t tid = strtoul(p, 0, 16);
    return SendStopReplyPacketForThread (tid);
}

rnb_err_t
RNBRemote::HandlePacket_qThreadInfo (const char *p)
{
    // We allow gdb to connect to a server that hasn't started running
    // the target yet.  gdb still wants to ask questions about it and
    // freaks out if it gets an error.  So just return OK here.
    nub_process_t pid = m_ctx.ProcessID();
    if (pid == INVALID_NUB_PROCESS)
        return SendPacket ("OK");

    // Only "qfThreadInfo" and "qsThreadInfo" get into this function so
    // we only need to check the second byte to tell which is which
    if (p[1] == 'f')
    {
        nub_size_t numthreads = DNBProcessGetNumThreads (pid);
        std::ostringstream ostrm;
        ostrm << "m";
        bool first = true;
        for (nub_size_t i = 0; i < numthreads; ++i)
        {
            if (first)
                first = false;
            else
                ostrm << ",";
            nub_thread_t th = DNBProcessGetThreadAtIndex (pid, i);
            ostrm << std::hex << th;
        }
        return SendPacket (ostrm.str ());
    }
    else
    {
        return SendPacket ("l");
    }
}

rnb_err_t
RNBRemote::HandlePacket_qThreadExtraInfo (const char *p)
{
    // We allow gdb to connect to a server that hasn't started running
    // the target yet.  gdb still wants to ask questions about it and
    // freaks out if it gets an error.  So just return OK here.
    nub_process_t pid = m_ctx.ProcessID();
    if (pid == INVALID_NUB_PROCESS)
        return SendPacket ("OK");

    /* This is supposed to return a string like 'Runnable' or
     'Blocked on Mutex'.
     The returned string is formatted like the "A" packet - a
     sequence of letters encoded in as 2-hex-chars-per-letter.  */
    p += strlen ("qThreadExtraInfo");
    if (*p++ != ',')
        return HandlePacket_ILLFORMED ("Ill formed qThreadExtraInfo packet");
    errno = 0;
    nub_thread_t tid = strtoul (p, NULL, 16);
    if (errno != 0 && tid == 0)
    {
        return HandlePacket_ILLFORMED ("Invalid thread number in qThreadExtraInfo packet");
    }

    const char * threadInfo = DNBThreadGetInfo(pid, tid);
    if (threadInfo != NULL && threadInfo[0])
    {
        return SendHexEncodedBytePacket(NULL, threadInfo, strlen(threadInfo), NULL);
    }
    else
    {
        // "OK" == 4f6b
        // Return "OK" as a ASCII hex byte stream if things go wrong
        return SendPacket ("4f6b");
    }

    return SendPacket ("");
}

rnb_err_t
RNBRemote::HandlePacket_qC (const char *p)
{
    nub_process_t pid;
    std::ostringstream rep;
    // If we haven't run the process yet, we tell the debugger the
    // pid is 0.  That way it can know to tell use to run later on.
    if (m_ctx.HasValidProcessID())
        pid = m_ctx.ProcessID();
    else
        pid = 0;
    rep << "QC" << std::hex << pid;
    return SendPacket (rep.str());
}

rnb_err_t
RNBRemote::HandlePacket_qRegisterInfo (const char *p)
{
    p += strlen ("qRegisterInfo");

    nub_size_t num_reg_sets = 0;
    const DNBRegisterSetInfo *reg_set_info = DNBGetRegisterSetInfo (&num_reg_sets);
    uint32_t reg_num = strtoul(p, 0, 16);

    if (reg_num < g_num_reg_entries)
    {
        const register_map_entry_t *reg_entry = &g_reg_entries[reg_num];
        std::ostringstream ostrm;
        ostrm << "name:" << reg_entry->gdb_name << ';';

        if (reg_entry->nub_info.name && ::strcmp (reg_entry->gdb_name, reg_entry->nub_info.name))
            ostrm << "alt-name:" << reg_entry->nub_info.name << ';';
        else if (reg_entry->nub_info.alt && ::strcmp (reg_entry->gdb_name, reg_entry->nub_info.alt))
            ostrm << "alt-name:" << reg_entry->nub_info.alt << ';';

        ostrm << "bitsize:" << std::dec << reg_entry->gdb_size * 8 << ';';
        ostrm << "offset:" << std::dec << reg_entry->nub_info.offset << ';';

        switch (reg_entry->nub_info.type)
        {
            case Uint:      ostrm << "encoding:uint;"; break;
            case Sint:      ostrm << "encoding:sint;"; break;
            case IEEE754:   ostrm << "encoding:ieee754;"; break;
            case Vector:    ostrm << "encoding:vector;"; break;
        }

        switch (reg_entry->nub_info.format)
        {
            case Binary:            ostrm << "format:binary;"; break;
            case Decimal:           ostrm << "format:decimal;"; break;
            case Hex:               ostrm << "format:hex;"; break;
            case Float:             ostrm << "format:float;"; break;
            case VectorOfSInt8:     ostrm << "format:vector-sint8;"; break;
            case VectorOfUInt8:     ostrm << "format:vector-uint8;"; break;
            case VectorOfSInt16:    ostrm << "format:vector-sint16;"; break;
            case VectorOfUInt16:    ostrm << "format:vector-uint16;"; break;
            case VectorOfSInt32:    ostrm << "format:vector-sint32;"; break;
            case VectorOfUInt32:    ostrm << "format:vector-uint32;"; break;
            case VectorOfFloat32:   ostrm << "format:vector-float32;"; break;
            case VectorOfUInt128:   ostrm << "format:vector-uint128;"; break;
        };

        if (reg_set_info && reg_entry->nub_info.set < num_reg_sets)
            ostrm << "set:" << reg_set_info[reg_entry->nub_info.set].name << ';';


        if (g_reg_entries != g_dynamic_register_map.data())
        {
            if (reg_entry->nub_info.reg_gdb != INVALID_NUB_REGNUM && reg_entry->nub_info.reg_gdb != reg_num)
            {
                printf("register %s is getting gdb reg_num of %u when the register info says %u\n",
                       reg_entry->gdb_name, reg_num, reg_entry->nub_info.reg_gdb);
            }
        }

        if (reg_entry->nub_info.reg_gcc != INVALID_NUB_REGNUM)
            ostrm << "gcc:" << std::dec << reg_entry->nub_info.reg_gcc << ';';

        if (reg_entry->nub_info.reg_dwarf != INVALID_NUB_REGNUM)
            ostrm << "dwarf:" << std::dec << reg_entry->nub_info.reg_dwarf << ';';


        switch (reg_entry->nub_info.reg_generic)
        {
            case GENERIC_REGNUM_FP:     ostrm << "generic:fp;"; break;
            case GENERIC_REGNUM_PC:     ostrm << "generic:pc;"; break;
            case GENERIC_REGNUM_SP:     ostrm << "generic:sp;"; break;
            case GENERIC_REGNUM_RA:     ostrm << "generic:ra;"; break;
            case GENERIC_REGNUM_FLAGS:  ostrm << "generic:flags;"; break;
            default: break;
        }

        return SendPacket (ostrm.str ());
    }
    return SendPacket ("E45");
}


/* This expects a packet formatted like

 QSetLogging:bitmask=LOG_ALL|LOG_RNB_REMOTE;

 with the "QSetLogging:" already removed from the start.  Maybe in the
 future this packet will include other keyvalue pairs like

