hw/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.h"
  26 #include "fw_cfg.h"
  27 #include "multiboot.h"
  28 #include "loader.h"
  29 #include "elf.h"
  30 #include "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
  58     MBI_SIZE        = 88,
  59
  60     /* Multiboot modules */
  61     MB_MOD_START    = 0,
  62     MB_MOD_END      = 4,
  63     MB_MOD_CMDLINE  = 8,
  64
  65     MB_MOD_SIZE     = 16,
  66
  67     /* Region offsets */
  68     ADDR_E820_MAP = MULTIBOOT_STRUCT_ADDR + 0,
  69     ADDR_MBI      = ADDR_E820_MAP + 0x500,
  70
  71     /* Multiboot flags */
  72     MULTIBOOT_FLAGS_MEMORY      = 1 << 0,
  73     MULTIBOOT_FLAGS_BOOT_DEVICE = 1 << 1,
  74     MULTIBOOT_FLAGS_CMDLINE     = 1 << 2,
  75     MULTIBOOT_FLAGS_MODULES     = 1 << 3,
  76     MULTIBOOT_FLAGS_MMAP        = 1 << 6,
  77 };
  78
  79 typedef struct {
  80     /* buffer holding kernel, cmdlines and mb_infos */
  81     void *mb_buf;
  82     /* address in target */
  83     target_phys_addr_t mb_buf_phys;
  84     /* size of mb_buf in bytes */
  85     unsigned mb_buf_size;
  86     /* offset of mb-info's in bytes */
  87     target_phys_addr_t offset_mbinfo;
  88     /* offset in buffer for cmdlines in bytes */
  89     target_phys_addr_t offset_cmdlines;
  90     /* offset of modules in bytes */
  91     target_phys_addr_t offset_mods;
  92     /* available slots for mb modules infos */
  93     int mb_mods_avail;
  94     /* currently used slots of mb modules */
  95     int mb_mods_count;
  96 } MultibootState;
  97
  98 static uint32_t mb_add_cmdline(MultibootState *s, const char *cmdline)
  99 {
 100     int len = strlen(cmdline) + 1;
 101     target_phys_addr_t p = s->offset_cmdlines;
 102
 103     pstrcpy((char *)s->mb_buf + p, len, cmdline);
 104     s->offset_cmdlines += len;
 105     return s->mb_buf_phys + p;
 106 }
 107
 108 static void mb_add_mod(MultibootState *s,
 109                        target_phys_addr_t start, target_phys_addr_t end,
 110                        target_phys_addr_t cmdline_phys)
 111 {
 112     char *p;
 113     assert(s->mb_mods_count < s->mb_mods_avail);
 114
 115     p = (char *)s->mb_buf + s->offset_mbinfo + MB_MOD_SIZE * s->mb_mods_count;
 116
 117     stl_p(p + MB_MOD_START,   start);
 118     stl_p(p + MB_MOD_END,     end);
 119     stl_p(p + MB_MOD_CMDLINE, cmdline_phys);
 120
 121     mb_debug("mod%02d: %08x - %08x\n", s->mb_mods_count, start, end);
 122
 123     s->mb_mods_count++;
 124 }
 125
 126 int load_multiboot(void *fw_cfg,
 127                    FILE *f,
 128                    const char *kernel_filename,
 129                    const char *initrd_filename,
 130                    const char *kernel_cmdline,
 131                    int kernel_file_size,
 132                    uint8_t *header)
 133 {
 134     int i, is_multiboot = 0;
 135     uint32_t flags = 0;
 136     uint32_t mh_entry_addr;
 137     uint32_t mh_load_addr;
 138     uint32_t mb_kernel_size;
 139     MultibootState mbs;
 140     uint8_t bootinfo[MBI_SIZE];
 141     uint8_t *mb_bootinfo_data;
 142
 143     /* Ok, let's see if it is a multiboot image.
