nios2: add kgdb support
Signed-off-by: Ley Foon Tan <lftan@altera.com>
diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
index f77991e..4375554 100644
--- a/arch/nios2/Kconfig
+++ b/arch/nios2/Kconfig
@@ -8,6 +8,7 @@
select GENERIC_IRQ_PROBE
select GENERIC_IRQ_SHOW
select HAVE_ARCH_TRACEHOOK
+ select HAVE_ARCH_KGDB
select IRQ_DOMAIN
select MODULES_USE_ELF_RELA
select OF
diff --git a/arch/nios2/include/asm/kgdb.h b/arch/nios2/include/asm/kgdb.h
new file mode 100644
index 0000000..8fd5e3b
--- /dev/null
+++ b/arch/nios2/include/asm/kgdb.h
@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2015 Altera Corporation
+ * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
+ *
+ * Based on the code posted by Kazuyasu on the Altera Forum at:
+ * http://www.alteraforum.com/forum/showpost.php?p=77003&postcount=20
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef _ASM_NIOS2_KGDB_H
+#define _ASM_NIOS2_KGDB_H
+
+#define CACHE_FLUSH_IS_SAFE 1
+#define BUFMAX 2048
+
+enum regnames {
+ GDB_R0 = 0,
+ GDB_AT,
+ GDB_R2,
+ GDB_R3,
+ GDB_R4,
+ GDB_R5,
+ GDB_R6,
+ GDB_R7,
+ GDB_R8,
+ GDB_R9,
+ GDB_R10,
+ GDB_R11,
+ GDB_R12,
+ GDB_R13,
+ GDB_R14,
+ GDB_R15,
+ GDB_R16,
+ GDB_R17,
+ GDB_R18,
+ GDB_R19,
+ GDB_R20,
+ GDB_R21,
+ GDB_R22,
+ GDB_R23,
+ GDB_ET,
+ GDB_BT,
+ GDB_GP,
+ GDB_SP,
+ GDB_FP,
+ GDB_EA,
+ GDB_BA,
+ GDB_RA,
+ GDB_PC,
+ GDB_STATUS,
+ GDB_ESTATUS,
+ GDB_BSTATUS,
+ GDB_IENABLE,
+ GDB_IPENDING,
+ GDB_CPUID,
+ GDB_CTL6,
+ GDB_EXCEPTION,
+ GDB_PTEADDR,
+ GDB_TLBACC,
+ GDB_TLBMISC,
+ GDB_ECCINJ,
+ GDB_BADADDR,
+ GDB_CONFIG,
+ GDB_MPUBASE,
+ GDB_MPUACC,
+ /* do not change the last entry or anything below! */
+ GDB_NUMREGBYTES /* number of registers */
+};
+
+#define GDB_SIZEOF_REG sizeof(u32)
+#define DBG_MAX_REG_NUM (49)
+#define NUMREGBYTES (DBG_MAX_REG_NUM * sizeof(GDB_SIZEOF_REG))
+
+#define BREAK_INSTR_SIZE 4
+static inline void arch_kgdb_breakpoint(void)
+{
+ __asm__ __volatile__("trap 30\n");
+}
+
+#endif /* _ASM_NIOS2_KGDB_H */
diff --git a/arch/nios2/kernel/Makefile b/arch/nios2/kernel/Makefile
index eaaa894..1aae257 100644
--- a/arch/nios2/kernel/Makefile
+++ b/arch/nios2/kernel/Makefile
@@ -21,5 +21,6 @@
obj-y += traps.o
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
+obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_MODULES) += module.o
obj-$(CONFIG_NIOS2_ALIGNMENT_TRAP) += misaligned.o
diff --git a/arch/nios2/kernel/entry.S b/arch/nios2/kernel/entry.S
index 0bdfd13..7729bd3 100644
--- a/arch/nios2/kernel/entry.S
+++ b/arch/nios2/kernel/entry.S
@@ -121,7 +121,11 @@
.word instruction_trap /* 27 */
.word instruction_trap /* 28 */
.word instruction_trap /* 29 */
- .word instruction_trap /* 30 */
+#ifdef CONFIG_KGDB
