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 get_bounce_buffer(struct lb_memory *mem)
  96 {
  97         unsigned long lb_size;
  98         unsigned long mem_entries;
  99         unsigned long buffer;
 100         int i;
 101         lb_size = (unsigned long)(&_eram_seg - &_ram_seg);
 102         /* Double coreboot size so I have somewhere to place a copy to return to */
 103         lb_size = lb_size + lb_size;
 104         mem_entries = (mem->size - sizeof(*mem))/sizeof(mem->map[0]);
 105         buffer = 0;
 106         for(i = 0; i < mem_entries; i++) {
 107                 unsigned long mstart, mend;
 108                 unsigned long msize;
 109                 unsigned long tbuffer;
 110                 if (mem->map[i].type != LB_MEM_RAM)
 111                         continue;
 112                 if (unpack_lb64(mem->map[i].start) > MAX_ADDR)
 113                         continue;
 114                 if (unpack_lb64(mem->map[i].size) < lb_size)
 115                         continue;
 116                 mstart = unpack_lb64(mem->map[i].start);
 117                 msize = MAX_ADDR - mstart +1;
 118                 if (msize > unpack_lb64(mem->map[i].size))
 119                         msize = unpack_lb64(mem->map[i].size);
 120                 mend = mstart + msize;
 121                 tbuffer = mend - lb_size;
 122                 if (tbuffer < buffer)
 123                         continue;
 124                 buffer = tbuffer;
 125         }
 126         return buffer;
 127 }
 128
 129 static int valid_area(struct lb_memory *mem, unsigned long buffer,
 130         unsigned long start, unsigned long len)
 131 {
 132         /* Check through all of the memory segments and ensure
 133          * the segment that was passed in is completely contained
 134          * in RAM.
 135          */
 136         int i;
 137         unsigned long end = start + len;
 138         unsigned long mem_entries = (mem->size - sizeof(*mem))/sizeof(mem->map[0]);
 139
 140         /* See if I conflict with the bounce buffer */
 141         if (end >= buffer) {
 142                 return 0;
 143         }
 144
 145         /* Walk through the table of valid memory ranges and see if I
 146          * have a match.
 147          */
 148         for(i = 0; i < mem_entries; i++) {
 149                 uint64_t mstart, mend;
 150                 uint32_t mtype;
 151                 mtype = mem->map[i].type;
 152                 mstart = unpack_lb64(mem->map[i].start);
 153                 mend = mstart + unpack_lb64(mem->map[i].size);
 154                 if ((mtype == LB_MEM_RAM) && (start < mend) && (end > mstart)) {
 155                         break;
 156                 }
 157                 if ((mtype == LB_MEM_TABLE) && (start < mend) && (end > mstart)) {
 158                         printk_err("Payload is overwriting Coreboot tables.\n");
 159                         break;
 160                 }
 161         }
 162         if (i == mem_entries) {
 163                 printk_err("No matching ram area found for range:\n");
 164                 printk_err("  [0x%016lx, 0x%016lx)\n", start, end);
 165                 printk_err("Ram areas\n");
 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                         printk_err("  [0x%016lx, 0x%016lx) %s\n",
 173                                 (unsigned long)mstart,
 174                                 (unsigned long)mend,
 175                                 (mtype == LB_MEM_RAM)?"RAM":"Reserved");
 176
 177                 }
 178                 return 0;
 179         }
 180         return 1;
 181 }
 182
 183 static void relocate_segment(unsigned long buffer, struct segment *seg)
 184 {
 185         /* Modify all segments that want to load onto coreboot
 186          * to load onto the bounce buffer instead.
 187          */
 188         unsigned long lb_start = (unsigned long)&_ram_seg;
 189         unsigned long lb_end = (unsigned long)&_eram_seg;
 190         unsigned long start, middle, end;
 191
 192         printk_spew("lb: [0x%016lx, 0x%016lx)\n",
 193                 lb_start, lb_end);
 194
 195         start = seg->s_dstaddr;
 196         middle = start + seg->s_filesz;
 197         end = start + seg->s_memsz;
 198         /* I don't conflict with coreboot so get out of here */
 199         if ((end <= lb_start) || (start >= lb_end))
 200                 return;
 201
 202         printk_spew("segment: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 203                 start, middle, end);
 204
 205         if (seg->compression == CBFS_COMPRESS_NONE) {
 206                 /* Slice off a piece at the beginning
 207                  * that doesn't conflict with coreboot.