 QSetLogging:bitmask=LOG_ALL;mode=asl;
 */

rnb_err_t
set_logging (const char *p)
{
    int bitmask = 0;
    while (p && *p != '\0')
    {
        if (strncmp (p, "bitmask=", sizeof ("bitmask=") - 1) == 0)
        {
            p += sizeof ("bitmask=") - 1;
            while (p && *p != '\0' && *p != ';')
            {
                if (*p == '|')
                    p++;
                if (strncmp (p, "LOG_VERBOSE", sizeof ("LOG_VERBOSE") - 1) == 0)
                {
                    p += sizeof ("LOG_VERBOSE") - 1;
                    bitmask |= LOG_VERBOSE;
                }
                else if (strncmp (p, "LOG_PROCESS", sizeof ("LOG_PROCESS") - 1) == 0)
                {
                    p += sizeof ("LOG_PROCESS") - 1;
                    bitmask |= LOG_PROCESS;
                }
                else if (strncmp (p, "LOG_THREAD", sizeof ("LOG_THREAD") - 1) == 0)
                {
                    p += sizeof ("LOG_THREAD") - 1;
                    bitmask |= LOG_THREAD;
                }
                else if (strncmp (p, "LOG_EXCEPTIONS", sizeof ("LOG_EXCEPTIONS") - 1) == 0)
                {
                    p += sizeof ("LOG_EXCEPTIONS") - 1;
                    bitmask |= LOG_EXCEPTIONS;
                }
                else if (strncmp (p, "LOG_SHLIB", sizeof ("LOG_SHLIB") - 1) == 0)
                {
                    p += sizeof ("LOG_SHLIB") - 1;
                    bitmask |= LOG_SHLIB;
                }
                else if (strncmp (p, "LOG_MEMORY", sizeof ("LOG_MEMORY") - 1) == 0)
                {
                    p += sizeof ("LOG_MEMORY") - 1;
                    bitmask |= LOG_MEMORY;
                }
                else if (strncmp (p, "LOG_MEMORY_DATA_SHORT", sizeof ("LOG_MEMORY_DATA_SHORT") - 1) == 0)
                {
                    p += sizeof ("LOG_MEMORY_DATA_SHORT") - 1;
                    bitmask |= LOG_MEMORY_DATA_SHORT;
                }
                else if (strncmp (p, "LOG_MEMORY_DATA_LONG", sizeof ("LOG_MEMORY_DATA_LONG") - 1) == 0)
                {
                    p += sizeof ("LOG_MEMORY_DATA_LONG") - 1;
                    bitmask |= LOG_MEMORY_DATA_LONG;
                }
                else if (strncmp (p, "LOG_BREAKPOINTS", sizeof ("LOG_BREAKPOINTS") - 1) == 0)
                {
                    p += sizeof ("LOG_BREAKPOINTS") - 1;
                    bitmask |= LOG_BREAKPOINTS;
                }
                else if (strncmp (p, "LOG_ALL", sizeof ("LOG_ALL") - 1) == 0)
                {
                    p += sizeof ("LOG_ALL") - 1;
                    bitmask |= LOG_ALL;
                }
                else if (strncmp (p, "LOG_EVENTS", sizeof ("LOG_EVENTS") - 1) == 0)
                {
                    p += sizeof ("LOG_EVENTS") - 1;
                    bitmask |= LOG_EVENTS;
                }
                else if (strncmp (p, "LOG_DEFAULT", sizeof ("LOG_DEFAULT") - 1) == 0)
                {
                    p += sizeof ("LOG_DEFAULT") - 1;
                    bitmask |= LOG_DEFAULT;
                }
                else if (strncmp (p, "LOG_NONE", sizeof ("LOG_NONE") - 1) == 0)
                {
                    p += sizeof ("LOG_NONE") - 1;
                    bitmask = 0;
                }
                else if (strncmp (p, "LOG_RNB_MINIMAL", sizeof ("LOG_RNB_MINIMAL") - 1) == 0)
                {
                    p += sizeof ("LOG_RNB_MINIMAL") - 1;
                    bitmask |= LOG_RNB_MINIMAL;
                }
                else if (strncmp (p, "LOG_RNB_MEDIUM", sizeof ("LOG_RNB_MEDIUM") - 1) == 0)
                {
                    p += sizeof ("LOG_RNB_MEDIUM") - 1;
                    bitmask |= LOG_RNB_MEDIUM;
                }
                else if (strncmp (p, "LOG_RNB_MAX", sizeof ("LOG_RNB_MAX") - 1) == 0)
                {
                    p += sizeof ("LOG_RNB_MAX") - 1;
                    bitmask |= LOG_RNB_MAX;
                }
                else if (strncmp (p, "LOG_RNB_COMM", sizeof ("LOG_RNB_COMM") - 1) == 0)
                {
                    p += sizeof ("LOG_RNB_COMM") - 1;
                    bitmask |= LOG_RNB_COMM;
                }
                else if (strncmp (p, "LOG_RNB_REMOTE", sizeof ("LOG_RNB_REMOTE") - 1) == 0)
                {
                    p += sizeof ("LOG_RNB_REMOTE") - 1;
                    bitmask |= LOG_RNB_REMOTE;
                }
                else if (strncmp (p, "LOG_RNB_EVENTS", sizeof ("LOG_RNB_EVENTS") - 1) == 0)
                {
                    p += sizeof ("LOG_RNB_EVENTS") - 1;
                    bitmask |= LOG_RNB_EVENTS;
                }
                else if (strncmp (p, "LOG_RNB_PROC", sizeof ("LOG_RNB_PROC") - 1) == 0)
                {
                    p += sizeof ("LOG_RNB_PROC") - 1;
                    bitmask |= LOG_RNB_PROC;
                }
                else if (strncmp (p, "LOG_RNB_PACKETS", sizeof ("LOG_RNB_PACKETS") - 1) == 0)
                {
                    p += sizeof ("LOG_RNB_PACKETS") - 1;
                    bitmask |= LOG_RNB_PACKETS;
                }
                else if (strncmp (p, "LOG_RNB_ALL", sizeof ("LOG_RNB_ALL") - 1) == 0)
                {
                    p += sizeof ("LOG_RNB_ALL") - 1;
                    bitmask |= LOG_RNB_ALL;
                }
                else if (strncmp (p, "LOG_RNB_DEFAULT", sizeof ("LOG_RNB_DEFAULT") - 1) == 0)
                {
                    p += sizeof ("LOG_RNB_DEFAULT") - 1;
                    bitmask |= LOG_RNB_DEFAULT;
                }
                else if (strncmp (p, "LOG_RNB_NONE", sizeof ("LOG_RNB_NONE") - 1) == 0)
                {
                    p += sizeof ("LOG_RNB_NONE") - 1;
                    bitmask = 0;
                }
                else
                {
                    /* Unrecognized logging bit; ignore it.  */
                    const char *c = strchr (p, '|');
                    if (c)
                    {
                        p = c;
                    }
                    else
                    {
                        c = strchr (p, ';');
                        if (c)
                        {
                            p = c;
                        }
                        else
                        {
                            // Improperly terminated word; just go to end of str
                            p = strchr (p, '\0');
                        }
                    }
                }
            }
            // Did we get a properly formatted logging bitmask?
            if (*p == ';')
            {
                // Enable DNB logging
                DNBLogSetLogCallback(ASLLogCallback, NULL);
                DNBLogSetLogMask (bitmask);
                p++;
            }
        }
        // We're not going to support logging to a file for now.  All logging
        // goes through ASL.
#if 0
        else if (strncmp (p, "mode=", sizeof ("mode=") - 1) == 0)
        {
            p += sizeof ("mode=") - 1;
            if (strncmp (p, "asl;", sizeof ("asl;") - 1) == 0)
            {
                DNBLogToASL ();
                p += sizeof ("asl;") - 1;
            }
            else if (strncmp (p, "file;", sizeof ("file;") - 1) == 0)
            {
                DNBLogToFile ();
                p += sizeof ("file;") - 1;
            }
            else
            {
                // Ignore unknown argument
                const char *c = strchr (p, ';');
                if (c)
                    p = c + 1;
                else
                    p = strchr (p, '\0');
            }
        }
        else if (strncmp (p, "filename=", sizeof ("filename=") - 1) == 0)
        {
            p += sizeof ("filename=") - 1;
            const char *c = strchr (p, ';');
            if (c == NULL)
            {
                c = strchr (p, '\0');
                continue;
            }
            char *fn = (char *) alloca (c - p + 1);
            strncpy (fn, p, c - p);
            fn[c - p] = '\0';