+ .word handle_kgdb_breakpoint /* 30 KGDB breakpoint */
+#else
+ .word instruction_trap /* 30 */
+#endif
.word handle_breakpoint /* 31 */
.text
@@ -445,6 +449,12 @@
call handle_diverror_c
br ret_from_exception
+#ifdef CONFIG_KGDB
+handle_kgdb_breakpoint:
+ call kgdb_breakpoint_c
+ br ret_from_exception
+#endif
+
/*
* Beware - when entering resume, prev (the current task) is
* in r4, next (the new task) is in r5, don't change these
diff --git a/arch/nios2/kernel/kgdb.c b/arch/nios2/kernel/kgdb.c
new file mode 100644
index 0000000..1178591
--- /dev/null
+++ b/arch/nios2/kernel/kgdb.c
@@ -0,0 +1,171 @@
+/*
+ * Nios2 KGDB support
+ *
+ * Copyright (C) 2015 Altera Corporation
+ * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
+ *
+ * Based on the code posted by Kazuyasu on the Altera Forum at:
+ * http://www.alteraforum.com/forum/showpost.php?p=77003&postcount=20
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#include <linux/ptrace.h>
+#include <linux/kgdb.h>
+#include <linux/kdebug.h>
+#include <linux/io.h>
+
+static int wait_for_remote_debugger;
+
+struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
+{
+ { "zero", GDB_SIZEOF_REG, -1 },
+ { "at", GDB_SIZEOF_REG, offsetof(struct pt_regs, r1) },
+ { "r2", GDB_SIZEOF_REG, offsetof(struct pt_regs, r2) },
+ { "r3", GDB_SIZEOF_REG, offsetof(struct pt_regs, r3) },
+ { "r4", GDB_SIZEOF_REG, offsetof(struct pt_regs, r4) },
+ { "r5", GDB_SIZEOF_REG, offsetof(struct pt_regs, r5) },
+ { "r6", GDB_SIZEOF_REG, offsetof(struct pt_regs, r6) },
+ { "r7", GDB_SIZEOF_REG, offsetof(struct pt_regs, r7) },
+ { "r8", GDB_SIZEOF_REG, offsetof(struct pt_regs, r8) },
+ { "r9", GDB_SIZEOF_REG, offsetof(struct pt_regs, r9) },
+ { "r10", GDB_SIZEOF_REG, offsetof(struct pt_regs, r10) },
+ { "r11", GDB_SIZEOF_REG, offsetof(struct pt_regs, r11) },
+ { "r12", GDB_SIZEOF_REG, offsetof(struct pt_regs, r12) },
+ { "r13", GDB_SIZEOF_REG, offsetof(struct pt_regs, r13) },
+ { "r14", GDB_SIZEOF_REG, offsetof(struct pt_regs, r14) },
+ { "r15", GDB_SIZEOF_REG, offsetof(struct pt_regs, r15) },
+ { "r16", GDB_SIZEOF_REG, -1 },
+ { "r17", GDB_SIZEOF_REG, -1 },
+ { "r18", GDB_SIZEOF_REG, -1 },
+ { "r19", GDB_SIZEOF_REG, -1 },
+ { "r20", GDB_SIZEOF_REG, -1 },
+ { "r21", GDB_SIZEOF_REG, -1 },
+ { "r22", GDB_SIZEOF_REG, -1 },
+ { "r23", GDB_SIZEOF_REG, -1 },
+ { "et", GDB_SIZEOF_REG, -1 },
+ { "bt", GDB_SIZEOF_REG, -1 },
+ { "gp", GDB_SIZEOF_REG, offsetof(struct pt_regs, gp) },
+ { "sp", GDB_SIZEOF_REG, offsetof(struct pt_regs, sp) },
+ { "fp", GDB_SIZEOF_REG, offsetof(struct pt_regs, fp) },
+ { "ea", GDB_SIZEOF_REG, -1 },
+ { "ba", GDB_SIZEOF_REG, -1 },
+ { "ra", GDB_SIZEOF_REG, offsetof(struct pt_regs, ra) },
