func: int load_multiboot(void *fw_cfg,
  
                     FILE *f,
  
                     const char *kernel_filename,
  
                     const char *initrd_filename,
  
                     const char *kernel_cmdline,
  
                     int kernel_file_size,
  
                     uint8_t *header)
  
  {
  
      int i, is_multiboot = 0;
  
      uint32_t flags = 0;
  
      uint32_t mh_entry_addr;
  
      uint32_t mh_load_addr;
  
      uint32_t mb_kernel_size;
  
      MultibootState mbs;
  
      uint8_t bootinfo[MBI_SIZE];
  
      uint8_t *mb_bootinfo_data;
  
  
  
      /* Ok, let's see if it is a multiboot image.
  
         The header is 12x32bit long, so the latest entry may be 8192 - 48. */
  
      for (i = 0; i < (8192 - 48); i += 4) {
  
          if (ldl_p(header+i) == 0x1BADB002) {
  
              uint32_t checksum = ldl_p(header+i+8);
  
              flags = ldl_p(header+i+4);
  
              checksum += flags;
  
              checksum += (uint32_t)0x1BADB002;
  
              if (!checksum) {
  
                  is_multiboot = 1;
  
                  break;
  
              }
  
          }
  
      }
  
  
  
      if (!is_multiboot)
  
          return 0; /* no multiboot */
  
  
  
      mb_debug("qemu: I believe we found a multiboot image!\n");
  
      memset(bootinfo, 0, sizeof(bootinfo));
  
      memset(&mbs, 0, sizeof(mbs));
  
  
  
      if (flags & 0x00000004) { /* MULTIBOOT_HEADER_HAS_VBE */
  
          fprintf(stderr, "qemu: multiboot knows VBE. we don't.\n");
  
      }
  
      if (!(flags & 0x00010000)) { /* MULTIBOOT_HEADER_HAS_ADDR */
  
          uint64_t elf_entry;
  
          uint64_t elf_low, elf_high;
  
          int kernel_size;
  
          fclose(f);
  
  
  
          if (((struct elf64_hdr*)header)->e_machine == EM_X86_64) {
  
              fprintf(stderr, "Cannot load x86-64 image, give a 32bit one.\n");
  
              exit(1);
  
          }
  
  
  
          kernel_size = load_elf(kernel_filename, NULL, NULL, &elf_entry,
  
                                 &elf_low, &elf_high, 0, ELF_MACHINE, 0);
  
          if (kernel_size < 0) {
  
              fprintf(stderr, "Error while loading elf kernel\n");
  
              exit(1);
  
          }
  
          mh_load_addr = elf_low;
  
          mb_kernel_size = elf_high - elf_low;
  
          mh_entry_addr = elf_entry;
  
  
  
          mbs.mb_buf = g_malloc(mb_kernel_size);
  
          if (rom_copy(mbs.mb_buf, mh_load_addr, mb_kernel_size) != mb_kernel_size) {
  
              fprintf(stderr, "Error while fetching elf kernel from rom\n");
  
              exit(1);
  
          }
  
  
  
          mb_debug("qemu: loading multiboot-elf kernel (%#x bytes) with entry %#zx\n",
  
                    mb_kernel_size, (size_t)mh_entry_addr);
  
      } else {
  
          /* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_ADDR. */
  
          uint32_t mh_header_addr = ldl_p(header+i+12);
  
          uint32_t mh_load_end_addr = ldl_p(header+i+20);
  
          uint32_t mh_bss_end_addr = ldl_p(header+i+24);
  
          mh_load_addr = ldl_p(header+i+16);
  
          uint32_t mb_kernel_text_offset = i - (mh_header_addr - mh_load_addr);
  
          uint32_t mb_load_size = 0;
  
          mh_entry_addr = ldl_p(header+i+28);
  
  
  
          if (mh_load_end_addr) {
  
              mb_kernel_size = mh_bss_end_addr - mh_load_addr;
  
              mb_load_size = mh_load_end_addr - mh_load_addr;
  
