H. Peter Anvin | 6260731 | 2007-07-11 12:18:54 -0700 | [diff] [blame] | 1 | /* -*- linux-c -*- ------------------------------------------------------- * |
| 2 | * |
| 3 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 4 | * Copyright 2007 rPath, Inc. - All Rights Reserved |
| 5 | * |
| 6 | * This file is part of the Linux kernel, and is made available under |
| 7 | * the terms of the GNU General Public License version 2. |
| 8 | * |
| 9 | * ----------------------------------------------------------------------- */ |
| 10 | |
| 11 | /* |
| 12 | * arch/i386/boot/main.c |
| 13 | * |
| 14 | * Main module for the real-mode kernel code |
| 15 | */ |
| 16 | |
| 17 | #include "boot.h" |
| 18 | |
| 19 | struct boot_params boot_params __attribute__((aligned(16))); |
| 20 | |
| 21 | char *HEAP = _end; |
| 22 | char *heap_end = _end; /* Default end of heap = no heap */ |
| 23 | |
| 24 | /* |
| 25 | * Copy the header into the boot parameter block. Since this |
| 26 | * screws up the old-style command line protocol, adjust by |
| 27 | * filling in the new-style command line pointer instead. |
| 28 | */ |
| 29 | #define OLD_CL_MAGIC 0xA33F |
| 30 | #define OLD_CL_ADDRESS 0x20 |
| 31 | |
| 32 | static void copy_boot_params(void) |
| 33 | { |
| 34 | struct old_cmdline { |
| 35 | u16 cl_magic; |
| 36 | u16 cl_offset; |
| 37 | }; |
| 38 | const struct old_cmdline * const oldcmd = |
| 39 | (const struct old_cmdline *)OLD_CL_ADDRESS; |
| 40 | |
| 41 | BUILD_BUG_ON(sizeof boot_params != 4096); |
| 42 | memcpy(&boot_params.hdr, &hdr, sizeof hdr); |
| 43 | |
| 44 | if (!boot_params.hdr.cmd_line_ptr && |
| 45 | oldcmd->cl_magic == OLD_CL_MAGIC) { |
| 46 | /* Old-style command line protocol. */ |
| 47 | u16 cmdline_seg; |
| 48 | |
| 49 | /* Figure out if the command line falls in the region |
| 50 | of memory that an old kernel would have copied up |
| 51 | to 0x90000... */ |
| 52 | if (oldcmd->cl_offset < boot_params.hdr.setup_move_size) |
| 53 | cmdline_seg = ds(); |
| 54 | else |
| 55 | cmdline_seg = 0x9000; |
| 56 | |
| 57 | boot_params.hdr.cmd_line_ptr = |
| 58 | (cmdline_seg << 4) + oldcmd->cl_offset; |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | /* |
| 63 | * Set the keyboard repeat rate to maximum. Unclear why this |
| 64 | * is done here; this might be possible to kill off as stale code. |
| 65 | */ |
| 66 | static void keyboard_set_repeat(void) |
| 67 | { |
| 68 | u16 ax = 0x0305; |
| 69 | u16 bx = 0; |
| 70 | asm volatile("int $0x16" |
| 71 | : "+a" (ax), "+b" (bx) |
| 72 | : : "ecx", "edx", "esi", "edi"); |
| 73 | } |
| 74 | |
| 75 | /* |
| 76 | * Get Intel SpeedStep IST information. |
| 77 | */ |
| 78 | static void query_speedstep_ist(void) |
| 79 | { |
| 80 | asm("int $0x15" |
| 81 | : "=a" (boot_params.speedstep_info[0]), |
| 82 | "=b" (boot_params.speedstep_info[1]), |
| 83 | "=c" (boot_params.speedstep_info[2]), |
| 84 | "=d" (boot_params.speedstep_info[3]) |
| 85 | : "a" (0x0000e980), /* IST Support */ |
| 86 | "d" (0x47534943)); /* Request value */ |
| 87 | } |
| 88 | |
| 89 | /* |
| 90 | * Tell the BIOS what CPU mode we intend to run in. |
| 91 | */ |
| 92 | static void set_bios_mode(void) |
| 93 | { |
| 94 | #ifdef CONFIG_X86_64 |
| 95 | u32 eax, ebx; |
| 96 | |
| 97 | eax = 0xec00; |
| 98 | ebx = 2; |
| 99 | asm volatile("int $0x15" |
| 100 | : "+a" (eax), "+b" (ebx) |
| 101 | : : "ecx", "edx", "esi", "edi"); |
| 102 | #endif |
| 103 | } |
| 104 | |
| 105 | void main(void) |
| 106 | { |
| 107 | /* First, copy the boot header into the "zeropage" */ |
| 108 | copy_boot_params(); |
| 109 | |
| 110 | /* End of heap check */ |
| 111 | if (boot_params.hdr.loadflags & CAN_USE_HEAP) { |
| 112 | heap_end = (char *)(boot_params.hdr.heap_end_ptr |
| 113 | +0x200-STACK_SIZE); |
| 114 | } else { |
| 115 | /* Boot protocol 2.00 only, no heap available */ |
| 116 | puts("WARNING: Ancient bootloader, some functionality " |
| 117 | "may be limited!\n"); |
| 118 | } |
| 119 | |
| 120 | /* Make sure we have all the proper CPU support */ |
| 121 | if (validate_cpu()) { |
| 122 | puts("Unable to boot - please use a kernel appropriate " |
| 123 | "for your CPU.\n"); |
| 124 | die(); |
| 125 | } |
| 126 | |
| 127 | /* Tell the BIOS what CPU mode we intend to run in. */ |
| 128 | set_bios_mode(); |
| 129 | |
| 130 | /* Detect memory layout */ |
| 131 | detect_memory(); |
| 132 | |
| 133 | /* Set keyboard repeat rate (why?) */ |
| 134 | keyboard_set_repeat(); |
| 135 | |
| 136 | /* Set the video mode */ |
| 137 | set_video(); |
| 138 | |
| 139 | /* Query MCA information */ |
| 140 | query_mca(); |
| 141 | |
| 142 | /* Voyager */ |
| 143 | #ifdef CONFIG_X86_VOYAGER |
| 144 | query_voyager(); |
| 145 | #endif |
| 146 | |
| 147 | /* Query SpeedStep IST information */ |
| 148 | query_speedstep_ist(); |
| 149 | |
| 150 | /* Query APM information */ |
| 151 | #if defined(CONFIG_APM) || defined(CONFIG_APM_MODULE) |
| 152 | query_apm_bios(); |
| 153 | #endif |
| 154 | |
| 155 | /* Query EDD information */ |
| 156 | #if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE) |
| 157 | query_edd(); |
| 158 | #endif |
| 159 | /* Do the last things and invoke protected mode */ |
| 160 | go_to_protected_mode(); |
| 161 | } |