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 u32 image_offset __section(".data"); 27 static efi_loaded_image_t *image = NULL; 28 29 typedef union sev_memory_acceptance_protocol sev_memory_acceptance_protocol_t; 30 union sev_memory_acceptance_protocol { 31 struct { 32 efi_status_t (__efiapi * allow_unaccepted_memory)( 33 sev_memory_acceptance_protocol_t *); 34 }; 35 struct { 36 u32 allow_unaccepted_memory; 37 } mixed_mode; 38 }; 39 40 static efi_status_t 41 preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom) 42 { 43 struct pci_setup_rom *rom = NULL; 44 efi_status_t status; 45 unsigned long size; 46 uint64_t romsize; 47 void *romimage; 48 49 /* 50 * Some firmware images contain EFI function pointers at the place where 51 * the romimage and romsize fields are supposed to be. Typically the EFI 52 * code is mapped at high addresses, translating to an unrealistically 53 * large romsize. The UEFI spec limits the size of option ROMs to 16 54 * MiB so we reject any ROMs over 16 MiB in size to catch this. 55 */ 56 romimage = efi_table_attr(pci, romimage); 57 romsize = efi_table_attr(pci, romsize); 58 if (!romimage || !romsize || romsize > SZ_16M) 59 return EFI_INVALID_PARAMETER; 60 61 size = romsize + sizeof(*rom); 62 63 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 64 (void **)&rom); 65 if (status != EFI_SUCCESS) { 66 efi_err("Failed to allocate memory for 'rom'\n"); 67 return status; 68 } 69 70 memset(rom, 0, sizeof(*rom)); 71 72 rom->data.type = SETUP_PCI; 73 rom->data.len = size - sizeof(struct setup_data); 74 rom->data.next = 0; 75 rom->pcilen = pci->romsize; 76 *__rom = rom; 77 78 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16, 79 PCI_VENDOR_ID, 1, &rom->vendor); 80 81 if (status != EFI_SUCCESS) { 82 efi_err("Failed to read rom->vendor\n"); 83 goto free_struct; 84 } 85 86 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16, 87 PCI_DEVICE_ID, 1, &rom->devid); 88 89 if (status != EFI_SUCCESS) { 90 efi_err("Failed to read rom->devid\n"); 91 goto free_struct; 92 } 93 94 status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus, 95 &rom->device, &rom->function); 96 97 if (status != EFI_SUCCESS) 98 goto free_struct; 99 100 memcpy(rom->romdata, romimage, romsize); 101 return status; 102 103 free_struct: 104 efi_bs_call(free_pool, rom); 105 return status; 106 } 107 108 /* 109 * There's no way to return an informative status from this function, 110 * because any analysis (and printing of error messages) needs to be 111 * done directly at the EFI function call-site. 112 * 113 * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we 114 * just didn't find any PCI devices, but there's no way to tell outside 115 * the context of the call. 116 */ 117 static void setup_efi_pci(struct boot_params *params) 118 { 119 efi_status_t status; 120 void **pci_handle = NULL; 121 efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID; 122 unsigned long size = 0; 123 struct setup_data *data; 124 efi_handle_t h; 125 int i; 126 127 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 128 &pci_proto, NULL, &size, pci_handle); 129 130 if (status == EFI_BUFFER_TOO_SMALL) { 131 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 132 (void **)&pci_handle); 133 134 if (status != EFI_SUCCESS) { 135 efi_err("Failed to allocate memory for 'pci_handle'\n"); 136 return; 137 } 138 139 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 140 &pci_proto, NULL, &size, pci_handle); 141 } 142 143 if (status != EFI_SUCCESS) 144 goto free_handle; 145 146 data = (struct setup_data *)(unsigned long)params->hdr.setup_data; 147 148 while (data && data->next) 149 data = (struct setup_data *)(unsigned long)data->next; 150 151 for_each_efi_handle(h, pci_handle, size, i) { 152 efi_pci_io_protocol_t *pci = NULL; 153 struct pci_setup_rom *rom; 154 155 status = efi_bs_call(handle_protocol, h, &pci_proto, 156 (void **)&pci); 157 if (status != EFI_SUCCESS || !pci) 158 