            // A file name of "asl" is special and is another way to indicate
            // that logging should be done via ASL, not by file.
            if (strcmp (fn, "asl") == 0)
            {
                DNBLogToASL ();
            }
            else
            {
                FILE *f = fopen (fn, "w");
                if (f)
                {
                    DNBLogSetLogFile (f);
                    DNBEnableLogging (f, DNBLogGetLogMask ());
                    DNBLogToFile ();
                }
            }
            p = c + 1;
        }
#endif /* #if 0 to enforce ASL logging only.  */
        else
        {
            // Ignore unknown argument
            const char *c = strchr (p, ';');
            if (c)
                p = c + 1;
            else
                p = strchr (p, '\0');
        }
    }

    return rnb_success;
}



rnb_err_t
RNBRemote::HandlePacket_Q (const char *p)
{
    if (p == NULL || strlen (p) <= 1)
    {
        return HandlePacket_ILLFORMED ("No subtype specified in Q packet");
    }

    /* Switch to no-ack protocol mode after the "OK" packet is sent
     and the ack for that comes back from gdb.  */

    if (strcmp (p, "QStartNoAckMode") == 0)
    {
        rnb_err_t result = SendPacket ("OK");
        m_noack_mode = true;
        return result;
    }

    if (strncmp (p, "QSetLogging:", sizeof ("QSetLogging:") - 1) == 0)
    {
        p += sizeof ("QSetLogging:") - 1;
        rnb_err_t result = set_logging (p);
        if (result == rnb_success)
            return SendPacket ("OK");
        else
            return SendPacket ("E35");
    }

    /* The number of characters in a packet payload that gdb is
     prepared to accept.  The packet-start char, packet-end char,
     2 checksum chars and terminating null character are not included
     in this size.  */
    if (strncmp (p, "QSetMaxPayloadSize:", sizeof ("QSetMaxPayloadSize:") - 1) == 0)
    {
        p += sizeof ("QSetMaxPayloadSize:") - 1;
        errno = 0;
        uint32_t size = strtoul (p, NULL, 16);
        if (errno != 0 && size == 0)
        {
            return HandlePacket_ILLFORMED ("Invalid length in QSetMaxPayloadSize packet");
        }
        m_max_payload_size = size;
        return SendPacket ("OK");
    }

    /* This tells us the largest packet that gdb can handle.
     i.e. the size of gdb's packet-reading buffer.
     QSetMaxPayloadSize is preferred because it is less ambiguous.  */

    if (strncmp (p, "QSetMaxPacketSize:", sizeof ("QSetMaxPacketSize:") - 1) == 0)
    {
        p += sizeof ("QSetMaxPacketSize:") - 1;
        errno = 0;
        uint32_t size = strtoul (p, NULL, 16);
        if (errno != 0 && size == 0)
        {
            return HandlePacket_ILLFORMED ("Invalid length in QSetMaxPacketSize packet");
        }
        m_max_payload_size = size - 5;
        return SendPacket ("OK");
    }

    /* This sets the environment for the target program.  The packet is of the form:

     QEnvironment:VARIABLE=VALUE

     */

    if (strncmp (p, "QEnvironment:", sizeof ("QEnvironment:") - 1) == 0)
    {
        DNBLogThreadedIf (LOG_RNB_REMOTE, "%8u RNBRemote::%s Handling QEnvironment: \"%s\"",
                          (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__, p);

        p += sizeof ("QEnvironment:") - 1;
        RNBContext& ctx = Context();

        ctx.PushEnvironment (p);
        return SendPacket ("OK");
    }

    // Unrecognized Q packet
    return SendPacket ("");
}

void
append_hex_value (std::ostream& ostrm, const uint8_t* buf, size_t buf_size, bool swap)
{
    int i;
    if (swap)
    {
        for (i = buf_size-1; i >= 0; i--)
            ostrm << RAWHEX8(buf[i]);
    }
    else
    {
        for (i = 0; i < buf_size; i++)
            ostrm << RAWHEX8(buf[i]);
    }
}


void
register_value_in_hex_fixed_width
(
 std::ostream& ostrm,
 nub_process_t pid,
 nub_thread_t tid,
 const register_map_entry_t* reg
 )
{
    if (reg != NULL)
    {
        DNBRegisterValue val;
        if (DNBThreadGetRegisterValueByID (pid, tid, reg->nub_info.set, reg->nub_info.reg, &val))
        {
            append_hex_value (ostrm, val.value.v_uint8, reg->gdb_size, false);
        }
        else
        {
            // If we fail to read a regiser value, check if it has a default
            // fail value. If it does, return this instead in case some of
            // the registers are not available on the current system.
            if (reg->gdb_size > 0)
            {
                if (reg->fail_value != NULL)
                {
                    append_hex_value (ostrm, reg->fail_value, reg->gdb_size, false);
                }
                else
                {
                    std::basic_string<uint8_t> zeros(reg->gdb_size, '\0');
                    append_hex_value (ostrm, zeros.data(), zeros.size(), false);
                }
            }
        }
    }
}


void
gdb_regnum_with_fixed_width_hex_register_value
(
 std::ostream& ostrm,
 nub_process_t pid,
 nub_thread_t tid,
 const register_map_entry_t* reg
 )
{
    // Output the register number as 'NN:VVVVVVVV;' where NN is a 2 bytes HEX
    // gdb register number, and VVVVVVVV is the correct number of hex bytes
    // as ASCII for the register value.
    if (reg != NULL)
    {
        ostrm << RAWHEX8(reg->gdb_regnum) << ':';
        register_value_in_hex_fixed_width (ostrm, pid, tid, reg);
        ostrm << ';';
    }
}

rnb_err_t
RNBRemote::SendStopReplyPacketForThread (nub_thread_t tid)
{
    const nub_process_t pid = m_ctx.ProcessID();
    if (pid == INVALID_NUB_PROCESS)
        return SendPacket("E50");

    struct DNBThreadStopInfo tid_stop_info;

    /* Fill the remaining space in this packet with as many registers
     as we can stuff in there.  */

    if (DNBThreadGetStopReason (pid, tid, &tid_stop_info))
    {
        std::ostringstream ostrm;
        // Output the T packet with the thread
        ostrm << 'T';
        int signum = tid_stop_info.details.signal.signo;
        DNBLogThreadedIf (LOG_RNB_PROC, "%8d %s got signal signo = %u, exc_type = %u", (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__, tid_stop_info.details.signal.signo, tid_stop_info.details.exception.type);

