LXR qemu/hw/multiboot.c

   1/*
   2 * QEMU PC System Emulator
   3 *
   4 * Copyright (c) 2003-2004 Fabrice Bellard
   5 *
   6 * Permission is hereby granted, free of charge, to any person obtaining a copy
   7 * of this software and associated documentation files (the "Software"), to deal
   8 * in the Software without restriction, including without limitation the rights
   9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10 * copies of the Software, and to permit persons to whom the Software is
  11 * furnished to do so, subject to the following conditions:
  12 *
  13 * The above copyright notice and this permission notice shall be included in
  14 * all copies or substantial portions of the Software.
  15 *
  16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22 * THE SOFTWARE.
  23 */
  24
  25#include "hw.h"
  26#include "fw_cfg.h"
  27#include "multiboot.h"
  28#include "loader.h"
  29#include "elf.h"
  30#include "sysemu/sysemu.h"
  31
  32/* Show multiboot debug output */
  33//#define DEBUG_MULTIBOOT
  34
  35#ifdef DEBUG_MULTIBOOT
  36#define mb_debug(a...) fprintf(stderr, ## a)
  37#else
  38#define mb_debug(a...)
  39#endif
  40
  41#define MULTIBOOT_STRUCT_ADDR 0x9000
  42
  43#if MULTIBOOT_STRUCT_ADDR > 0xf0000
  44#error multiboot struct needs to fit in 16 bit real mode
  45#endif
  46
  47enum {
  48    /* Multiboot info */
  49    MBI_FLAGS       = 0,
  50    MBI_MEM_LOWER   = 4,
  51    MBI_MEM_UPPER   = 8,
  52    MBI_BOOT_DEVICE = 12,
  53    MBI_CMDLINE     = 16,
  54    MBI_MODS_COUNT  = 20,
  55    MBI_MODS_ADDR   = 24,
  56    MBI_MMAP_ADDR   = 48,
  57
  58    MBI_SIZE        = 88,
  59
  60    /* Multiboot modules */
  61    MB_MOD_START    = 0,
  62    MB_MOD_END      = 4,
  63    MB_MOD_CMDLINE  = 8,
  64
  65    MB_MOD_SIZE     = 16,
  66
  67    /* Region offsets */
  68    ADDR_E820_MAP = MULTIBOOT_STRUCT_ADDR + 0,
  69    ADDR_MBI      = ADDR_E820_MAP + 0x500,
  70
  71    /* Multiboot flags */
  72    MULTIBOOT_FLAGS_MEMORY      = 1 << 0,
  73    MULTIBOOT_FLAGS_BOOT_DEVICE = 1 << 1,
  74    MULTIBOOT_FLAGS_CMDLINE     = 1 << 2,
  75    MULTIBOOT_FLAGS_MODULES     = 1 << 3,
  76    MULTIBOOT_FLAGS_MMAP        = 1 << 6,
  77};
  78
  79typedef struct {
  80    /* buffer holding kernel, cmdlines and mb_infos */
  81    void *mb_buf;
  82    /* address in target */
  83    hwaddr mb_buf_phys;
  84    /* size of mb_buf in bytes */
  85    unsigned mb_buf_size;
  86    /* offset of mb-info's in bytes */
  87    hwaddr offset_mbinfo;
  88    /* offset in buffer for cmdlines in bytes */
  89    hwaddr offset_cmdlines;
  90    /* offset of modules in bytes */
  91    hwaddr offset_mods;
  92    /* available slots for mb modules infos */
  93    int mb_mods_avail;
  94    /* currently used slots of mb modules */
  95    int mb_mods_count;
  96} MultibootState;
  97
  98static uint32_t mb_add_cmdline(MultibootState *s, const char *cmdline)
  99{
 100    hwaddr p = s->offset_cmdlines;
 101    char *b = (char *)s->mb_buf + p;
 102
 103    get_opt_value(b, strlen(cmdline) + 1, cmdline);
 104    s->offset_cmdlines += strlen(b) + 1;
 105    return s->mb_buf_phys + p;
 106}
 107
 108static void mb_add_mod(MultibootState *s,
 109                       hwaddr start, hwaddr end,
 110                       hwaddr cmdline_phys)
 111{
 112    char *p;
 113    assert(s->mb_mods_count < s->mb_mods_avail);
 114
 115    p = (char *)s->mb_buf + s->offset_mbinfo + MB_MOD_SIZE * s->mb_mods_count;
 116
 117    stl_p(p + MB_MOD_START,   start);
 118    stl_p(p + MB_MOD_END,     end);
 119    stl_p(p + MB_MOD_CMDLINE, cmdline_phys);
 120
 121    mb_debug("mod%02d: "TARGET_FMT_plx" - "TARGET_FMT_plx"\n",
