src/boot/selfboot.c

   1 /*
   2  * This file is part of the coreboot project.
   3  *
   4  * Copyright (C) 2003 Eric W. Biederman <ebiederm@xmission.com>
   5  * Copyright (C) 2009 Ron Minnich <rminnich@gmail.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; version 2 of the License.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA
  19  */
  20
  21 #include <console/console.h>
  22 #include <part/fallback_boot.h>
  23 #include <boot/elf.h>
  24 #include <boot/elf_boot.h>
  25 #include <boot/coreboot_tables.h>
  26 #include <ip_checksum.h>
  27 #include <stream/read_bytes.h>
  28 #include <stdint.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <cbfs.h>
  32
  33 #ifndef CONFIG_BIG_ENDIAN
  34 #define ntohl(x) ( ((x&0xff)<<24) | ((x&0xff00)<<8) | \
  35                 ((x&0xff0000) >> 8) | ((x&0xff000000) >> 24) )
  36 #else
  37 #define ntohl(x) (x)
  38 #endif
  39
  40 /* Maximum physical address we can use for the coreboot bounce buffer.
  41  */
  42 #ifndef MAX_ADDR
  43 #define MAX_ADDR -1UL
  44 #endif
  45
  46 extern unsigned char _ram_seg;
  47 extern unsigned char _eram_seg;
  48
  49 struct segment {
  50         struct segment *next;
  51         struct segment *prev;
  52         struct segment *phdr_next;
  53         struct segment *phdr_prev;
  54         unsigned long s_dstaddr;
  55         unsigned long s_srcaddr;
  56         unsigned long s_memsz;
  57         unsigned long s_filesz;
  58         int compression;
  59 };
  60
  61 struct verify_callback {
  62         struct verify_callback *next;
  63         int (*callback)(struct verify_callback *vcb,
  64                 Elf_ehdr *ehdr, Elf_phdr *phdr, struct segment *head);
  65         unsigned long desc_offset;
  66         unsigned long desc_addr;
  67 };
  68
  69 struct ip_checksum_vcb {
  70         struct verify_callback data;
  71         unsigned short ip_checksum;
  72 };
  73
  74 /* The problem:
  75  * Static executables all want to share the same addresses
  76  * in memory because only a few addresses are reliably present on
  77  * a machine, and implementing general relocation is hard.
  78  *
  79  * The solution:
  80  * - Allocate a buffer twice the size of the coreboot image.
  81  * - Anything that would overwrite coreboot copy into the lower half of
  82  *   the buffer.
  83  * - After loading an ELF image copy coreboot to the upper half of the
  84  *   buffer.
  85  * - Then jump to the loaded image.
  86  *
  87  * Benefits:
  88  * - Nearly arbitrary standalone executables can be loaded.
  89  * - Coreboot is preserved, so it can be returned to.
  90  * - The implementation is still relatively simple,
  91  *   and much simpler then the general case implemented in kexec.
  92  *
  93  */
  94
  95 static unsigned long bounce_size, bounce_buffer;
  96
  97 static void get_bounce_buffer(struct lb_memory *mem, unsigned long bounce_size)
  98 {
  99         unsigned long lb_size;
 100         unsigned long mem_entries;
 101         unsigned long buffer;
 102         int i;
 103         lb_size = (unsigned long)(&_eram_seg - &_ram_seg);
 104         /* Double coreboot size so I have somewhere to place a copy to return to */
 105         lb_size = bounce_size + lb_size;
 106         mem_entries = (mem->size - sizeof(*mem))/sizeof(mem->map[0]);
 107         buffer = 0;
 108         for(i = 0; i < mem_entries; i++) {
 109                 unsigned long mstart, mend;
 110                 unsigned long msize;
 111                 unsigned long tbuffer;
 112                 if (mem->map[i].type != LB_MEM_RAM)
 113                         continue;
 114                 if (unpack_lb64(mem->map[i].start) > MAX_ADDR)
 115                         continue;
 116                 if (unpack_lb64(mem->map[i].size) < lb_size)
 117                         continue;
 118                 mstart = unpack_lb64(mem->map[i].start);
 119                 msize = MAX_ADDR - mstart +1;
 120                 if (msize > unpack_lb64(mem->map[i].size))
 121                         msize = unpack_lb64(mem->map[i].size);
 122                 mend = mstart + msize;
 123                 tbuffer = mend - lb_size;
 124                 if (tbuffer < buffer)
 125                         continue;
 126                 buffer = tbuffer;
 127         }
 128         bounce_buffer = buffer;
 129 }
 130
 131 static int valid_area(struct lb_memory *mem, unsigned long buffer,
 132         unsigned long start, unsigned long len)
 133 {
 134         /* Check through all of the memory segments and ensure
 135          * the segment that was passed in is completely contained
 136          * in RAM.
