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 const efi_dxe_services_table_t *efi_dxe_table; 26 extern u32 image_offset; 27 static efi_loaded_image_t *image = NULL; 28 29 static efi_status_t 30 preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom) 31 { 32 struct pci_setup_rom *rom = NULL; 33 efi_status_t status; 34 unsigned long size; 35 uint64_t romsize; 36 void *romimage; 37 38 /* 39 * Some firmware images contain EFI function pointers at the place where 40 * the romimage and romsize fields are supposed to be. Typically the EFI 41 * code is mapped at high addresses, translating to an unrealistically 42 * large romsize. The UEFI spec limits the size of option ROMs to 16 43 * MiB so we reject any ROMs over 16 MiB in size to catch this. 44 */ 45 romimage = efi_table_attr(pci, romimage); 46 romsize = efi_table_attr(pci, romsize); 47 if (!romimage || !romsize || romsize > SZ_16M) 48 return EFI_INVALID_PARAMETER; 49 50 size = romsize + sizeof(*rom); 51 52 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 53 (void **)&rom); 54 if (status != EFI_SUCCESS) { 55 efi_err("Failed to allocate memory for 'rom'\n"); 56 return status; 57 } 58 59 memset(rom, 0, sizeof(*rom)); 60 61 rom->data.type = SETUP_PCI; 62 rom->data.len = size - sizeof(struct setup_data); 63 rom->data.next = 0; 64 rom->pcilen = pci->romsize; 65 *__rom = rom; 66 67 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16, 68 PCI_VENDOR_ID, 1, &rom->vendor); 69 70 if (status != EFI_SUCCESS) { 71 efi_err("Failed to read rom->vendor\n"); 72 goto free_struct; 73 } 74 75 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16, 76 PCI_DEVICE_ID, 1, &rom->devid); 77 78 if (status != EFI_SUCCESS) { 79 efi_err("Failed to read rom->devid\n"); 80 goto free_struct; 81 } 82 83 status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus, 84 &rom->device, &rom->function); 85 86 if (status != EFI_SUCCESS) 87 goto free_struct; 88 89 memcpy(rom->romdata, romimage, romsize); 90 return status; 91 92 free_struct: 93 efi_bs_call(free_pool, rom); 94 return status; 95 } 96 97 /* 98 * There's no way to return an informative status from this function, 99 * because any analysis (and printing of error messages) needs to be 100 * done directly at the EFI function call-site. 101 * 102 * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we 103 * just didn't find any PCI devices, but there's no way to tell outside 104 * the context of the call. 105 */ 106 static void setup_efi_pci(struct boot_params *params) 107 { 108 efi_status_t status; 109 void **pci_handle = NULL; 110 efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID; 111 unsigned long size = 0; 112 struct setup_data *data; 113 efi_handle_t h; 114 int i; 115 116 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 117 &pci_proto, NULL, &size, pci_handle); 118 119 if (status == EFI_BUFFER_TOO_SMALL) { 120 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 121 (void **)&pci_handle); 122 123 if (status != EFI_SUCCESS) { 124 efi_err("Failed to allocate memory for 'pci_handle'\n"); 125 return; 126 } 127 128 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 129 &pci_proto, NULL, &size, pci_handle); 130 } 131 132 if (status != EFI_SUCCESS) 133 goto free_handle; 134 135 data = (struct setup_data *)(unsigned long)params->hdr.setup_data; 136 137 while (data && data->next) 138 data = (struct setup_data *)(unsigned long)data->next; 139 140 for_each_efi_handle(h, pci_handle, size, i) { 141 efi_pci_io_protocol_t *pci = NULL; 142 struct pci_setup_rom *rom; 143 144 status = efi_bs_call(handle_protocol, h, &pci_proto, 145 (void **)&pci); 146 if (status != EFI_SUCCESS || !pci) 147 continue; 148 149 status = preserve_pci_rom_image(pci, &rom); 150 if (status != EFI_SUCCESS) 