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 <fallback.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 <stdint.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <cbfs.h>
  31 #include <lib.h>
  32
  33 #if !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 static int selfboot(struct lb_memory *mem, struct cbfs_payload *payload);
  75
  76 void * cbfs_load_payload(struct lb_memory *lb_mem, const char *name)
  77 {
  78         struct cbfs_payload *payload;
  79
  80         payload = (struct cbfs_payload *)cbfs_find_file(name, CBFS_TYPE_PAYLOAD);
  81         if (payload == NULL)
  82                 return (void *) -1;
  83         printk(BIOS_DEBUG, "Got a payload\n");
  84
  85         selfboot(lb_mem, payload);
  86         printk(BIOS_EMERG, "SELFBOOT RETURNED!\n");
  87
  88         return (void *) -1;
  89 }
  90
  91 /* The problem:
  92  * Static executables all want to share the same addresses
  93  * in memory because only a few addresses are reliably present on
  94  * a machine, and implementing general relocation is hard.
  95  *
  96  * The solution:
  97  * - Allocate a buffer the size of the coreboot image plus additional
  98  *   required space.
  99  * - Anything that would overwrite coreboot copy into the lower part of
 100  *   the buffer.
 101  * - After loading an ELF image copy coreboot to the top of the buffer.
 102  * - Then jump to the loaded image.
 103  *
 104  * Benefits:
 105  * - Nearly arbitrary standalone executables can be loaded.
 106  * - Coreboot is preserved, so it can be returned to.
 107  * - The implementation is still relatively simple,
 108  *   and much simpler than the general case implemented in kexec.
 109  *
 110  */
 111
 112 static unsigned long bounce_size, bounce_buffer;
 113
 114 static void get_bounce_buffer(struct lb_memory *mem, unsigned long req_size)
 115 {
 116         unsigned long lb_size;
 117         unsigned long mem_entries;
 118         unsigned long buffer;
 119         int i;
 120         lb_size = (unsigned long)(&_eram_seg - &_ram_seg);
 121         /* Double coreboot size so I have somewhere to place a copy to return to */
 122         lb_size = req_size + lb_size;
 123         mem_entries = (mem->size - sizeof(*mem))/sizeof(mem->map[0]);
 124         buffer = 0;
 125         for(i = 0; i < mem_entries; i++) {
 126                 unsigned long mstart, mend;
 127                 unsigned long msize;
 128                 unsigned long tbuffer;
 129                 if (mem->map[i].type != LB_MEM_RAM)
 130                         continue;
 131                 if (unpack_lb64(mem->map[i].start) > MAX_ADDR)
 132                         continue;
 133                 if (unpack_lb64(mem->map[i].size) < lb_size)
 134                         continue;
 135                 mstart = unpack_lb64(mem->map[i].start);
 136                 msize = MAX_ADDR - mstart +1;
 137                 if (msize > unpack_lb64(mem->map[i].size))
 138                         msize = unpack_lb64(mem->map[i].size);
 139                 mend = mstart + msize;
 140                 tbuffer = mend - lb_size;
 141                 if (tbuffer < buffer)
 142                         continue;
 143                 buffer = tbuffer;
 144         }
 145         bounce_buffer = buffer;
 146         bounce_size = req_size;
 147 }
 148
 149 static int valid_area(struct lb_memory *mem, unsigned long buffer,
 150         unsigned long start, unsigned long len)
 151 {
 152         /* Check through all of the memory segments and ensure
 153          * the segment that was passed in is completely contained
 154          * in RAM.
 155          */
 156         int i;
 157         unsigned long end = start + len;
 158         unsigned long mem_entries = (mem->size - sizeof(*mem))/sizeof(mem->map[0]);
 159
 160         /* See if I conflict with the bounce buffer */
 161         if (end >= buffer) {
 162                 return 0;
 163         }
 164
 165         /* Walk through the table of valid memory ranges and see if I
 166          * have a match.