 137          */
 138         int i;
 139         unsigned long end = start + len;
 140         unsigned long mem_entries = (mem->size - sizeof(*mem))/sizeof(mem->map[0]);
 141
 142         /* See if I conflict with the bounce buffer */
 143         if (end >= buffer) {
 144                 return 0;
 145         }
 146
 147         /* Walk through the table of valid memory ranges and see if I
 148          * have a match.
 149          */
 150         for(i = 0; i < mem_entries; i++) {
 151                 uint64_t mstart, mend;
 152                 uint32_t mtype;
 153                 mtype = mem->map[i].type;
 154                 mstart = unpack_lb64(mem->map[i].start);
 155                 mend = mstart + unpack_lb64(mem->map[i].size);
 156                 if ((mtype == LB_MEM_RAM) && (start < mend) && (end > mstart)) {
 157                         break;
 158                 }
 159                 if ((mtype == LB_MEM_TABLE) && (start < mend) && (end > mstart)) {
 160                         printk_err("Payload is overwriting Coreboot tables.\n");
 161                         break;
 162                 }
 163         }
 164         if (i == mem_entries) {
 165                 printk_err("No matching ram area found for range:\n");
 166                 printk_err("  [0x%016lx, 0x%016lx)\n", start, end);
 167                 printk_err("Ram areas\n");
 168                 for(i = 0; i < mem_entries; i++) {
 169                         uint64_t mstart, mend;
 170                         uint32_t mtype;
 171                         mtype = mem->map[i].type;
 172                         mstart = unpack_lb64(mem->map[i].start);
 173                         mend = mstart + unpack_lb64(mem->map[i].size);
 174                         printk_err("  [0x%016lx, 0x%016lx) %s\n",
 175                                 (unsigned long)mstart,
 176                                 (unsigned long)mend,
 177                                 (mtype == LB_MEM_RAM)?"RAM":"Reserved");
 178
 179                 }
 180                 return 0;
 181         }
 182         return 1;
 183 }
 184
 185 static const unsigned long lb_start = (unsigned long)&_ram_seg;
 186 static const unsigned long lb_end = (unsigned long)&_eram_seg;
 187
 188 static int overlaps_coreboot(struct segment *seg)
 189 {
 190         unsigned long start, end;
 191         start = seg->s_dstaddr;
 192         end = start + seg->s_memsz;
 193         return !((end <= lb_start) || (start >= lb_end));
 194 }
 195
 196 static void relocate_segment(unsigned long buffer, struct segment *seg)
 197 {
 198         /* Modify all segments that want to load onto coreboot
 199          * to load onto the bounce buffer instead.
 200          */
 201         unsigned long start, middle, end;
 202
 203         printk_spew("lb: [0x%016lx, 0x%016lx)\n",
 204                 lb_start, lb_end);
 205
 206         /* I don't conflict with coreboot so get out of here */
 207         if (!overlaps_coreboot(seg))
 208                 return;
 209
 210         start = seg->s_dstaddr;
 211         middle = start + seg->s_filesz;
 212         end = start + seg->s_memsz;
 213
 214         printk_spew("segment: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 215                 start, middle, end);
 216
 217         if (seg->compression == CBFS_COMPRESS_NONE) {
 218                 /* Slice off a piece at the beginning
 219                  * that doesn't conflict with coreboot.