 208                  */
 209                 if (start < lb_start) {
 210                         struct segment *new;
 211                         unsigned long len = lb_start - start;
 212                         new = malloc(sizeof(*new));
 213                         *new = *seg;
 214                         new->s_memsz = len;
 215                         seg->s_memsz -= len;
 216                         seg->s_dstaddr += len;
 217                         seg->s_srcaddr += len;
 218                         if (seg->s_filesz > len) {
 219                                 new->s_filesz = len;
 220                                 seg->s_filesz -= len;
 221                         } else {
 222                                 seg->s_filesz = 0;
 223                         }
 224
 225                         /* Order by stream offset */
 226                         new->next = seg;
 227                         new->prev = seg->prev;
 228                         seg->prev->next = new;
 229                         seg->prev = new;
 230                         /* Order by original program header order */
 231                         new->phdr_next = seg;
 232                         new->phdr_prev = seg->phdr_prev;
 233                         seg->phdr_prev->phdr_next = new;
 234                         seg->phdr_prev = new;
 235
 236                         /* compute the new value of start */
 237                         start = seg->s_dstaddr;
 238
 239                         printk_spew("   early: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 240                                 new->s_dstaddr,
 241                                 new->s_dstaddr + new->s_filesz,
 242                                 new->s_dstaddr + new->s_memsz);
 243                         }
 244
 245                         /* Slice off a piece at the end
 246                  * that doesn't conflict with coreboot
 247                  */
 248                 if (end > lb_end) {
 249                         unsigned long len = lb_end - start;
 250                         struct segment *new;
 251                         new = malloc(sizeof(*new));
 252                         *new = *seg;
 253                         seg->s_memsz = len;
 254                         new->s_memsz -= len;
 255                         new->s_dstaddr += len;
 256                         new->s_srcaddr += len;
 257                         if (seg->s_filesz > len) {
 258                                 seg->s_filesz = len;
 259                                 new->s_filesz -= len;
 260                         } else {
 261                                 new->s_filesz = 0;
 262                         }
 263                         /* Order by stream offset */
 264                         new->next = seg->next;
 265                         new->prev = seg;
 266                         seg->next->prev = new;
 267                         seg->next = new;
 268                         /* Order by original program header order */
 269                         new->phdr_next = seg->phdr_next;
 270                         new->phdr_prev = seg;
 271                         seg->phdr_next->phdr_prev = new;
 272                         seg->phdr_next = new;
 273
 274                         /* compute the new value of end */
 275                         end = start + len;
 276
 277                         printk_spew("   late: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 278                                 new->s_dstaddr,
 279                                 new->s_dstaddr + new->s_filesz,
 280                                 new->s_dstaddr + new->s_memsz);
 281
 282                 }
 283         }
 284         /* Now retarget this segment onto the bounce buffer */
 285         /* sort of explanation: the buffer is a 1:1 mapping to coreboot.
 286          * so you will make the dstaddr be this buffer, and it will get copied
 287          * later to where coreboot lives.