 122             s->mb_mods_count, start, end);
 123
 124    s->mb_mods_count++;
 125}
 126
 127int load_multiboot(void *fw_cfg,
 128                   FILE *f,
 129                   const char *kernel_filename,
 130                   const char *initrd_filename,
 131                   const char *kernel_cmdline,
 132                   int kernel_file_size,
 133                   uint8_t *header)
 134{
 135    int i, is_multiboot = 0;
 136    uint32_t flags = 0;
 137    uint32_t mh_entry_addr;
 138    uint32_t mh_load_addr;
 139    uint32_t mb_kernel_size;
 140    MultibootState mbs;
 141    uint8_t bootinfo[MBI_SIZE];
 142    uint8_t *mb_bootinfo_data;
 143
 144    /* Ok, let's see if it is a multiboot image.
 145       The header is 12x32bit long, so the latest entry may be 8192 - 48. */
 146    for (i = 0; i < (8192 - 48); i += 4) {
 147        if (ldl_p(header+i) == 0x1BADB002) {
 148            uint32_t checksum = ldl_p(header+i+8);
 149            flags = ldl_p(header+i+4);
 150            checksum += flags;
 151            checksum += (uint32_t)0x1BADB002;
 152            if (!checksum) {
 153                is_multiboot = 1;
 154                break;
 155            }
 156        }
 157    }
 158
 159    if (!is_multiboot)
 160        return 0; /* no multiboot */
 161
 162    mb_debug("qemu: I believe we found a multiboot image!\n");
 163    memset(bootinfo, 0, sizeof(bootinfo));
 164    memset(&mbs, 0, sizeof(mbs));
 165
 166    if (flags & 0x00000004) { /* MULTIBOOT_HEADER_HAS_VBE */
 167        fprintf(stderr, "qemu: multiboot knows VBE. we don't.\n");
 168    }
 169    if (!(flags & 0x00010000)) { /* MULTIBOOT_HEADER_HAS_ADDR */
 170        uint64_t elf_entry;
 171        uint64_t elf_low, elf_high;
 172        int kernel_size;
 173        fclose(f);
 174
 175        if (((struct elf64_hdr*)header)->e_machine == EM_X86_64) {
 176            fprintf(stderr, "Cannot load x86-64 image, give a 32bit one.\n");
 177            exit(1);
 178        }
 179
 180        kernel_size = load_elf(kernel_filename, NULL, NULL, &elf_entry,
 181                               &elf_low, &elf_high, 0, ELF_MACHINE, 0);
 182        if (kernel_size < 0) {
 183            fprintf(stderr, "Error while loading elf kernel\n");
 184            exit(1);
 185        }
 186        mh_load_addr = elf_low;
 187        mb_kernel_size = elf_high - elf_low;
 188        mh_entry_addr = elf_entry;
 189
 190        mbs.mb_buf = g_malloc(mb_kernel_size);
 191        if (rom_copy(mbs.mb_buf, mh_load_addr, mb_kernel_size) != mb_kernel_size) {
 192            fprintf(stderr, "Error while fetching elf kernel from rom\n");
 193            exit(1);
 194        }
 195
 196        mb_debug("qemu: loading multiboot-elf kernel (%#x bytes) with entry %#zx\n",
 197                  mb_kernel_size, (size_t)mh_entry_addr);
 198    } else {
 199        /* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_ADDR. */
 200        uint32_t mh_header_addr = ldl_p(header+i+12);
 201        uint32_t mh_load_end_addr = ldl_p(header+i+20);
 202        uint32_t mh_bss_end_addr = ldl_p(header+i+24);
 203        mh_load_addr = ldl_p(header+i+16);
 204        uint32_t mb_kernel_text_offset = i - (mh_header_addr - mh_load_addr);
 205        uint32_t mb_load_size = 0;
 206        mh_entry_addr = ldl_p(header+i+28);
 207
 208        if (mh_load_end_addr) {
 209            mb_kernel_size = mh_bss_end_addr - mh_load_addr;
 210            mb_load_size = mh_load_end_addr - mh_load_addr;
 211        } else {
 212            mb_kernel_size = kernel_file_size - mb_kernel_text_offset;
 213            mb_load_size = mb_kernel_size;
 214        }
 215
 216        /* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_VBE.