 167          */
 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                 if ((mtype == LB_MEM_RAM) && (start < mend) && (end > mstart)) {
 175                         break;
 176                 }
 177                 if ((mtype == LB_MEM_TABLE) && (start < mend) && (end > mstart)) {
 178                         printk(BIOS_ERR, "Payload is overwriting coreboot tables.\n");
 179                         break;
 180                 }
 181         }
 182         if (i == mem_entries) {
 183                 printk(BIOS_ERR, "No matching ram area found for range:\n");
 184                 printk(BIOS_ERR, "  [0x%016lx, 0x%016lx)\n", start, end);
 185                 printk(BIOS_ERR, "Ram areas\n");
 186                 for(i = 0; i < mem_entries; i++) {
 187                         uint64_t mstart, mend;
 188                         uint32_t mtype;
 189                         mtype = mem->map[i].type;
 190                         mstart = unpack_lb64(mem->map[i].start);
 191                         mend = mstart + unpack_lb64(mem->map[i].size);
 192                         printk(BIOS_ERR, "  [0x%016lx, 0x%016lx) %s\n",
 193                                 (unsigned long)mstart,
 194                                 (unsigned long)mend,
 195                                 (mtype == LB_MEM_RAM)?"RAM":"Reserved");
 196
 197                 }
 198                 return 0;
 199         }
 200         return 1;
 201 }
 202
 203 static const unsigned long lb_start = (unsigned long)&_ram_seg;
 204 static const unsigned long lb_end = (unsigned long)&_eram_seg;
 205
 206 static int overlaps_coreboot(struct segment *seg)
 207 {
 208         unsigned long start, end;
 209         start = seg->s_dstaddr;
 210         end = start + seg->s_memsz;
 211         return !((end <= lb_start) || (start >= lb_end));
 212 }
 213
 214 static int relocate_segment(unsigned long buffer, struct segment *seg)
 215 {
 216         /* Modify all segments that want to load onto coreboot
 217          * to load onto the bounce buffer instead.
 218          */
 219         /* ret:  1 : A new segment is inserted before the seg.
 220          *       0 : A new segment is inserted after the seg, or no new one. */
 221         unsigned long start, middle, end, ret = 0;
 222
 223         printk(BIOS_SPEW, "lb: [0x%016lx, 0x%016lx)\n",
 224                 lb_start, lb_end);
 225
 226         /* I don't conflict with coreboot so get out of here */
 227         if (!overlaps_coreboot(seg))
 228                 return 0;
 229
 230         start = seg->s_dstaddr;
 231         middle = start + seg->s_filesz;
 232         end = start + seg->s_memsz;
 233
 234         printk(BIOS_SPEW, "segment: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 235                 start, middle, end);
 236
 237         if (seg->compression == CBFS_COMPRESS_NONE) {
 238                 /* Slice off a piece at the beginning
 239                  * that doesn't conflict with coreboot.
 240                  */
 241                 if (start < lb_start) {
 242                         struct segment *new;
 243                         unsigned long len = lb_start - start;
 244                         new = malloc(sizeof(*new));
 245                         *new = *seg;
 246                         new->s_memsz = len;
 247                         seg->s_memsz -= len;
 248                         seg->s_dstaddr += len;
 249                         seg->s_srcaddr += len;
 250                         if (seg->s_filesz > len) {
 251                                 new->s_filesz = len;
 252                                 seg->s_filesz -= len;
 253                         } else {
 254                                 seg->s_filesz = 0;
 255                         }
 256
 257                         /* Order by stream offset */
 258                         new->next = seg;
 259                         new->prev = seg->prev;
 260                         seg->prev->next = new;
 261                         seg->prev = new;
 262                         /* Order by original program header order */
 263                         new->phdr_next = seg;
 264                         new->phdr_prev = seg->phdr_prev;
 265                         seg->phdr_prev->phdr_next = new;
 266                         seg->phdr_prev = new;
 267
 268                         /* compute the new value of start */
 269                         start = seg->s_dstaddr;
 270
 271                         printk(BIOS_SPEW, "   early: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 272                                 new->s_dstaddr,
 273                                 new->s_dstaddr + new->s_filesz,
 274                                 new->s_dstaddr + new->s_memsz);
 275
 276                         ret = 1;
 277                 }
 278
 279                 /* Slice off a piece at the end
 280                  * that doesn't conflict with coreboot
 281                  */
 282                 if (end > lb_end) {
 283                         unsigned long len = lb_end - start;
 284                         struct segment *new;
 285                         new = malloc(sizeof(*new));
 286                         *new = *seg;
 287                         seg->s_memsz = len;
 288                         new->s_memsz -= len;
 289                         new->s_dstaddr += len;
 290                         new->s_srcaddr += len;
 291                         if (seg->s_filesz > len) {
 292                                 seg->s_filesz = len;
 293                                 new->s_filesz -= len;
 294                         } else {
 295                                 new->s_filesz = 0;
 296                         }
 297                         /* Order by stream offset */
 298                         new->next = seg->next;
 299                         new->prev = seg;
 300                         seg->next->prev = new;
 301                         seg->next = new;
 302                         /* Order by original program header order */
 303                         new->phdr_next = seg->phdr_next;
 304                         new->phdr_prev = seg;
 305                         seg->phdr_next->phdr_prev = new;
 306                         seg->phdr_next = new;
 307
 308                         printk(BIOS_SPEW, "   late: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 309                                 new->s_dstaddr,
 310                                 new->s_dstaddr + new->s_filesz,
 311                                 new->s_dstaddr + new->s_memsz);
 312                 }
 313         }
 314
 315         /* Now retarget this segment onto the bounce buffer */
 316         /* sort of explanation: the buffer is a 1:1 mapping to coreboot.
