LXR qemu/hw/i386/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 "qemu/osdep.h"
  26#include "qemu-common.h"
  27#include "cpu.h"
  28#include "hw/hw.h"
  29#include "hw/nvram/fw_cfg.h"
  30#include "multiboot.h"
  31#include "hw/loader.h"
  32#include "elf.h"
  33#include "sysemu/sysemu.h"
  34
  35/* Show multiboot debug output */
  36//#define DEBUG_MULTIBOOT
  37
  38#ifdef DEBUG_MULTIBOOT
  39#define mb_debug(a...) fprintf(stderr, ## a)
  40#else
  41#define mb_debug(a...)
  42#endif
  43
  44#define MULTIBOOT_STRUCT_ADDR 0x9000
  45
  46#if MULTIBOOT_STRUCT_ADDR > 0xf0000
  47#error multiboot struct needs to fit in 16 bit real mode
  48#endif
  49
  50enum {
  51    /* Multiboot info */
  52    MBI_FLAGS       = 0,
  53    MBI_MEM_LOWER   = 4,
  54    MBI_MEM_UPPER   = 8,
  55    MBI_BOOT_DEVICE = 12,
  56    MBI_CMDLINE     = 16,
  57    MBI_MODS_COUNT  = 20,
  58    MBI_MODS_ADDR   = 24,
  59    MBI_MMAP_ADDR   = 48,
  60    MBI_BOOTLOADER  = 64,
  61
  62    MBI_SIZE        = 88,
  63
  64    /* Multiboot modules */
  65    MB_MOD_START    = 0,
  66    MB_MOD_END      = 4,
  67    MB_MOD_CMDLINE  = 8,
  68
  69    MB_MOD_SIZE     = 16,
  70
  71    /* Region offsets */
  72    ADDR_E820_MAP = MULTIBOOT_STRUCT_ADDR + 0,
  73    ADDR_MBI      = ADDR_E820_MAP + 0x500,
  74
  75    /* Multiboot flags */
  76    MULTIBOOT_FLAGS_MEMORY      = 1 << 0,
  77    MULTIBOOT_FLAGS_BOOT_DEVICE = 1 << 1,
  78    MULTIBOOT_FLAGS_CMDLINE     = 1 << 2,
  79    MULTIBOOT_FLAGS_MODULES     = 1 << 3,
  80    MULTIBOOT_FLAGS_MMAP        = 1 << 6,
  81    MULTIBOOT_FLAGS_BOOTLOADER  = 1 << 9,
  82};
  83
  84typedef struct {
  85    /* buffer holding kernel, cmdlines and mb_infos */
  86    void *mb_buf;
  87    /* address in target */
  88    hwaddr mb_buf_phys;
  89    /* size of mb_buf in bytes */
  90    unsigned mb_buf_size;
  91    /* offset of mb-info's in bytes */
  92    hwaddr offset_mbinfo;
  93    /* offset in buffer for cmdlines in bytes */
  94    hwaddr offset_cmdlines;
  95    /* offset in buffer for bootloader name in bytes */
  96    hwaddr offset_bootloader;
  97    /* offset of modules in bytes */
  98    hwaddr offset_mods;
  99    /* available slots for mb modules infos */
 100    int mb_mods_avail;
 101    /* currently used slots of mb modules */
 102    int mb_mods_count;
 103} MultibootState;
 104
 105const char *bootloader_name = "qemu";
 106
 107static uint32_t mb_add_cmdline(MultibootState *s, const char *cmdline)
 108{
 109    hwaddr p = s->offset_cmdlines;
 110    char *b = (char *)s->mb_buf + p;
 111
 112    memcpy(b, cmdline, strlen(cmdline) + 1);
 113    s->offset_cmdlines += strlen(b) + 1;
 114    return s->mb_buf_phys + p;
 115}
 116
 117static uint32_t mb_add_bootloader(MultibootState *s, const char *bootloader)
 118{
 119    hwaddr p = s->offset_bootloader;
 120    char *b = (char *)s->mb_buf + p;
 121
 122    memcpy(b, bootloader, strlen(bootloader) + 1);
 123    s->offset_bootloader += strlen(b) + 1;
 124    return s->mb_buf_phys + p;
 125}
 126
 127static void mb_add_mod(MultibootState *s,
 128                       hwaddr start, hwaddr end,
 129                       hwaddr cmdline_phys)
 130{
 131    char *p;
 132    assert(s->mb_mods_count < s->mb_mods_avail);
 133
 134    p = (char *)s->mb_buf + s->offset_mbinfo + MB_MOD_SIZE * s->mb_mods_count;
 135
 136    stl_p(p + MB_MOD_START,   start);
 137    stl_p(p + MB_MOD_END,     end);
 138    stl_p(p + MB_MOD_CMDLINE, cmdline_phys);
 139
 140    mb_debug("mod%02d: "TARGET_FMT_plx" - "TARGET_FMT_plx"\n",
 141             s->mb_mods_count, start, end);
 142
 143    s->mb_mods_count++;
 144}
 145
 146int load_multiboot(FWCfgState *fw_cfg,
 147                   FILE *f,
 148                   const char *kernel_filename,
 149                   const char *initrd_filename,
 150                   const char *kernel_cmdline,
 151                   int kernel_file_size,
 152                   uint8_t *header)
 153{
 154    int i, is_multiboot = 0;
 155    uint32_t flags = 0;