continue; 159 160 status = preserve_pci_rom_image(pci, &rom); 161 if (status != EFI_SUCCESS) 162 continue; 163 164 if (data) 165 data->next = (unsigned long)rom; 166 else 167 params->hdr.setup_data = (unsigned long)rom; 168 169 data = (struct setup_data *)rom; 170 } 171 172 free_handle: 173 efi_bs_call(free_pool, pci_handle); 174 } 175 176 static void retrieve_apple_device_properties(struct boot_params *boot_params) 177 { 178 efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID; 179 struct setup_data *data, *new; 180 efi_status_t status; 181 u32 size = 0; 182 apple_properties_protocol_t *p; 183 184 status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p); 185 if (status != EFI_SUCCESS) 186 return; 187 188 if (efi_table_attr(p, version) != 0x10000) { 189 efi_err("Unsupported properties proto version\n"); 190 return; 191 } 192 193 efi_call_proto(p, get_all, NULL, &size); 194 if (!size) 195 return; 196 197 do { 198 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, 199 size + sizeof(struct setup_data), 200 (void **)&new); 201 if (status != EFI_SUCCESS) { 202 efi_err("Failed to allocate memory for 'properties'\n"); 203 return; 204 } 205 206 status = efi_call_proto(p, get_all, new->data, &size); 207 208 if (status == EFI_BUFFER_TOO_SMALL) 209 efi_bs_call(free_pool, new); 210 } while (status == EFI_BUFFER_TOO_SMALL); 211 212 new->type = SETUP_APPLE_PROPERTIES; 213 new->len = size; 214 new->next = 0; 215 216 data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data; 217 if (!data) { 218 boot_params->hdr.setup_data = (unsigned long)new; 219 } else { 220 while (data->next) 221 data = (struct setup_data *)(unsigned long)data->next; 222 data->next = (unsigned long)new; 223 } 224 } 225 226 static void 227 adjust_memory_range_protection(unsigned long start, unsigned long size) 228 { 229 efi_status_t status; 230 efi_gcd_memory_space_desc_t desc; 231 unsigned long end, next; 232 unsigned long rounded_start, rounded_end; 233 unsigned long unprotect_start, unprotect_size; 234 235 if (efi_dxe_table == NULL) 236 return; 237 238 rounded_start = rounddown(start, EFI_PAGE_SIZE); 239 rounded_end = roundup(start + size, EFI_PAGE_SIZE); 240 241 /* 242 * Don't modify memory region attributes, they are 243 * already suitable, to lower the possibility to 244 * encounter firmware bugs. 245 */ 246 247 for (end = start + size; start < end; start = next) { 248 249 status = efi_dxe_call(get_memory_space_descriptor, start, &desc); 250 251 if (status != EFI_SUCCESS) 252 return; 253 254 next = desc.base_address + desc.length; 255 256 /* 257 * Only system memory is suitable for trampoline/kernel image placement, 258 * so only this type of memory needs its attributes to be modified. 259 */ 260 261 if (desc.gcd_memory_type != EfiGcdMemoryTypeSystemMemory || 262 (desc.attributes & (EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0) 263 continue; 264 265 unprotect_start = max(rounded_start, (unsigned long)desc.base_address); 266 unprotect_size = min(rounded_end, next) - unprotect_start; 267 268 status = efi_dxe_call(set_memory_space_attributes, 269 unprotect_start, unprotect_size, 270 EFI_MEMORY_WB); 271 272 if (status != EFI_SUCCESS) { 273 efi_warn("Unable to unprotect memory range [%08lx,%08lx]: %lx\n", 274 unprotect_start, 275 unprotect_start + unprotect_size, 276 status); 277 } 278 } 279 } 280 281 /* 282 * Trampoline takes 2 pages and can be loaded in first megabyte of memory 283 * with its end placed between 128k and 640k where BIOS might start. 284 * (see arch/x86/boot/compressed/pgtable_64.c) 285 * 286 * We cannot find exact trampoline placement since memory map 287 * can be modified by UEFI, and it can alter the computed address. 288 */ 289 290 #define TRAMPOLINE_PLACEMENT_BASE ((128 - 8)*1024) 291 #define TRAMPOLINE_PLACEMENT_SIZE (640*1024 - (128 - 8)*1024) 292 293 void startup_32(struct boot_params *boot_params); 294 295 static void 296 setup_memory_protection(unsigned long image_base, unsigned long image_size) 297 { 298 /* 299 * Allow execution of possible trampoline used 300 * for switching between 4- and 5-level page tables 301 * and relocated kernel image. 