        // Translate any mach exceptions to gdb versions, unless they are
        // common exceptions like a breakpoint or a soft signal.
        switch (tid_stop_info.details.exception.type)
        {
            default:                    signum = 0; break;
            case EXC_BREAKPOINT:        signum = SIGTRAP; break;
            case EXC_BAD_ACCESS:        signum = TARGET_EXC_BAD_ACCESS; break;
            case EXC_BAD_INSTRUCTION:   signum = TARGET_EXC_BAD_INSTRUCTION; break;
            case EXC_ARITHMETIC:        signum = TARGET_EXC_ARITHMETIC; break;
            case EXC_EMULATION:         signum = TARGET_EXC_EMULATION; break;
            case EXC_SOFTWARE:
                if (tid_stop_info.details.exception.data_count == 2 &&
                    tid_stop_info.details.exception.data[0] == EXC_SOFT_SIGNAL)
                    signum = tid_stop_info.details.exception.data[1];
                else
                    signum = TARGET_EXC_SOFTWARE;
                break;
        }

        ostrm << RAWHEX8(signum & 0xff);

        ostrm << std::hex << "thread:" << tid << ';';

        const char *thread_name = DNBThreadGetName (pid, tid);
        if (thread_name && thread_name[0])
            ostrm << std::hex << "name:" << thread_name << ';';

        thread_identifier_info_data_t thread_ident_info;
        if (DNBThreadGetIdentifierInfo (pid, tid, &thread_ident_info))
        {
            if (thread_ident_info.dispatch_qaddr != 0)
                ostrm << std::hex << "dispatchqaddr:" << thread_ident_info.dispatch_qaddr << ';';
        }
        DNBRegisterValue reg_value;
        for (uint32_t reg = 0; reg < g_num_reg_entries; reg++)
        {
            if (g_reg_entries[reg].expedite)
            {
                if (!DNBThreadGetRegisterValueByID (pid, tid, g_reg_entries[reg].nub_info.set, g_reg_entries[reg].nub_info.reg, &reg_value))
                    continue;

                gdb_regnum_with_fixed_width_hex_register_value (ostrm, pid, tid, &g_reg_entries[reg]);
            }
        }

        if (tid_stop_info.details.exception.type)
        {
            ostrm << "metype:" << std::hex << tid_stop_info.details.exception.type << ";";
            ostrm << "mecount:" << std::hex << tid_stop_info.details.exception.data_count << ";";
            for (int i = 0; i < tid_stop_info.details.exception.data_count; ++i)
                ostrm << "medata:" << std::hex << tid_stop_info.details.exception.data[i] << ";";
        }
        return SendPacket (ostrm.str ());
    }
    return SendPacket("E51");
}

/* `?'
 The stop reply packet - tell gdb what the status of the inferior is.
 Often called the questionmark_packet.  */

rnb_err_t
RNBRemote::HandlePacket_last_signal (const char *unused)
{
    if (!m_ctx.HasValidProcessID())
    {
        // Inferior is not yet specified/running
        return SendPacket ("E02");
    }

    nub_process_t pid = m_ctx.ProcessID();
    nub_state_t pid_state = DNBProcessGetState (pid);

    switch (pid_state)
    {
        case eStateAttaching:
        case eStateLaunching:
        case eStateRunning:
        case eStateStepping:
            return rnb_success;  // Ignore

        case eStateSuspended:
        case eStateStopped:
        case eStateCrashed:
        {
            nub_thread_t tid = DNBProcessGetCurrentThread (pid);
            // Make sure we set the current thread so g and p packets return
            // the data the gdb will expect.
            SetCurrentThread (tid);

            SendStopReplyPacketForThread (tid);
        }
            break;

        case eStateInvalid:
        case eStateUnloaded:
        case eStateExited:
        {
            char pid_exited_packet[16] = "";
            int pid_status = 0;
            // Process exited with exit status
            if (!DNBProcessGetExitStatus(pid, &pid_status))
                pid_status = 0;

            if (pid_status)
            {
                if (WIFEXITED (pid_status))
                    snprintf (pid_exited_packet, sizeof(pid_exited_packet), "W%02x", WEXITSTATUS (pid_status));
                else if (WIFSIGNALED (pid_status))
                    snprintf (pid_exited_packet, sizeof(pid_exited_packet), "X%02x", WEXITSTATUS (pid_status));
                else if (WIFSTOPPED (pid_status))
                    snprintf (pid_exited_packet, sizeof(pid_exited_packet), "S%02x", WSTOPSIG (pid_status));
            }

            // If we have an empty exit packet, lets fill one in to be safe.
            if (!pid_exited_packet[0])
            {
                strncpy (pid_exited_packet, "W00", sizeof(pid_exited_packet)-1);
                pid_exited_packet[sizeof(pid_exited_packet)-1] = '\0';
            }

            return SendPacket (pid_exited_packet);
        }
            break;
    }
    return rnb_success;
}

rnb_err_t
RNBRemote::HandlePacket_M (const char *p)
{
    if (p == NULL || p[0] == '\0' || strlen (p) < 3)
    {
        return HandlePacket_ILLFORMED ("Too short M packet");
    }

    char *c;
    p++;
    errno = 0;
    nub_addr_t addr = strtoull (p, &c, 16);
    if (errno != 0 && addr == 0)
    {
        return HandlePacket_ILLFORMED ("Invalid address in M packet");
    }
    if (*c != ',')
    {
        return HandlePacket_ILLFORMED ("Comma sep missing in M packet");
    }

    /* Advance 'p' to the length part of the packet.  */
    p += (c - p) + 1;

    errno = 0;
    uint32_t length = strtoul (p, &c, 16);
    if (errno != 0 && length == 0)
    {
        return HandlePacket_ILLFORMED ("Invalid length in M packet");
    }
    if (length == 0)
    {
        return SendPacket ("OK");
    }

    if (*c != ':')
    {
        return HandlePacket_ILLFORMED ("Missing colon in M packet");
    }
    /* Advance 'p' to the data part of the packet.  */
    p += (c - p) + 1;

    int datalen = strlen (p);
    if (datalen & 0x1)
    {
        return HandlePacket_ILLFORMED ("Uneven # of hex chars for data in M packet");
    }
    if (datalen == 0)
    {
        return SendPacket ("OK");
    }

    uint8_t *buf = (uint8_t *) alloca (datalen / 2);
    uint8_t *i = buf;

    while (*p != '\0' && *(p + 1) != '\0')
    {
        char hexbuf[3];
        hexbuf[0] = *p;
        hexbuf[1] = *(p + 1);
        hexbuf[2] = '\0';
        errno = 0;
        uint8_t byte = strtoul (hexbuf, NULL, 16);
        if (errno != 0 && byte == 0)
        {
            return HandlePacket_ILLFORMED ("Invalid hex byte in M packet");
        }
        *i++ = byte;
        p += 2;
    }

    nub_size_t wrote = DNBProcessMemoryWrite (m_ctx.ProcessID(), addr, length, buf);
    if (wrote != length)
        return SendPacket ("E09");
    else
        return SendPacket ("OK");
}


rnb_err_t
RNBRemote::HandlePacket_m (const char *p)
{
    if (p == NULL || p[0] == '\0' || strlen (p) < 3)
    {
        return HandlePacket_ILLFORMED ("Too short m packet");
    }

    char *c;
    p++;
    errno = 0;
    nub_addr_t addr = strtoull (p, &c, 16);
    if (errno != 0 && addr == 0)
    {
        return HandlePacket_ILLFORMED ("Invalid address in m packet");
    }
    if (*c != ',')
    {
        return HandlePacket_ILLFORMED ("Comma sep missing in m packet");
    }

    /* Advance 'p' to the length part of the packet.  */
    p += (c - p) + 1;

    errno = 0;
    uint32_t length = strtoul (p, NULL, 16);
    if (errno != 0 && length == 0)
    {
        return HandlePacket_ILLFORMED ("Invalid length in m packet");
    }
    if (length == 0)
    {
        return SendPacket ("");
    }

    uint8_t buf[length];
    int bytes_read = DNBProcessMemoryRead (m_ctx.ProcessID(), addr, length, buf);
    if (bytes_read == 0)
    {
        return SendPacket ("E08");
    }

    // "The reply may contain fewer bytes than requested if the server was able
    //  to read only part of the region of memory."
    length = bytes_read;

    std::ostringstream ostrm;
    for (int i = 0; i < length; i++)
        ostrm << RAWHEX8(buf[i]);
    return SendPacket (ostrm.str ());
}

rnb_err_t
RNBRemote::HandlePacket_X (const char *p)
{
    if (p == NULL || p[0] == '\0' || strlen (p) < 3)
    {
        return HandlePacket_ILLFORMED ("Too short X packet");
    }

    char *c;
    p++;
    errno = 0;
    nub_addr_t addr = strtoull (p, &c, 16);
    if (errno != 0 && addr == 0)
    {
        return HandlePacket_ILLFORMED ("Invalid address in X packet");
    }
    if (*c != ',')
    {
        return HandlePacket_ILLFORMED ("Comma sep missing in X packet");
    }

