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 void * cbfs_load_payload(struct lb_memory *lb_mem, const char *name)
  75 {
  76         int selfboot(struct lb_memory *mem, struct cbfs_payload *payload);
  77         struct cbfs_payload *payload;
  78
  79         payload = (struct cbfs_payload *)cbfs_find_file(name, CBFS_TYPE_PAYLOAD);
  80         if (payload == NULL)
  81                 return (void *) -1;
  82         printk_debug("Got a payload\n");
  83
  84         selfboot(lb_mem, payload);
  85         printk_emerg("SELFBOOT RETURNED!\n");
  86
  87         return (void *) -1;
  88 }
  89
  90 /* The problem:
  91  * Static executables all want to share the same addresses
  92  * in memory because only a few addresses are reliably present on
  93  * a machine, and implementing general relocation is hard.
  94  *
  95  * The solution:
  96  * - Allocate a buffer the size of the coreboot image plus additional
  97  *   required space.
  98  * - Anything that would overwrite coreboot copy into the lower part of
  99  *   the buffer.
 100  * - After loading an ELF image copy coreboot to the top of the buffer.
 101  * - Then jump to the loaded image.
 102  *
 103  * Benefits:
 104  * - Nearly arbitrary standalone executables can be loaded.
 105  * - Coreboot is preserved, so it can be returned to.
 106  * - The implementation is still relatively simple,
 107  *   and much simpler then the general case implemented in kexec.
 108  *
 109  */
 110
 111 static unsigned long bounce_size, bounce_buffer;
 112
 113 static void get_bounce_buffer(struct lb_memory *mem, unsigned long bounce_size)
 114 {
 115         unsigned long lb_size;
 116         unsigned long mem_entries;
 117         unsigned long buffer;
 118         int i;
 119         lb_size = (unsigned long)(&_eram_seg - &_ram_seg);
 120         /* Double coreboot size so I have somewhere to place a copy to return to */
 121         lb_size = bounce_size + lb_size;
 122         mem_entries = (mem->size - sizeof(*mem))/sizeof(mem->map[0]);
 123         buffer = 0;
 124         for(i = 0; i < mem_entries; i++) {
 125                 unsigned long mstart, mend;
 126                 unsigned long msize;
 127                 unsigned long tbuffer;
 128                 if (mem->map[i].type != LB_MEM_RAM)
 129                         continue;
 130                 if (unpack_lb64(mem->map[i].start) > MAX_ADDR)
 131                         continue;
 132                 if (unpack_lb64(mem->map[i].size) < lb_size)
 133                         continue;
 134                 mstart = unpack_lb64(mem->map[i].start);
 135                 msize = MAX_ADDR - mstart +1;
 136                 if (msize > unpack_lb64(mem->map[i].size))
 137                         msize = unpack_lb64(mem->map[i].size);
 138                 mend = mstart + msize;
 139                 tbuffer = mend - lb_size;
 140                 if (tbuffer < buffer)
 141                         continue;
 142                 buffer = tbuffer;
 143         }
 144         bounce_buffer = buffer;
 145 }
 146
 147 static int valid_area(struct lb_memory *mem, unsigned long buffer,
 148         unsigned long start, unsigned long len)
 149 {
 150         /* Check through all of the memory segments and ensure
 151          * the segment that was passed in is completely contained
 152          * in RAM.
 153          */
 154         int i;
 155         unsigned long end = start + len;
 156         unsigned long mem_entries = (mem->size - sizeof(*mem))/sizeof(mem->map[0]);
 157
 158         /* See if I conflict with the bounce buffer */
 159         if (end >= buffer) {
 160                 return 0;
 161         }
 162
 163         /* Walk through the table of valid memory ranges and see if I
 164          * have a match.