302 */ 303 304 adjust_memory_range_protection(TRAMPOLINE_PLACEMENT_BASE, 305 TRAMPOLINE_PLACEMENT_SIZE); 306 307 #ifdef CONFIG_64BIT 308 if (image_base != (unsigned long)startup_32) 309 adjust_memory_range_protection(image_base, image_size); 310 #else 311 /* 312 * Clear protection flags on a whole range of possible 313 * addresses used for KASLR. We don't need to do that 314 * on x86_64, since KASLR/extraction is performed after 315 * dedicated identity page tables are built and we only 316 * need to remove possible protection on relocated image 317 * itself disregarding further relocations. 318 */ 319 adjust_memory_range_protection(LOAD_PHYSICAL_ADDR, 320 KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR); 321 #endif 322 } 323 324 static void setup_unaccepted_memory(void) 325 { 326 efi_guid_t mem_acceptance_proto = OVMF_SEV_MEMORY_ACCEPTANCE_PROTOCOL_GUID; 327 sev_memory_acceptance_protocol_t *proto; 328 efi_status_t status; 329 330 if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) 331 return; 332 333 /* 334 * Enable unaccepted memory before calling exit boot services in order 335 * for the UEFI to not accept all memory on EBS. 336 */ 337 status = efi_bs_call(locate_protocol, &mem_acceptance_proto, NULL, 338 (void **)&proto); 339 if (status != EFI_SUCCESS) 340 return; 341 342 status = efi_call_proto(proto, allow_unaccepted_memory); 343 if (status != EFI_SUCCESS) 344 efi_err("Memory acceptance protocol failed\n"); 345 } 346 347 static const efi_char16_t apple[] = L"Apple"; 348 349 static void setup_quirks(struct boot_params *boot_params, 350 unsigned long image_base, 351 unsigned long image_size) 352 { 353 efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long) 354 efi_table_attr(efi_system_table, fw_vendor); 355 356 if (!memcmp(fw_vendor, apple, sizeof(apple))) { 357 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES)) 358 retrieve_apple_device_properties(boot_params); 359 } 360 361 if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES)) 362 setup_memory_protection(image_base, image_size); 363 } 364 365 /* 366 * See if we have Universal Graphics Adapter (UGA) protocol 367 */ 368 static efi_status_t 369 setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size) 370 { 371 efi_status_t status; 372 u32 width, height; 373 void **uga_handle = NULL; 374 efi_uga_draw_protocol_t *uga = NULL, *first_uga; 375 efi_handle_t handle; 376 int i; 377 378 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 379 (void **)&uga_handle); 380 if (status != EFI_SUCCESS) 381 return status; 382 383 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 384 uga_proto, NULL, &size, uga_handle); 385 if (status != EFI_SUCCESS) 386 goto free_handle; 387 388 height = 0; 389 width = 0; 390 391 first_uga = NULL; 392 for_each_efi_handle(handle, uga_handle, size, i) { 393 efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID; 394 u32 w, h, depth, refresh; 395 void *pciio; 396 397 status = efi_bs_call(handle_protocol, handle, uga_proto, 398 (void **)&uga); 399 if (status != EFI_SUCCESS) 400 continue; 401 402 pciio = NULL; 403 efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio); 404 405 status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh); 406 if (status == EFI_SUCCESS && (!first_uga || pciio)) { 407 width = w; 408 height = h; 409 410 /* 411 * Once we've found a UGA supporting PCIIO, 412 * don't bother looking any further. 