151 continue; 152 153 if (data) 154 data->next = (unsigned long)rom; 155 else 156 params->hdr.setup_data = (unsigned long)rom; 157 158 data = (struct setup_data *)rom; 159 } 160 161 free_handle: 162 efi_bs_call(free_pool, pci_handle); 163 } 164 165 static void retrieve_apple_device_properties(struct boot_params *boot_params) 166 { 167 efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID; 168 struct setup_data *data, *new; 169 efi_status_t status; 170 u32 size = 0; 171 apple_properties_protocol_t *p; 172 173 status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p); 174 if (status != EFI_SUCCESS) 175 return; 176 177 if (efi_table_attr(p, version) != 0x10000) { 178 efi_err("Unsupported properties proto version\n"); 179 return; 180 } 181 182 efi_call_proto(p, get_all, NULL, &size); 183 if (!size) 184 return; 185 186 do { 187 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, 188 size + sizeof(struct setup_data), 189 (void **)&new); 190 if (status != EFI_SUCCESS) { 191 efi_err("Failed to allocate memory for 'properties'\n"); 192 return; 193 } 194 195 status = efi_call_proto(p, get_all, new->data, &size); 196 197 if (status == EFI_BUFFER_TOO_SMALL) 198 efi_bs_call(free_pool, new); 199 } while (status == EFI_BUFFER_TOO_SMALL); 200 201 new->type = SETUP_APPLE_PROPERTIES; 202 new->len = size; 203 new->next = 0; 204 205 data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data; 206 if (!data) { 207 boot_params->hdr.setup_data = (unsigned long)new; 208 } else { 209 while (data->next) 210 data = (struct setup_data *)(unsigned long)data->next; 211 data->next = (unsigned long)new; 212 } 213 } 214 215 static void 216 adjust_memory_range_protection(unsigned long start, unsigned long size) 217 { 218 efi_status_t status; 219 efi_gcd_memory_space_desc_t desc; 220 unsigned long end, next; 221 unsigned long rounded_start, rounded_end; 222 unsigned long unprotect_start, unprotect_size; 223 224 if (efi_dxe_table == NULL) 225 return; 226 227 rounded_start = rounddown(start, EFI_PAGE_SIZE); 228 rounded_end = roundup(start + size, EFI_PAGE_SIZE); 229 230 /* 231 * Don't modify memory region attributes, they are 232 * already suitable, to lower the possibility to 233 * encounter firmware bugs. 234 */ 235 236 for (end = start + size; start < end; start = next) { 237 238 status = efi_dxe_call(get_memory_space_descriptor, start, &desc); 239 240 if (status != EFI_SUCCESS) 241 return; 242 243 next = desc.base_address + desc.length; 244 245 /* 246 * Only system memory is suitable for trampoline/kernel image placement, 247 * so only this type of memory needs its attributes to be modified. 248 */ 249 250 if (desc.gcd_memory_type != EfiGcdMemoryTypeSystemMemory || 251 (desc.attributes & (EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0) 252 continue; 253 254 unprotect_start = max(rounded_start, (unsigned long)desc.base_address); 255 unprotect_size = min(rounded_end, next) - unprotect_start; 256 257 status = efi_dxe_call(set_memory_space_attributes, 258 unprotect_start, unprotect_size, 259 EFI_MEMORY_WB); 260 261 if (status != EFI_SUCCESS) { 262 efi_warn("Unable to unprotect memory range [%08lx,%08lx]: %lx\n", 263 unprotect_start, 264 unprotect_start + unprotect_size, 265 status); 266 } 267 } 268 } 269 270 /* 271 * Trampoline takes 2 pages and can be loaded in first megabyte of memory 272 * with its end placed between 128k and 640k where BIOS might start. 273 * (see arch/x86/boot/compressed/pgtable_64.c) 274 * 275 * We cannot find exact trampoline placement since memory map 276 * can be modified by UEFI, and it can alter the computed address. 