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 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_debug("Got a payload\n");
  84
  85         selfboot(lb_mem, payload);
  86         printk_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 then 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_err("Payload is overwriting Coreboot tables.\n");
 179                         break;
 180                 }
 181         }
 182         if (i == mem_entries) {
 183                 printk_err("No matching ram area found for range:\n");
 184                 printk_err("  [0x%016lx, 0x%016lx)\n", start, end);
 185                 printk_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_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 void 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         unsigned long start, middle, end;
 220
 221         printk_spew("lb: [0x%016lx, 0x%016lx)\n",
 222                 lb_start, lb_end);
 223
 224         /* I don't conflict with coreboot so get out of here */
 225         if (!overlaps_coreboot(seg))
 226                 return;
 227
 228         start = seg->s_dstaddr;
 229         middle = start + seg->s_filesz;
 230         end = start + seg->s_memsz;
 231
 232         printk_spew("segment: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 233                 start, middle, end);
 234
 235         if (seg->compression == CBFS_COMPRESS_NONE) {
 236                 /* Slice off a piece at the beginning
 237                  * that doesn't conflict with coreboot.
 238                  */
 239                 if (start < lb_start) {
 240                         struct segment *new;
 241                         unsigned long len = lb_start - start;
 242                         new = malloc(sizeof(*new));
 243                         *new = *seg;
 244                         new->s_memsz = len;
 245                         seg->s_memsz -= len;
 246                         seg->s_dstaddr += len;
 247                         seg->s_srcaddr += len;
 248                         if (seg->s_filesz > len) {
 249                                 new->s_filesz = len;
 250                                 seg->s_filesz -= len;
 251                         } else {
 252                                 seg->s_filesz = 0;
 253                         }
 254
 255                         /* Order by stream offset */
 256                         new->next = seg;
 257                         new->prev = seg->prev;
 258                         seg->prev->next = new;
 259                         seg->prev = new;
 260                         /* Order by original program header order */
 261                         new->phdr_next = seg;
 262                         new->phdr_prev = seg->phdr_prev;
 263                         seg->phdr_prev->phdr_next = new;
 264                         seg->phdr_prev = new;
 265
 266                         /* compute the new value of start */
 267                         start = seg->s_dstaddr;
 268
 269                         printk_spew("   early: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 270                                 new->s_dstaddr,
 271                                 new->s_dstaddr + new->s_filesz,
 272                                 new->s_dstaddr + new->s_memsz);
 273                 }
 274
 275                 /* Slice off a piece at the end
 276                  * that doesn't conflict with coreboot
 277                  */
 278                 if (end > lb_end) {
 279                         unsigned long len = lb_end - start;
 280                         struct segment *new;
 281                         new = malloc(sizeof(*new));
 282                         *new = *seg;
 283                         seg->s_memsz = len;
 284                         new->s_memsz -= len;
 285                         new->s_dstaddr += len;
 286                         new->s_srcaddr += len;
 287                         if (seg->s_filesz > len) {
 288                                 seg->s_filesz = len;
 289                                 new->s_filesz -= len;
 290                         } else {
 291                                 new->s_filesz = 0;
 292                         }
 293                         /* Order by stream offset */
 294                         new->next = seg->next;
 295                         new->prev = seg;
 296                         seg->next->prev = new;
 297                         seg->next = new;
 298                         /* Order by original program header order */
 299                         new->phdr_next = seg->phdr_next;
 300                         new->phdr_prev = seg;
 301                         seg->phdr_next->phdr_prev = new;
 302                         seg->phdr_next = new;
 303
 304                         printk_spew("   late: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 305                                 new->s_dstaddr,
 306                                 new->s_dstaddr + new->s_filesz,
 307                                 new->s_dstaddr + new->s_memsz);
 308                 }
 309         }
 310
 311         /* Now retarget this segment onto the bounce buffer */
 312         /* sort of explanation: the buffer is a 1:1 mapping to coreboot.
 313          * so you will make the dstaddr be this buffer, and it will get copied
 314          * later to where coreboot lives.