 317          * so you will make the dstaddr be this buffer, and it will get copied
 318          * later to where coreboot lives.
 319          */
 320         seg->s_dstaddr = buffer + (seg->s_dstaddr - lb_start);
 321
 322         printk(BIOS_SPEW, " bounce: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 323                 seg->s_dstaddr,
 324                 seg->s_dstaddr + seg->s_filesz,
 325                 seg->s_dstaddr + seg->s_memsz);
 326
 327         return ret;
 328 }
 329
 330
 331 static int build_self_segment_list(
 332         struct segment *head,
 333         struct lb_memory *mem,
 334         struct cbfs_payload *payload, u32 *entry)
 335 {
 336         struct segment *new;
 337         struct segment *ptr;
 338         struct cbfs_payload_segment *segment, *first_segment;
 339         memset(head, 0, sizeof(*head));
 340         head->phdr_next = head->phdr_prev = head;
 341         head->next = head->prev = head;
 342         first_segment = segment = &payload->segments;
 343
 344         while(1) {
 345                 printk(BIOS_DEBUG, "Loading segment from rom address 0x%p\n", segment);
 346                 switch(segment->type) {
 347                 case PAYLOAD_SEGMENT_PARAMS:
 348                         printk(BIOS_DEBUG, "  parameter section (skipped)\n");
 349                         segment++;
 350                         continue;
 351
 352                 case PAYLOAD_SEGMENT_CODE:
 353                 case PAYLOAD_SEGMENT_DATA:
 354                         printk(BIOS_DEBUG, "  %s (compression=%x)\n",
 355                                         segment->type == PAYLOAD_SEGMENT_CODE ?  "code" : "data",
 356                                         ntohl(segment->compression));
 357                         new = malloc(sizeof(*new));
 358                         new->s_dstaddr = ntohl((u32) segment->load_addr);
 359                         new->s_memsz = ntohl(segment->mem_len);
 360                         new->compression = ntohl(segment->compression);
 361
 362                         new->s_srcaddr = (u32) ((unsigned char *) first_segment) + ntohl(segment->offset);
 363                         new->s_filesz = ntohl(segment->len);
 364                         printk(BIOS_DEBUG, "  New segment dstaddr 0x%lx memsize 0x%lx srcaddr 0x%lx filesize 0x%lx\n",
 365                                 new->s_dstaddr, new->s_memsz, new->s_srcaddr, new->s_filesz);
 366                         /* Clean up the values */
 367                         if (new->s_filesz > new->s_memsz)  {
 368                                 new->s_filesz = new->s_memsz;
 369                         }
 370                         printk(BIOS_DEBUG, "  (cleaned up) New segment addr 0x%lx size 0x%lx offset 0x%lx filesize 0x%lx\n",
 371                                 new->s_dstaddr, new->s_memsz, new->s_srcaddr, new->s_filesz);
 372                         break;
 373
 374                 case PAYLOAD_SEGMENT_BSS:
 375                         printk(BIOS_DEBUG, "  BSS 0x%p (%d byte)\n", (void *) ntohl((u32) segment->load_addr),
 376                                  ntohl(segment->mem_len));
 377                         new = malloc(sizeof(*new));
 378                         new->s_filesz = 0;
 379                         new->s_dstaddr = ntohl((u32) segment->load_addr);
 380                         new->s_memsz = ntohl(segment->mem_len);
 381                         break;
 382
 383                 case PAYLOAD_SEGMENT_ENTRY:
 384                         printk(BIOS_DEBUG, "  Entry Point 0x%p\n", (void *) ntohl((u32) segment->load_addr));
 385                         *entry =  ntohl((u32) segment->load_addr);
 386                         /* Per definition, a payload always has the entry point
 387                          * as last segment. Thus, we use the occurence of the
 388                          * entry point as break condition for the loop.
