drivers/firmware/efi/libstub/x86-stub.c

   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 extern const u8 startup_32[], startup_64[];
 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 = &params->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 static void __noreturn enter_kernel(unsigned long kernel_addr,
 807                                     struct boot_params *boot_params)
 808 {
 809         /* enter decompressed kernel with boot_params pointer in RSI/ESI */
 810         asm("jmp *%0"::"r"(kernel_addr), "S"(boot_params));
 811
 812         unreachable();
 813 }
 814
 815 /*
 816  * On success, this routine will jump to the relocated image directly and never
 817  * return.  On failure, it will exit to the firmware via efi_exit() instead of
 818  * returning.
 819  */
 820 void __noreturn efi_stub_entry(efi_handle_t handle,
 821                                efi_system_table_t *sys_table_arg,
 822                                struct boot_params *boot_params)
 823 {
 824         unsigned long bzimage_addr = (unsigned long)startup_32;
 825         unsigned long buffer_start, buffer_end;
 826         struct setup_header *hdr = &boot_params->hdr;
 827         const struct linux_efi_initrd *initrd = NULL;
 828         efi_status_t status;
 829
 830         efi_system_table = sys_table_arg;
 831         /* Check if we were booted by the EFI firmware */
 832         if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
 833                 efi_exit(handle, EFI_INVALID_PARAMETER);
 834
 835         efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID);
 836         if (efi_dxe_table &&
 837             efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) {
 838                 efi_warn("Ignoring DXE services table: invalid signature\n");
 839                 efi_dxe_table = NULL;
 840         }
 841
 842         /*
 843          * If the kernel isn't already loaded at a suitable address,
 844          * relocate it.
 845          *
 846          * It must be loaded above LOAD_PHYSICAL_ADDR.
 847          *
 848          * The maximum address for 64-bit is 1 << 46 for 4-level paging. This
 849          * is defined as the macro MAXMEM, but unfortunately that is not a
 850          * compile-time constant if 5-level paging is configured, so we instead
 851          * define our own macro for use here.
 852          *
 853          * For 32-bit, the maximum address is complicated to figure out, for
 854          * now use KERNEL_IMAGE_SIZE, which will be 512MiB, the same as what
 855          * KASLR uses.
 856          *
 857          * Also relocate it if image_offset is zero, i.e. the kernel wasn't
 858          * loaded by LoadImage, but rather by a bootloader that called the
 859          * handover entry. The reason we must always relocate in this case is
 860          * to handle the case of systemd-boot booting a unified kernel image,
 861          * which is a PE executable that contains the bzImage and an initrd as
 862          * COFF sections. The initrd section is placed after the bzImage
 863          * without ensuring that there are at least init_size bytes available
 864          * for the bzImage, and thus the compressed kernel's startup code may
 865          * overwrite the initrd unless it is moved out of the way.
 866          */
 867
 868         buffer_start = ALIGN(bzimage_addr - image_offset,
 869                              hdr->kernel_alignment);
 870         buffer_end = buffer_start + hdr->init_size;
 871
 872         if ((buffer_start < LOAD_PHYSICAL_ADDR)                              ||
 873             (IS_ENABLED(CONFIG_X86_32) && buffer_end > KERNEL_IMAGE_SIZE)    ||
 874             (IS_ENABLED(CONFIG_X86_64) && buffer_end > MAXMEM_X86_64_4LEVEL) ||
 875             (image_offset == 0)) {
 876                 extern char _bss[];
 877
 878                 status = efi_relocate_kernel(&bzimage_addr,
 879                                              (unsigned long)_bss - bzimage_addr,
 880                                              hdr->init_size,
 881                                              hdr->pref_address,
 882                                              hdr->kernel_alignment,
 883                                              LOAD_PHYSICAL_ADDR);
 884                 if (status != EFI_SUCCESS) {
 885                         efi_err("efi_relocate_kernel() failed!\n");
 886                         goto fail;
 887                 }
 888                 /*
 889                  * Now that we've copied the kernel elsewhere, we no longer
 890                  * have a set up block before startup_32(), so reset image_offset
 891                  * to zero in case it was set earlier.