 315          */
 316         seg->s_dstaddr = buffer + (seg->s_dstaddr - lb_start);
 317
 318         printk_spew(" bounce: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 319                 seg->s_dstaddr,
 320                 seg->s_dstaddr + seg->s_filesz,
 321                 seg->s_dstaddr + seg->s_memsz);
 322 }
 323
 324
 325 static int build_self_segment_list(
 326         struct segment *head,
 327         struct lb_memory *mem,
 328         struct cbfs_payload *payload, u32 *entry)
 329 {
 330         struct segment *new;
 331         struct segment *ptr;
 332         struct cbfs_payload_segment *segment, *first_segment;
 333         memset(head, 0, sizeof(*head));
 334         head->phdr_next = head->phdr_prev = head;
 335         head->next = head->prev = head;
 336         first_segment = segment = &payload->segments;
 337
 338         while(1) {
 339                 printk_debug("Loading segment from rom address 0x%p\n", segment);
 340                 switch(segment->type) {
 341                 case PAYLOAD_SEGMENT_PARAMS:
 342                         printk_debug("  parameter section (skipped)\n");
 343                         segment++;
 344                         continue;
 345
 346                 case PAYLOAD_SEGMENT_CODE:
 347                 case PAYLOAD_SEGMENT_DATA:
 348                         printk_debug("  %s (compression=%x)\n",
 349                                         segment->type == PAYLOAD_SEGMENT_CODE ?  "code" : "data",
 350                                         ntohl(segment->compression));
 351                         new = malloc(sizeof(*new));
 352                         new->s_dstaddr = ntohl((u32) segment->load_addr);
 353                         new->s_memsz = ntohl(segment->mem_len);
 354                         new->compression = ntohl(segment->compression);
 355
 356                         new->s_srcaddr = (u32) ((unsigned char *) first_segment) + ntohl(segment->offset);
 357                         new->s_filesz = ntohl(segment->len);
 358                         printk_debug("  New segment dstaddr 0x%lx memsize 0x%lx srcaddr 0x%lx filesize 0x%lx\n",
 359                                 new->s_dstaddr, new->s_memsz, new->s_srcaddr, new->s_filesz);
 360                         /* Clean up the values */
 361                         if (new->s_filesz > new->s_memsz)  {
 362                                 new->s_filesz = new->s_memsz;
 363                         }
 364                         printk_debug("  (cleaned up) New segment addr 0x%lx size 0x%lx offset 0x%lx filesize 0x%lx\n",
 365                                 new->s_dstaddr, new->s_memsz, new->s_srcaddr, new->s_filesz);
 366                         break;
 367
 368                 case PAYLOAD_SEGMENT_BSS:
 369                         printk_debug("  BSS 0x%p (%d byte)\n", (void *) ntohl((u32) segment->load_addr),
 370                                  ntohl(segment->mem_len));
 371                         new = malloc(sizeof(*new));
 372                         new->s_filesz = 0;
 373                         new->s_dstaddr = ntohl((u32) segment->load_addr);
 374                         new->s_memsz = ntohl(segment->mem_len);
 375                         break;
 376
 377                 case PAYLOAD_SEGMENT_ENTRY:
 378                         printk_debug("  Entry Point 0x%p\n", (void *) ntohl((u32) segment->load_addr));
 379                         *entry =  ntohl((u32) segment->load_addr);
 380                         /* Per definition, a payload always has the entry point
 381                          * as last segment. Thus, we use the occurence of the
 382                          * entry point as break condition for the loop.
 383                          * Can we actually just look at the number of section?
 384                          */
 385                         return 1;
 386
 387                 default:
 388                         /* We found something that we don't know about. Throw
 389                          * hands into the sky and run away!
 390                          */
 391                         printk_emerg("Bad segment type %x\n", segment->type);
 392                         return -1;
 393                 }
 394
 395                 segment++;
 396
 397                 for(ptr = head->next; ptr != head; ptr = ptr->next) {
 398                         if (new->s_srcaddr < ntohl((u32) segment->load_addr))
 399                                 break;
 400                 }
 401
 402                 /* Order by stream offset */
 403                 new->next = ptr;
 404                 new->prev = ptr->prev;
 405                 ptr->prev->next = new;
 406                 ptr->prev = new;
 407
 408                 /* Order by original program header order */
 409                 new->phdr_next = head;
 410                 new->phdr_prev = head->phdr_prev;
 411                 head->phdr_prev->phdr_next  = new;
 412                 head->phdr_prev = new;
 413         }
 414
 415         return 1;
 416 }
 417
 418 static int load_self_segments(
 419         struct segment *head,
 420         struct lb_memory *mem,
 421         struct cbfs_payload *payload)
 422 {
 423         struct segment *ptr;
 424
 425         unsigned long required_bounce_size = lb_end - lb_start;
 426         for(ptr = head->next; ptr != head; ptr = ptr->next) {
 427                 if (!overlaps_coreboot(ptr)) continue;
 428                 unsigned long bounce = ptr->s_dstaddr + ptr->s_memsz - lb_start;
 429                 if (bounce > required_bounce_size)
 430                         required_bounce_size = bounce;
 431         }
 432         get_bounce_buffer(mem, required_bounce_size);
 433         if (!bounce_buffer) {
 434                 printk_err("Could not find a bounce buffer...\n");
 435                 return 0;
 436         }
 437         for(ptr = head->next; ptr != head; ptr = ptr->next) {
 438                 /* Verify the memory addresses in the segment are valid */
 439                 if (!valid_area(mem, bounce_buffer, ptr->s_dstaddr, ptr->s_memsz))
 440                         return 0;
 441         }
 442         for(ptr = head->next; ptr != head; ptr = ptr->next) {
 443                 unsigned char *dest, *src;
 444                 printk_debug("Loading Segment: addr: 0x%016lx memsz: 0x%016lx filesz: 0x%016lx\n",
 445                         ptr->s_dstaddr, ptr->s_memsz, ptr->s_filesz);
 446
 447                 /* Modify the segment to load onto the bounce_buffer if necessary.