413 */ 414 if (pciio) 415 break; 416 417 first_uga = uga; 418 } 419 } 420 421 if (!width && !height) 422 goto free_handle; 423 424 /* EFI framebuffer */ 425 si->orig_video_isVGA = VIDEO_TYPE_EFI; 426 427 si->lfb_depth = 32; 428 si->lfb_width = width; 429 si->lfb_height = height; 430 431 si->red_size = 8; 432 si->red_pos = 16; 433 si->green_size = 8; 434 si->green_pos = 8; 435 si->blue_size = 8; 436 si->blue_pos = 0; 437 si->rsvd_size = 8; 438 si->rsvd_pos = 24; 439 440 free_handle: 441 efi_bs_call(free_pool, uga_handle); 442 443 return status; 444 } 445 446 static void setup_graphics(struct boot_params *boot_params) 447 { 448 efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID; 449 struct screen_info *si; 450 efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID; 451 efi_status_t status; 452 unsigned long size; 453 void **gop_handle = NULL; 454 void **uga_handle = NULL; 455 456 si = &boot_params->screen_info; 457 memset(si, 0, sizeof(*si)); 458 459 size = 0; 460 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 461 &graphics_proto, NULL, &size, gop_handle); 462 if (status == EFI_BUFFER_TOO_SMALL) 463 status = efi_setup_gop(si, &graphics_proto, size); 464 465 if (status != EFI_SUCCESS) { 466 size = 0; 467 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, 468 &uga_proto, NULL, &size, uga_handle); 469 if (status == EFI_BUFFER_TOO_SMALL) 470 setup_uga(si, &uga_proto, size); 471 } 472 } 473 474 475 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status) 476 { 477 efi_bs_call(exit, handle, status, 0, NULL); 478 for(;;) 479 asm("hlt"); 480 } 481 482 void __noreturn efi_stub_entry(efi_handle_t handle, 483 efi_system_table_t *sys_table_arg, 484 struct boot_params *boot_params); 485 486 /* 487 * Because the x86 boot code expects to be passed a boot_params we 488 * need to create one ourselves (usually the bootloader would create 489 * one for us). 490 */ 491 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, 492 efi_system_table_t *sys_table_arg) 493 { 494 struct boot_params *boot_params; 495 struct setup_header *hdr; 496 void *image_base; 497 efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID; 498 int options_size = 0; 499 efi_status_t status; 500 char *cmdline_ptr; 501 502 efi_system_table = sys_table_arg; 503 504 /* Check if we were booted by the EFI firmware */ 505 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) 506 efi_exit(handle, EFI_INVALID_PARAMETER); 507 508 status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image); 509 if (status != EFI_SUCCESS) { 510 efi_err("Failed to get handle for LOADED_IMAGE_PROTOCOL\n"); 511 efi_exit(handle, status); 512 } 513 514 image_base = efi_table_attr(image, image_base); 515 image_offset = (void *)startup_32 - image_base; 516 517 status = efi_allocate_pages(sizeof(struct boot_params), 518 (unsigned long *)&boot_params, ULONG_MAX); 519 if (status != EFI_SUCCESS) { 520 efi_err("Failed to allocate lowmem for boot params\n"); 521 efi_exit(handle, status); 522 } 523 524 memset(boot_params, 0x0, sizeof(struct boot_params)); 525 526 hdr = &boot_params->hdr; 527 528 /* Copy the setup header from the second sector to boot_params */ 529 memcpy(&hdr->jump, image_base + 512, 530 sizeof(struct setup_header) - offsetof(struct setup_header, jump)); 531 532 /* 533 * Fill out some of the header fields ourselves because the 534 * EFI firmware loader doesn't load the first sector. 535 */ 536 hdr->root_flags = 1; 537 hdr->vid_mode = 0xffff; 538 hdr->boot_flag = 0xAA55; 539 540 hdr->type_of_loader = 0x21; 541 542 /* Convert unicode cmdline to ascii */ 543 cmdline_ptr = efi_convert_cmdline(image, &options_size); 544 if (!cmdline_ptr) 545 goto fail; 546 547 efi_set_u64_split((unsigned long)cmdline_ptr, 548 &hdr->cmd_line_ptr, &boot_params->ext_cmd_line_ptr); 549 550 hdr->ramdisk_image = 0; 551 hdr->ramdisk_size = 0; 552 553 /* 554 * Disregard any setup data that was provided by the bootloader: 555 * setup_data could be pointing anywhere, and we have no way of 556 * authenticating or validating the payload. 