277 */ 278 279 #define TRAMPOLINE_PLACEMENT_BASE ((128 - 8)*1024) 280 #define TRAMPOLINE_PLACEMENT_SIZE (640*1024 - (128 - 8)*1024) 281 282 void startup_32(struct boot_params *boot_params); 283 284 static void 285 setup_memory_protection(unsigned long image_base, unsigned long image_size) 286 { 287 /* 288 * Allow execution of possible trampoline used 289 * for switching between 4- and 5-level page tables 290 * and relocated kernel image. 291 */ 292 293 adjust_memory_range_protection(TRAMPOLINE_PLACEMENT_BASE, 294 TRAMPOLINE_PLACEMENT_SIZE); 295 296 #ifdef CONFIG_64BIT 297 if (image_base != (unsigned long)startup_32) 298 adjust_memory_range_protection(image_base, image_size); 299 #else 300 /* 301 * Clear protection flags on a whole range of possible 302 * addresses used for KASLR. We don't need to do that 303 * on x86_64, since KASLR/extraction is performed after 304 * dedicated identity page tables are built and we only 305 * need to remove possible protection on relocated image 306 * itself disregarding further relocations. 307 */ 308 adjust_memory_range_protection(LOAD_PHYSICAL_ADDR, 309 KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR); 310 #endif 311 } 312 313 static const efi_char16_t apple[] = L"Apple"; 314 315 static void setup_quirks(struct boot_params *boot_params, 316 unsigned long image_base, 317 unsigned long image_size) 318 { 319 efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long) 320 efi_table_attr(efi_system_table, fw_vendor); 321 322 if (!memcmp(fw_vendor, apple, sizeof(apple))) { 323 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES)) 324 retrieve_apple_device_properties(boot_params); 325 } 326 327 if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES)) 328 setup_memory_protection(image_base, image_size); 329 } 330 331 /* 332 * See if we have Universal Graphics Adapter (UGA) protocol 333 */ 334 static efi_status_t 335 setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size) 336 { 337 efi_status_t status; 338 u32 width, height; 339 void **uga_handle = NULL; 340 efi_uga_draw_protocol_t *uga = NULL, *first_uga; 341 efi_handle_t handle; 342 int i; 343 344 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 345 (void **)&uga_handle); 346 if (status != EFI_SUCCESS) 347 return status; 348 349 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 350 uga_proto, NULL, &size, uga_handle); 351 if (status != EFI_SUCCESS) 352 goto free_handle; 353 354 height = 0; 355 width = 0; 356 357 first_uga = NULL; 358 for_each_efi_handle(handle, uga_handle, size, i) { 359 efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID; 360 u32 w, h, depth, refresh; 361 void *pciio; 362 363 status = efi_bs_call(handle_protocol, handle, uga_proto, 364 (void **)&uga); 365 if (status != EFI_SUCCESS) 366 continue; 367 368 pciio = NULL; 369 efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio); 370 371 status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh); 372 if (status == EFI_SUCCESS && (!first_uga || pciio)) { 373 width = w; 374 height = h; 375 376 /* 377 * Once we've found a UGA supporting PCIIO, 378 * don't bother looking any further. 379 */ 380 if (pciio) 381 break; 382 383 first_uga = uga; 384 } 385 } 386 387 if (!width && !height) 388 goto free_handle; 389 390 /* EFI framebuffer */ 391 si->orig_video_isVGA = VIDEO_TYPE_EFI; 392 393 si->lfb_depth = 32; 394 si->lfb_width = width; 395 si->lfb_height = height; 396 397 si->red_size = 8; 398 si->red_pos = 16; 399 si->green_size = 8; 400 si->green_pos = 8; 401 si->blue_size = 8; 402 si->blue_pos = 0; 403 si->rsvd_size = 8; 404 si->rsvd_pos = 24; 405 406 free_handle: 407 efi_bs_call(free_pool, uga_handle); 408 409 return status; 410 } 411 412 static void setup_graphics(struct boot_params *boot_params) 413 { 414 efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID; 415 struct screen_info *si; 416 efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID; 