 288          */
 289         seg->s_dstaddr = buffer + (seg->s_dstaddr - lb_start);
 290
 291         printk_spew(" bounce: [0x%016lx, 0x%016lx, 0x%016lx)\n",
 292                 seg->s_dstaddr,
 293                 seg->s_dstaddr + seg->s_filesz,
 294                 seg->s_dstaddr + seg->s_memsz);
 295 }
 296
 297
 298 static int build_self_segment_list(
 299         struct segment *head,
 300         unsigned long bounce_buffer, struct lb_memory *mem,
 301         struct cbfs_payload *payload, u32 *entry)
 302 {
 303         struct segment *new;
 304         struct segment *ptr;
 305         u8 *data;
 306         int datasize;
 307         struct cbfs_payload_segment *segment, *first_segment;
 308         memset(head, 0, sizeof(*head));
 309         head->phdr_next = head->phdr_prev = head;
 310         head->next = head->prev = head;
 311         first_segment = segment = &payload->segments;
 312
 313         while(1) {
 314                 printk_debug("Segment %p\n", segment);
 315                 switch(segment->type) {
 316                 default: printk_emerg("Bad segment type %x\n", segment->type);
 317                         return -1;
 318                 case PAYLOAD_SEGMENT_PARAMS:
 319                         printk_info("found param section\n");
 320                         segment++;
 321                         continue;
 322                 case PAYLOAD_SEGMENT_CODE:
 323                 case PAYLOAD_SEGMENT_DATA:
 324                         printk_info( "%s: ", segment->type == PAYLOAD_SEGMENT_CODE ?
 325                                 "code" : "data");
 326                 new = malloc(sizeof(*new));
 327                 new->s_dstaddr = ntohl((u32) segment->load_addr);
 328                 new->s_memsz = ntohl(segment->mem_len);
 329                 new->compression = ntohl(segment->compression);
 330
 331                 datasize = ntohl(segment->len);
 332                 new->s_srcaddr = (u32) ((unsigned char *) first_segment) + ntohl(segment->offset);
 333                 new->s_filesz = ntohl(segment->len);
 334                 printk_debug("New segment dstaddr 0x%lx memsize 0x%lx srcaddr 0x%lx filesize 0x%lx\n",
 335                         new->s_dstaddr, new->s_memsz, new->s_srcaddr, new->s_filesz);
 336                 /* Clean up the values */
 337                 if (new->s_filesz > new->s_memsz)  {
 338                         new->s_filesz = new->s_memsz;
 339                 }
 340                 printk_debug("(cleaned up) New segment addr 0x%lx size 0x%lx offset 0x%lx filesize 0x%lx\n",
 341                         new->s_dstaddr, new->s_memsz, new->s_srcaddr, new->s_filesz);
 342                 break;
 343                 case PAYLOAD_SEGMENT_BSS:
 344                         printk_info("BSS %p/%d\n", (void *) ntohl((u32) segment->load_addr),
 345                                  ntohl(segment->mem_len));
 346                         new = malloc(sizeof(*new));
 347                         new->s_filesz = 0;
 348                         new->s_dstaddr = ntohl((u32) segment->load_addr);
 349                         new->s_memsz = ntohl(segment->mem_len);
 350
 351                         break;
 352
 353                 case PAYLOAD_SEGMENT_ENTRY:
 354                         printk_info("Entry %p\n", (void *) ntohl((u32) segment->load_addr));
 355                         *entry =  (void *) ntohl((u32) segment->load_addr);
 356                         return 1;
 357                 }
 358                 segment++;
 359                 for(ptr = head->next; ptr != head; ptr = ptr->next) {
 360                         if (new->s_srcaddr < ntohl((u32) segment->load_addr))
 361                                 break;
 362                 }
 363                 /* Order by stream offset */
 364                 new->next = ptr;
 365                 new->prev = ptr->prev;
 366                 ptr->prev->next = new;
 367                 ptr->prev = new;
 368                 /* Order by original program header order */
 369                 new->phdr_next = head;
 370                 new->phdr_prev = head->phdr_prev;
 371                 head->phdr_prev->phdr_next  = new;
 372                 head->phdr_prev = new;
 373
 374                 /* Verify the memory addresses in the segment are valid */
 375                 if (!valid_area(mem, bounce_buffer, new->s_dstaddr, new->s_memsz))
 376                         goto out;
 377
 378                 /* Modify the segment to load onto the bounce_buffer if necessary.
