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/option.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 #include "qemu/error-report.h"
  35
  36 /* Show multiboot debug output */
  37 //#define DEBUG_MULTIBOOT
  38
  39 #ifdef DEBUG_MULTIBOOT
  40 #define mb_debug(a...) error_report(a)
  41 #else
  42 #define mb_debug(a...)
  43 #endif
  44
  45 #define MULTIBOOT_STRUCT_ADDR 0x9000
  46
  47 #if MULTIBOOT_STRUCT_ADDR > 0xf0000
  48 #error multiboot struct needs to fit in 16 bit real mode
  49 #endif
  50
  51 enum {
  52     /* Multiboot info */
  53     MBI_FLAGS       = 0,
  54     MBI_MEM_LOWER   = 4,
  55     MBI_MEM_UPPER   = 8,
  56     MBI_BOOT_DEVICE = 12,
  57     MBI_CMDLINE     = 16,
  58     MBI_MODS_COUNT  = 20,
  59     MBI_MODS_ADDR   = 24,
  60     MBI_MMAP_ADDR   = 48,
  61     MBI_BOOTLOADER  = 64,
  62
  63     MBI_SIZE        = 88,
  64
  65     /* Multiboot modules */
  66     MB_MOD_START    = 0,
  67     MB_MOD_END      = 4,
  68     MB_MOD_CMDLINE  = 8,
  69
  70     MB_MOD_SIZE     = 16,
  71
  72     /* Region offsets */
  73     ADDR_E820_MAP = MULTIBOOT_STRUCT_ADDR + 0,
  74     ADDR_MBI      = ADDR_E820_MAP + 0x500,
  75
  76     /* Multiboot flags */
  77     MULTIBOOT_FLAGS_MEMORY      = 1 << 0,
  78     MULTIBOOT_FLAGS_BOOT_DEVICE = 1 << 1,
  79     MULTIBOOT_FLAGS_CMDLINE     = 1 << 2,
  80     MULTIBOOT_FLAGS_MODULES     = 1 << 3,
  81     MULTIBOOT_FLAGS_MMAP        = 1 << 6,
  82     MULTIBOOT_FLAGS_BOOTLOADER  = 1 << 9,
  83 };
  84
  85 typedef struct {
  86     /* buffer holding kernel, cmdlines and mb_infos */
  87     void *mb_buf;
  88     /* address in target */
  89     hwaddr mb_buf_phys;
  90     /* size of mb_buf in bytes */
  91     unsigned mb_buf_size;
  92     /* offset of mb-info's in bytes */
  93     hwaddr offset_mbinfo;
  94     /* offset in buffer for cmdlines in bytes */
  95     hwaddr offset_cmdlines;
  96     /* offset in buffer for bootloader name in bytes */
  97     hwaddr offset_bootloader;
  98     /* offset of modules in bytes */
  99     hwaddr offset_mods;
 100     /* available slots for mb modules infos */
 101     int mb_mods_avail;
 102     /* currently used slots of mb modules */
 103     int mb_mods_count;
 104 } MultibootState;
 105
 106 const char *bootloader_name = "qemu";
 107
 108 static uint32_t mb_add_cmdline(MultibootState *s, const char *cmdline)
 109 {
 110     hwaddr p = s->offset_cmdlines;
 111     char *b = (char *)s->mb_buf + p;
 112
 113     memcpy(b, cmdline, strlen(cmdline) + 1);
 114     s->offset_cmdlines += strlen(b) + 1;
 115     return s->mb_buf_phys + p;
 116 }
 117
 118 static uint32_t mb_add_bootloader(MultibootState *s, const char *bootloader)
 119 {
 120     hwaddr p = s->offset_bootloader;
 121     char *b = (char *)s->mb_buf + p;
 122
 123     memcpy(b, bootloader, strlen(bootloader) + 1);
 124     s->offset_bootloader += strlen(b) + 1;
 125     return s->mb_buf_phys + p;
 126 }
 127
 128 static void mb_add_mod(MultibootState *s,
 129                        hwaddr start, hwaddr end,
 130                        hwaddr cmdline_phys)
 131 {
 132     char *p;
 133     assert(s->mb_mods_count < s->mb_mods_avail);
 134
 135     p = (char *)s->mb_buf + s->offset_mbinfo + MB_MOD_SIZE * s->mb_mods_count;
 136
 137     stl_p(p + MB_MOD_START,   start);
 138     stl_p(p + MB_MOD_END,     end);
 139     stl_p(p + MB_MOD_CMDLINE, cmdline_phys);
 140
 141     mb_debug("mod%02d: "TARGET_FMT_plx" - "TARGET_FMT_plx,
 142              s->mb_mods_count, start, end);
 143
 144     s->mb_mods_count++;
 145 }
 146
 147 int load_multiboot(FWCfgState *fw_cfg,
 148                    FILE *f,
 149                    const char *kernel_filename,
 150                    const char *initrd_filename,
 151                    const char *kernel_cmdline,
 152                    int kernel_file_size,
 153                    uint8_t *header)
 154 {
 155     int i, is_multiboot = 0;
 156     uint32_t flags = 0;
 157     uint32_t mh_entry_addr;
 158     uint32_t mh_load_addr;
 159     uint32_t mb_kernel_size;
 160     MultibootState mbs;
 161     uint8_t bootinfo[MBI_SIZE];
 162     uint8_t *mb_bootinfo_data;
 163     uint32_t cmdline_len;
 164
 165     /* Ok, let's see if it is a multiboot image.