 144        The header is 12x32bit long, so the latest entry may be 8192 - 48. */
 145     for (i = 0; i < (8192 - 48); i += 4) {
 146         if (ldl_p(header+i) == 0x1BADB002) {
 147             uint32_t checksum = ldl_p(header+i+8);
 148             flags = ldl_p(header+i+4);
 149             checksum += flags;
 150             checksum += (uint32_t)0x1BADB002;
 151             if (!checksum) {
 152                 is_multiboot = 1;
 153                 break;
 154             }
 155         }
 156     }
 157
 158     if (!is_multiboot)
 159         return 0; /* no multiboot */
 160
 161     mb_debug("qemu: I believe we found a multiboot image!\n");
 162     memset(bootinfo, 0, sizeof(bootinfo));
 163     memset(&mbs, 0, sizeof(mbs));
 164
 165     if (flags & 0x00000004) { /* MULTIBOOT_HEADER_HAS_VBE */
 166         fprintf(stderr, "qemu: multiboot knows VBE. we don't.\n");
 167     }
 168     if (!(flags & 0x00010000)) { /* MULTIBOOT_HEADER_HAS_ADDR */
 169         uint64_t elf_entry;
 170         uint64_t elf_low, elf_high;
 171         int kernel_size;
 172         fclose(f);
 173         kernel_size = load_elf(kernel_filename, NULL, NULL, &elf_entry,
 174                                &elf_low, &elf_high, 0, ELF_MACHINE, 0);
 175         if (kernel_size < 0) {
 176             fprintf(stderr, "Error while loading elf kernel\n");
 177             exit(1);
 178         }
 179         mh_load_addr = elf_low;
 180         mb_kernel_size = elf_high - elf_low;
 181         mh_entry_addr = elf_entry;
 182
 183         mbs.mb_buf = qemu_malloc(mb_kernel_size);
 184         if (rom_copy(mbs.mb_buf, mh_load_addr, mb_kernel_size) != mb_kernel_size) {
 185             fprintf(stderr, "Error while fetching elf kernel from rom\n");
 186             exit(1);
 187         }
 188
 189         mb_debug("qemu: loading multiboot-elf kernel (%#x bytes) with entry %#zx\n",
 190                   mb_kernel_size, (size_t)mh_entry_addr);
 191     } else {
 192         /* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_ADDR. */
 193         uint32_t mh_header_addr = ldl_p(header+i+12);
 194         mh_load_addr = ldl_p(header+i+16);
 195         uint32_t mb_kernel_text_offset = i - (mh_header_addr - mh_load_addr);
 196
 197         mh_entry_addr = ldl_p(header+i+28);
 198         mb_kernel_size = kernel_file_size - mb_kernel_text_offset;
 199
 200         /* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_VBE.
 201         uint32_t mh_mode_type = ldl_p(header+i+32);
 202         uint32_t mh_width = ldl_p(header+i+36);
 203         uint32_t mh_height = ldl_p(header+i+40);
 204         uint32_t mh_depth = ldl_p(header+i+44); */
 205
 206         mb_debug("multiboot: mh_header_addr = %#x\n", mh_header_addr);
 207         mb_debug("multiboot: mh_load_addr = %#x\n", mh_load_addr);
 208         mb_debug("multiboot: mh_load_end_addr = %#x\n", ldl_p(header+i+20));
 209         mb_debug("multiboot: mh_bss_end_addr = %#x\n", ldl_p(header+i+24));
 210         mb_debug("qemu: loading multiboot kernel (%#x bytes) at %#x\n",
 211                  mb_kernel_size, mh_load_addr);
 212
 213         mbs.mb_buf = qemu_malloc(mb_kernel_size);
 214         fseek(f, mb_kernel_text_offset, SEEK_SET);
 215         if (fread(mbs.mb_buf, 1, mb_kernel_size, f) != mb_kernel_size) {
 216             fprintf(stderr, "fread() failed\n");
 217             exit(1);
 218         }
 219         fclose(f);
 220     }
 221
 222     mbs.mb_buf_phys = mh_load_addr;
 223
 224     mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_kernel_size);
 225     mbs.offset_mbinfo = mbs.mb_buf_size;
 226
 227     /* Calculate space for cmdlines and mb_mods */
 228     mbs.mb_buf_size += strlen(kernel_filename) + 1;
 229     mbs.mb_buf_size += strlen(kernel_cmdline) + 1;
 230     if (initrd_filename) {
 231         const char *r = initrd_filename;
 232         mbs.mb_buf_size += strlen(r) + 1;
 233         mbs.mb_mods_avail = 1;
 234         while ((r = strchr(r, ','))) {
 235            mbs.mb_mods_avail++;
 236            r++;
 237         }
 238         mbs.mb_buf_size += MB_MOD_SIZE * mbs.mb_mods_avail;
 239     }
 240
 241     mbs.mb_buf_size = TARGET_PAGE_ALIGN(mbs.mb_buf_size);
 242
 243     /* enlarge mb_buf to hold cmdlines and mb-info structs */