          } else {
  
              mb_kernel_size = kernel_file_size - mb_kernel_text_offset;
  
              mb_load_size = mb_kernel_size;
  
          }
  
  
  
          /* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_VBE.
  
          uint32_t mh_mode_type = ldl_p(header+i+32);
  
          uint32_t mh_width = ldl_p(header+i+36);
  
          uint32_t mh_height = ldl_p(header+i+40);
  
          uint32_t mh_depth = ldl_p(header+i+44); */
  
  
  
          mb_debug("multiboot: mh_header_addr = %#x\n", mh_header_addr);
  
          mb_debug("multiboot: mh_load_addr = %#x\n", mh_load_addr);
  
          mb_debug("multiboot: mh_load_end_addr = %#x\n", mh_load_end_addr);
  
          mb_debug("multiboot: mh_bss_end_addr = %#x\n", mh_bss_end_addr);
  
          mb_debug("qemu: loading multiboot kernel (%#x bytes) at %#x\n",
  
                   mb_load_size, mh_load_addr);
  
  
  
          mbs.mb_buf = g_malloc(mb_kernel_size);
  
          fseek(f, mb_kernel_text_offset, SEEK_SET);
  
          if (fread(mbs.mb_buf, 1, mb_load_size, f) != mb_load_size) {
  
              fprintf(stderr, "fread() failed\n");
  
              exit(1);
  
          }
  
          memset(mbs.mb_buf + mb_load_size, 0, mb_kernel_size - mb_load_size);
  
          fclose(f);
  
      }
  
  
  
      mbs.mb_buf_phys = mh_load_addr;
  
  
  
      mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_kernel_size);
  
      mbs.offset_mbinfo = mbs.mb_buf_size;
  
  
  
      /* Calculate space for cmdlines and mb_mods */
  
      mbs.mb_buf_size += strlen(kernel_filename) + 1;
  
      mbs.mb_buf_size += strlen(kernel_cmdline) + 1;
  
      if (initrd_filename) {
  
          const char *r = initrd_filename;
  
          mbs.mb_buf_size += strlen(r) + 1;
  
          mbs.mb_mods_avail = 1;
  
          while (*(r = get_opt_value(NULL, 0, r))) {
  
             mbs.mb_mods_avail++;
  
             r++;
  
          }
  
          mbs.mb_buf_size += MB_MOD_SIZE * mbs.mb_mods_avail;
  
      }
  
  
  
      mbs.mb_buf_size = TARGET_PAGE_ALIGN(mbs.mb_buf_size);
  
  
  
      /* enlarge mb_buf to hold cmdlines and mb-info structs */
  
      mbs.mb_buf          = g_realloc(mbs.mb_buf, mbs.mb_buf_size);
  
      mbs.offset_cmdlines = mbs.offset_mbinfo + mbs.mb_mods_avail * MB_MOD_SIZE;
  
  
  
      if (initrd_filename) {
  
          char *next_initrd, not_last;
  
  
  
          mbs.offset_mods = mbs.mb_buf_size;
  
  
  
          do {
  
              char *next_space;
  
              int mb_mod_length;
  
              uint32_t offs = mbs.mb_buf_size;
  
  
  
              next_initrd = (char *)get_opt_value(NULL, 0, initrd_filename);
  
              not_last = *next_initrd;
  
              *next_initrd = '\0';
  
              /* if a space comes after the module filename, treat everything
  
                 after that as parameters */
  
              target_phys_addr_t c = mb_add_cmdline(&mbs, initrd_filename);
  
              if ((next_space = strchr(initrd_filename, ' ')))
  
                  *next_space = '\0';
  
              mb_debug("multiboot loading module: %s\n", initrd_filename);
  
              mb_mod_length = get_image_size(initrd_filename);
  
              if (mb_mod_length < 0) {
  
                  fprintf(stderr, "Failed to open file '%s'\n", initrd_filename);
  
                  exit(1);
  