 156    uint32_t mh_entry_addr;
 157    uint32_t mh_load_addr;
 158    uint32_t mb_kernel_size;
 159    MultibootState mbs;
 160    uint8_t bootinfo[MBI_SIZE];
 161    uint8_t *mb_bootinfo_data;
 162    uint32_t cmdline_len;
 163
 164    /* Ok, let's see if it is a multiboot image.
 165       The header is 12x32bit long, so the latest entry may be 8192 - 48. */
 166    for (i = 0; i < (8192 - 48); i += 4) {
 167        if (ldl_p(header+i) == 0x1BADB002) {
 168            uint32_t checksum = ldl_p(header+i+8);
 169            flags = ldl_p(header+i+4);
 170            checksum += flags;
 171            checksum += (uint32_t)0x1BADB002;
 172            if (!checksum) {
 173                is_multiboot = 1;
 174                break;
 175            }
 176        }
 177    }
 178
 179    if (!is_multiboot)
 180        return 0; /* no multiboot */
 181
 182    mb_debug("qemu: I believe we found a multiboot image!\n");
 183    memset(bootinfo, 0, sizeof(bootinfo));
 184    memset(&mbs, 0, sizeof(mbs));
 185
 186    if (flags & 0x00000004) { /* MULTIBOOT_HEADER_HAS_VBE */
 187        fprintf(stderr, "qemu: multiboot knows VBE. we don't.\n");
 188    }
 189    if (!(flags & 0x00010000)) { /* MULTIBOOT_HEADER_HAS_ADDR */
 190        uint64_t elf_entry;
 191        uint64_t elf_low, elf_high;
 192        int kernel_size;
 193        fclose(f);
 194
 195        if (((struct elf64_hdr*)header)->e_machine == EM_X86_64) {
 196            fprintf(stderr, "Cannot load x86-64 image, give a 32bit one.\n");
 197            exit(1);
 198        }
 199
 200        kernel_size = load_elf(kernel_filename, NULL, NULL, &elf_entry,
 201                               &elf_low, &elf_high, 0, I386_ELF_MACHINE,
 202                               0, 0);
 203        if (kernel_size < 0) {
 204            fprintf(stderr, "Error while loading elf kernel\n");
 205            exit(1);
 206        }
 207        mh_load_addr = elf_low;
 208        mb_kernel_size = elf_high - elf_low;
 209        mh_entry_addr = elf_entry;
 210
 211        mbs.mb_buf = g_malloc(mb_kernel_size);
 212        if (rom_copy(mbs.mb_buf, mh_load_addr, mb_kernel_size) != mb_kernel_size) {
 213            fprintf(stderr, "Error while fetching elf kernel from rom\n");
 214            exit(1);
 215        }
 216
 217        mb_debug("qemu: loading multiboot-elf kernel (%#x bytes) with entry %#zx\n",
 218                  mb_kernel_size, (size_t)mh_entry_addr);
 219    } else {
 220        /* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_ADDR. */
 221        uint32_t mh_header_addr = ldl_p(header+i+12);
 222        uint32_t mh_load_end_addr = ldl_p(header+i+20);
 223        uint32_t mh_bss_end_addr = ldl_p(header+i+24);
 224
 225        mh_load_addr = ldl_p(header+i+16);
 226        if (mh_header_addr < mh_load_addr) {
 227            fprintf(stderr, "invalid mh_load_addr address\n");
 228            exit(1);
 229        }
 230
 231        uint32_t mb_kernel_text_offset = i - (mh_header_addr - mh_load_addr);
 232        uint32_t mb_load_size = 0;
 233        mh_entry_addr = ldl_p(header+i+28);
 234
 235        if (mh_load_end_addr) {
 236            if (mh_bss_end_addr < mh_load_addr) {
 237                fprintf(stderr, "invalid mh_bss_end_addr address\n");
 238                exit(1);
 239            }
 240            mb_kernel_size = mh_bss_end_addr - mh_load_addr;
 241
 242            if (mh_load_end_addr < mh_load_addr) {
 243                fprintf(stderr, "invalid mh_load_end_addr address\n");
 244                exit(1);
 245            }
 246            mb_load_size = mh_load_end_addr - mh_load_addr;
 247        } else {
 248            if (kernel_file_size < mb_kernel_text_offset) {
 249                fprintf(stderr, "invalid kernel_file_size\n");
 250                exit(1);
 251            }
 252            mb_kernel_size = kernel_file_size - mb_kernel_text_offset;
 253            mb_load_size = mb_kernel_size;
 254        }
 255
 256        /* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_VBE.