 892                  */
 893                 image_offset = 0;
 894         }
 895
 896 #ifdef CONFIG_CMDLINE_BOOL
 897         status = efi_parse_options(CONFIG_CMDLINE);
 898         if (status != EFI_SUCCESS) {
 899                 efi_err("Failed to parse options\n");
 900                 goto fail;
 901         }
 902 #endif
 903         if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
 904                 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr |
 905                                                ((u64)boot_params->ext_cmd_line_ptr << 32));
 906                 status = efi_parse_options((char *)cmdline_paddr);
 907                 if (status != EFI_SUCCESS) {
 908                         efi_err("Failed to parse options\n");
 909                         goto fail;
 910                 }
 911         }
 912
 913         /*
 914          * At this point, an initrd may already have been loaded by the
 915          * bootloader and passed via bootparams. We permit an initrd loaded
 916          * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it.
 917          *
 918          * If the device path is not present, any command-line initrd=
 919          * arguments will be processed only if image is not NULL, which will be
 920          * the case only if we were loaded via the PE entry point.
 921          */
 922         status = efi_load_initrd(image, hdr->initrd_addr_max, ULONG_MAX,
 923                                  &initrd);
 924         if (status != EFI_SUCCESS)
 925                 goto fail;
 926         if (initrd && initrd->size > 0) {
 927                 efi_set_u64_split(initrd->base, &hdr->ramdisk_image,
 928                                   &boot_params->ext_ramdisk_image);
 929                 efi_set_u64_split(initrd->size, &hdr->ramdisk_size,
 930                                   &boot_params->ext_ramdisk_size);
 931         }
 932
 933
 934         /*
 935          * If the boot loader gave us a value for secure_boot then we use that,
 936          * otherwise we ask the BIOS.
 937          */
 938         if (boot_params->secure_boot == efi_secureboot_mode_unset)
 939                 boot_params->secure_boot = efi_get_secureboot();
 940
 941         /* Ask the firmware to clear memory on unclean shutdown */
 942         efi_enable_reset_attack_mitigation();
 943
 944         efi_random_get_seed();
 945
 946         efi_retrieve_tpm2_eventlog();
 947
 948         setup_graphics(boot_params);
 949
 950         setup_efi_pci(boot_params);
 951
 952         setup_quirks(boot_params, bzimage_addr, buffer_end - buffer_start);
 953
 954         setup_unaccepted_memory();
 955
 956         status = exit_boot(boot_params, handle);
 957         if (status != EFI_SUCCESS) {
 958                 efi_err("exit_boot() failed!\n");
 959                 goto fail;
 960         }
 961
 962         if (IS_ENABLED(CONFIG_X86_64))
 963                 bzimage_addr += startup_64 - startup_32;
 964
 965         enter_kernel(bzimage_addr, boot_params);
 966 fail:
 967         efi_err("efi_stub_entry() failed!\n");
 968
 969         efi_exit(handle, status);
 970 }
 971
 972 #ifdef CONFIG_EFI_HANDOVER_PROTOCOL
 973 void efi_handover_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
 974                         struct boot_params *boot_params)
 975 {
 976         extern char _bss[], _ebss[];
 977
 978         memset(_bss, 0, _ebss - _bss);
 979         efi_stub_entry(handle, sys_table_arg, boot_params);
 980 }
 981
 982 #ifndef CONFIG_EFI_MIXED
 983 extern __alias(efi_handover_entry)
 984 void efi32_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
 985                       struct boot_params *boot_params);
 986
 987 extern __alias(efi_handover_entry)
 988 void efi64_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
 989                       struct boot_params *boot_params);
 990 #endif
 991 #endif