              }
  
  
  
              mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_mod_length + mbs.mb_buf_size);
  
              mbs.mb_buf = g_realloc(mbs.mb_buf, mbs.mb_buf_size);
  
  
  
              load_image(initrd_filename, (unsigned char *)mbs.mb_buf + offs);
  
              mb_add_mod(&mbs, mbs.mb_buf_phys + offs,
  
                         mbs.mb_buf_phys + offs + mb_mod_length, c);
  
  
  
              mb_debug("mod_start: %p\nmod_end:   %p\n  cmdline: "TARGET_FMT_plx"\n",
  
                       (char *)mbs.mb_buf + offs,
  
                       (char *)mbs.mb_buf + offs + mb_mod_length, c);
  
              initrd_filename = next_initrd+1;
  
          } while (not_last);
  
      }
  
  
  
      /* Commandline support */
  
      char kcmdline[strlen(kernel_filename) + strlen(kernel_cmdline) + 2];
  
      snprintf(kcmdline, sizeof(kcmdline), "%s %s",
  
               kernel_filename, kernel_cmdline);
  
      stl_p(bootinfo + MBI_CMDLINE, mb_add_cmdline(&mbs, kcmdline));
  
  
  
      stl_p(bootinfo + MBI_MODS_ADDR,  mbs.mb_buf_phys + mbs.offset_mbinfo);
  
      stl_p(bootinfo + MBI_MODS_COUNT, mbs.mb_mods_count); /* mods_count */
  
  
  
      /* the kernel is where we want it to be now */
  
      stl_p(bootinfo + MBI_FLAGS, MULTIBOOT_FLAGS_MEMORY
  
                                  | MULTIBOOT_FLAGS_BOOT_DEVICE
  
                                  | MULTIBOOT_FLAGS_CMDLINE
  
                                  | MULTIBOOT_FLAGS_MODULES
  
                                  | MULTIBOOT_FLAGS_MMAP);
  
      stl_p(bootinfo + MBI_MEM_LOWER,   640);
  
      stl_p(bootinfo + MBI_MEM_UPPER,   (ram_size / 1024) - 1024);
  
      stl_p(bootinfo + MBI_BOOT_DEVICE, 0x8000ffff); /* XXX: use the -boot switch? */
  
      stl_p(bootinfo + MBI_MMAP_ADDR,   ADDR_E820_MAP);
  
  
  
      mb_debug("multiboot: mh_entry_addr = %#x\n", mh_entry_addr);
  
      mb_debug("           mb_buf_phys   = "TARGET_FMT_plx"\n", mbs.mb_buf_phys);
  
      mb_debug("           mod_start     = "TARGET_FMT_plx"\n", mbs.mb_buf_phys + mbs.offset_mods);
  
      mb_debug("           mb_mods_count = %d\n", mbs.mb_mods_count);
  
  
  
      /* save bootinfo off the stack */
  
      mb_bootinfo_data = g_malloc(sizeof(bootinfo));
  
      memcpy(mb_bootinfo_data, bootinfo, sizeof(bootinfo));
  
  
  
      /* Pass variables to option rom */
  
      fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ENTRY, mh_entry_addr);
  
      fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, mh_load_addr);
  
      fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, mbs.mb_buf_size);
  
      fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA,
  
                       mbs.mb_buf, mbs.mb_buf_size);
  
  
  
      fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_ADDR, ADDR_MBI);
  
      fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_SIZE, sizeof(bootinfo));
  
      fw_cfg_add_bytes(fw_cfg, FW_CFG_INITRD_DATA, mb_bootinfo_data,
  
                       sizeof(bootinfo));
  
  
  
      option_rom[nb_option_roms].name = "multiboot.bin";
  
      option_rom[nb_option_roms].bootindex = 0;
  
      nb_option_roms++;
  
  
  
      return 1; /* yes, we are multiboot */
  
  }
  