 244     mbs.mb_buf          = qemu_realloc(mbs.mb_buf, mbs.mb_buf_size);
 245     mbs.offset_cmdlines = mbs.offset_mbinfo + mbs.mb_mods_avail * MB_MOD_SIZE;
 246
 247     if (initrd_filename) {
 248         char *next_initrd;
 249
 250         mbs.offset_mods = mbs.mb_buf_size;
 251
 252         do {
 253             char *next_space;
 254             uint32_t mb_mod_length;
 255             uint32_t offs = mbs.mb_buf_size;
 256
 257             next_initrd = strchr(initrd_filename, ',');
 258             if (next_initrd)
 259                 *next_initrd = '\0';
 260             /* if a space comes after the module filename, treat everything
 261                after that as parameters */
 262             target_phys_addr_t c = mb_add_cmdline(&mbs, initrd_filename);
 263             if ((next_space = strchr(initrd_filename, ' ')))
 264                 *next_space = '\0';
 265             mb_debug("multiboot loading module: %s\n", initrd_filename);
 266             mb_mod_length = get_image_size(initrd_filename);
 267             if (mb_mod_length < 0) {
 268                 fprintf(stderr, "failed to get %s image size\n", initrd_filename);
 269                 exit(1);
 270             }
 271
 272             mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_mod_length + mbs.mb_buf_size);
 273             mbs.mb_buf = qemu_realloc(mbs.mb_buf, mbs.mb_buf_size);
 274
 275             load_image(initrd_filename, (unsigned char *)mbs.mb_buf + offs);
 276             mb_add_mod(&mbs, mbs.mb_buf_phys + offs,
 277                        mbs.mb_buf_phys + offs + mb_mod_length, c);
 278
 279             mb_debug("mod_start: %p\nmod_end:   %p\n  cmdline: %#x\n",
 280                      (char *)mbs.mb_buf + offs,
 281                      (char *)mbs.mb_buf + offs + mb_mod_length, c);
 282             initrd_filename = next_initrd+1;
 283         } while (next_initrd);
 284     }
 285
 286     /* Commandline support */
 287     char kcmdline[strlen(kernel_filename) + strlen(kernel_cmdline) + 2];
 288     snprintf(kcmdline, sizeof(kcmdline), "%s %s",
 289              kernel_filename, kernel_cmdline);
 290     stl_p(bootinfo + MBI_CMDLINE, mb_add_cmdline(&mbs, kcmdline));
 291
 292     stl_p(bootinfo + MBI_MODS_ADDR,  mbs.mb_buf_phys + mbs.offset_mbinfo);
 293     stl_p(bootinfo + MBI_MODS_COUNT, mbs.mb_mods_count); /* mods_count */
 294
 295     /* the kernel is where we want it to be now */
 296     stl_p(bootinfo + MBI_FLAGS, MULTIBOOT_FLAGS_MEMORY
 297                                 | MULTIBOOT_FLAGS_BOOT_DEVICE
 298                                 | MULTIBOOT_FLAGS_CMDLINE
 299                                 | MULTIBOOT_FLAGS_MODULES
 300                                 | MULTIBOOT_FLAGS_MMAP);
 301     stl_p(bootinfo + MBI_MEM_LOWER,   640);
 302     stl_p(bootinfo + MBI_MEM_UPPER,   ram_size / 1024);
 303     stl_p(bootinfo + MBI_BOOT_DEVICE, 0x8001ffff); /* XXX: use the -boot switch? */
 304     stl_p(bootinfo + MBI_MMAP_ADDR,   ADDR_E820_MAP);
 305
 306     mb_debug("multiboot: mh_entry_addr = %#x\n", mh_entry_addr);
 307     mb_debug("           mb_buf_phys   = %x\n", mbs.mb_buf_phys);
 308     mb_debug("           mod_start     = %x\n", mbs.mb_buf_phys + mbs.offset_mods);
 309     mb_debug("           mb_mods_count = %d\n", mbs.mb_mods_count);
 310
 311     /* save bootinfo off the stack */
 312     mb_bootinfo_data = qemu_malloc(sizeof(bootinfo));
 313     memcpy(mb_bootinfo_data, bootinfo, sizeof(bootinfo));
 314
 315     /* Pass variables to option rom */
 316     fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ENTRY, mh_entry_addr);
 317     fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, mh_load_addr);
 318     fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, mbs.mb_buf_size);
 319     fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA,
 320                      mbs.mb_buf, mbs.mb_buf_size);
 321
 322     fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_ADDR, ADDR_MBI);
 323     fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_SIZE, sizeof(bootinfo));
 324     fw_cfg_add_bytes(fw_cfg, FW_CFG_INITRD_DATA, mb_bootinfo_data,
 325                      sizeof(bootinfo));
 326
 327     option_rom[nb_option_roms] = "multiboot.bin";
 328     nb_option_roms++;
 329
 330     return 1; /* yes, we are multiboot */
 331 }