 166        The header is 12x32bit long, so the latest entry may be 8192 - 48. */
 167     for (i = 0; i < (8192 - 48); i += 4) {
 168         if (ldl_p(header+i) == 0x1BADB002) {
 169             uint32_t checksum = ldl_p(header+i+8);
 170             flags = ldl_p(header+i+4);
 171             checksum += flags;
 172             checksum += (uint32_t)0x1BADB002;
 173             if (!checksum) {
 174                 is_multiboot = 1;
 175                 break;
 176             }
 177         }
 178     }
 179
 180     if (!is_multiboot)
 181         return 0; /* no multiboot */
 182
 183     mb_debug("qemu: I believe we found a multiboot image!");
 184     memset(bootinfo, 0, sizeof(bootinfo));
 185     memset(&mbs, 0, sizeof(mbs));
 186
 187     if (flags & 0x00000004) { /* MULTIBOOT_HEADER_HAS_VBE */
 188         error_report("qemu: multiboot knows VBE. we don't.");
 189     }
 190     if (!(flags & 0x00010000)) { /* MULTIBOOT_HEADER_HAS_ADDR */
 191         uint64_t elf_entry;
 192         uint64_t elf_low, elf_high;
 193         int kernel_size;
 194         fclose(f);
 195
 196         if (((struct elf64_hdr*)header)->e_machine == EM_X86_64) {
 197             error_report("Cannot load x86-64 image, give a 32bit one.");
 198             exit(1);
 199         }
 200
 201         kernel_size = load_elf(kernel_filename, NULL, NULL, &elf_entry,
 202                                &elf_low, &elf_high, 0, I386_ELF_MACHINE,
 203                                0, 0);
 204         if (kernel_size < 0) {
 205             error_report("Error while loading elf kernel");
 206             exit(1);
 207         }
 208         mh_load_addr = elf_low;
 209         mb_kernel_size = elf_high - elf_low;
 210         mh_entry_addr = elf_entry;
 211
 212         mbs.mb_buf = g_malloc(mb_kernel_size);
 213         if (rom_copy(mbs.mb_buf, mh_load_addr, mb_kernel_size) != mb_kernel_size) {
 214             error_report("Error while fetching elf kernel from rom");
 215             exit(1);
 216         }
 217
 218         mb_debug("qemu: loading multiboot-elf kernel "
 219                  "(%#x bytes) with entry %#zx",
 220                  mb_kernel_size, (size_t)mh_entry_addr);
 221     } else {
 222         /* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_ADDR. */
 223         uint32_t mh_header_addr = ldl_p(header+i+12);
 224         uint32_t mh_load_end_addr = ldl_p(header+i+20);
 225         uint32_t mh_bss_end_addr = ldl_p(header+i+24);
 226
 227         mh_load_addr = ldl_p(header+i+16);
 228         if (mh_header_addr < mh_load_addr) {
 229             error_report("invalid load_addr address");
 230             exit(1);
 231         }
 232         if (mh_header_addr - mh_load_addr > i) {
 233             error_report("invalid header_addr address");
 234             exit(1);
 235         }
 236
 237         uint32_t mb_kernel_text_offset = i - (mh_header_addr - mh_load_addr);
 238         uint32_t mb_load_size = 0;
 239         mh_entry_addr = ldl_p(header+i+28);
 240
 241         if (mh_load_end_addr) {
 242             if (mh_load_end_addr < mh_load_addr) {
 243                 error_report("invalid load_end_addr address");
 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                 error_report("invalid kernel_file_size");
 250                 exit(1);
 251             }
 252             mb_load_size = kernel_file_size - mb_kernel_text_offset;
 253         }
 254         if (mb_load_size > UINT32_MAX - mh_load_addr) {