417 efi_status_t status; 418 unsigned long size; 419 void **gop_handle = NULL; 420 void **uga_handle = NULL; 421 422 si = &boot_params->screen_info; 423 memset(si, 0, sizeof(*si)); 424 425 size = 0; 426 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 427 &graphics_proto, NULL, &size, gop_handle); 428 if (status == EFI_BUFFER_TOO_SMALL) 429 status = efi_setup_gop(si, &graphics_proto, size); 430 431 if (status != EFI_SUCCESS) { 432 size = 0; 433 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 434 &uga_proto, NULL, &size, uga_handle); 435 if (status == EFI_BUFFER_TOO_SMALL) 436 setup_uga(si, &uga_proto, size); 437 } 438 } 439 440 441 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status) 442 { 443 efi_bs_call(exit, handle, status, 0, NULL); 444 for(;;) 445 asm("hlt"); 446 } 447 448 void __noreturn efi_stub_entry(efi_handle_t handle, 449 efi_system_table_t *sys_table_arg, 450 struct boot_params *boot_params); 451 452 /* 453 * Because the x86 boot code expects to be passed a boot_params we 454 * need to create one ourselves (usually the bootloader would create 455 * one for us). 456 */ 457 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, 458 efi_system_table_t *sys_table_arg) 459 { 460 struct boot_params *boot_params; 461 struct setup_header *hdr; 462 void *image_base; 463 efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID; 464 int options_size = 0; 465 efi_status_t status; 466 char *cmdline_ptr; 467 468 efi_system_table = sys_table_arg; 469 470 /* Check if we were booted by the EFI firmware */ 471 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) 472 efi_exit(handle, EFI_INVALID_PARAMETER); 473 474 status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image); 475 if (status != EFI_SUCCESS) { 476 efi_err("Failed to get handle for LOADED_IMAGE_PROTOCOL\n"); 477 efi_exit(handle, status); 478 } 479 480 image_base = efi_table_attr(image, image_base); 481 image_offset = (void *)startup_32 - image_base; 482 483 status = efi_allocate_pages(sizeof(struct boot_params), 484 (unsigned long *)&boot_params, ULONG_MAX); 485 if (status != EFI_SUCCESS) { 486 efi_err("Failed to allocate lowmem for boot params\n"); 487 efi_exit(handle, status); 488 } 489 490 memset(boot_params, 0x0, sizeof(struct boot_params)); 491 492 hdr = &boot_params->hdr; 493 494 /* Copy the setup header from the second sector to boot_params */ 495 memcpy(&hdr->jump, image_base + 512, 496 sizeof(struct setup_header) - offsetof(struct setup_header, jump)); 497 498 /* 499 * Fill out some of the header fields ourselves because the 500 * EFI firmware loader doesn't load the first sector. 501 */ 502 hdr->root_flags = 1; 503 hdr->vid_mode = 0xffff; 504 hdr->boot_flag = 0xAA55; 505 506 hdr->type_of_loader = 0x21; 507 508 /* Convert unicode cmdline to ascii */ 509 cmdline_ptr = efi_convert_cmdline(image, &options_size); 510 if (!cmdline_ptr) 511 goto fail; 512 513 efi_set_u64_split((unsigned long)cmdline_ptr, 514 &hdr->cmd_line_ptr, &boot_params->ext_cmd_line_ptr); 515 516 hdr->ramdisk_image = 0; 517 hdr->ramdisk_size = 0; 518 519 /* 520 * Disregard any setup data that was provided by the bootloader: 521 * setup_data could be pointing anywhere, and we have no way of 522 * authenticating or validating the payload. 