1 // SPDX-License-Identifier: GPL-2.0-only 2 3 /* ----------------------------------------------------------------------- 4 * 5 * Copyright 2011 Intel Corporation; author Matt Fleming 6 * 7 * ----------------------------------------------------------------------- */ 8 9 #include <linux/efi.h> 10 #include <linux/pci.h> 11 #include <linux/stddef.h> 12 13 #include <asm/efi.h> 14 #include <asm/e820/types.h> 15 #include <asm/setup.h> 16 #include <asm/desc.h> 17 #include <asm/boot.h> 18 19 #include "efistub.h" 20 21 /* Maximum physical address for 64-bit kernel with 4-level paging */ 22 #define MAXMEM_X86_64_4LEVEL (1ull << 46) 23 24 const efi_system_table_t *efi_system_table; 25 extern u32 image_offset; 26 static efi_loaded_image_t *image = NULL; 27 28 static efi_status_t 29 preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom) 30 { 31 struct pci_setup_rom *rom = NULL; 32 efi_status_t status; 33 unsigned long size; 34 uint64_t romsize; 35 void *romimage; 36 37 /* 38 * Some firmware images contain EFI function pointers at the place where 39 * the romimage and romsize fields are supposed to be. Typically the EFI 40 * code is mapped at high addresses, translating to an unrealistically 41 * large romsize. The UEFI spec limits the size of option ROMs to 16 42 * MiB so we reject any ROMs over 16 MiB in size to catch this. 43 */ 44 romimage = efi_table_attr(pci, romimage); 45 romsize = efi_table_attr(pci, romsize); 46 if (!romimage || !romsize || romsize > SZ_16M) 47 return EFI_INVALID_PARAMETER; 48 49 size = romsize + sizeof(*rom); 50 51 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 52 (void **)&rom); 53 if (status != EFI_SUCCESS) { 54 efi_err("Failed to allocate memory for 'rom'\n"); 55 return status; 56 } 57 58 memset(rom, 0, sizeof(*rom)); 59 60 rom->data.type = SETUP_PCI; 61 rom->data.len = size - sizeof(struct setup_data); 62 rom->data.next = 0; 63 rom->pcilen = pci->romsize; 64 *__rom = rom; 65 66 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16, 67 PCI_VENDOR_ID, 1, &rom->vendor); 68 69 if (status != EFI_SUCCESS) { 70 efi_err("Failed to read rom->vendor\n"); 71 goto free_struct; 72 } 73 74 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16, 75 PCI_DEVICE_ID, 1, &rom->devid); 76 77 if (status != EFI_SUCCESS) { 78 efi_err("Failed to read rom->devid\n"); 79 goto free_struct; 80 } 81 82 status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus, 83 &rom->device, &rom->function); 84 85 if (status != EFI_SUCCESS) 86 goto free_struct; 87 88 memcpy(rom->romdata, romimage, romsize); 89 return status; 90 91 free_struct: 92 efi_bs_call(free_pool, rom); 93 return status; 94 } 95 96 /* 97 * There's no way to return an informative status from this function, 98 * because any analysis (and printing of error messages) needs to be 99 * done directly at the EFI function call-site. 100 * 101 * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we 102 * just didn't find any PCI devices, but there's no way to tell outside 103 * the context of the call. 104 */ 105 static void setup_efi_pci(struct boot_params *params) 106 { 107 efi_status_t status; 108 void **pci_handle = NULL; 109 efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID; 110 unsigned long size = 0; 111 struct setup_data *data; 112 efi_handle_t h; 113 int i; 114 115 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 116 &pci_proto, NULL, &size, pci_handle); 117 118 if (status == EFI_BUFFER_TOO_SMALL) { 119 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 120 (void **)&pci_handle); 121 122 if (status != EFI_SUCCESS) { 123 efi_err("Failed to allocate memory for 'pci_handle'\n"); 124 return; 125 } 126 127 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 128 &pci_proto, NULL, &size, pci_handle); 129 } 130 131 if (status != EFI_SUCCESS) 132 goto free_handle; 133 134 data = (struct setup_data *)(unsigned long)params->hdr.setup_data; 