    /* Advance 'p' to the length part of the packet.  */
    p += (c - p) + 1;

    errno = 0;
    int length = strtoul (p, NULL, 16);
    if (errno != 0 && length == 0)
    {
        return HandlePacket_ILLFORMED ("Invalid length in m packet");
    }

    // I think gdb sends a zero length write request to test whether this
    // packet is accepted.
    if (length == 0)
    {
        return SendPacket ("OK");
    }

    std::vector<uint8_t> data = decode_binary_data (c, -1);
    std::vector<uint8_t>::const_iterator it;
    uint8_t *buf = (uint8_t *) alloca (data.size ());
    uint8_t *i = buf;
    for (it = data.begin (); it != data.end (); ++it)
    {
        *i++ = *it;
    }

    nub_size_t wrote = DNBProcessMemoryWrite (m_ctx.ProcessID(), addr, data.size(), buf);
    if (wrote != data.size ())
        return SendPacket ("E08");
    return SendPacket ("OK");
}

/* `g' -- read registers
 Get the contents of the registers for the current thread,
 send them to gdb.
 Should the setting of the Hg packet determine which thread's registers
 are returned?  */

rnb_err_t
RNBRemote::HandlePacket_g (const char *p)
{
    std::ostringstream ostrm;
    if (!m_ctx.HasValidProcessID())
    {
        return SendPacket ("E11");
    }
    nub_process_t pid = m_ctx.ProcessID ();
    nub_thread_t tid = GetCurrentThread();

    if (m_use_native_regs)
    {
        // Get the register context size first by calling with NULL buffer
        nub_size_t reg_ctx_size = DNBThreadGetRegisterContext(pid, tid, NULL, 0);
        if (reg_ctx_size)
        {
            // Now allocate enough space for the entire register context
            std::vector<uint8_t> reg_ctx;
            reg_ctx.resize(reg_ctx_size);
            // Now read the register context
            reg_ctx_size = DNBThreadGetRegisterContext(pid, tid, &reg_ctx[0], reg_ctx.size());
            if (reg_ctx_size)
            {
                append_hex_value (ostrm, reg_ctx.data(), reg_ctx.size(), false);
                return SendPacket (ostrm.str ());
            }
        }
    }
    
    for (uint32_t reg = 0; reg < g_num_reg_entries; reg++)
        register_value_in_hex_fixed_width (ostrm, pid, tid, &g_reg_entries[reg]);

    return SendPacket (ostrm.str ());
}

/* `G XXX...' -- write registers
 How is the thread for these specified, beyond "the current thread"?
 Does gdb actually use the Hg packet to set this?  */

rnb_err_t
RNBRemote::HandlePacket_G (const char *p)
{
    if (!m_ctx.HasValidProcessID())
    {
        return SendPacket ("E11");
    }
    StringExtractor packet(p);
    packet.SetFilePos(1); // Skip the 'G'
    
    nub_process_t pid = m_ctx.ProcessID();
    nub_thread_t tid = GetCurrentThread();

    if (m_use_native_regs)
    {
        // Get the register context size first by calling with NULL buffer
        nub_size_t reg_ctx_size = DNBThreadGetRegisterContext(pid, tid, NULL, 0);
        if (reg_ctx_size)
        {
            // Now allocate enough space for the entire register context
            std::vector<uint8_t> reg_ctx;
            reg_ctx.resize(reg_ctx_size);
            
            if (packet.GetHexBytes (&reg_ctx[0], reg_ctx.size(), 0xcc) == reg_ctx.size())
            {
                // Now write the register context
                reg_ctx_size = DNBThreadSetRegisterContext(pid, tid, reg_ctx.data(), reg_ctx.size());
                if (reg_ctx_size == reg_ctx.size())
                    return SendPacket ("OK");
                else 
                    return SendPacket ("E55");
            }
        }
    }


    DNBRegisterValue reg_value;
    for (uint32_t reg = 0; reg < g_num_reg_entries; reg++)
    {
        const register_map_entry_t *reg_entry = &g_reg_entries[reg];

        reg_value.info = reg_entry->nub_info;
        if (packet.GetHexBytes (reg_value.value.v_sint8, reg_entry->gdb_size, 0xcc) != reg_entry->gdb_size)
            break;

        if (!DNBThreadSetRegisterValueByID (pid, tid, reg_entry->nub_info.set, reg_entry->nub_info.reg, &reg_value))
            return SendPacket ("E15");
    }
    return SendPacket ("OK");
}

static bool
RNBRemoteShouldCancelCallback (void *not_used)
{
    RNBRemoteSP remoteSP(g_remoteSP);
    if (remoteSP.get() != NULL)
    {
        RNBRemote* remote = remoteSP.get();
        if (remote->Comm().IsConnected())
            return false;
        else
            return true;
    }
    return true;
}


// FORMAT: _MXXXXXX,PPP   
//      XXXXXX: big endian hex chars
//      PPP: permissions can be any combo of r w x chars
//
// RESPONSE: XXXXXX
//      XXXXXX: hex address of the newly allocated memory
//      EXX: error code
//
// EXAMPLES:
//      _M123000,rw
//      _M123000,rwx
//      _M123000,xw

rnb_err_t
RNBRemote::HandlePacket_AllocateMemory (const char *p)
{
    StringExtractor packet (p);
    packet.SetFilePos(2); // Skip the "_M"
    
    nub_addr_t size = packet.GetHexMaxU64 (StringExtractor::BigEndian, 0);
    if (size != 0)
    {
        if (packet.GetChar() == ',')
        {
            uint32_t permissions = 0;
            char ch;
            bool success = true;
            while (success && (ch = packet.GetChar()) != '\0')
            {
                switch (ch)
                {
                case 'r':   permissions |= eMemoryPermissionsReadable; break;
                case 'w':   permissions |= eMemoryPermissionsWritable; break;
                case 'x':   permissions |= eMemoryPermissionsExecutable; break;
                default:    success = false; break;
                }
            }
            
            if (success)
            {
                nub_addr_t addr = DNBProcessMemoryAllocate (m_ctx.ProcessID(), size, permissions);
                if (addr != INVALID_NUB_ADDRESS)
                {
                    std::ostringstream ostrm;
                    ostrm << RAW_HEXBASE << addr;
                    return SendPacket (ostrm.str ());
                }
            }
        }
    }
    return SendPacket ("E53");
}

// FORMAT: _mXXXXXX   
//      XXXXXX: address that was previosly allocated
//
// RESPONSE: XXXXXX
//      OK: address was deallocated
//      EXX: error code
//
// EXAMPLES: 
//      _m123000

rnb_err_t
RNBRemote::HandlePacket_DeallocateMemory (const char *p)
{
    StringExtractor packet (p);
    packet.SetFilePos(2); // Skip the "_m"
    nub_addr_t addr = packet.GetHexMaxU64 (StringExtractor::BigEndian, INVALID_NUB_ADDRESS);

    if (addr != INVALID_NUB_ADDRESS)
    {
        if (DNBProcessMemoryDeallocate (m_ctx.ProcessID(), addr))
            return SendPacket ("OK");
    }
    return SendPacket ("E54");
}

/*
 vAttach;pid

 Attach to a new process with the specified process ID. pid is a hexadecimal integer
 identifying the process. If the stub is currently controlling a process, it is
 killed. The attached process is stopped.This packet is only available in extended
 mode (see extended mode).