523 */ 524 hdr->setup_data = 0; 525 526 efi_stub_entry(handle, sys_table_arg, boot_params); 527 /* not reached */ 528 529 fail: 530 efi_free(sizeof(struct boot_params), (unsigned long)boot_params); 531 532 efi_exit(handle, status); 533 } 534 535 static void add_e820ext(struct boot_params *params, 536 struct setup_data *e820ext, u32 nr_entries) 537 { 538 struct setup_data *data; 539 540 e820ext->type = SETUP_E820_EXT; 541 e820ext->len = nr_entries * sizeof(struct boot_e820_entry); 542 e820ext->next = 0; 543 544 data = (struct setup_data *)(unsigned long)params->hdr.setup_data; 545 546 while (data && data->next) 547 data = (struct setup_data *)(unsigned long)data->next; 548 549 if (data) 550 data->next = (unsigned long)e820ext; 551 else 552 params->hdr.setup_data = (unsigned long)e820ext; 553 } 554 555 static efi_status_t 556 setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size) 557 { 558 struct boot_e820_entry *entry = params->e820_table; 559 struct efi_info *efi = ¶ms->efi_info; 560 struct boot_e820_entry *prev = NULL; 561 u32 nr_entries; 562 u32 nr_desc; 563 int i; 564 565 nr_entries = 0; 566 nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size; 567 568 for (i = 0; i < nr_desc; i++) { 569 efi_memory_desc_t *d; 570 unsigned int e820_type = 0; 571 unsigned long m = efi->efi_memmap; 572 573 #ifdef CONFIG_X86_64 574 m |= (u64)efi->efi_memmap_hi << 32; 575 #endif 576 577 d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i); 578 switch (d->type) { 579 case EFI_RESERVED_TYPE: 580 case EFI_RUNTIME_SERVICES_CODE: 581 case EFI_RUNTIME_SERVICES_DATA: 582 case EFI_MEMORY_MAPPED_IO: 583 case EFI_MEMORY_MAPPED_IO_PORT_SPACE: 584 case EFI_PAL_CODE: 585 e820_type = E820_TYPE_RESERVED; 586 break; 587 588 case EFI_UNUSABLE_MEMORY: 589 e820_type = E820_TYPE_UNUSABLE; 590 break; 591 592 case EFI_ACPI_RECLAIM_MEMORY: 593 e820_type = E820_TYPE_ACPI; 594 break; 595 596 case EFI_LOADER_CODE: 597 case EFI_LOADER_DATA: 598 case EFI_BOOT_SERVICES_CODE: 599 case EFI_BOOT_SERVICES_DATA: 600 case EFI_CONVENTIONAL_MEMORY: 601 if (efi_soft_reserve_enabled() && 602 (d->attribute & EFI_MEMORY_SP)) 603 e820_type = E820_TYPE_SOFT_RESERVED; 604 else 605 e820_type = E820_TYPE_RAM; 606 break; 607 608 case EFI_ACPI_MEMORY_NVS: 609 e820_type = E820_TYPE_NVS; 610 break; 611 612 case EFI_PERSISTENT_MEMORY: 613 e820_type = E820_TYPE_PMEM; 614 break; 615 616 default: 617 continue; 618 } 619 620 /* Merge adjacent mappings */ 621 if (prev && prev->type == e820_type && 622 (prev->addr + prev->size) == d->phys_addr) { 623 prev->size += d->num_pages << 12; 624 continue; 625 } 626 627 if (nr_entries == ARRAY_SIZE(params->e820_table)) { 628 u32 need = (nr_desc - i) * sizeof(struct e820_entry) + 629 sizeof(struct setup_data); 630 631 if (!e820ext || e820ext_size < need) 632 return EFI_BUFFER_TOO_SMALL; 633 634 /* boot_params map full, switch to e820 extended */ 635 entry = (struct boot_e820_entry *)e820ext->data; 636 } 637 638 entry->addr = d->phys_addr; 639 entry->size = d->num_pages << PAGE_SHIFT; 640 entry->type = e820_type; 641 prev = entry++; 642 nr_entries++; 643 } 644 645 if (nr_entries > ARRAY_SIZE(params->e820_table)) { 646 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table); 647 648 add_e820ext(params, e820ext, nr_e820ext); 649 nr_entries -= nr_e820ext; 650 } 651 652 params->e820_entries = (u8)nr_entries; 653 654 return EFI_SUCCESS; 655 } 656 657 static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext, 658 u32 *e820ext_size) 659 { 660 efi_status_t status; 661 unsigned long size; 662 663 size = sizeof(struct setup_data) + 664 sizeof(struct e820_entry) * nr_desc; 665 666 if (*e820ext) { 667 efi_bs_call(free_pool, *e820ext); 668 *e820ext = NULL; 669 *e820ext_size = 0; 670 } 671 672 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 673 (void **)e820ext); 674 if (status == EFI_SUCCESS) 675 *e820ext_size = size; 676 677 return status; 678 } 679 680 static efi_status_t allocate_e820(struct boot_params *params, 681 struct setup_data **e820ext, 682 u32 *e820ext_size) 683 { 684 unsigned long map_size, desc_size, map_key; 685 efi_status_t status; 686 __u32 nr_desc, desc_version; 687 688 /* Only need the size of the mem map and size