135 136 while (data && data->next) 137 data = (struct setup_data *)(unsigned long)data->next; 138 139 for_each_efi_handle(h, pci_handle, size, i) { 140 efi_pci_io_protocol_t *pci = NULL; 141 struct pci_setup_rom *rom; 142 143 status = efi_bs_call(handle_protocol, h, &pci_proto, 144 (void **)&pci); 145 if (status != EFI_SUCCESS || !pci) 146 continue; 147 148 status = preserve_pci_rom_image(pci, &rom); 149 if (status != EFI_SUCCESS) 150 continue; 151 152 if (data) 153 data->next = (unsigned long)rom; 154 else 155 params->hdr.setup_data = (unsigned long)rom; 156 157 data = (struct setup_data *)rom; 158 } 159 160 free_handle: 161 efi_bs_call(free_pool, pci_handle); 162 } 163 164 static void retrieve_apple_device_properties(struct boot_params *boot_params) 165 { 166 efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID; 167 struct setup_data *data, *new; 168 efi_status_t status; 169 u32 size = 0; 170 apple_properties_protocol_t *p; 171 172 status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p); 173 if (status != EFI_SUCCESS) 174 return; 175 176 if (efi_table_attr(p, version) != 0x10000) { 177 efi_err("Unsupported properties proto version\n"); 178 return; 179 } 180 181 efi_call_proto(p, get_all, NULL, &size); 182 if (!size) 183 return; 184 185 do { 186 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, 187 size + sizeof(struct setup_data), 188 (void **)&new); 189 if (status != EFI_SUCCESS) { 190 efi_err("Failed to allocate memory for 'properties'\n"); 191 return; 192 } 193 194 status = efi_call_proto(p, get_all, new->data, &size); 195 196 if (status == EFI_BUFFER_TOO_SMALL) 197 efi_bs_call(free_pool, new); 198 } while (status == EFI_BUFFER_TOO_SMALL); 199 200 new->type = SETUP_APPLE_PROPERTIES; 201 new->len = size; 202 new->next = 0; 203 204 data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data; 205 if (!data) { 206 boot_params->hdr.setup_data = (unsigned long)new; 207 } else { 208 while (data->next) 209 data = (struct setup_data *)(unsigned long)data->next; 210 data->next = (unsigned long)new; 211 } 212 } 213 214 static const efi_char16_t apple[] = L"Apple"; 215 216 static void setup_quirks(struct boot_params *boot_params) 217 { 218 efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long) 219 efi_table_attr(efi_system_table, fw_vendor); 220 221 if (!memcmp(fw_vendor, apple, sizeof(apple))) { 222 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES)) 223 retrieve_apple_device_properties(boot_params); 224 } 225 } 226 227 /* 228 * See if we have Universal Graphics Adapter (UGA) protocol 229 */ 230 static efi_status_t 231 setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size) 232 { 233 efi_status_t status; 234 u32 width, height; 235 void **uga_handle = NULL; 236 efi_uga_draw_protocol_t *uga = NULL, *first_uga; 237 efi_handle_t handle; 238 int i; 239 240 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 241 (void **)&uga_handle); 242 if (status != EFI_SUCCESS) 243 return status; 244 245 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 246 uga_proto, NULL, &size, uga_handle); 247 if (status != EFI_SUCCESS) 248 goto free_handle; 249 250 height = 0; 251 width = 0; 252 253 first_uga = NULL; 254 for_each_efi_handle(handle, uga_handle, size, i) { 255 efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID; 256 u32 w, h, depth, refresh; 257 void *pciio; 258 259 status = efi_bs_call(handle_protocol, handle, uga_proto, 260 (void **)&uga); 261 if (status != EFI_SUCCESS) 262 continue; 263 264 pciio = NULL; 265 efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio); 266 267 status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh); 268 if (status == EFI_SUCCESS && (!first_uga || pciio)) { 269 width = w; 270 height = h; 271 272 /* 273 * Once we've found a UGA supporting PCIIO, 274 * don't bother looking any further. 