 217        uint32_t mh_mode_type = ldl_p(header+i+32);
 218        uint32_t mh_width = ldl_p(header+i+36);
 219        uint32_t mh_height = ldl_p(header+i+40);
 220        uint32_t mh_depth = ldl_p(header+i+44); */
 221
 222        mb_debug("multiboot: mh_header_addr = %#x\n", mh_header_addr);
 223        mb_debug("multiboot: mh_load_addr = %#x\n", mh_load_addr);
 224        mb_debug("multiboot: mh_load_end_addr = %#x\n", mh_load_end_addr);
 225        mb_debug("multiboot: mh_bss_end_addr = %#x\n", mh_bss_end_addr);
 226        mb_debug("qemu: loading multiboot kernel (%#x bytes) at %#x\n",
 227                 mb_load_size, mh_load_addr);
 228
 229        mbs.mb_buf = g_malloc(mb_kernel_size);
 230        fseek(f, mb_kernel_text_offset, SEEK_SET);
 231        if (fread(mbs.mb_buf, 1, mb_load_size, f) != mb_load_size) {
 232            fprintf(stderr, "fread() failed\n");
 233            exit(1);
 234        }
 235        memset(mbs.mb_buf + mb_load_size, 0, mb_kernel_size - mb_load_size);
 236        fclose(f);
 237    }
 238
 239    mbs.mb_buf_phys = mh_load_addr;
 240
 241    mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_kernel_size);
 242    mbs.offset_mbinfo = mbs.mb_buf_size;
 243
 244    /* Calculate space for cmdlines and mb_mods */
 245    mbs.mb_buf_size += strlen(kernel_filename) + 1;
 246    mbs.mb_buf_size += strlen(kernel_cmdline) + 1;
 247    if (initrd_filename) {
 248        const char *r = initrd_filename;
 249        mbs.mb_buf_size += strlen(r) + 1;
 250        mbs.mb_mods_avail = 1;
 251        while (*(r = get_opt_value(NULL, 0, r))) {
 252           mbs.mb_mods_avail++;
 253           r++;
 254        }
 255        mbs.mb_buf_size += MB_MOD_SIZE * mbs.mb_mods_avail;
 256    }
 257
 258    mbs.mb_buf_size = TARGET_PAGE_ALIGN(mbs.mb_buf_size);
 259
 260    /* enlarge mb_buf to hold cmdlines and mb-info structs */
 261    mbs.mb_buf          = g_realloc(mbs.mb_buf, mbs.mb_buf_size);
 262    mbs.offset_cmdlines = mbs.offset_mbinfo + mbs.mb_mods_avail * MB_MOD_SIZE;
 263
 264    if (initrd_filename) {
 265        char *next_initrd, not_last;
 266
 267        mbs.offset_mods = mbs.mb_buf_size;
 268
 269        do {
 270            char *next_space;
 271            int mb_mod_length;
 272            uint32_t offs = mbs.mb_buf_size;
 273
 274            next_initrd = (char *)get_opt_value(NULL, 0, initrd_filename);
 275            not_last = *next_initrd;
 276            *next_initrd = '\0';
 277            /* if a space comes after the module filename, treat everything
 278               after that as parameters */
 279            hwaddr c = mb_add_cmdline(&mbs, initrd_filename);
 280            if ((next_space = strchr(initrd_filename, ' ')))
 281                *next_space = '\0';
 282            mb_debug("multiboot loading module: %s\n", initrd_filename);
 283            mb_mod_length = get_image_size(initrd_filename);
 284            if (mb_mod_length < 0) {
 285                fprintf(stderr, "Failed to open file '%s'\n", initrd_filename);
 286                exit(1);
 287            }
 288