 257        uint32_t mh_mode_type = ldl_p(header+i+32);
 258        uint32_t mh_width = ldl_p(header+i+36);
 259        uint32_t mh_height = ldl_p(header+i+40);
 260        uint32_t mh_depth = ldl_p(header+i+44); */
 261
 262        mb_debug("multiboot: mh_header_addr = %#x\n", mh_header_addr);
 263        mb_debug("multiboot: mh_load_addr = %#x\n", mh_load_addr);
 264        mb_debug("multiboot: mh_load_end_addr = %#x\n", mh_load_end_addr);
 265        mb_debug("multiboot: mh_bss_end_addr = %#x\n", mh_bss_end_addr);
 266        mb_debug("qemu: loading multiboot kernel (%#x bytes) at %#x\n",
 267                 mb_load_size, mh_load_addr);
 268
 269        mbs.mb_buf = g_malloc(mb_kernel_size);
 270        fseek(f, mb_kernel_text_offset, SEEK_SET);
 271        if (fread(mbs.mb_buf, 1, mb_load_size, f) != mb_load_size) {
 272            fprintf(stderr, "fread() failed\n");
 273            exit(1);
 274        }
 275        memset(mbs.mb_buf + mb_load_size, 0, mb_kernel_size - mb_load_size);
 276        fclose(f);
 277    }
 278
 279    mbs.mb_buf_phys = mh_load_addr;
 280
 281    mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_kernel_size);
 282    mbs.offset_mbinfo = mbs.mb_buf_size;
 283
 284    /* Calculate space for cmdlines, bootloader name, and mb_mods */
 285    cmdline_len = strlen(kernel_filename) + 1;
 286    cmdline_len += strlen(kernel_cmdline) + 1;
 287    if (initrd_filename) {
 288        const char *r = initrd_filename;
 289        cmdline_len += strlen(r) + 1;
 290        mbs.mb_mods_avail = 1;
 291        while (*(r = get_opt_value(NULL, 0, r))) {
 292           mbs.mb_mods_avail++;
 293           r++;
 294        }
 295    }
 296
 297    mbs.mb_buf_size += cmdline_len;
 298    mbs.mb_buf_size += MB_MOD_SIZE * mbs.mb_mods_avail;
 299    mbs.mb_buf_size += strlen(bootloader_name) + 1;
 300
 301    mbs.mb_buf_size = TARGET_PAGE_ALIGN(mbs.mb_buf_size);
 302
 303    /* enlarge mb_buf to hold cmdlines, bootloader, mb-info structs */
 304    mbs.mb_buf            = g_realloc(mbs.mb_buf, mbs.mb_buf_size);
 305    mbs.offset_cmdlines   = mbs.offset_mbinfo + mbs.mb_mods_avail * MB_MOD_SIZE;
 306    mbs.offset_bootloader = mbs.offset_cmdlines + cmdline_len;
 307
 308    if (initrd_filename) {
 309        const char *next_initrd;
 310        char not_last, tmpbuf[strlen(initrd_filename) + 1];
 311
 312        mbs.offset_mods = mbs.mb_buf_size;
 313
 314        do {
 315            char *next_space;
 316            int mb_mod_length;
 317            uint32_t offs = mbs.mb_buf_size;
 318
 319            next_initrd = get_opt_value(tmpbuf, sizeof(tmpbuf), initrd_filename);
 320            not_last = *next_initrd;
 321            /* if a space comes after the module filename, treat everything
 322               after that as parameters */
 323            hwaddr c = mb_add_cmdline(&mbs, tmpbuf);
 324            if ((next_space = strchr(tmpbuf, ' ')))
 325                *next_space = '\0';
 326            mb_debug("multiboot loading module: %s\n", tmpbuf);
 327            mb_mod_length = get_image_size(tmpbuf);
 328            if (mb_mod_length < 0) {
 329                fprintf(stderr, "Failed to open file '%s'\n", tmpbuf);