275 */ 276 if (pciio) 277 break; 278 279 first_uga = uga; 280 } 281 } 282 283 if (!width && !height) 284 goto free_handle; 285 286 /* EFI framebuffer */ 287 si->orig_video_isVGA = VIDEO_TYPE_EFI; 288 289 si->lfb_depth = 32; 290 si->lfb_width = width; 291 si->lfb_height = height; 292 293 si->red_size = 8; 294 si->red_pos = 16; 295 si->green_size = 8; 296 si->green_pos = 8; 297 si->blue_size = 8; 298 si->blue_pos = 0; 299 si->rsvd_size = 8; 300 si->rsvd_pos = 24; 301 302 free_handle: 303 efi_bs_call(free_pool, uga_handle); 304 305 return status; 306 } 307 308 static void setup_graphics(struct boot_params *boot_params) 309 { 310 efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID; 311 struct screen_info *si; 312 efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID; 313 efi_status_t status; 314 unsigned long size; 315 void **gop_handle = NULL; 316 void **uga_handle = NULL; 317 318 si = &boot_params->screen_info; 319 memset(si, 0, sizeof(*si)); 320 321 size = 0; 322 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 323 &graphics_proto, NULL, &size, gop_handle); 324 if (status == EFI_BUFFER_TOO_SMALL) 325 status = efi_setup_gop(si, &graphics_proto, size); 326 327 if (status != EFI_SUCCESS) { 328 size = 0; 329 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 330 &uga_proto, NULL, &size, uga_handle); 331 if (status == EFI_BUFFER_TOO_SMALL) 332 setup_uga(si, &uga_proto, size); 333 } 334 } 335 336 337 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status) 338 { 339 efi_bs_call(exit, handle, status, 0, NULL); 340 for(;;) 341 asm("hlt"); 342 } 343 344 void startup_32(struct boot_params *boot_params); 345 346 void __noreturn efi_stub_entry(efi_handle_t handle, 347 efi_system_table_t *sys_table_arg, 348 struct boot_params *boot_params); 349 350 /* 351 * Because the x86 boot code expects to be passed a boot_params we 352 * need to create one ourselves (usually the bootloader would create 353 * one for us). 354 */ 355 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, 356 efi_system_table_t *sys_table_arg) 357 { 358 struct boot_params *boot_params; 359 struct setup_header *hdr; 360 void *image_base; 361 efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID; 362 int options_size = 0; 363 efi_status_t status; 364 char *cmdline_ptr; 365 366 efi_system_table = sys_table_arg; 367 368 /* Check if we were booted by the EFI firmware */ 369 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) 370 efi_exit(handle, EFI_INVALID_PARAMETER); 371 372 status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image); 373 if (status != EFI_SUCCESS) { 374 efi_err("Failed to get handle for LOADED_IMAGE_PROTOCOL\n"); 375 efi_exit(handle, status); 376 } 377 378 image_base = efi_table_attr(image, image_base); 379 image_offset = (void *)startup_32 - image_base; 380 381 status = efi_allocate_pages(sizeof(struct boot_params), 382 (unsigned long *)&boot_params, ULONG_MAX); 383 if (status != EFI_SUCCESS) { 384 efi_err("Failed to allocate lowmem for boot params\n"); 385 efi_exit(handle, status); 386 } 387 388 memset(boot_params, 0x0, sizeof(struct boot_params)); 389 390 hdr = &boot_params->hdr; 391 392 /* Copy the setup header from the second sector to boot_params */ 393 memcpy(&hdr->jump, image_base + 512, 394 sizeof(struct setup_header) - offsetof(struct setup_header, jump)); 395 396 /* 397 * Fill out some of the header fields ourselves because the 398 * EFI firmware loader doesn't load the first sector. 