 448                  */
 449                 relocate_segment(bounce_buffer, ptr);
 450
 451                 printk_debug("Post relocation: addr: 0x%016lx memsz: 0x%016lx filesz: 0x%016lx\n",
 452                         ptr->s_dstaddr, ptr->s_memsz, ptr->s_filesz);
 453
 454                 /* Compute the boundaries of the segment */
 455                 dest = (unsigned char *)(ptr->s_dstaddr);
 456                 src = (unsigned char *)(ptr->s_srcaddr);
 457
 458                 /* Copy data from the initial buffer */
 459                 if (ptr->s_filesz) {
 460                         unsigned char *middle, *end;
 461                         size_t len;
 462                         len = ptr->s_filesz;
 463                         switch(ptr->compression) {
 464                                 case CBFS_COMPRESS_LZMA: {
 465                                         printk_debug("using LZMA\n");
 466                                         unsigned long ulzma(unsigned char *src, unsigned char *dst);
 467                                         len = ulzma(src, dest);
 468                                         break;
 469                                 }
 470 #if CONFIG_COMPRESSED_PAYLOAD_NRV2B==1
 471                                 case CBFS_COMPRESS_NRV2B: {
 472                                         printk_debug("using NRV2B\n");
 473                                         unsigned long unrv2b(u8 *src, u8 *dst, unsigned long *ilen_p);
 474                                         unsigned long tmp;
 475                                         len = unrv2b(src, dest, &tmp);
 476                                         break;
 477                                 }
 478 #endif
 479                                 case CBFS_COMPRESS_NONE: {
 480                                         printk_debug("it's not compressed!\n");
 481                                         memcpy(dest, src, len);
 482                                         break;
 483                                 }
 484                                 default:
 485                                         printk_info( "CBFS:  Unknown compression type %d\n", ptr->compression);
 486                                         return -1;
 487                         }
 488                         end = dest + ptr->s_memsz;
 489                         middle = dest + len;
 490                         printk_spew("[ 0x%016lx, %016lx, 0x%016lx) <- %016lx\n",
 491                                 (unsigned long)dest,
 492                                 (unsigned long)middle,
 493                                 (unsigned long)end,
 494                                 (unsigned long)src);
 495
 496                         /* Zero the extra bytes between middle & end */
 497                         if (middle < end) {
 498                                 printk_debug("Clearing Segment: addr: 0x%016lx memsz: 0x%016lx\n",
 499                                         (unsigned long)middle, (unsigned long)(end - middle));
 500
 501                                 /* Zero the extra bytes */
 502                                 memset(middle, 0, end - middle);
 503                         }
 504                 }
 505         }
 506         return 1;
 507 }
 508
 509 static int selfboot(struct lb_memory *mem, struct cbfs_payload *payload)
 510 {
 511         u32 entry=0;
 512         struct segment head;
 513
 514         /* Preprocess the self segments */
 515         if (!build_self_segment_list(&head, mem, payload, &entry))
 516                 goto out;
 517
 518         /* Load the segments */
 519         if (!load_self_segments(&head, mem, payload))
 520                 goto out;
 521
 522         printk_spew("Loaded segments\n");
 523
 524         /* Reset to booting from this image as late as possible */
 525         boot_successful();
 526
 527         printk_debug("Jumping to boot code at %x\n", entry);
 528         post_code(0xfe);
 529
 530         /* Jump to kernel */
 531         jmp_to_elf_entry((void*)entry, bounce_buffer, bounce_size);
 532         return 1;
 533
 534  out:
 535         return 0;
 536 }
 537