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/nvram/fw_cfg.h"
  29 #include "multiboot.h"
  30 #include "hw/loader.h"
  31 #include "elf.h"
  32 #include "sysemu/sysemu.h"
  33 #include "qemu/error-report.h"
  34
  35 /* Show multiboot debug output */
  36 //#define DEBUG_MULTIBOOT
  37
  38 #ifdef DEBUG_MULTIBOOT
  39 #define mb_debug(a...) error_report(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
  50 enum {
  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
  84 typedef 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
 105 const char *bootloader_name = "qemu";
 106
 107 static 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
 117 static 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
 127 static 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: "HWADDR_FMT_plx" - "HWADDR_FMT_plx,
 141              s->mb_mods_count, start, end);
 142
 143     s->mb_mods_count++;
 144 }
 145
 146 int load_multiboot(X86MachineState *x86ms,
 147                    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     bool multiboot_dma_enabled = X86_MACHINE_GET_CLASS(x86ms)->fwcfg_dma_enabled;
 156     int i, is_multiboot = 0;
 157     uint32_t flags = 0;
 158     uint32_t mh_entry_addr;
 159     uint32_t mh_load_addr;
 160     uint32_t mb_kernel_size;
 161     MultibootState mbs;
 162     uint8_t bootinfo[MBI_SIZE];
 163     uint8_t *mb_bootinfo_data;
 164     uint32_t cmdline_len;
 165     GList *mods = NULL;
 166     g_autofree char *kcmdline = NULL;
 167
 168     /* Ok, let's see if it is a multiboot image.
 169        The header is 12x32bit long, so the latest entry may be 8192 - 48. */
 170     for (i = 0; i < (8192 - 48); i += 4) {
 171         if (ldl_p(header+i) == 0x1BADB002) {
 172             uint32_t checksum = ldl_p(header+i+8);
 173             flags = ldl_p(header+i+4);
 174             checksum += flags;
 175             checksum += (uint32_t)0x1BADB002;
 176             if (!checksum) {
 177                 is_multiboot = 1;
 178                 break;
 179             }
 180         }
 181     }
 182
 183     if (!is_multiboot)
 184         return 0; /* no multiboot */
 185
 186     mb_debug("I believe we found a multiboot image!");
 187     memset(bootinfo, 0, sizeof(bootinfo));
 188     memset(&mbs, 0, sizeof(mbs));
 189
 190     if (flags & 0x00000004) { /* MULTIBOOT_HEADER_HAS_VBE */
 191         error_report("multiboot knows VBE. we don't");
 192     }
 193     if (!(flags & 0x00010000)) { /* MULTIBOOT_HEADER_HAS_ADDR */
 194         uint64_t elf_entry;
 195         uint64_t elf_low, elf_high;
 196         int kernel_size;
 197         fclose(f);
 198
 199         if (((struct elf64_hdr*)header)->e_machine == EM_X86_64) {
 200             error_report("Cannot load x86-64 image, give a 32bit one.");
 201             exit(1);
 202         }
 203
 204         kernel_size = load_elf(kernel_filename, NULL, NULL, NULL, &elf_entry,
 205                                &elf_low, &elf_high, NULL, 0, I386_ELF_MACHINE,
 206                                0, 0);
 207         if (kernel_size < 0) {
 208             error_report("Error while loading elf kernel");
 209             exit(1);
 210         }
 211         mh_load_addr = elf_low;
 212         mb_kernel_size = elf_high - elf_low;
 213         mh_entry_addr = elf_entry;
 214
 215         mbs.mb_buf = g_malloc(mb_kernel_size);
 216         if (rom_copy(mbs.mb_buf, mh_load_addr, mb_kernel_size) != mb_kernel_size) {
 217             error_report("Error while fetching elf kernel from rom");
 218             exit(1);
 219         }
 220
 221         mb_debug("loading multiboot-elf kernel "
 222                  "(%#x bytes) with entry %#zx",
 223                  mb_kernel_size, (size_t)mh_entry_addr);
 224     } else {
 225         /* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_ADDR. */