399 */ 400 hdr->root_flags = 1; 401 hdr->vid_mode = 0xffff; 402 hdr->boot_flag = 0xAA55; 403 404 hdr->type_of_loader = 0x21; 405 406 /* Convert unicode cmdline to ascii */ 407 cmdline_ptr = efi_convert_cmdline(image, &options_size); 408 if (!cmdline_ptr) 409 goto fail; 410 411 efi_set_u64_split((unsigned long)cmdline_ptr, 412 &hdr->cmd_line_ptr, &boot_params->ext_cmd_line_ptr); 413 414 hdr->ramdisk_image = 0; 415 hdr->ramdisk_size = 0; 416 417 efi_stub_entry(handle, sys_table_arg, boot_params); 418 /* not reached */ 419 420 fail: 421 efi_free(sizeof(struct boot_params), (unsigned long)boot_params); 422 423 efi_exit(handle, status); 424 } 425 426 static void add_e820ext(struct boot_params *params, 427 struct setup_data *e820ext, u32 nr_entries) 428 { 429 struct setup_data *data; 430 431 e820ext->type = SETUP_E820_EXT; 432 e820ext->len = nr_entries * sizeof(struct boot_e820_entry); 433 e820ext->next = 0; 434 435 data = (struct setup_data *)(unsigned long)params->hdr.setup_data; 436 437 while (data && data->next) 438 data = (struct setup_data *)(unsigned long)data->next; 439 440 if (data) 441 data->next = (unsigned long)e820ext; 442 else 443 params->hdr.setup_data = (unsigned long)e820ext; 444 } 445 446 static efi_status_t 447 setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size) 448 { 449 struct boot_e820_entry *entry = params->e820_table; 450 struct efi_info *efi = ¶ms->efi_info; 451 struct boot_e820_entry *prev = NULL; 452 u32 nr_entries; 453 u32 nr_desc; 454 int i; 455 456 nr_entries = 0; 457 nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size; 458 459 for (i = 0; i < nr_desc; i++) { 460 efi_memory_desc_t *d; 461 unsigned int e820_type = 0; 462 unsigned long m = efi->efi_memmap; 463 464 #ifdef CONFIG_X86_64 465 m |= (u64)efi->efi_memmap_hi << 32; 466 #endif 467 468 d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i); 469 switch (d->type) { 470 case EFI_RESERVED_TYPE: 471 case EFI_RUNTIME_SERVICES_CODE: 472 case EFI_RUNTIME_SERVICES_DATA: 473 case EFI_MEMORY_MAPPED_IO: 474 case EFI_MEMORY_MAPPED_IO_PORT_SPACE: 475 case EFI_PAL_CODE: 476 e820_type = E820_TYPE_RESERVED; 477 break; 478 479 case EFI_UNUSABLE_MEMORY: 480 e820_type = E820_TYPE_UNUSABLE; 481 break; 482 483 case EFI_ACPI_RECLAIM_MEMORY: 484 e820_type = E820_TYPE_ACPI; 485 break; 486 487 case EFI_LOADER_CODE: 488 case EFI_LOADER_DATA: 489 case EFI_BOOT_SERVICES_CODE: 490 case EFI_BOOT_SERVICES_DATA: 491 case EFI_CONVENTIONAL_MEMORY: 492 if (efi_soft_reserve_enabled() && 493 (d->attribute & EFI_MEMORY_SP)) 494 e820_type = E820_TYPE_SOFT_RESERVED; 495 else 496 e820_type = E820_TYPE_RAM; 497 break; 498 499 case EFI_ACPI_MEMORY_NVS: 500 e820_type = E820_TYPE_NVS; 501 break; 502 503 case EFI_PERSISTENT_MEMORY: 504 e820_type = E820_TYPE_PMEM; 505 break; 506 507 default: 508 continue; 509 } 510 511 /* Merge adjacent mappings */ 512 if (prev && prev->type == e820_type && 513 (prev->addr + prev->size) == d->phys_addr) { 514 prev->size += d->num_pages << 12; 515 continue; 516 } 517 518 if (nr_entries == ARRAY_SIZE(params->e820_table)) { 519 u32 need = (nr_desc - i) * sizeof(struct e820_entry) + 520 sizeof(struct setup_data); 521 522 if (!e820ext || e820ext_size < need) 523 return EFI_BUFFER_TOO_SMALL; 524 525 /* boot_params map full, switch to e820 extended */ 526 entry = (struct boot_e820_entry *)e820ext->data; 527 } 528 529 entry->addr = d->phys_addr; 530 entry->size = d->num_pages << PAGE_SHIFT; 531 entry->type = e820_type; 532 prev = entry++; 533 nr_entries++; 534 } 535 536 if (nr_entries > ARRAY_SIZE(params->e820_table)) { 537 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table); 538 539 add_e820ext(params, e820ext, nr_e820ext); 540 nr_entries -= nr_e820ext; 541 } 542 543 params->e820_entries = (u8)nr_entries; 544 545 return EFI_SUCCESS; 546 } 547 548 static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext, 549 u32 *e820ext_size) 550 { 551 efi_status_t status; 552 unsigned long size; 553 554 size = sizeof(struct setup_data) + 555 sizeof(struct e820_entry) * nr_desc; 556 557 if (*e820ext) { 558 efi_bs_call(free_pool, *e820ext); 559 *e820ext = NULL; 560 *e820ext_size = 0; 561 } 562 563 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 564 (void **)e820ext); 565 if (status == EFI_SUCCESS) 566 *e820ext_size = size; 567 568 return status; 569 } 