 330                exit(1);
 331            }
 332
 333            mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_mod_length + mbs.mb_buf_size);
 334            mbs.mb_buf = g_realloc(mbs.mb_buf, mbs.mb_buf_size);
 335
 336            load_image(tmpbuf, (unsigned char *)mbs.mb_buf + offs);
 337            mb_add_mod(&mbs, mbs.mb_buf_phys + offs,
 338                       mbs.mb_buf_phys + offs + mb_mod_length, c);
 339
 340            mb_debug("mod_start: %p\nmod_end:   %p\n  cmdline: "TARGET_FMT_plx"\n",
 341                     (char *)mbs.mb_buf + offs,
 342                     (char *)mbs.mb_buf + offs + mb_mod_length, c);
 343            initrd_filename = next_initrd+1;
 344        } while (not_last);
 345    }
 346
 347    /* Commandline support */
 348    char kcmdline[strlen(kernel_filename) + strlen(kernel_cmdline) + 2];
 349    snprintf(kcmdline, sizeof(kcmdline), "%s %s",
 350             kernel_filename, kernel_cmdline);
 351    stl_p(bootinfo + MBI_CMDLINE, mb_add_cmdline(&mbs, kcmdline));
 352
 353    stl_p(bootinfo + MBI_BOOTLOADER, mb_add_bootloader(&mbs, bootloader_name));
 354
 355    stl_p(bootinfo + MBI_MODS_ADDR,  mbs.mb_buf_phys + mbs.offset_mbinfo);
 356    stl_p(bootinfo + MBI_MODS_COUNT, mbs.mb_mods_count); /* mods_count */
 357
 358    /* the kernel is where we want it to be now */
 359    stl_p(bootinfo + MBI_FLAGS, MULTIBOOT_FLAGS_MEMORY
 360                                | MULTIBOOT_FLAGS_BOOT_DEVICE
 361                                | MULTIBOOT_FLAGS_CMDLINE
 362                                | MULTIBOOT_FLAGS_MODULES
 363                                | MULTIBOOT_FLAGS_MMAP
 364                                | MULTIBOOT_FLAGS_BOOTLOADER);
 365    stl_p(bootinfo + MBI_BOOT_DEVICE, 0x8000ffff); /* XXX: use the -boot switch? */
 366    stl_p(bootinfo + MBI_MMAP_ADDR,   ADDR_E820_MAP);
 367
 368    mb_debug("multiboot: mh_entry_addr = %#x\n", mh_entry_addr);
 369    mb_debug("           mb_buf_phys   = "TARGET_FMT_plx"\n", mbs.mb_buf_phys);
 370    mb_debug("           mod_start     = "TARGET_FMT_plx"\n", mbs.mb_buf_phys + mbs.offset_mods);
 371    mb_debug("           mb_mods_count = %d\n", mbs.mb_mods_count);
 372
 373    /* save bootinfo off the stack */
 374    mb_bootinfo_data = g_memdup(bootinfo, sizeof(bootinfo));
 375
 376    /* Pass variables to option rom */
 377    fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ENTRY, mh_entry_addr);
 378    fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, mh_load_addr);
 379    fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, mbs.mb_buf_size);
 380    fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA,
 381                     mbs.mb_buf, mbs.mb_buf_size);
 382
 383    fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_ADDR, ADDR_MBI);
 384    fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_SIZE, sizeof(bootinfo));
 385    fw_cfg_add_bytes(fw_cfg, FW_CFG_INITRD_DATA, mb_bootinfo_data,
 386                     sizeof(bootinfo));
 387
 388    option_rom[nb_option_roms].name = "multiboot.bin";
 389    option_rom[nb_option_roms].bootindex = 0;
 390    nb_option_roms++;
 391
 392    return 1; /* yes, we are multiboot */
 393}
 394