 220                  */
 221                 if (start < lb_start) {
 222                         struct segment *new;
 223                         unsigned long len = lb_start - start;
 224                         new = malloc(sizeof(*new));
 225                         *new = *seg;
 226                         new->s_memsz = len;
 227                         seg->s_memsz -= len;
 228                         seg->s_dstaddr += len;
 229                         seg->s_srcaddr += len;
 230                         if (seg->s_filesz > len) {
 231                                 new->s_filesz = len;
 232                                 seg->s_filesz -= len;
 233                         } else {
 234                                 seg->s_filesz = 0;
 235                         }
 236
 237                         /* Order by stream offset */
 238                         new->next = seg;
 239                         new->prev = seg->prev;
 240                         seg->prev->next = new;
 241                         seg->prev = new;
 242                         /* Order by original program header order */
 243                         new->phdr_next = seg;
 244                         new->phdr_prev = seg->phdr_prev;
 245                         seg->phdr_prev->phdr_next = new;
 246                         seg->phdr_prev = new;
 247
 248                         /* compute the new value of start */
 249                         start = seg->s_dstaddr;
 250
 251                         printk_spew("   early: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 252                                 new->s_dstaddr,
 253                                 new->s_dstaddr + new->s_filesz,
 254                                 new->s_dstaddr + new->s_memsz);
 255                         }
 256
 257                         /* Slice off a piece at the end
 258                  * that doesn't conflict with coreboot
 259                  */
 260                 if (end > lb_end) {
 261                         unsigned long len = lb_end - start;
 262                         struct segment *new;
 263                         new = malloc(sizeof(*new));
 264                         *new = *seg;
 265                         seg->s_memsz = len;
 266                         new->s_memsz -= len;
 267                         new->s_dstaddr += len;
 268                         new->s_srcaddr += len;
 269                         if (seg->s_filesz > len) {
 270                                 seg->s_filesz = len;
 271                                 new->s_filesz -= len;
 272                         } else {
 273                                 new->s_filesz = 0;
 274                         }
 275                         /* Order by stream offset */
 276                         new->next = seg->next;
 277                         new->prev = seg;
 278                         seg->next->prev = new;
 279                         seg->next = new;
 280                         /* Order by original program header order */
 281                         new->phdr_next = seg->phdr_next;
 282                         new->phdr_prev = seg;
 283                         seg->phdr_next->phdr_prev = new;
 284                         seg->phdr_next = new;
 285
 286                         /* compute the new value of end */
 287                         end = start + len;
 288
 289                         printk_spew("   late: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 290                                 new->s_dstaddr,
 291                                 new->s_dstaddr + new->s_filesz,
 292                                 new->s_dstaddr + new->s_memsz);
 293
 294                 }
 295         }
 296         /* Now retarget this segment onto the bounce buffer */
 297         /* sort of explanation: the buffer is a 1:1 mapping to coreboot.
 298          * so you will make the dstaddr be this buffer, and it will get copied
 299          * later to where coreboot lives.
 300          */
 301         seg->s_dstaddr = buffer + (seg->s_dstaddr - lb_start);
 302
 303         printk_spew(" bounce: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 304                 seg->s_dstaddr,
 305                 seg->s_dstaddr + seg->s_filesz,
 306                 seg->s_dstaddr + seg->s_memsz);
 307 }
 308
 309
 310 static int build_self_segment_list(
 311         struct segment *head,
 312         struct lb_memory *mem,
 313         struct cbfs_payload *payload, u32 *entry)
 314 {
 315         struct segment *new;
 316         struct segment *ptr;
 317         int datasize;
 318         struct cbfs_payload_segment *segment, *first_segment;
 319         memset(head, 0, sizeof(*head));
 320         head->phdr_next = head->phdr_prev = head;
 321         head->next = head->prev = head;
 322         first_segment = segment = &payload->segments;
 323
 324         while(1) {
 325                 printk_debug("Segment %p\n", segment);
 326                 switch(segment->type) {
 327                 default: printk_emerg("Bad segment type %x\n", segment->type);
 328                         return -1;
 329                 case PAYLOAD_SEGMENT_PARAMS:
 330                         printk_info("found param section\n");
 331                         segment++;
 332                         continue;
 333                 case PAYLOAD_SEGMENT_CODE:
 334                 case PAYLOAD_SEGMENT_DATA:
 335                         printk_info( "%s: ", segment->type == PAYLOAD_SEGMENT_CODE ?