570 571 static efi_status_t allocate_e820(struct boot_params *params, 572 struct setup_data **e820ext, 573 u32 *e820ext_size) 574 { 575 unsigned long map_size, desc_size, map_key; 576 efi_status_t status; 577 __u32 nr_desc, desc_version; 578 579 /* Only need the size of the mem map and size of each mem descriptor */ 580 map_size = 0; 581 status = efi_bs_call(get_memory_map, &map_size, NULL, &map_key, 582 &desc_size, &desc_version); 583 if (status != EFI_BUFFER_TOO_SMALL) 584 return (status != EFI_SUCCESS) ? status : EFI_UNSUPPORTED; 585 586 nr_desc = map_size / desc_size + EFI_MMAP_NR_SLACK_SLOTS; 587 588 if (nr_desc > ARRAY_SIZE(params->e820_table)) { 589 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table); 590 591 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size); 592 if (status != EFI_SUCCESS) 593 return status; 594 } 595 596 return EFI_SUCCESS; 597 } 598 599 struct exit_boot_struct { 600 struct boot_params *boot_params; 601 struct efi_info *efi; 602 }; 603 604 static efi_status_t exit_boot_func(struct efi_boot_memmap *map, 605 void *priv) 606 { 607 const char *signature; 608 struct exit_boot_struct *p = priv; 609 610 signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE 611 : EFI32_LOADER_SIGNATURE; 612 memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32)); 613 614 efi_set_u64_split((unsigned long)efi_system_table, 615 &p->efi->efi_systab, &p->efi->efi_systab_hi); 616 p->efi->efi_memdesc_size = *map->desc_size; 617 p->efi->efi_memdesc_version = *map->desc_ver; 618 efi_set_u64_split((unsigned long)*map->map, 619 &p->efi->efi_memmap, &p->efi->efi_memmap_hi); 620 p->efi->efi_memmap_size = *map->map_size; 621 622 return EFI_SUCCESS; 623 } 624 625 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle) 626 { 627 unsigned long map_sz, key, desc_size, buff_size; 628 efi_memory_desc_t *mem_map; 629 struct setup_data *e820ext = NULL; 630 __u32 e820ext_size = 0; 631 efi_status_t status; 632 __u32 desc_version; 633 struct efi_boot_memmap map; 634 struct exit_boot_struct priv; 635 636 map.map = &mem_map; 637 map.map_size = &map_sz; 638 map.desc_size = &desc_size; 639 map.desc_ver = &desc_version; 640 map.key_ptr = &key; 641 map.buff_size = &buff_size; 642 priv.boot_params = boot_params; 643 priv.efi = &boot_params->efi_info; 644 645 status = allocate_e820(boot_params, &e820ext, &e820ext_size); 646 if (status != EFI_SUCCESS) 647 return status; 648 649 /* Might as well exit boot services now */ 650 status = efi_exit_boot_services(handle, &map, &priv, exit_boot_func); 651 if (status != EFI_SUCCESS) 652 return status; 653 654 /* Historic? */ 655 boot_params->alt_mem_k = 32 * 1024; 656 657 status = setup_e820(boot_params, e820ext, e820ext_size); 658 if (status != EFI_SUCCESS) 659 return status; 660 661 return EFI_SUCCESS; 662 } 663 664 /* 665 * On success, we return the address of startup_32, which has potentially been 666 * relocated by efi_relocate_kernel. 667 * On failure, we exit to the firmware via efi_exit instead of returning. 668 */ 669 unsigned long efi_main(efi_handle_t handle, 670 efi_system_table_t *sys_table_arg, 671 struct boot_params *boot_params) 672 { 673 unsigned long bzimage_addr = (unsigned long)startup_32; 674 unsigned long buffer_start, buffer_end; 675 struct setup_header *hdr = &boot_params->hdr; 676 unsigned long addr, size; 677 efi_status_t status; 678 679 efi_system_table = sys_table_arg; 680 681 /* Check if we were booted by the EFI firmware */ 682 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) 683 efi_exit(handle, EFI_INVALID_PARAMETER); 684 685 /* 686 * If the kernel isn't already loaded at a suitable address, 687 * relocate it. 688 * 689 * It must be loaded above LOAD_PHYSICAL_ADDR. 690 * 691 * The maximum address for 64-bit is 1 << 46 for 4-level paging. This 692 * is defined as the macro MAXMEM, but unfortunately that is not a 693 * compile-time