 255             error_report("kernel does not fit in address space");
 256             exit(1);
 257         }
 258         if (mh_bss_end_addr) {
 259             if (mh_bss_end_addr < (mh_load_addr + mb_load_size)) {
 260                 error_report("invalid bss_end_addr address");
 261                 exit(1);
 262             }
 263             mb_kernel_size = mh_bss_end_addr - mh_load_addr;
 264         } else {
 265             mb_kernel_size = mb_load_size;
 266         }
 267
 268         mb_debug("multiboot: header_addr = %#x", mh_header_addr);
 269         mb_debug("multiboot: load_addr = %#x", mh_load_addr);
 270         mb_debug("multiboot: load_end_addr = %#x", mh_load_end_addr);
 271         mb_debug("multiboot: bss_end_addr = %#x", mh_bss_end_addr);
 272         mb_debug("qemu: loading multiboot kernel (%#x bytes) at %#x",
 273                  mb_load_size, mh_load_addr);
 274
 275         mbs.mb_buf = g_malloc(mb_kernel_size);
 276         fseek(f, mb_kernel_text_offset, SEEK_SET);
 277         if (fread(mbs.mb_buf, 1, mb_load_size, f) != mb_load_size) {
 278             error_report("fread() failed");
 279             exit(1);
 280         }
 281         memset(mbs.mb_buf + mb_load_size, 0, mb_kernel_size - mb_load_size);
 282         fclose(f);
 283     }
 284
 285     mbs.mb_buf_phys = mh_load_addr;
 286
 287     mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_kernel_size);
 288     mbs.offset_mbinfo = mbs.mb_buf_size;
 289
 290     /* Calculate space for cmdlines, bootloader name, and mb_mods */
 291     cmdline_len = strlen(kernel_filename) + 1;
 292     cmdline_len += strlen(kernel_cmdline) + 1;
 293     if (initrd_filename) {
 294         const char *r = get_opt_value(initrd_filename, NULL);
 295         cmdline_len += strlen(initrd_filename) + 1;
 296         while (1) {
 297             mbs.mb_mods_avail++;
 298             r = get_opt_value(r, NULL);
 299             if (!*r) {
 300                 break;
 301             }
 302             r++;
 303         }
 304     }
 305
 306     mbs.mb_buf_size += cmdline_len;
 307     mbs.mb_buf_size += MB_MOD_SIZE * mbs.mb_mods_avail;
 308     mbs.mb_buf_size += strlen(bootloader_name) + 1;
 309
 310     mbs.mb_buf_size = TARGET_PAGE_ALIGN(mbs.mb_buf_size);
 311
 312     /* enlarge mb_buf to hold cmdlines, bootloader, mb-info structs */
 313     mbs.mb_buf            = g_realloc(mbs.mb_buf, mbs.mb_buf_size);
 314     mbs.offset_cmdlines   = mbs.offset_mbinfo + mbs.mb_mods_avail * MB_MOD_SIZE;
 315     mbs.offset_bootloader = mbs.offset_cmdlines + cmdline_len;
 316
 317     if (initrd_filename) {
 318         const char *next_initrd;
 319         char not_last;
 320         char *one_file = NULL;
 321
 322         mbs.offset_mods = mbs.mb_buf_size;
 323
 324         do {
 325             char *next_space;
 326             int mb_mod_length;
 327             uint32_t offs = mbs.mb_buf_size;
 328
 329             next_initrd = get_opt_value(initrd_filename, &one_file);
 330             not_last = *next_initrd;
 331             /* if a space comes after the module filename, treat everything
 332                after that as parameters */
 333             hwaddr c = mb_add_cmdline(&mbs, one_file);
 334             next_space = strchr(one_file, ' ');
 335             if (next_space) {
 336                 *next_space = '\0';
 337             }
 338             mb_debug("multiboot loading module: %s", one_file);