 Reply:
 "ENN"                      for an error
 "Any Stop Reply Packet"     for success
 */

rnb_err_t
RNBRemote::HandlePacket_v (const char *p)
{
    if (strcmp (p, "vCont;c") == 0)
    {
        // Simple continue
        return RNBRemote::HandlePacket_c("c");
    }
    else if (strcmp (p, "vCont;s") == 0)
    {
        // Simple step
        return RNBRemote::HandlePacket_s("s");
    }
    else if (strstr (p, "vCont") == p)
    {
        rnb_err_t rnb_err = rnb_success;
        typedef struct
        {
            nub_thread_t tid;
            char action;
            int signal;
        } vcont_action_t;

        DNBThreadResumeActions thread_actions;
        char *c = (char *)(p += strlen("vCont"));
        char *c_end = c + strlen(c);
        if (*c == '?')
            return SendPacket ("vCont;c;C;s;S");

        while (c < c_end && *c == ';')
        {
            ++c;    // Skip the semi-colon
            DNBThreadResumeAction thread_action;
            thread_action.tid = INVALID_NUB_THREAD;
            thread_action.state = eStateInvalid;
            thread_action.signal = 0;
            thread_action.addr = INVALID_NUB_ADDRESS;

            char action = *c++;

            switch (action)
            {
                case 'C':
                    errno = 0;
                    thread_action.signal = strtoul (c, &c, 16);
                    if (errno != 0)
                        return HandlePacket_ILLFORMED ("Could not parse signal in vCont packet");
                    // Fall through to next case...

                case 'c':
                    // Continue
                    thread_action.state = eStateRunning;
                    break;

                case 'S':
                    errno = 0;
                    thread_action.signal = strtoul (c, &c, 16);
                    if (errno != 0)
                        return HandlePacket_ILLFORMED ("Could not parse signal in vCont packet");
                    // Fall through to next case...

                case 's':
                    // Step
                    thread_action.state = eStateStepping;
                    break;

                    break;

                default:
                    rnb_err = HandlePacket_ILLFORMED ("Unsupported action in vCont packet");
                    break;
            }
            if (*c == ':')
            {
                errno = 0;
                thread_action.tid = strtoul (++c, &c, 16);
                if (errno != 0)
                    return HandlePacket_ILLFORMED ("Could not parse thread number in vCont packet");
            }

            thread_actions.Append (thread_action);
        }

        // If a default action for all other threads wasn't mentioned
        // then we should stop the threads
        thread_actions.SetDefaultThreadActionIfNeeded (eStateStopped, 0);
        DNBProcessResume(m_ctx.ProcessID(), thread_actions.GetFirst (), thread_actions.GetSize());
        return rnb_success;
    }
    else if (strstr (p, "vAttach") == p)
    {
        nub_process_t attach_pid = INVALID_NUB_PROCESS;
        char err_str[1024]={'\0'};
        if (strstr (p, "vAttachWait;") == p)
        {
            p += strlen("vAttachWait;");
            std::string attach_name;
            while (*p != '\0')
            {
                char smallbuf[3];
                smallbuf[0] = *p;
                smallbuf[1] = *(p + 1);
                smallbuf[2] = '\0';

                errno = 0;
                int ch = strtoul (smallbuf, NULL, 16);
                if (errno != 0 && ch == 0)
                {
                    return HandlePacket_ILLFORMED ("non-hex char in arg on 'vAttachWait' pkt");
                }

                attach_name.push_back(ch);
                p += 2;
            }

            attach_pid = DNBProcessAttachWait(attach_name.c_str (), m_ctx.LaunchFlavor(), NULL, 1000, err_str, sizeof(err_str), RNBRemoteShouldCancelCallback);

        }
        else if (strstr (p, "vAttach;") == p)
        {
            p += strlen("vAttach;");
            char *end = NULL;
            attach_pid = strtoul (p, &end, 16);    // PID will be in hex, so use base 16 to decode
            if (p != end && *end == '\0')
            {
                // Wait at most 30 second for attach
                struct timespec attach_timeout_abstime;
                DNBTimer::OffsetTimeOfDay(&attach_timeout_abstime, 30, 0);
                attach_pid = DNBProcessAttach(attach_pid, &attach_timeout_abstime, err_str, sizeof(err_str));
            }
        }
        else
            return HandlePacket_UNIMPLEMENTED(p);


        if (attach_pid != INVALID_NUB_PROCESS)
        {
            if (m_ctx.ProcessID() != attach_pid)
                m_ctx.SetProcessID(attach_pid);
            // Send a stop reply packet to indicate we successfully attached!
            NotifyThatProcessStopped ();
            return rnb_success;
        }
        else
        {
            m_ctx.LaunchStatus().SetError(-1, DNBError::Generic);
            if (err_str[0])
                m_ctx.LaunchStatus().SetErrorString(err_str);
            else
                m_ctx.LaunchStatus().SetErrorString("attach failed");
            return SendPacket ("E01");  // E01 is our magic error value for attach failed.
        }
    }

    // All other failures come through here
    return HandlePacket_UNIMPLEMENTED(p);
}

/* `T XX' -- status of thread
 Check if the specified thread is alive.
 The thread number is in hex?  */

rnb_err_t
RNBRemote::HandlePacket_T (const char *p)
{
    p++;
    if (p == NULL || *p == '\0')
    {
        return HandlePacket_ILLFORMED ("No thread specified in T packet");
    }
    if (!m_ctx.HasValidProcessID())
    {
        return SendPacket ("E15");
    }
    errno = 0;
    nub_thread_t tid = strtoul (p, NULL, 16);
    if (errno != 0 && tid == 0)
    {
        return HandlePacket_ILLFORMED ("Could not parse thread number in T packet");
    }

    nub_state_t state = DNBThreadGetState (m_ctx.ProcessID(), tid);
    if (state == eStateInvalid || state == eStateExited || state == eStateCrashed)
    {
        return SendPacket ("E16");
    }

    return SendPacket ("OK");
}


rnb_err_t
RNBRemote::HandlePacket_z (const char *p)
{
    if (p == NULL || *p == '\0')
        return HandlePacket_ILLFORMED ("No thread specified in z packet");

    if (!m_ctx.HasValidProcessID())
        return SendPacket ("E15");

    char packet_cmd = *p++;
    char break_type = *p++;

    if (*p++ != ',')
        return HandlePacket_ILLFORMED ("Comma separator missing in z packet");

    char *c = NULL;
    nub_process_t pid = m_ctx.ProcessID();
    errno = 0;
    nub_addr_t addr = strtoull (p, &c, 16);
    if (errno != 0 && addr == 0)
        return HandlePacket_ILLFORMED ("Invalid address in z packet");
    p = c;
    if (*p++ != ',')
        return HandlePacket_ILLFORMED ("Comma separator missing in z packet");

    errno = 0;
    uint32_t byte_size = strtoul (p, &c, 16);
    if (errno != 0 && byte_size == 0)
        return HandlePacket_ILLFORMED ("Invalid length in z packet");

    if (packet_cmd == 'Z')
    {
        // set
        switch (break_type)
        {
            case '0':   // set software breakpoint
            case '1':   // set hardware breakpoint
            {
                // gdb can send multiple Z packets for the same address and
                // these calls must be ref counted.
                bool hardware = (break_type == '1');

                // Check if we currently have a breakpoint already set at this address
                BreakpointMapIter pos = m_breakpoints.find(addr);
                if (pos != m_breakpoints.end())
                {
                    // We do already have a breakpoint at this address, increment
                    // its reference count and return OK
                    pos->second.Retain();
                    return SendPacket ("OK");
                }
                else
                {
                    // We do NOT already have a breakpoint at this address, So lets
                    // create one.
                    nub_break_t break_id = DNBBreakpointSet (pid, addr, byte_size, hardware);
                    if (break_id != INVALID_NUB_BREAK_ID)
                    {
                        // We successfully created a breakpoint, now lets full out
                        // a ref count structure with the breakID and add it to our
                        // map.
                        Breakpoint rnbBreakpoint(break_id);
                        m_breakpoints[addr] = rnbBreakpoint;
                        return SendPacket ("OK");
                    }
                    else
                    {
                        // We failed to set the software breakpoint
                        return SendPacket ("E09");
                    }
                }
            }
                break;

            case '2':   // set write watchpoint
            case '3':   // set read watchpoint
            case '4':   // set access watchpoint
            {
                bool hardware = true;
                uint32_t watch_flags = 0;
                if (break_type == '2')
                    watch_flags = WATCH_TYPE_WRITE;
                else if (break_type == '3')
                    watch_flags = WATCH_TYPE_READ;
                else
                    watch_flags = WATCH_TYPE_READ | WATCH_TYPE_WRITE;

