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