557 */ 558 hdr->setup_data = 0; 559 560 efi_stub_entry(handle, sys_table_arg, boot_params); 561 /* not reached */ 562 563 fail: 564 efi_free(sizeof(struct boot_params), (unsigned long)boot_params); 565 566 efi_exit(handle, status); 567 } 568 569 static void add_e820ext(struct boot_params *params, 570 struct setup_data *e820ext, u32 nr_entries) 571 { 572 struct setup_data *data; 573 574 e820ext->type = SETUP_E820_EXT; 575 e820ext->len = nr_entries * sizeof(struct boot_e820_entry); 576 e820ext->next = 0; 577 578 data = (struct setup_data *)(unsigned long)params->hdr.setup_data; 579 580 while (data && data->next) 581 data = (struct setup_data *)(unsigned long)data->next; 582 583 if (data) 584 data->next = (unsigned long)e820ext; 585 else 586 params->hdr.setup_data = (unsigned long)e820ext; 587 } 588 589 static efi_status_t 590 setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size) 591 { 592 struct boot_e820_entry *entry = params->e820_table; 593 struct efi_info *efi = ¶ms->efi_info; 594 struct boot_e820_entry *prev = NULL; 595 u32 nr_entries; 596 u32 nr_desc; 597 int i; 598 599 nr_entries = 0; 600 nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size; 601 602 for (i = 0; i < nr_desc; i++) { 603 efi_memory_desc_t *d; 604 unsigned int e820_type = 0; 605 unsigned long m = efi->efi_memmap; 606 607 #ifdef CONFIG_X86_64 608 m |= (u64)efi->efi_memmap_hi << 32; 609 #endif 610 611 d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i); 612 switch (d->type) { 613 case EFI_RESERVED_TYPE: 614 case EFI_RUNTIME_SERVICES_CODE: 615 case EFI_RUNTIME_SERVICES_DATA: 616 case EFI_MEMORY_MAPPED_IO: 617 case EFI_MEMORY_MAPPED_IO_PORT_SPACE: 618 case EFI_PAL_CODE: 619 e820_type = E820_TYPE_RESERVED; 620 break; 621 622 case EFI_UNUSABLE_MEMORY: 623 e820_type = E820_TYPE_UNUSABLE; 624 break; 625 626 case EFI_ACPI_RECLAIM_MEMORY: 627 e820_type = E820_TYPE_ACPI; 628 break; 629 630 case EFI_LOADER_CODE: 631 case EFI_LOADER_DATA: 632 case EFI_BOOT_SERVICES_CODE: 633 case EFI_BOOT_SERVICES_DATA: 634 case EFI_CONVENTIONAL_MEMORY: 635 if (efi_soft_reserve_enabled() && 636 (d->attribute & EFI_MEMORY_SP)) 637 e820_type = E820_TYPE_SOFT_RESERVED; 638 else 639 e820_type = E820_TYPE_RAM; 640 break; 641 642 case EFI_ACPI_MEMORY_NVS: 643 e820_type = E820_TYPE_NVS; 644 break; 645 646 case EFI_PERSISTENT_MEMORY: 647 e820_type = E820_TYPE_PMEM; 648 break; 649 650 case EFI_UNACCEPTED_MEMORY: 651 if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) { 652 efi_warn_once( 653 "The system has unaccepted memory, but kernel does not support it\nConsider enabling CONFIG_UNACCEPTED_MEMORY\n"); 654 continue; 655 } 656 e820_type = E820_TYPE_RAM; 657 process_unaccepted_memory(d->phys_addr, 658 d->phys_addr + PAGE_SIZE * d->num_pages); 659 break; 660 default: 661 continue; 662 } 663 664 /* Merge adjacent mappings */ 665 if (prev && prev->type == e820_type && 666 (prev->addr + prev->size) == d->phys_addr) { 667 prev->size += d->num_pages << 12; 668 continue; 669 } 670 671 if (nr_entries == ARRAY_SIZE(params->e820_table)) { 672 u32 need = (nr_desc - i) * sizeof(struct e820_entry) + 673 sizeof(struct setup_data); 674 675 if (!e820ext || e820ext_size < need) 676 return EFI_BUFFER_TOO_SMALL; 677 678 /* boot_params map full, switch to e820 extended */ 679 entry = (struct boot_e820_entry *)e820ext->data; 680 } 681 682 entry->addr = d->phys_addr; 683 entry->size = d->num_pages << PAGE_SHIFT; 684 entry->type = e820_type; 685 prev = entry++; 686 nr_entries++; 687 } 688 689 if (nr_entries > ARRAY_SIZE(params->e820_table)) { 690 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table); 691 692 add_e820ext(params, e820ext, nr_e820ext); 693 nr_entries -= nr_e820ext; 694 } 695 696 params->e820_entries = (u8)nr_entries; 697 698 return EFI_SUCCESS; 699 } 700 701 static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext, 702 u32 *e820ext_size) 703 { 704 efi_status_t status; 705 unsigned long size; 706 707 size = sizeof(struct setup_data) + 708 sizeof(struct e820_entry) * nr_desc; 709 710 if (*e820ext) { 711 efi_bs_call(free_pool, *e820ext); 712 *e820ext = NULL; 713 *e820ext_size = 0; 714 } 715 716 