 336                                 "code" : "data");
 337                 new = malloc(sizeof(*new));
 338                 new->s_dstaddr = ntohl((u32) segment->load_addr);
 339                 new->s_memsz = ntohl(segment->mem_len);
 340                 new->compression = ntohl(segment->compression);
 341
 342                 datasize = ntohl(segment->len);
 343                 new->s_srcaddr = (u32) ((unsigned char *) first_segment) + ntohl(segment->offset);
 344                 new->s_filesz = ntohl(segment->len);
 345                 printk_debug("New segment dstaddr 0x%lx memsize 0x%lx srcaddr 0x%lx filesize 0x%lx\n",
 346                         new->s_dstaddr, new->s_memsz, new->s_srcaddr, new->s_filesz);
 347                 /* Clean up the values */
 348                 if (new->s_filesz > new->s_memsz)  {
 349                         new->s_filesz = new->s_memsz;
 350                 }
 351                 printk_debug("(cleaned up) New segment addr 0x%lx size 0x%lx offset 0x%lx filesize 0x%lx\n",
 352                         new->s_dstaddr, new->s_memsz, new->s_srcaddr, new->s_filesz);
 353                 break;
 354                 case PAYLOAD_SEGMENT_BSS:
 355                         printk_info("BSS %p/%d\n", (void *) ntohl((u32) segment->load_addr),
 356                                  ntohl(segment->mem_len));
 357                         new = malloc(sizeof(*new));
 358                         new->s_filesz = 0;
 359                         new->s_dstaddr = ntohl((u32) segment->load_addr);
 360                         new->s_memsz = ntohl(segment->mem_len);
 361
 362                         break;
 363
 364                 case PAYLOAD_SEGMENT_ENTRY:
 365                         printk_info("Entry %p\n", (void *) ntohl((u32) segment->load_addr));
 366                         *entry =  ntohl((u32) segment->load_addr);
 367                         return 1;
 368                 }
 369                 segment++;
 370                 for(ptr = head->next; ptr != head; ptr = ptr->next) {
 371                         if (new->s_srcaddr < ntohl((u32) segment->load_addr))
 372                                 break;
 373                 }
 374                 /* Order by stream offset */
 375                 new->next = ptr;
 376                 new->prev = ptr->prev;
 377                 ptr->prev->next = new;
 378                 ptr->prev = new;
 379                 /* Order by original program header order */
 380                 new->phdr_next = head;
 381                 new->phdr_prev = head->phdr_prev;
 382                 head->phdr_prev->phdr_next  = new;
 383                 head->phdr_prev = new;
 384         }
 385         return 1;
 386 }
 387
 388 static int load_self_segments(
 389         struct segment *head,
 390         struct lb_memory *mem,
 391         struct cbfs_payload *payload)
 392 {
 393         unsigned long offset;
 394         struct segment *ptr;
 395
 396         offset = 0;
 397         unsigned long required_bounce_size = lb_end - lb_start;
 398         for(ptr = head->next; ptr != head; ptr = ptr->next) {
 399                 if (!overlaps_coreboot(ptr)) continue;
 400                 unsigned long bounce = ptr->s_dstaddr + ptr->s_memsz - lb_start;
 401                 if (bounce > required_bounce_size) required_bounce_size = bounce;
 402         }
 403         get_bounce_buffer(mem, required_bounce_size);
 404         if (!bounce_buffer) {
 405                 printk_err("Could not find a bounce buffer...\n");
 406                 return 0;
 407         }
 408         for(ptr = head->next; ptr != head; ptr = ptr->next) {
 409                 /* Verify the memory addresses in the segment are valid */
 410                 if (!valid_area(mem, bounce_buffer, ptr->s_dstaddr, ptr->s_memsz))
 411                         return 0;
 412         }
 413         for(ptr = head->next; ptr != head; ptr = ptr->next) {
 414                 unsigned char *dest, *middle, *end, *src;
 415                 printk_debug("Loading Segment: addr: 0x%016lx memsz: 0x%016lx filesz: 0x%016lx\n",
 416                         ptr->s_dstaddr, ptr->s_memsz, ptr->s_filesz);
 417
 418                 /* Modify the segment to load onto the bounce_buffer if necessary.