                // Check if we currently have a watchpoint already set at this address
                BreakpointMapIter pos = m_watchpoints.find(addr);
                if (pos != m_watchpoints.end())
                {
                    // We do already have a watchpoint at this address, increment
                    // its reference count and return OK
                    pos->second.Retain();
                    return SendPacket ("OK");
                }
                else
                {
                    // We do NOT already have a breakpoint at this address, So lets
                    // create one.
                    nub_watch_t watch_id = DNBWatchpointSet (pid, addr, byte_size, watch_flags, hardware);
                    if (watch_id != INVALID_NUB_BREAK_ID)
                    {
                        // We successfully created a watchpoint, now lets full out
                        // a ref count structure with the watch_id and add it to our
                        // map.
                        Breakpoint rnbWatchpoint(watch_id);
                        m_watchpoints[addr] = rnbWatchpoint;
                        return SendPacket ("OK");
                    }
                    else
                    {
                        // We failed to set the watchpoint
                        return SendPacket ("E09");
                    }
                }
            }
                break;

            default:
                break;
        }
    }
    else if (packet_cmd == 'z')
    {
        // remove
        switch (break_type)
        {
            case '0':   // remove software breakpoint
            case '1':   // remove hardware breakpoint
            {
                // gdb can send multiple z packets for the same address and
                // these calls must be ref counted.
                BreakpointMapIter pos = m_breakpoints.find(addr);
                if (pos != m_breakpoints.end())
                {
                    // We currently have a breakpoint at address ADDR. Decrement
                    // its reference count, and it that count is now zero we
                    // can clear the breakpoint.
                    pos->second.Release();
                    if (pos->second.RefCount() == 0)
                    {
                        if (DNBBreakpointClear (pid, pos->second.BreakID()))
                        {
                            m_breakpoints.erase(pos);
                            return SendPacket ("OK");
                        }
                        else
                        {
                            return SendPacket ("E08");
                        }
                    }
                    else
                    {
                        // We still have references to this breakpoint don't
                        // delete it, just decrementing the reference count
                        // is enough.
                        return SendPacket ("OK");
                    }
                }
                else
                {
                    // We don't know about any breakpoints at this address
                    return SendPacket ("E08");
                }
            }
                break;

            case '2':   // remove write watchpoint
            case '3':   // remove read watchpoint
            case '4':   // remove access watchpoint
            {
                // gdb can send multiple z packets for the same address and
                // these calls must be ref counted.
                BreakpointMapIter pos = m_watchpoints.find(addr);
                if (pos != m_watchpoints.end())
                {
                    // We currently have a watchpoint at address ADDR. Decrement
                    // its reference count, and it that count is now zero we
                    // can clear the watchpoint.
                    pos->second.Release();
                    if (pos->second.RefCount() == 0)
                    {
                        if (DNBWatchpointClear (pid, pos->second.BreakID()))
                        {
                            m_watchpoints.erase(pos);
                            return SendPacket ("OK");
                        }
                        else
                        {
                            return SendPacket ("E08");
                        }
                    }
                    else
                    {
                        // We still have references to this watchpoint don't
                        // delete it, just decrementing the reference count
                        // is enough.
                        return SendPacket ("OK");
                    }
                }
                else
                {
                    // We don't know about any watchpoints at this address
                    return SendPacket ("E08");
                }
            }
                break;

            default:
                break;
        }
    }
    return HandlePacket_UNIMPLEMENTED(p);
}

/* `p XX'
 print the contents of register X */

rnb_err_t
RNBRemote::HandlePacket_p (const char *p)
{
    if (p == NULL || *p == '\0')
    {
        return HandlePacket_ILLFORMED ("No thread specified in p packet");
    }
    if (!m_ctx.HasValidProcessID())
    {
        return SendPacket ("E15");
    }
    nub_process_t pid = m_ctx.ProcessID();
    errno = 0;
    uint32_t reg = strtoul (p + 1, NULL, 16);
    if (errno != 0 && reg == 0)
    {
        return HandlePacket_ILLFORMED ("Could not parse thread number in p packet");
    }

    const register_map_entry_t *reg_entry;

    if (reg < g_num_reg_entries)
        reg_entry = &g_reg_entries[reg];
    else
        reg_entry = NULL;

    std::ostringstream ostrm;
    if (reg_entry == NULL)
    {
        DNBLogError("RNBRemote::HandlePacket_p(%s): unknown register number %u requested\n", p, reg);
        ostrm << "00000000";
    }
    else if (reg_entry->nub_info.reg == -1)
    {
        if (reg_entry->gdb_size > 0)
        {
            if (reg_entry->fail_value != NULL)
            {
                append_hex_value(ostrm, reg_entry->fail_value, reg_entry->gdb_size, false);
            }
            else
            {
                std::basic_string<uint8_t> zeros(reg_entry->gdb_size, '\0');
                append_hex_value(ostrm, zeros.data(), zeros.size(), false);
            }
        }
    }
    else
    {
        nub_thread_t tid = GetCurrentThread();
        register_value_in_hex_fixed_width (ostrm, pid, tid, reg_entry);
    }
    return SendPacket (ostrm.str());
}

/* `Pnn=rrrrr'
 Set register number n to value r.
 n and r are hex strings.  */

rnb_err_t
RNBRemote::HandlePacket_P (const char *p)
{
    if (p == NULL || *p == '\0')
    {
        return HandlePacket_ILLFORMED ("Empty P packet");
    }
    if (!m_ctx.HasValidProcessID())
    {
        return SendPacket ("E28");
    }

    nub_process_t pid = m_ctx.ProcessID();

    StringExtractor packet (p);

    const char cmd_char = packet.GetChar();
    // Register ID is always in big endian
    const uint32_t reg = packet.GetHexMaxU32 (false, UINT32_MAX);
    const char equal_char = packet.GetChar();

    if (cmd_char != 'P')
        return HandlePacket_ILLFORMED ("Improperly formed P packet");

    if (reg == UINT32_MAX)
        return SendPacket ("E29");

    if (equal_char != '=')
        return SendPacket ("E30");

    const register_map_entry_t *reg_entry;

    if (reg >= g_num_reg_entries)
        return SendPacket("E47");

    reg_entry = &g_reg_entries[reg];

    if (reg_entry->nub_info.set == -1 && reg_entry->nub_info.reg == -1)
    {
        DNBLogError("RNBRemote::HandlePacket_P(%s): unknown register number %u requested\n", p, reg);
        return SendPacket("E48");
    }

    DNBRegisterValue reg_value;
    reg_value.info = reg_entry->nub_info;
    packet.GetHexBytes (reg_value.value.v_sint8, reg_entry->gdb_size, 0xcc);

    nub_thread_t tid;
    tid = GetCurrentThread ();

    if (!DNBThreadSetRegisterValueByID (pid, tid, reg_entry->nub_info.set, reg_entry->nub_info.reg, &reg_value))
    {
        return SendPacket ("E32");
    }
    return SendPacket ("OK");
}

/* `c [addr]'
 Continue, optionally from a specified address. */

rnb_err_t
RNBRemote::HandlePacket_c (const char *p)
{
    const nub_process_t pid = m_ctx.ProcessID();

    if (pid == INVALID_NUB_PROCESS)
        return SendPacket ("E23");