of each mem descriptor */ 689 map_size = 0; 690 status = efi_bs_call(get_memory_map, &map_size, NULL, &map_key, 691 &desc_size, &desc_version); 692 if (status != EFI_BUFFER_TOO_SMALL) 693 return (status != EFI_SUCCESS) ? status : EFI_UNSUPPORTED; 694 695 nr_desc = map_size / desc_size + EFI_MMAP_NR_SLACK_SLOTS; 696 697 if (nr_desc > ARRAY_SIZE(params->e820_table)) { 698 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table); 699 700 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size); 701 if (status != EFI_SUCCESS) 702 return status; 703 } 704 705 return EFI_SUCCESS; 706 } 707 708 struct exit_boot_struct { 709 struct boot_params *boot_params; 710 struct efi_info *efi; 711 }; 712 713 static efi_status_t exit_boot_func(struct efi_boot_memmap *map, 714 void *priv) 715 { 716 const char *signature; 717 struct exit_boot_struct *p = priv; 718 719 signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE 720 : EFI32_LOADER_SIGNATURE; 721 memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32)); 722 723 efi_set_u64_split((unsigned long)efi_system_table, 724 &p->efi->efi_systab, &p->efi->efi_systab_hi); 725 p->efi->efi_memdesc_size = map->desc_size; 726 p->efi->efi_memdesc_version = map->desc_ver; 727 efi_set_u64_split((unsigned long)map->map, 728 &p->efi->efi_memmap, &p->efi->efi_memmap_hi); 729 p->efi->efi_memmap_size = map->map_size; 730 731 return EFI_SUCCESS; 732 } 733 734 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle) 735 { 736 struct setup_data *e820ext = NULL; 737 __u32 e820ext_size = 0; 738 efi_status_t status; 739 struct exit_boot_struct priv; 740 741 priv.boot_params = boot_params; 742 priv.efi = &boot_params->efi_info; 743 744 status = allocate_e820(boot_params, &e820ext, &e820ext_size); 745 if (status != EFI_SUCCESS) 746 return status; 747 748 /* Might as well exit boot services now */ 749 status = efi_exit_boot_services(handle, &priv, exit_boot_func); 750 if (status != EFI_SUCCESS) 751 return status; 752 753 /* Historic? */ 754 boot_params->alt_mem_k = 32 * 1024; 755 756 status = setup_e820(boot_params, e820ext, e820ext_size); 757 if (status != EFI_SUCCESS) 758 return status; 759 760 return EFI_SUCCESS; 761 } 762 763 /* 764 * On success, we return the address of startup_32, which has potentially been 765 * relocated by efi_relocate_kernel. 766 * On failure, we exit to the firmware via efi_exit instead of returning. 767 */ 768 asmlinkage unsigned long efi_main(efi_handle_t handle, 769 efi_system_table_t *sys_table_arg, 770 struct boot_params *boot_params) 771 { 772 unsigned long bzimage_addr = (unsigned long)startup_32; 773 unsigned long buffer_start, buffer_end; 774 struct setup_header *hdr = &boot_params->hdr; 775 const struct linux_efi_initrd *initrd = NULL; 776 efi_status_t status; 777 778 efi_system_table = sys_table_arg; 779 /* Check if we were booted by the EFI firmware */ 780 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) 781 efi_exit(handle, EFI_INVALID_PARAMETER); 782 783 efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID); 784 if (efi_dxe_table && 785 efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) { 786 efi_warn("Ignoring DXE services table: invalid signature\n"); 787 efi_dxe_table = NULL; 788 } 789 790 /* 791 * If the kernel isn't already loaded at a suitable address, 792 * relocate it. 793 * 794 * It must be loaded above LOAD_PHYSICAL_ADDR. 795 * 796 * The maximum address for 64-bit is 1 << 46 for 4-level paging. This 797 * is defined as the macro MAXMEM, but unfortunately that is not a 798 * compile-time constant if 5-level paging is configured, so we instead 799 * define our own macro for use here. 800 * 801 * For 32-bit, the maximum address is complicated to figure out, for 802 * now use