 389                          * Can we actually just look at the number of section?
 390                          */
 391                         return 1;
 392
 393                 default:
 394                         /* We found something that we don't know about. Throw
 395                          * hands into the sky and run away!
 396                          */
 397                         printk(BIOS_EMERG, "Bad segment type %x\n", segment->type);
 398                         return -1;
 399                 }
 400
 401                 segment++;
 402
 403                 // FIXME: Explain what this is
 404                 for(ptr = head->next; ptr != head; ptr = ptr->next) {
 405                         if (new->s_srcaddr < ntohl((u32) segment->load_addr))
 406                                 break;
 407                 }
 408
 409                 /* Order by stream offset */
 410                 new->next = ptr;
 411                 new->prev = ptr->prev;
 412                 ptr->prev->next = new;
 413                 ptr->prev = new;
 414
 415                 /* Order by original program header order */
 416                 new->phdr_next = head;
 417                 new->phdr_prev = head->phdr_prev;
 418                 head->phdr_prev->phdr_next  = new;
 419                 head->phdr_prev = new;
 420         }
 421
 422         return 1;
 423 }
 424
 425 static int load_self_segments(
 426         struct segment *head,
 427         struct lb_memory *mem,
 428         struct cbfs_payload *payload)
 429 {
 430         struct segment *ptr;
 431
 432         unsigned long bounce_high = lb_end;
 433         for(ptr = head->next; ptr != head; ptr = ptr->next) {
 434                 if (!overlaps_coreboot(ptr)) continue;
 435                 if (ptr->s_dstaddr + ptr->s_memsz > bounce_high)
 436                         bounce_high = ptr->s_dstaddr + ptr->s_memsz;
 437         }
 438         get_bounce_buffer(mem, bounce_high - lb_start);
 439         if (!bounce_buffer) {
 440                 printk(BIOS_ERR, "Could not find a bounce buffer...\n");
 441                 return 0;
 442         }
 443         for(ptr = head->next; ptr != head; ptr = ptr->next) {
 444                 /* Verify the memory addresses in the segment are valid */
 445                 if (!valid_area(mem, bounce_buffer, ptr->s_dstaddr, ptr->s_memsz))
 446                         return 0;
 447         }
 448         for(ptr = head->next; ptr != head; ptr = ptr->next) {
 449                 unsigned char *dest, *src;
 450                 printk(BIOS_DEBUG, "Loading Segment: addr: 0x%016lx memsz: 0x%016lx filesz: 0x%016lx\n",
 451                         ptr->s_dstaddr, ptr->s_memsz, ptr->s_filesz);
 452
 453                 /* Modify the segment to load onto the bounce_buffer if necessary.