    DNBThreadResumeAction action = { INVALID_NUB_THREAD, eStateRunning, 0, INVALID_NUB_ADDRESS };

    if (*(p + 1) != '\0')
    {
        action.tid = GetContinueThread();
        errno = 0;
        action.addr = strtoull (p + 1, NULL, 16);
        if (errno != 0 && action.addr == 0)
            return HandlePacket_ILLFORMED ("Could not parse address in c packet");
    }

    DNBThreadResumeActions thread_actions;
    thread_actions.Append(action);
    thread_actions.SetDefaultThreadActionIfNeeded(eStateRunning, 0);
    if (!DNBProcessResume (pid, thread_actions.GetFirst(), thread_actions.GetSize()))
        return SendPacket ("E25");
    // Don't send an "OK" packet; response is the stopped/exited message.
    return rnb_success;
}

/* `C sig [;addr]'
 Resume with signal sig, optionally at address addr.  */

rnb_err_t
RNBRemote::HandlePacket_C (const char *p)
{
    const nub_process_t pid = m_ctx.ProcessID();

    if (pid == INVALID_NUB_PROCESS)
        return SendPacket ("E36");

    DNBThreadResumeAction action = { INVALID_NUB_THREAD, eStateRunning, 0, INVALID_NUB_ADDRESS };
    int process_signo = -1;
    if (*(p + 1) != '\0')
    {
        action.tid = GetContinueThread();
        char *end = NULL;
        errno = 0;
        process_signo = strtoul (p + 1, &end, 16);
        if (errno != 0)
            return HandlePacket_ILLFORMED ("Could not parse signal in C packet");
        else if (*end == ';')
        {
            errno = 0;
            action.addr = strtoull (end + 1, NULL, 16);
            if (errno != 0 && action.addr == 0)
                return HandlePacket_ILLFORMED ("Could not parse address in C packet");
        }
    }

    DNBThreadResumeActions thread_actions;
    thread_actions.Append (action);
    thread_actions.SetDefaultThreadActionIfNeeded (eStateRunning, action.signal);
    if (!DNBProcessSignal(pid, process_signo))
        return SendPacket ("E52");
    if (!DNBProcessResume (pid, thread_actions.GetFirst(), thread_actions.GetSize()))
        return SendPacket ("E38");
    /* Don't send an "OK" packet; response is the stopped/exited message.  */
    return rnb_success;
}

//----------------------------------------------------------------------
// 'D' packet
// Detach from gdb.
//----------------------------------------------------------------------
rnb_err_t
RNBRemote::HandlePacket_D (const char *p)
{
    SendPacket ("OK");
    if (m_ctx.HasValidProcessID())
        DNBProcessDetach(m_ctx.ProcessID());
    return rnb_success;
}

/* `k'
 Kill the inferior process.  */

rnb_err_t
RNBRemote::HandlePacket_k (const char *p)
{
    if (!m_ctx.HasValidProcessID())
        return SendPacket ("E26");
    if (!DNBProcessKill (m_ctx.ProcessID()))
        return SendPacket ("E27");
    return SendPacket ("OK");
}

rnb_err_t
RNBRemote::HandlePacket_stop_process (const char *p)
{
    DNBProcessSignal (m_ctx.ProcessID(), SIGSTOP);
    //DNBProcessSignal (m_ctx.ProcessID(), SIGINT);
    // Do not send any response packet! Wait for the stop reply packet to naturally happen
    return rnb_success;
}

/* `s'
 Step the inferior process.  */

rnb_err_t
RNBRemote::HandlePacket_s (const char *p)
{
    const nub_process_t pid = m_ctx.ProcessID();
    if (pid == INVALID_NUB_PROCESS)
        return SendPacket ("E32");

    // Hardware supported stepping not supported on arm
    nub_thread_t tid = GetContinueThread ();
    if (tid == 0 || tid == -1)
        tid = GetCurrentThread();

    if (tid == INVALID_NUB_THREAD)
        return SendPacket ("E33");

    DNBThreadResumeActions thread_actions;
    thread_actions.AppendAction(tid, eStateStepping);

    // Make all other threads stop when we are stepping
    thread_actions.SetDefaultThreadActionIfNeeded (eStateStopped, 0);
    if (!DNBProcessResume (pid, thread_actions.GetFirst(), thread_actions.GetSize()))
        return SendPacket ("E49");
    // Don't send an "OK" packet; response is the stopped/exited message.
    return rnb_success;
}

/* `S sig [;addr]'
 Step with signal sig, optionally at address addr.  */

rnb_err_t
RNBRemote::HandlePacket_S (const char *p)
{
    const nub_process_t pid = m_ctx.ProcessID();
    if (pid == INVALID_NUB_PROCESS)
        return SendPacket ("E36");

    DNBThreadResumeAction action = { INVALID_NUB_THREAD, eStateStepping, 0, INVALID_NUB_ADDRESS };

    if (*(p + 1) != '\0')
    {
        char *end = NULL;
        errno = 0;
        action.signal = strtoul (p + 1, &end, 16);
        if (errno != 0)
            return HandlePacket_ILLFORMED ("Could not parse signal in S packet");
        else if (*end == ';')
        {
            errno = 0;
            action.addr = strtoull (end + 1, NULL, 16);
            if (errno != 0 && action.addr == 0)
            {
                return HandlePacket_ILLFORMED ("Could not parse address in S packet");
            }
        }
    }

    action.tid = GetContinueThread ();
    if (action.tid == 0 || action.tid == -1)
        return SendPacket ("E40");

    nub_state_t tstate = DNBThreadGetState (pid, action.tid);
    if (tstate == eStateInvalid || tstate == eStateExited)
        return SendPacket ("E37");


    DNBThreadResumeActions thread_actions;
    thread_actions.Append (action);

    // Make all other threads stop when we are stepping
    thread_actions.SetDefaultThreadActionIfNeeded(eStateStopped, 0);
    if (!DNBProcessResume (pid, thread_actions.GetFirst(), thread_actions.GetSize()))
        return SendPacket ("E39");

    // Don't send an "OK" packet; response is the stopped/exited message.
    return rnb_success;
}

rnb_err_t
RNBRemote::HandlePacket_qHostInfo (const char *p)
{
    std::ostringstream strm;

    uint32_t cputype, is_64_bit_capable;
    size_t len = sizeof(cputype);
    bool promoted_to_64 = false;
    if  (::sysctlbyname("hw.cputype", &cputype, &len, NULL, 0) == 0)
    {
        len = sizeof (is_64_bit_capable);
        if  (::sysctlbyname("hw.cpu64bit_capable", &is_64_bit_capable, &len, NULL, 0) == 0)
        {
            if (is_64_bit_capable && ((cputype & CPU_ARCH_ABI64) == 0))
            {
                promoted_to_64 = true;
                cputype |= CPU_ARCH_ABI64;
            }
        }
        
        strm << "cputype:" << std::dec << cputype << ';';
    }

    uint32_t cpusubtype;
    len = sizeof(cpusubtype);
    if (::sysctlbyname("hw.cpusubtype", &cpusubtype, &len, NULL, 0) == 0)
    {
        if (promoted_to_64 && 
            cputype == CPU_TYPE_X86_64 && 
            cpusubtype == CPU_SUBTYPE_486)
            cpusubtype = CPU_SUBTYPE_X86_64_ALL;

        strm << "cpusubtype:" << std::dec << cpusubtype << ';';
    }

    char ostype[64];
    len = sizeof(ostype);
    if (::sysctlbyname("kern.ostype", &ostype, &len, NULL, 0) == 0)
        strm << "ostype:" << std::dec << ostype << ';';

    strm << "vendor:apple;";

#if defined (__LITTLE_ENDIAN__)
    strm << "endian:little;";
#elif defined (__BIG_ENDIAN__)
    strm << "endian:big;";
#elif defined (__PDP_ENDIAN__)
    strm << "endian:pdp;";
#endif

    strm << "ptrsize:" << std::dec << sizeof(void *) << ';';
    return SendPacket (strm.str());
}