 226         uint32_t mh_header_addr = ldl_p(header+i+12);
 227         uint32_t mh_load_end_addr = ldl_p(header+i+20);
 228         uint32_t mh_bss_end_addr = ldl_p(header+i+24);
 229
 230         mh_load_addr = ldl_p(header+i+16);
 231         if (mh_header_addr < mh_load_addr) {
 232             error_report("invalid load_addr address");
 233             exit(1);
 234         }
 235         if (mh_header_addr - mh_load_addr > i) {
 236             error_report("invalid header_addr address");
 237             exit(1);
 238         }
 239
 240         uint32_t mb_kernel_text_offset = i - (mh_header_addr - mh_load_addr);
 241         uint32_t mb_load_size = 0;
 242         mh_entry_addr = ldl_p(header+i+28);
 243
 244         if (mh_load_end_addr) {
 245             if (mh_load_end_addr < mh_load_addr) {
 246                 error_report("invalid load_end_addr address");
 247                 exit(1);
 248             }
 249             mb_load_size = mh_load_end_addr - mh_load_addr;
 250         } else {
 251             if (kernel_file_size < mb_kernel_text_offset) {
 252                 error_report("invalid kernel_file_size");
 253                 exit(1);
 254             }
 255             mb_load_size = kernel_file_size - mb_kernel_text_offset;
 256         }
 257         if (mb_load_size > UINT32_MAX - mh_load_addr) {
 258             error_report("kernel does not fit in address space");
 259             exit(1);
 260         }
 261         if (mh_bss_end_addr) {
 262             if (mh_bss_end_addr < (mh_load_addr + mb_load_size)) {
 263                 error_report("invalid bss_end_addr address");
 264                 exit(1);
 265             }
 266             mb_kernel_size = mh_bss_end_addr - mh_load_addr;
 267         } else {
 268             mb_kernel_size = mb_load_size;
 269         }
 270
 271         mb_debug("multiboot: header_addr = %#x", mh_header_addr);
 272         mb_debug("multiboot: load_addr = %#x", mh_load_addr);
 273         mb_debug("multiboot: load_end_addr = %#x", mh_load_end_addr);
 274         mb_debug("multiboot: bss_end_addr = %#x", mh_bss_end_addr);
 275         mb_debug("loading multiboot kernel (%#x bytes) at %#x",
 276                  mb_load_size, mh_load_addr);
 277
 278         mbs.mb_buf = g_malloc(mb_kernel_size);
 279         fseek(f, mb_kernel_text_offset, SEEK_SET);
 280         if (fread(mbs.mb_buf, 1, mb_load_size, f) != mb_load_size) {
 281             error_report("fread() failed");
 282             exit(1);
 283         }
 284         memset(mbs.mb_buf + mb_load_size, 0, mb_kernel_size - mb_load_size);
 285         fclose(f);
 286     }
 287
 288     mbs.mb_buf_phys = mh_load_addr;
 289
 290     mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_kernel_size);
 291     mbs.offset_mbinfo = mbs.mb_buf_size;
 292
 293     /* Calculate space for cmdlines, bootloader name, and mb_mods */
 294     cmdline_len = strlen(kernel_filename) + 1;
 295     cmdline_len += strlen(kernel_cmdline) + 1;
 296     if (initrd_filename) {
 297         const char *r = initrd_filename;
 298         cmdline_len += strlen(initrd_filename) + 1;
 299         while (*r) {
 300             char *value;
 301             r = get_opt_value(r, &value);
 302             mbs.mb_mods_avail++;
 303             mods = g_list_append(mods, value);
 304             if (*r) {
 305                 r++;
 306             }
 307         }
 308     }
 309
 310     mbs.mb_buf_size += cmdline_len;
 311     mbs.mb_buf_size += MB_MOD_SIZE * mbs.mb_mods_avail;
 312     mbs.mb_buf_size += strlen(bootloader_name) + 1;
 313
 314     mbs.mb_buf_size = TARGET_PAGE_ALIGN(mbs.mb_buf_size);
 315
 316     /* enlarge mb_buf to hold cmdlines, bootloader, mb-info structs */
 317     mbs.mb_buf            = g_realloc(mbs.mb_buf, mbs.mb_buf_size);