 165          */
 166         for(i = 0; i < mem_entries; i++) {
 167                 uint64_t mstart, mend;
 168                 uint32_t mtype;
 169                 mtype = mem->map[i].type;
 170                 mstart = unpack_lb64(mem->map[i].start);
 171                 mend = mstart + unpack_lb64(mem->map[i].size);
 172                 if ((mtype == LB_MEM_RAM) && (start < mend) && (end > mstart)) {
 173                         break;
 174                 }
 175                 if ((mtype == LB_MEM_TABLE) && (start < mend) && (end > mstart)) {
 176                         printk_err("Payload is overwriting Coreboot tables.\n");
 177                         break;
 178                 }
 179         }
 180         if (i == mem_entries) {
 181                 printk_err("No matching ram area found for range:\n");
 182                 printk_err("  [0x%016lx, 0x%016lx)\n", start, end);
 183                 printk_err("Ram areas\n");
 184                 for(i = 0; i < mem_entries; i++) {
 185                         uint64_t mstart, mend;
 186                         uint32_t mtype;
 187                         mtype = mem->map[i].type;
 188                         mstart = unpack_lb64(mem->map[i].start);
 189                         mend = mstart + unpack_lb64(mem->map[i].size);
 190                         printk_err("  [0x%016lx, 0x%016lx) %s\n",
 191                                 (unsigned long)mstart,
 192                                 (unsigned long)mend,
 193                                 (mtype == LB_MEM_RAM)?"RAM":"Reserved");
 194
 195                 }
 196                 return 0;
 197         }
 198         return 1;
 199 }
 200
 201 static const unsigned long lb_start = (unsigned long)&_ram_seg;
 202 static const unsigned long lb_end = (unsigned long)&_eram_seg;
 203
 204 static int overlaps_coreboot(struct segment *seg)
 205 {
 206         unsigned long start, end;
 207         start = seg->s_dstaddr;
 208         end = start + seg->s_memsz;
 209         return !((end <= lb_start) || (start >= lb_end));
 210 }
 211
 212 static void relocate_segment(unsigned long buffer, struct segment *seg)
 213 {
 214         /* Modify all segments that want to load onto coreboot
 215          * to load onto the bounce buffer instead.
 216          */
 217         unsigned long start, middle, end;
 218
 219         printk_spew("lb: [0x%016lx, 0x%016lx)\n",
 220                 lb_start, lb_end);
 221
 222         /* I don't conflict with coreboot so get out of here */
 223         if (!overlaps_coreboot(seg))
 224                 return;
 225
 226         start = seg->s_dstaddr;
 227         middle = start + seg->s_filesz;
 228         end = start + seg->s_memsz;
 229
 230         printk_spew("segment: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 231                 start, middle, end);
 232
 233         if (seg->compression == CBFS_COMPRESS_NONE) {
 234                 /* Slice off a piece at the beginning
 235                  * that doesn't conflict with coreboot.
 236                  */
 237                 if (start < lb_start) {
 238                         struct segment *new;
 239                         unsigned long len = lb_start - start;
 240                         new = malloc(sizeof(*new));
 241                         *new = *seg;
 242                         new->s_memsz = len;
 243                         seg->s_memsz -= len;
 244                         seg->s_dstaddr += len;
 245                         seg->s_srcaddr += len;
 246                         if (seg->s_filesz > len) {
 247                                 new->s_filesz = len;
 248                                 seg->s_filesz -= len;
 249                         } else {
 250                                 seg->s_filesz = 0;
 251                         }
 252
 253                         /* Order by stream offset */
 254                         new->next = seg;
 255                         new->prev = seg->prev;
 256                         seg->prev->next = new;
 257                         seg->prev = new;
 258                         /* Order by original program header order */
 259                         new->phdr_next = seg;
 260                         new->phdr_prev = seg->phdr_prev;
 261                         seg->phdr_prev->phdr_next = new;
 262                         seg->phdr_prev = new;
 263
 264                         /* compute the new value of start */
 265                         start = seg->s_dstaddr;
 266
 267                         printk_spew("   early: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 268                                 new->s_dstaddr,
 269                                 new->s_dstaddr + new->s_filesz,
 270                                 new->s_dstaddr + new->s_memsz);
 271                 }
 272
 273                 /* Slice off a piece at the end
 274                  * that doesn't conflict with coreboot
 275                  */
 276                 if (end > lb_end) {
 277                         unsigned long len = lb_end - start;
 278                         struct segment *new;
 279                         new = malloc(sizeof(*new));
 280                         *new = *seg;
 281                         seg->s_memsz = len;
 282                         new->s_memsz -= len;
 283                         new->s_dstaddr += len;
 284                         new->s_srcaddr += len;
 285                         if (seg->s_filesz > len) {
 286                                 seg->s_filesz = len;
 287                                 new->s_filesz -= len;
 288                         } else {
 289                                 new->s_filesz = 0;
 290                         }
 291                         /* Order by stream offset */
 292                         new->next = seg->next;
 293                         new->prev = seg;
 294                         seg->next->prev = new;
 295                         seg->next = new;
 296                         /* Order by original program header order */
 297                         new->phdr_next = seg->phdr_next;
 298                         new->phdr_prev = seg;
 299                         seg->phdr_next->phdr_prev = new;
 300                         seg->phdr_next = new;
 301
 302                         printk_spew("   late: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 303                                 new->s_dstaddr,
 304                                 new->s_dstaddr + new->s_filesz,
 305                                 new->s_dstaddr + new->s_memsz);
 306                 }
 307         }
 308
 309         /* Now retarget this segment onto the bounce buffer */
 310         /* sort of explanation: the buffer is a 1:1 mapping to coreboot.
 311          * so you will make the dstaddr be this buffer, and it will get copied
 312          * later to where coreboot lives.