+ { "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, ea) },
+ { "status", GDB_SIZEOF_REG, -1 },
+ { "estatus", GDB_SIZEOF_REG, offsetof(struct pt_regs, estatus) },
+ { "bstatus", GDB_SIZEOF_REG, -1 },
+ { "ienable", GDB_SIZEOF_REG, -1 },
+ { "ipending", GDB_SIZEOF_REG, -1},
+ { "cpuid", GDB_SIZEOF_REG, -1 },
+ { "ctl6", GDB_SIZEOF_REG, -1 },
+ { "exception", GDB_SIZEOF_REG, -1 },
+ { "pteaddr", GDB_SIZEOF_REG, -1 },
+ { "tlbacc", GDB_SIZEOF_REG, -1 },
+ { "tlbmisc", GDB_SIZEOF_REG, -1 },
+ { "eccinj", GDB_SIZEOF_REG, -1 },
+ { "badaddr", GDB_SIZEOF_REG, -1 },
+ { "config", GDB_SIZEOF_REG, -1 },
+ { "mpubase", GDB_SIZEOF_REG, -1 },
+ { "mpuacc", GDB_SIZEOF_REG, -1 },
+};
+
+char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
+{
+ if (regno >= DBG_MAX_REG_NUM || regno < 0)
+ return NULL;
+
+ if (dbg_reg_def[regno].offset != -1)
+ memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
+ dbg_reg_def[regno].size);
+ else
+ memset(mem, 0, dbg_reg_def[regno].size);
+
+ return dbg_reg_def[regno].name;
+}
+
+int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
+{
+ if (regno >= DBG_MAX_REG_NUM || regno < 0)
+ return -EINVAL;
+
+ if (dbg_reg_def[regno].offset != -1)
+ memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
+ dbg_reg_def[regno].size);
+
+ return 0;
+}
+
+void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
+{
+ memset((char *)gdb_regs, 0, NUMREGBYTES);
+ gdb_regs[GDB_SP] = p->thread.kregs->sp;
+ gdb_regs[GDB_PC] = p->thread.kregs->ea;
+}
+
+void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
+{
+ regs->ea = pc;
+}
+
+int kgdb_arch_handle_exception(int vector, int signo, int err_code,
+ char *remcom_in_buffer, char *remcom_out_buffer,
+ struct pt_regs *regs)
+{
+ char *ptr;
+ unsigned long addr;
+
+ switch (remcom_in_buffer[0]) {
+ case 's':
+ case 'c':
+ /* handle the optional parameters */
+ ptr = &remcom_in_buffer[1];
+ if (kgdb_hex2long(&ptr, &addr))
+ regs->ea = addr;
+
+ return 0;
+ }
+
+ return -1; /* this means that we do not want to exit from the handler */
+}
+
+asmlinkage void kgdb_breakpoint_c(struct pt_regs *regs)
+{
+ /*
+ * The breakpoint entry code has moved the PC on by 4 bytes, so we must
+ * move it back. This could be done on the host but we do it here
+ */
+ if (!wait_for_remote_debugger)
+ regs->ea -= 4;
+ else /* pass the first trap 30 code */
+ wait_for_remote_debugger = 0;
+
+ kgdb_handle_exception(30, SIGTRAP, 0, regs);
+}
+
+int kgdb_arch_init(void)
+{
+ wait_for_remote_debugger = 1;
+ return 0;
+}
+
+void kgdb_arch_exit(void)
+{
+ /* Nothing to do */
+}
+
+struct kgdb_arch arch_kgdb_ops = {
+ /* Breakpoint instruction: trap 30 */
+ .gdb_bpt_instr = { 0xba, 0x6f, 0x3b, 0x00 },
+};