 419                  */
 420                 relocate_segment(bounce_buffer, ptr);
 421
 422                 printk_debug("Post relocation: addr: 0x%016lx memsz: 0x%016lx filesz: 0x%016lx\n",
 423                         ptr->s_dstaddr, ptr->s_memsz, ptr->s_filesz);
 424
 425                 /* Compute the boundaries of the segment */
 426                 dest = (unsigned char *)(ptr->s_dstaddr);
 427                 src = (unsigned char *)(ptr->s_srcaddr);
 428
 429                 /* Copy data from the initial buffer */
 430                 if (ptr->s_filesz) {
 431                         size_t len;
 432                         len = ptr->s_filesz;
 433                         switch(ptr->compression) {
 434 #if CONFIG_COMPRESSED_PAYLOAD_LZMA==1
 435                                 case CBFS_COMPRESS_LZMA: {
 436                                         printk_debug("using LZMA\n");
 437                                         unsigned long ulzma(unsigned char *src, unsigned char *dst);
 438                                         len = ulzma(src, dest);
 439                                         break;
 440                                 }
 441 #endif
 442 #if CONFIG_COMPRESSED_PAYLOAD_NRV2B==1
 443                                 case CBFS_COMPRESS_NRV2B: {
 444                                         printk_debug("using NRV2B\n");
 445                                         unsigned long unrv2b(u8 *src, u8 *dst, unsigned long *ilen_p);
 446                                         unsigned long tmp;
 447                                         len = unrv2b(src, dest, &tmp);
 448                                         break;
 449                                 }
 450 #endif
 451                                 case CBFS_COMPRESS_NONE: {
 452                                         printk_debug("it's not compressed!\n");
 453                                         memcpy(dest, src, len);
 454                                         break;
 455                                 }
 456                                 default:
 457                                         printk_info( "CBFS:  Unknown compression type %d\n", ptr->compression);
 458                                         return -1;
 459                         }
 460                         end = dest + ptr->s_memsz;
 461                         middle = dest + len;
 462                         printk_spew("[ 0x%016lx, %016lx, 0x%016lx) <- %016lx\n",
 463                                 (unsigned long)dest,
 464                                 (unsigned long)middle,
 465                                 (unsigned long)end,
 466                                 (unsigned long)src);
 467                 }
 468                 /* Zero the extra bytes between middle & end */
 469                 if (middle < end) {
 470                         printk_debug("Clearing Segment: addr: 0x%016lx memsz: 0x%016lx\n",
 471                                 (unsigned long)middle, (unsigned long)(end - middle));
 472
 473                         /* Zero the extra bytes */
 474                         memset(middle, 0, end - middle);
 475                 }
 476         }
 477         return 1;
 478 }
 479
 480 int selfboot(struct lb_memory *mem, struct cbfs_payload *payload)
 481 {
 482         u32 entry=0;
 483         struct segment head;
 484
 485         /* Preprocess the self segments */
 486         if (!build_self_segment_list(&head, mem, payload, &entry))
 487                 goto out;
 488
 489         /* Load the segments */
 490         if (!load_self_segments(&head, mem, payload))
 491                 goto out;
 492
 493         printk_spew("Loaded segments\n");
 494
 495         /* Reset to booting from this image as late as possible */
 496         boot_successful();
 497
 498         printk_debug("Jumping to boot code at %x\n", entry);
 499         post_code(0xfe);
 500
 501         /* Jump to kernel */
 502         jmp_to_elf_entry((void*)entry, bounce_buffer, bounce_size);
 503         return 1;
 504
 505  out:
 506         return 0;
 507 }
 508