 289            mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_mod_length + mbs.mb_buf_size);
 290            mbs.mb_buf = g_realloc(mbs.mb_buf, mbs.mb_buf_size);
 291
 292            load_image(initrd_filename, (unsigned char *)mbs.mb_buf + offs);
 293            mb_add_mod(&mbs, mbs.mb_buf_phys + offs,
 294                       mbs.mb_buf_phys + offs + mb_mod_length, c);
 295
 296            mb_debug("mod_start: %p\nmod_end:   %p\n  cmdline: "TARGET_FMT_plx"\n",
 297                     (char *)mbs.mb_buf + offs,
 298                     (char *)mbs.mb_buf + offs + mb_mod_length, c);
 299            initrd_filename = next_initrd+1;
 300        } while (not_last);
 301    }
 302
 303    /* Commandline support */
 304    char kcmdline[strlen(kernel_filename) + strlen(kernel_cmdline) + 2];
 305    snprintf(kcmdline, sizeof(kcmdline), "%s %s",
 306             kernel_filename, kernel_cmdline);
 307    stl_p(bootinfo + MBI_CMDLINE, mb_add_cmdline(&mbs, kcmdline));
 308
 309    stl_p(bootinfo + MBI_MODS_ADDR,  mbs.mb_buf_phys + mbs.offset_mbinfo);
 310    stl_p(bootinfo + MBI_MODS_COUNT, mbs.mb_mods_count); /* mods_count */
 311
 312    /* the kernel is where we want it to be now */
 313    stl_p(bootinfo + MBI_FLAGS, MULTIBOOT_FLAGS_MEMORY
 314                                | MULTIBOOT_FLAGS_BOOT_DEVICE
 315                                | MULTIBOOT_FLAGS_CMDLINE
 316                                | MULTIBOOT_FLAGS_MODULES
 317                                | MULTIBOOT_FLAGS_MMAP);
 318    stl_p(bootinfo + MBI_MEM_LOWER,   640);
 319    stl_p(bootinfo + MBI_MEM_UPPER,   (ram_size / 1024) - 1024);
 320    stl_p(bootinfo + MBI_BOOT_DEVICE, 0x8000ffff); /* XXX: use the -boot switch? */
 321    stl_p(bootinfo + MBI_MMAP_ADDR,   ADDR_E820_MAP);
 322
 323    mb_debug("multiboot: mh_entry_addr = %#x\n", mh_entry_addr);
 324    mb_debug("           mb_buf_phys   = "TARGET_FMT_plx"\n", mbs.mb_buf_phys);
 325    mb_debug("           mod_start     = "TARGET_FMT_plx"\n", mbs.mb_buf_phys + mbs.offset_mods);
 326    mb_debug("           mb_mods_count = %d\n", mbs.mb_mods_count);
 327
 328    /* save bootinfo off the stack */
 329    mb_bootinfo_data = g_malloc(sizeof(bootinfo));
 330    memcpy(mb_bootinfo_data, bootinfo, sizeof(bootinfo));
 331
 332    /* Pass variables to option rom */
 333    fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ENTRY, mh_entry_addr);
 334    fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, mh_load_addr);
 335    fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, mbs.mb_buf_size);
 336    fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA,
 337                     mbs.mb_buf, mbs.mb_buf_size);
 338
 339    fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_ADDR, ADDR_MBI);
 340    fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_SIZE, sizeof(bootinfo));
 341    fw_cfg_add_bytes(fw_cfg, FW_CFG_INITRD_DATA, mb_bootinfo_data,
 342                     sizeof(bootinfo));
 343
 344    option_rom[nb_option_roms].name = "multiboot.bin";
 345    option_rom[nb_option_roms].bootindex = 0;
 346    nb_option_roms++;
 347
 348    return 1; /* yes, we are multiboot */
 349}
 350