 318     mbs.offset_cmdlines   = mbs.offset_mbinfo + mbs.mb_mods_avail * MB_MOD_SIZE;
 319     mbs.offset_bootloader = mbs.offset_cmdlines + cmdline_len;
 320
 321     if (mods) {
 322         GList *tmpl = mods;
 323         mbs.offset_mods = mbs.mb_buf_size;
 324
 325         while (tmpl) {
 326             char *next_space;
 327             int mb_mod_length;
 328             uint32_t offs = mbs.mb_buf_size;
 329             char *one_file = tmpl->data;
 330
 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             if (load_image_size(one_file, (unsigned char *)mbs.mb_buf + offs,
 349                                 mbs.mb_buf_size - offs) < 0) {
 350                 error_report("Error loading file '%s'", one_file);
 351                 exit(1);
 352             }
 353             mb_add_mod(&mbs, mbs.mb_buf_phys + offs,
 354                        mbs.mb_buf_phys + offs + mb_mod_length, c);
 355
 356             mb_debug("mod_start: %p\nmod_end:   %p\n  cmdline: "HWADDR_FMT_plx,
 357                      (char *)mbs.mb_buf + offs,
 358                      (char *)mbs.mb_buf + offs + mb_mod_length, c);
 359             g_free(one_file);
 360             tmpl = tmpl->next;
 361         }
 362         g_list_free(mods);
 363     }
 364
 365     /* Commandline support */
 366     kcmdline = g_strdup_printf("%s %s", kernel_filename, kernel_cmdline);
 367     stl_p(bootinfo + MBI_CMDLINE, mb_add_cmdline(&mbs, kcmdline));
 368
 369     stl_p(bootinfo + MBI_BOOTLOADER, mb_add_bootloader(&mbs, bootloader_name));
 370
 371     stl_p(bootinfo + MBI_MODS_ADDR,  mbs.mb_buf_phys + mbs.offset_mbinfo);
 372     stl_p(bootinfo + MBI_MODS_COUNT, mbs.mb_mods_count); /* mods_count */
 373
 374     /* the kernel is where we want it to be now */
 375     stl_p(bootinfo + MBI_FLAGS, MULTIBOOT_FLAGS_MEMORY
 376                                 | MULTIBOOT_FLAGS_BOOT_DEVICE
 377                                 | MULTIBOOT_FLAGS_CMDLINE
 378                                 | MULTIBOOT_FLAGS_MODULES
 379                                 | MULTIBOOT_FLAGS_MMAP
 380                                 | MULTIBOOT_FLAGS_BOOTLOADER);
 381     stl_p(bootinfo + MBI_BOOT_DEVICE, 0x8000ffff); /* XXX: use the -boot switch? */
 382     stl_p(bootinfo + MBI_MMAP_ADDR,   ADDR_E820_MAP);
 383
 384     mb_debug("multiboot: entry_addr = %#x", mh_entry_addr);
 385     mb_debug("           mb_buf_phys   = "HWADDR_FMT_plx, mbs.mb_buf_phys);
 386     mb_debug("           mod_start     = "HWADDR_FMT_plx,
 387              mbs.mb_buf_phys + mbs.offset_mods);
 388     mb_debug("           mb_mods_count = %d", mbs.mb_mods_count);
 389
 390     /* save bootinfo off the stack */
 391     mb_bootinfo_data = g_memdup(bootinfo, sizeof(bootinfo));
 392
 393     /* Pass variables to option rom */
 394     fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ENTRY, mh_entry_addr);
 395     fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, mh_load_addr);
 396     fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, mbs.mb_buf_size);
 397     fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA,
 398                      mbs.mb_buf, mbs.mb_buf_size);
 399
 400     fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_ADDR, ADDR_MBI);
 401     fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_SIZE, sizeof(bootinfo));
 402     fw_cfg_add_bytes(fw_cfg, FW_CFG_INITRD_DATA, mb_bootinfo_data,
 403                      sizeof(bootinfo));
 404
 405     if (multiboot_dma_enabled) {
 406         option_rom[nb_option_roms].name = "multiboot_dma.bin";
 407     } else {
 408         option_rom[nb_option_roms].name = "multiboot.bin";
 409     }
 410     option_rom[nb_option_roms].bootindex = 0;
 411     nb_option_roms++;
 412
 413     return 1; /* yes, we are multiboot */
 414 }