 313          */
 314         seg->s_dstaddr = buffer + (seg->s_dstaddr - lb_start);
 315
 316         printk_spew(" bounce: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 317                 seg->s_dstaddr,
 318                 seg->s_dstaddr + seg->s_filesz,
 319                 seg->s_dstaddr + seg->s_memsz);
 320 }
 321
 322
 323 static int build_self_segment_list(
 324         struct segment *head,
 325         struct lb_memory *mem,
 326         struct cbfs_payload *payload, u32 *entry)
 327 {
 328         struct segment *new;
 329         struct segment *ptr;
 330         struct cbfs_payload_segment *segment, *first_segment;
 331         memset(head, 0, sizeof(*head));
 332         head->phdr_next = head->phdr_prev = head;
 333         head->next = head->prev = head;
 334         first_segment = segment = &payload->segments;
 335
 336         while(1) {
 337                 printk_debug("Loading segment from rom address 0x%p\n", segment);
 338                 switch(segment->type) {
 339                 case PAYLOAD_SEGMENT_PARAMS:
 340                         printk_debug("  parameter section (skipped)\n");
 341                         segment++;
 342                         continue;
 343
 344                 case PAYLOAD_SEGMENT_CODE:
 345                 case PAYLOAD_SEGMENT_DATA:
 346                         printk_debug("  %s (compression=%x)\n",
 347                                         segment->type == PAYLOAD_SEGMENT_CODE ?  "code" : "data",
 348                                         ntohl(segment->compression));
 349                         new = malloc(sizeof(*new));
 350                         new->s_dstaddr = ntohl((u32) segment->load_addr);
 351                         new->s_memsz = ntohl(segment->mem_len);
 352                         new->compression = ntohl(segment->compression);
 353
 354                         new->s_srcaddr = (u32) ((unsigned char *) first_segment) + ntohl(segment->offset);
 355                         new->s_filesz = ntohl(segment->len);
 356                         printk_debug("  New segment dstaddr 0x%lx memsize 0x%lx srcaddr 0x%lx filesize 0x%lx\n",
 357                                 new->s_dstaddr, new->s_memsz, new->s_srcaddr, new->s_filesz);
 358                         /* Clean up the values */
 359                         if (new->s_filesz > new->s_memsz)  {
 360                                 new->s_filesz = new->s_memsz;
 361                         }
 362                         printk_debug("  (cleaned up) New segment addr 0x%lx size 0x%lx offset 0x%lx filesize 0x%lx\n",
 363                                 new->s_dstaddr, new->s_memsz, new->s_srcaddr, new->s_filesz);
 364                         break;
 365
 366                 case PAYLOAD_SEGMENT_BSS:
 367                         printk_debug("  BSS 0x%p (%d byte)\n", (void *) ntohl((u32) segment->load_addr),
 368                                  ntohl(segment->mem_len));
 369                         new = malloc(sizeof(*new));
 370                         new->s_filesz = 0;
 371                         new->s_dstaddr = ntohl((u32) segment->load_addr);
 372                         new->s_memsz = ntohl(segment->mem_len);
 373                         break;
 374
 375                 case PAYLOAD_SEGMENT_ENTRY:
 376                         printk_debug("  Entry Point 0x%p\n", (void *) ntohl((u32) segment->load_addr));
 377                         *entry =  ntohl((u32) segment->load_addr);
 378                         /* Per definition, a payload always has the entry point
 379                          * as last segment. Thus, we use the occurence of the
 380                          * entry point as break condition for the loop.
 381                          * Can we actually just look at the number of section?
 382                          */
 383                         return 1;
 384
 385                 default:
 386                         /* We found something that we don't know about. Throw
 387                          * hands into the sky and run away!
 388                          */
 389                         printk_emerg("Bad segment type %x\n", segment->type);
 390                         return -1;
 391                 }
 392
 393                 segment++;
 394
 395                 for(ptr = head->next; ptr != head; ptr = ptr->next) {
 396                         if (new->s_srcaddr < ntohl((u32) segment->load_addr))
 397                                 break;
 398                 }
 399
 400                 /* Order by stream offset */
 401                 new->next = ptr;
 402                 new->prev = ptr->prev;
 403                 ptr->prev->next = new;
 404                 ptr->prev = new;
 405
 406                 /* Order by original program header order */
 407                 new->phdr_next = head;
 408                 new->phdr_prev = head->phdr_prev;
 409                 head->phdr_prev->phdr_next  = new;
 410                 head->phdr_prev = new;
 411         }
 412
 413         return 1;
 414 }
 415
 416 static int load_self_segments(
 417         struct segment *head,
 418         struct lb_memory *mem,
 419         struct cbfs_payload *payload)
 420 {
 421         struct segment *ptr;
 422
 423         unsigned long required_bounce_size = lb_end - lb_start;
 424         for(ptr = head->next; ptr != head; ptr = ptr->next) {
 425                 if (!overlaps_coreboot(ptr)) continue;
 426                 unsigned long bounce = ptr->s_dstaddr + ptr->s_memsz - lb_start;
 427                 if (bounce > required_bounce_size) required_bounce_size = bounce;
 428         }
 429         get_bounce_buffer(mem, required_bounce_size);
 430         if (!bounce_buffer) {
 431                 printk_err("Could not find a bounce buffer...\n");
 432                 return 0;
 433         }
 434         for(ptr = head->next; ptr != head; ptr = ptr->next) {
 435                 /* Verify the memory addresses in the segment are valid */
 436                 if (!valid_area(mem, bounce_buffer, ptr->s_dstaddr, ptr->s_memsz))
 437                         return 0;
 438         }
 439         for(ptr = head->next; ptr != head; ptr = ptr->next) {
 440                 unsigned char *dest, *src;
 441                 printk_debug("Loading Segment: addr: 0x%016lx memsz: 0x%016lx filesz: 0x%016lx\n",
 442                         ptr->s_dstaddr, ptr->s_memsz, ptr->s_filesz);
 443
 444                 /* Modify the segment to load onto the bounce_buffer if necessary.