KERNEL_IMAGE_SIZE, which will be 512MiB, the same as what 803 * KASLR uses. 804 * 805 * Also relocate it if image_offset is zero, i.e. the kernel wasn't 806 * loaded by LoadImage, but rather by a bootloader that called the 807 * handover entry. The reason we must always relocate in this case is 808 * to handle the case of systemd-boot booting a unified kernel image, 809 * which is a PE executable that contains the bzImage and an initrd as 810 * COFF sections. The initrd section is placed after the bzImage 811 * without ensuring that there are at least init_size bytes available 812 * for the bzImage, and thus the compressed kernel's startup code may 813 * overwrite the initrd unless it is moved out of the way. 814 */ 815 816 buffer_start = ALIGN(bzimage_addr - image_offset, 817 hdr->kernel_alignment); 818 buffer_end = buffer_start + hdr->init_size; 819 820 if ((buffer_start < LOAD_PHYSICAL_ADDR) || 821 (IS_ENABLED(CONFIG_X86_32) && buffer_end > KERNEL_IMAGE_SIZE) || 822 (IS_ENABLED(CONFIG_X86_64) && buffer_end > MAXMEM_X86_64_4LEVEL) || 823 (image_offset == 0)) { 824 extern char _bss[]; 825 826 status = efi_relocate_kernel(&bzimage_addr, 827 (unsigned long)_bss - bzimage_addr, 828 hdr->init_size, 829 hdr->pref_address, 830 hdr->kernel_alignment, 831 LOAD_PHYSICAL_ADDR); 832 if (status != EFI_SUCCESS) { 833 efi_err("efi_relocate_kernel() failed!\n"); 834 goto fail; 835 } 836 /* 837 * Now that we've copied the kernel elsewhere, we no longer 838 * have a set up block before startup_32(), so reset image_offset 839 * to zero in case it was set earlier. 840 */ 841 image_offset = 0; 842 } 843 844 #ifdef CONFIG_CMDLINE_BOOL 845 status = efi_parse_options(CONFIG_CMDLINE); 846 if (status != EFI_SUCCESS) { 847 efi_err("Failed to parse options\n"); 848 goto fail; 849 } 850 #endif 851 if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) { 852 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr | 853 ((u64)boot_params->ext_cmd_line_ptr << 32)); 854 status = efi_parse_options((char *)cmdline_paddr); 855 if (status != EFI_SUCCESS) { 856 efi_err("Failed to parse options\n"); 857 goto fail; 858 } 859 } 860 861 /* 862 * At this point, an initrd may already have been loaded by the 863 * bootloader and passed via bootparams. We permit an initrd loaded 864 * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it. 865 * 866 * If the device path is not present, any command-line initrd= 867 * arguments will be processed only if image is not NULL, which will be 868 * the case only if we were loaded via the PE entry point. 869 */ 870 status = efi_load_initrd(image, hdr->initrd_addr_max, ULONG_MAX, 871 &initrd); 872 if (status != EFI_SUCCESS) 873 goto fail; 874 if (initrd && initrd->size > 0) { 875 efi_set_u64_split(initrd->base, &hdr->ramdisk_image, 876 &boot_params->ext_ramdisk_image); 877 efi_set_u64_split(initrd->size, &hdr->ramdisk_size, 878 &boot_params->ext_ramdisk_size); 879 } 880 881 882 /* 883 * If the boot loader gave us a value for secure_boot then we use that, 884 * otherwise we ask the BIOS. 885 */ 886 if (boot_params->secure_boot == efi_secureboot_mode_unset) 887 boot_params->secure_boot = efi_get_secureboot(); 888 889 /* Ask the firmware to clear memory on unclean shutdown */ 890 efi_enable_reset_attack_mitigation(); 891 892 efi_random_get_seed(); 893 894 efi_retrieve_tpm2_eventlog(); 895 896 setup_graphics(boot_params); 897 898 setup_efi_pci(boot_params); 899 900 setup_quirks(boot_params, bzimage_addr, buffer_end - buffer_start); 901 902 status = exit_boot(boot_params, handle); 903 if (status != EFI_SUCCESS) { 904 efi_err("exit_boot() failed!\n"); 905 goto fail; 906 } 907 908 return bzimage_addr; 909 fail: 910 efi_err("efi_main() failed!\n"); 911 912 efi_exit(handle, status); 913 } 914