 379                  */
 380                 relocate_segment(bounce_buffer, new);
 381         }
 382         return 1;
 383  out:
 384         return 0;
 385 }
 386
 387 static int load_self_segments(
 388         struct segment *head, struct cbfs_payload *payload)
 389 {
 390         unsigned long offset;
 391         struct segment *ptr;
 392
 393         offset = 0;
 394         for(ptr = head->next; ptr != head; ptr = ptr->next) {
 395                 unsigned long skip_bytes, read_bytes;
 396                 unsigned char *dest, *middle, *end, *src;
 397                 byte_offset_t result;
 398                 printk_debug("Loading Segment: addr: 0x%016lx memsz: 0x%016lx filesz: 0x%016lx\n",
 399                         ptr->s_dstaddr, ptr->s_memsz, ptr->s_filesz);
 400
 401                 /* Compute the boundaries of the segment */
 402                 dest = (unsigned char *)(ptr->s_dstaddr);
 403                 src = ptr->s_srcaddr;
 404
 405                 /* Copy data from the initial buffer */
 406                 if (ptr->s_filesz) {
 407                         size_t len;
 408                         len = ptr->s_filesz;
 409                         switch(ptr->compression) {
 410 #if CONFIG_COMPRESSED_PAYLOAD_LZMA==1
 411                                 case CBFS_COMPRESS_LZMA: {
 412                                         printk_debug("using LZMA\n");
 413                                         unsigned long ulzma(unsigned char *src, unsigned char *dst);
 414                                         len = ulzma(src, dest);
 415                                         break;
 416                                 }
 417 #endif
 418 #if CONFIG_COMPRESSED_PAYLOAD_NRV2B==1
 419                                 case CBFS_COMPRESS_NRV2B: {
 420                                         printk_debug("using NRV2B\n");
 421                                         unsigned long unrv2b(u8 *src, u8 *dst, unsigned long *ilen_p);
 422                                         unsigned long tmp;
 423                                         len = unrv2b(src, dest, &tmp);
 424                                         break;
 425                                 }
 426 #endif
 427                                 case CBFS_COMPRESS_NONE: {
 428                                         printk_debug("it's not compressed!\n");
 429                                         memcpy(dest, src, len);
 430                                         break;
 431                                 }
 432                                 default:
 433                                         printk_info( "CBFS:  Unknown compression type %d\n", ptr->compression);
 434                                         return -1;
 435                         }
 436                         end = dest + ptr->s_memsz;
 437                         middle = dest + len;
 438                         printk_spew("[ 0x%016lx, %016lx, 0x%016lx) <- %016lx\n",
 439                                 (unsigned long)dest,
 440                                 (unsigned long)middle,
 441                                 (unsigned long)end,
 442                                 (unsigned long)src);
 443                 }
 444                 /* Zero the extra bytes between middle & end */
 445                 if (middle < end) {
 446                         printk_debug("Clearing Segment: addr: 0x%016lx memsz: 0x%016lx\n",
 447                                 (unsigned long)middle, (unsigned long)(end - middle));
 448
 449                         /* Zero the extra bytes */
 450                         memset(middle, 0, end - middle);
 451                 }
 452         }
 453         return 1;
 454  out:
 455         return 0;
 456 }
 457
 458 int selfboot(struct lb_memory *mem, struct cbfs_payload *payload)
 459 {
 460         void *entry;
 461         struct segment head;
 462         unsigned long bounce_buffer;
 463
 464         /* Find a bounce buffer so I can load to coreboot's current location */
 465         bounce_buffer = get_bounce_buffer(mem);
 466         if (!bounce_buffer) {
 467                 printk_err("Could not find a bounce buffer...\n");
 468                 goto out;
 469         }
 470
 471         /* Preprocess the self segments */
 472         if (!build_self_segment_list(&head, bounce_buffer, mem, payload, &entry))
 473                 goto out;
 474
 475         /* Load the segments */
 476         if (!load_self_segments(&head, payload))
 477                 goto out;
 478
 479         printk_spew("Loaded segments\n");
 480
 481         /* Reset to booting from this image as late as possible */
 482         boot_successful();
 483
 484         printk_debug("Jumping to boot code at %p\n", entry);
 485         post_code(0xfe);
 486
 487         /* Jump to kernel */
 488         jmp_to_elf_entry(entry, bounce_buffer);
 489         return 1;
 490
 491  out:
 492         return 0;
 493 }
 494