 339             mb_mod_length = get_image_size(one_file);
 340             if (mb_mod_length < 0) {
 341                 error_report("Failed to open file '%s'", one_file);
 342                 exit(1);
 343             }
 344
 345             mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_mod_length + mbs.mb_buf_size);
 346             mbs.mb_buf = g_realloc(mbs.mb_buf, mbs.mb_buf_size);
 347
 348             load_image(one_file, (unsigned char *)mbs.mb_buf + offs);
 349             mb_add_mod(&mbs, mbs.mb_buf_phys + offs,
 350                        mbs.mb_buf_phys + offs + mb_mod_length, c);
 351
 352             mb_debug("mod_start: %p\nmod_end:   %p\n  cmdline: "TARGET_FMT_plx,
 353                      (char *)mbs.mb_buf + offs,
 354                      (char *)mbs.mb_buf + offs + mb_mod_length, c);
 355             initrd_filename = next_initrd+1;
 356             g_free(one_file);
 357             one_file = NULL;
 358         } while (not_last);
 359     }
 360
 361     /* Commandline support */
 362     char kcmdline[strlen(kernel_filename) + strlen(kernel_cmdline) + 2];
 363     snprintf(kcmdline, sizeof(kcmdline), "%s %s",
 364              kernel_filename, kernel_cmdline);
 365     stl_p(bootinfo + MBI_CMDLINE, mb_add_cmdline(&mbs, kcmdline));
 366
 367     stl_p(bootinfo + MBI_BOOTLOADER, mb_add_bootloader(&mbs, bootloader_name));
 368
 369     stl_p(bootinfo + MBI_MODS_ADDR,  mbs.mb_buf_phys + mbs.offset_mbinfo);
 370     stl_p(bootinfo + MBI_MODS_COUNT, mbs.mb_mods_count); /* mods_count */
 371
 372     /* the kernel is where we want it to be now */
 373     stl_p(bootinfo + MBI_FLAGS, MULTIBOOT_FLAGS_MEMORY
 374                                 | MULTIBOOT_FLAGS_BOOT_DEVICE
 375                                 | MULTIBOOT_FLAGS_CMDLINE
 376                                 | MULTIBOOT_FLAGS_MODULES
 377                                 | MULTIBOOT_FLAGS_MMAP
 378                                 | MULTIBOOT_FLAGS_BOOTLOADER);
 379     stl_p(bootinfo + MBI_BOOT_DEVICE, 0x8000ffff); /* XXX: use the -boot switch? */
 380     stl_p(bootinfo + MBI_MMAP_ADDR,   ADDR_E820_MAP);
 381
 382     mb_debug("multiboot: entry_addr = %#x", mh_entry_addr);
 383     mb_debug("           mb_buf_phys   = "TARGET_FMT_plx, mbs.mb_buf_phys);
 384     mb_debug("           mod_start     = "TARGET_FMT_plx,
 385              mbs.mb_buf_phys + mbs.offset_mods);
 386     mb_debug("           mb_mods_count = %d", mbs.mb_mods_count);
 387
 388     /* save bootinfo off the stack */
 389     mb_bootinfo_data = g_memdup(bootinfo, sizeof(bootinfo));
 390
 391     /* Pass variables to option rom */
 392     fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ENTRY, mh_entry_addr);
 393     fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, mh_load_addr);
 394     fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, mbs.mb_buf_size);
 395     fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA,
 396                      mbs.mb_buf, mbs.mb_buf_size);
 397
 398     fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_ADDR, ADDR_MBI);
 399     fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_SIZE, sizeof(bootinfo));
 400     fw_cfg_add_bytes(fw_cfg, FW_CFG_INITRD_DATA, mb_bootinfo_data,
 401                      sizeof(bootinfo));
 402
 403     option_rom[nb_option_roms].name = "multiboot.bin";
 404     option_rom[nb_option_roms].bootindex = 0;
 405     nb_option_roms++;
 406
 407     return 1; /* yes, we are multiboot */
 408 }