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, 717 (void **)e820ext); 718 if (status == EFI_SUCCESS) 719 *e820ext_size = size; 720 721 return status; 722 } 723 724 static efi_status_t allocate_e820(struct boot_params *params, 725 struct setup_data **e820ext, 726 u32 *e820ext_size) 727 { 728 struct efi_boot_memmap *map; 729 efi_status_t status; 730 __u32 nr_desc; 731 732 status = efi_get_memory_map(&map, false); 733 if (status != EFI_SUCCESS) 734 return status; 735 736 nr_desc = map->map_size / map->desc_size; 737 if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) { 738 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) + 739 EFI_MMAP_NR_SLACK_SLOTS; 740 741 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size); 742 } 743 744 if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && status == EFI_SUCCESS) 745 status = allocate_unaccepted_bitmap(nr_desc, map); 746 747 efi_bs_call(free_pool, map); 748 return status; 749 } 750 751 struct exit_boot_struct { 752 struct boot_params *boot_params; 753 struct efi_info *efi; 754 }; 755 756 static efi_status_t exit_boot_func(struct efi_boot_memmap *map, 757 void *priv) 758 { 759 const char *signature; 760 struct exit_boot_struct *p = priv; 761 762 signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE 763 : EFI32_LOADER_SIGNATURE; 764 memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32)); 765 766 efi_set_u64_split((unsigned long)efi_system_table, 767 &p->efi->efi_systab, &p->efi->efi_systab_hi); 768 p->efi->efi_memdesc_size = map->desc_size; 769 p->efi->efi_memdesc_version = map->desc_ver; 770 efi_set_u64_split((unsigned long)map->map, 771 &p->efi->efi_memmap, &p->efi->efi_memmap_hi); 772 p->efi->efi_memmap_size = map->map_size; 773 774 return EFI_SUCCESS; 775 } 776 777 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle) 778 { 779 struct setup_data *e820ext = NULL; 780 __u32 e820ext_size = 0; 781 efi_status_t status; 782 struct exit_boot_struct priv; 783 784 priv.boot_params = boot_params; 785 priv.efi = &boot_params->efi_info; 786 787 status = allocate_e820(boot_params, &e820ext, &e820ext_size); 788 if (status != EFI_SUCCESS) 789 return status; 790 791 /* Might as well exit boot services now */ 792 status = efi_exit_boot_services(handle, &priv, exit_boot_func); 793 if (status != EFI_SUCCESS) 794 return status; 795 796 /* Historic? */ 797 boot_params->alt_mem_k = 32 * 1024; 798 799 status = setup_e820(boot_params, e820ext, e820ext_size); 800 if (status != EFI_SUCCESS) 801 return status; 802 803 return EFI_SUCCESS; 804 } 805 806 /* 807 * On success, we return the address of startup_32, which has potentially been 808 * relocated by efi_relocate_kernel. 809 * On failure, we exit to the firmware via efi_exit instead of returning. 810 */ 811 asmlinkage unsigned long efi_main(efi_handle_t handle, 812 efi_system_table_t *sys_table_arg, 813 struct boot_params *boot_params) 814 { 815 unsigned long bzimage_addr = (unsigned long)startup_32; 816 unsigned long buffer_start, buffer_end; 817 struct setup_header *hdr = &boot_params->hdr; 818 const struct linux_efi_initrd *initrd = NULL; 819 efi_status_t status; 820 821 efi_system_table = sys_table_arg; 822 /* Check if we were booted by the EFI firmware */ 823 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) 824 efi_exit(handle, EFI_INVALID_PARAMETER); 825 826 efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID); 827 if (efi_dxe_table && 828 efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) { 829 efi_warn("Ignoring DXE services table: invalid signature\n"); 830 efi_dxe_table = NULL; 831 } 832 833 /* 834 * If the kernel isn't already loaded at a suitable address, 835 * relocate it. 836 * 837 * It must be loaded above LOAD_PHYSICAL_ADDR. 838 * 839 * The maximum address for 64-bit is 1 << 46 for 4-level paging. This 840 * is defined as the macro MAXMEM, but unfortunately that is not a 841 * compile-time constant if 5-level paging is configured, so