 445                  */
 446                 relocate_segment(bounce_buffer, ptr);
 447
 448                 printk_debug("Post relocation: addr: 0x%016lx memsz: 0x%016lx filesz: 0x%016lx\n",
 449                         ptr->s_dstaddr, ptr->s_memsz, ptr->s_filesz);
 450
 451                 /* Compute the boundaries of the segment */
 452                 dest = (unsigned char *)(ptr->s_dstaddr);
 453                 src = (unsigned char *)(ptr->s_srcaddr);
 454
 455                 /* Copy data from the initial buffer */
 456                 if (ptr->s_filesz) {
 457                         unsigned char *middle, *end;
 458                         size_t len;
 459                         len = ptr->s_filesz;
 460                         switch(ptr->compression) {
 461 #if CONFIG_COMPRESSED_PAYLOAD_LZMA==1
 462                                 case CBFS_COMPRESS_LZMA: {
 463                                         printk_debug("using LZMA\n");
 464                                         unsigned long ulzma(unsigned char *src, unsigned char *dst);
 465                                         len = ulzma(src, dest);
 466                                         break;
 467                                 }
 468 #endif
 469 #if CONFIG_COMPRESSED_PAYLOAD_NRV2B==1
 470                                 case CBFS_COMPRESS_NRV2B: {
 471                                         printk_debug("using NRV2B\n");
 472                                         unsigned long unrv2b(u8 *src, u8 *dst, unsigned long *ilen_p);
 473                                         unsigned long tmp;
 474                                         len = unrv2b(src, dest, &tmp);
 475                                         break;
 476                                 }
 477 #endif
 478                                 case CBFS_COMPRESS_NONE: {
 479                                         printk_debug("it's not compressed!\n");
 480                                         memcpy(dest, src, len);
 481                                         break;
 482                                 }
 483                                 default:
 484                                         printk_info( "CBFS:  Unknown compression type %d\n", ptr->compression);
 485                                         return -1;
 486                         }
 487                         end = dest + ptr->s_memsz;
 488                         middle = dest + len;
 489                         printk_spew("[ 0x%016lx, %016lx, 0x%016lx) <- %016lx\n",
 490                                 (unsigned long)dest,
 491                                 (unsigned long)middle,
 492                                 (unsigned long)end,
 493                                 (unsigned long)src);
 494
 495                         /* Zero the extra bytes between middle & end */
 496                         if (middle < end) {
 497                                 printk_debug("Clearing Segment: addr: 0x%016lx memsz: 0x%016lx\n",
 498                                         (unsigned long)middle, (unsigned long)(end - middle));
 499
 500                                 /* Zero the extra bytes */
 501                                 memset(middle, 0, end - middle);
 502                         }
 503                 }
 504         }
 505         return 1;
 506 }
 507
 508 int selfboot(struct lb_memory *mem, struct cbfs_payload *payload)
 509 {
 510         u32 entry=0;
 511         struct segment head;
 512
 513         /* Preprocess the self segments */
 514         if (!build_self_segment_list(&head, mem, payload, &entry))
 515                 goto out;
 516
 517         /* Load the segments */
 518         if (!load_self_segments(&head, mem, payload))
 519                 goto out;
 520
 521         printk_spew("Loaded segments\n");
 522
 523         /* Reset to booting from this image as late as possible */
 524         boot_successful();
 525
 526         printk_debug("Jumping to boot code at %x\n", entry);
 527         post_code(0xfe);
 528
 529         /* Jump to kernel */
 530         jmp_to_elf_entry((void*)entry, bounce_buffer, bounce_size);
 531         return 1;
 532
 533  out:
 534         return 0;
 535 }
 536