 454                  */
 455                 if (relocate_segment(bounce_buffer, ptr)) {
 456                         ptr = (ptr->prev)->prev;
 457                         continue;
 458                 }
 459
 460                 printk(BIOS_DEBUG, "Post relocation: addr: 0x%016lx memsz: 0x%016lx filesz: 0x%016lx\n",
 461                         ptr->s_dstaddr, ptr->s_memsz, ptr->s_filesz);
 462
 463                 /* Compute the boundaries of the segment */
 464                 dest = (unsigned char *)(ptr->s_dstaddr);
 465                 src = (unsigned char *)(ptr->s_srcaddr);
 466
 467                 /* Copy data from the initial buffer */
 468                 if (ptr->s_filesz) {
 469                         unsigned char *middle, *end;
 470                         size_t len;
 471                         len = ptr->s_filesz;
 472                         switch(ptr->compression) {
 473                                 case CBFS_COMPRESS_LZMA: {
 474                                         printk(BIOS_DEBUG, "using LZMA\n");
 475                                         len = ulzma(src, dest);
 476                                         if (!len) /* Decompression Error. */
 477                                                 return 0;
 478                                         break;
 479                                 }
 480 #if CONFIG_COMPRESSED_PAYLOAD_NRV2B
 481                                 case CBFS_COMPRESS_NRV2B: {
 482                                         printk(BIOS_DEBUG, "using NRV2B\n");
 483                                         unsigned long unrv2b(u8 *src, u8 *dst, unsigned long *ilen_p);
 484                                         unsigned long tmp;
 485                                         len = unrv2b(src, dest, &tmp);
 486                                         break;
 487                                 }
 488 #endif
 489                                 case CBFS_COMPRESS_NONE: {
 490                                         printk(BIOS_DEBUG, "it's not compressed!\n");
 491                                         memcpy(dest, src, len);
 492                                         break;
 493                                 }
 494                                 default:
 495                                         printk(BIOS_INFO,  "CBFS:  Unknown compression type %d\n", ptr->compression);
 496                                         return -1;
 497                         }
 498                         end = dest + ptr->s_memsz;
 499                         middle = dest + len;
 500                         printk(BIOS_SPEW, "[ 0x%08lx, %08lx, 0x%08lx) <- %08lx\n",
 501                                 (unsigned long)dest,
 502                                 (unsigned long)middle,
 503                                 (unsigned long)end,
 504                                 (unsigned long)src);
 505
 506                         /* Zero the extra bytes between middle & end */
 507                         if (middle < end) {
 508                                 printk(BIOS_DEBUG, "Clearing Segment: addr: 0x%016lx memsz: 0x%016lx\n",
 509                                         (unsigned long)middle, (unsigned long)(end - middle));
 510
 511                                 /* Zero the extra bytes */
 512                                 memset(middle, 0, end - middle);
 513                         }
 514                         /* Copy the data that's outside the area that shadows coreboot_ram */
 515                         printk(BIOS_DEBUG, "dest %p, end %p, bouncebuffer %lx\n", dest, end, bounce_buffer);
 516                         if ((unsigned long)end > bounce_buffer) {
 517                                 if ((unsigned long)dest < bounce_buffer) {
 518                                         unsigned char *from = dest;
 519                                         unsigned char *to = (unsigned char*)(lb_start-(bounce_buffer-(unsigned long)dest));
 520                                         unsigned long amount = bounce_buffer-(unsigned long)dest;
 521                                         printk(BIOS_DEBUG, "move prefix around: from %p, to %p, amount: %lx\n", from, to, amount);
 522                                         memcpy(to, from, amount);
 523                                 }
 524                                 if ((unsigned long)end > bounce_buffer + (lb_end - lb_start)) {
 525                                         unsigned long from = bounce_buffer + (lb_end - lb_start);
 526                                         unsigned long to = lb_end;
 527                                         unsigned long amount = (unsigned long)end - from;
 528                                         printk(BIOS_DEBUG, "move suffix around: from %lx, to %lx, amount: %lx\n", from, to, amount);
 529                                         memcpy((char*)to, (char*)from, amount);
 530                                 }
 531                         }
 532                 }
 533         }
 534         return 1;
 535 }
 536
 537 static int selfboot(struct lb_memory *mem, struct cbfs_payload *payload)
 538 {
 539         u32 entry=0;
 540         struct segment head;
 541
 542         /* Preprocess the self segments */
 543         if (!build_self_segment_list(&head, mem, payload, &entry))
 544                 goto out;
 545
 546         /* Load the segments */
 547         if (!load_self_segments(&head, mem, payload))
 548                 goto out;
 549
 550         printk(BIOS_SPEW, "Loaded segments\n");
 551
 552         /* Reset to booting from this image as late as possible */
 553         boot_successful();
 554
 555         printk(BIOS_DEBUG, "Jumping to boot code at %x\n", entry);
 556         post_code(POST_ENTER_ELF_BOOT);
 557
 558         /* Jump to kernel */
 559         jmp_to_elf_entry((void*)entry, bounce_buffer, bounce_size);
 560         return 1;
 561
 562  out:
 563         return 0;
 564 }
 565