we instead 842 * define our own macro for use here. 843 * 844 * For 32-bit, the maximum address is complicated to figure out, for 845 * now use KERNEL_IMAGE_SIZE, which will be 512MiB, the same as what 846 * KASLR uses. 847 * 848 * Also relocate it if image_offset is zero, i.e. the kernel wasn't 849 * loaded by LoadImage, but rather by a bootloader that called the 850 * handover entry. The reason we must always relocate in this case is 851 * to handle the case of systemd-boot booting a unified kernel image, 852 * which is a PE executable that contains the bzImage and an initrd as 853 * COFF sections. The initrd section is placed after the bzImage 854 * without ensuring that there are at least init_size bytes available 855 * for the bzImage, and thus the compressed kernel's startup code may 856 * overwrite the initrd unless it is moved out of the way. 857 */ 858 859 buffer_start = ALIGN(bzimage_addr - image_offset, 860 hdr->kernel_alignment); 861 buffer_end = buffer_start + hdr->init_size; 862 863 if ((buffer_start < LOAD_PHYSICAL_ADDR) || 864 (IS_ENABLED(CONFIG_X86_32) && buffer_end > KERNEL_IMAGE_SIZE) || 865 (IS_ENABLED(CONFIG_X86_64) && buffer_end > MAXMEM_X86_64_4LEVEL) || 866 (image_offset == 0)) { 867 extern char _bss[]; 868 869 status = efi_relocate_kernel(&bzimage_addr, 870 (unsigned long)_bss - bzimage_addr, 871 hdr->init_size, 872 hdr->pref_address, 873 hdr->kernel_alignment, 874 LOAD_PHYSICAL_ADDR); 875 if (status != EFI_SUCCESS) { 876 efi_err("efi_relocate_kernel() failed!\n"); 877 goto fail; 878 } 879 /* 880 * Now that we've copied the kernel elsewhere, we no longer 881 * have a set up block before startup_32(), so reset image_offset 882 * to zero in case it was set earlier. 883 */ 884 image_offset = 0; 885 } 886 887 #ifdef CONFIG_CMDLINE_BOOL 888 status = efi_parse_options(CONFIG_CMDLINE); 889 if (status != EFI_SUCCESS) { 890 efi_err("Failed to parse options\n"); 891 goto fail; 892 } 893 #endif 894 if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) { 895 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr | 896 ((u64)boot_params->ext_cmd_line_ptr << 32)); 897 status = efi_parse_options((char *)cmdline_paddr); 898 if (status != EFI_SUCCESS) { 899 efi_err("Failed to parse options\n"); 900 goto fail; 901 } 902 } 903 904 /* 905 * At this point, an initrd may already have been loaded by the 906 * bootloader and passed via bootparams. We permit an initrd loaded 907 * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it. 908 * 909 * If the device path is not present, any command-line initrd= 910 * arguments will be processed only if image is not NULL, which will be 911 * the case only if we were loaded via the PE entry point. 912 */ 913 status = efi_load_initrd(image, hdr->initrd_addr_max, ULONG_MAX, 914 &initrd); 915 if (status != EFI_SUCCESS) 916 goto fail; 917 if (initrd && initrd->size > 0) { 918 efi_set_u64_split(initrd->base, &hdr->ramdisk_image, 919 &boot_params->ext_ramdisk_image); 920 efi_set_u64_split(initrd->size, &hdr->ramdisk_size, 921 &boot_params->ext_ramdisk_size); 922 } 923 924 925 /* 926 * If the boot loader gave us a value for secure_boot then we use that, 927 * otherwise we ask the BIOS. 928 */ 929 if (boot_params->secure_boot == efi_secureboot_mode_unset) 930 boot_params->secure_boot = efi_get_secureboot(); 931 932 /* Ask the firmware to clear memory on unclean shutdown */ 933 efi_enable_reset_attack_mitigation(); 934 935 efi_random_get_seed(); 936 937 efi_retrieve_tpm2_eventlog(); 938 939 setup_graphics(boot_params); 940 941 setup_efi_pci(boot_params); 942 943 setup_quirks(boot_params, bzimage_addr, buffer_end - buffer_start); 944 945 setup_unaccepted_memory(); 946 947 status = exit_boot(boot_params, handle); 948 if (status != EFI_SUCCESS) { 949 efi_err("exit_boot() failed!\n"); 950 goto fail; 951 } 952 953 return bzimage_addr; 954 fail: 955 efi_err("efi_main() failed!\n"); 956 957 efi_exit(handle, status); 958 } 959