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