constant if 5-level paging is configured, so we instead 694 * define our own macro for use here. 695 * 696 * For 32-bit, the maximum address is complicated to figure out, for 697 * now use KERNEL_IMAGE_SIZE, which will be 512MiB, the same as what 698 * KASLR uses. 699 * 700 * Also relocate it if image_offset is zero, i.e. the kernel wasn't 701 * loaded by LoadImage, but rather by a bootloader that called the 702 * handover entry. The reason we must always relocate in this case is 703 * to handle the case of systemd-boot booting a unified kernel image, 704 * which is a PE executable that contains the bzImage and an initrd as 705 * COFF sections. The initrd section is placed after the bzImage 706 * without ensuring that there are at least init_size bytes available 707 * for the bzImage, and thus the compressed kernel's startup code may 708 * overwrite the initrd unless it is moved out of the way. 709 */ 710 711 buffer_start = ALIGN(bzimage_addr - image_offset, 712 hdr->kernel_alignment); 713 buffer_end = buffer_start + hdr->init_size; 714 715 if ((buffer_start < LOAD_PHYSICAL_ADDR) || 716 (IS_ENABLED(CONFIG_X86_32) && buffer_end > KERNEL_IMAGE_SIZE) || 717 (IS_ENABLED(CONFIG_X86_64) && buffer_end > MAXMEM_X86_64_4LEVEL) || 718 (image_offset == 0)) { 719 extern char _bss[]; 720 721 status = efi_relocate_kernel(&bzimage_addr, 722 (unsigned long)_bss - bzimage_addr, 723 hdr->init_size, 724 hdr->pref_address, 725 hdr->kernel_alignment, 726 LOAD_PHYSICAL_ADDR); 727 if (status != EFI_SUCCESS) { 728 efi_err("efi_relocate_kernel() failed!\n"); 729 goto fail; 730 } 731 /* 732 * Now that we've copied the kernel elsewhere, we no longer 733 * have a set up block before startup_32(), so reset image_offset 734 * to zero in case it was set earlier. 735 */ 736 image_offset = 0; 737 } 738 739 #ifdef CONFIG_CMDLINE_BOOL 740 status = efi_parse_options(CONFIG_CMDLINE); 741 if (status != EFI_SUCCESS) { 742 efi_err("Failed to parse options\n"); 743 goto fail; 744 } 745 #endif 746 if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) { 747 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr | 748 ((u64)boot_params->ext_cmd_line_ptr << 32)); 749 status = efi_parse_options((char *)cmdline_paddr); 750 if (status != EFI_SUCCESS) { 751 efi_err("Failed to parse options\n"); 752 goto fail; 753 } 754 } 755 756 /* 757 * At this point, an initrd may already have been loaded by the 758 * bootloader and passed via bootparams. We permit an initrd loaded 759 * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it. 760 * 761 * If the device path is not present, any command-line initrd= 762 * arguments will be processed only if image is not NULL, which will be 763 * the case only if we were loaded via the PE entry point. 764 */ 765 status = efi_load_initrd(image, &addr, &size, hdr->initrd_addr_max, 766 ULONG_MAX); 767 if (status != EFI_SUCCESS) 768 goto fail; 769 if (size > 0) { 770 efi_set_u64_split(addr, &hdr->ramdisk_image, 771 &boot_params->ext_ramdisk_image); 772 efi_set_u64_split(size, &hdr->ramdisk_size, 773 &boot_params->ext_ramdisk_size); 774 } 775 776 /* 777 * If the boot loader gave us a value for secure_boot then we use that, 778 * otherwise we ask the BIOS. 779 */ 780 if (boot_params->secure_boot == efi_secureboot_mode_unset) 781 boot_params->secure_boot = efi_get_secureboot(); 782 783 /* Ask the firmware to clear memory on unclean shutdown */ 784 efi_enable_reset_attack_mitigation(); 785 786 efi_random_get_seed(); 787 788 efi_retrieve_tpm2_eventlog(); 789 790 setup_graphics(boot_params); 791 792 setup_efi_pci(boot_params); 793 794 setup_quirks(boot_params); 795 796 status = exit_boot(boot_params, handle); 797 if (status != EFI_SUCCESS) { 798 efi_err("exit_boot() failed!\n"); 799 goto fail; 800 } 801 802 return bzimage_addr; 803 fail: 804 efi_err("efi_main() failed!\n"); 805 806 efi_exit(handle, status); 807 } 808