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
  12 #include <asm/efi.h>
  13 #include <asm/e820/types.h>
  14 #include <asm/setup.h>
  15 #include <asm/desc.h>
  16 #include <asm/boot.h>
  17
  18 #include "efistub.h"
  19
  20 /* Maximum physical address for 64-bit kernel with 4-level paging */
  21 #define MAXMEM_X86_64_4LEVEL (1ull << 46)
  22
  23 const efi_system_table_t *efi_system_table;
  24 extern u32 image_offset;
  25
  26 static efi_status_t
  27 preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
  28 {
  29         struct pci_setup_rom *rom = NULL;
  30         efi_status_t status;
  31         unsigned long size;
  32         uint64_t romsize;
  33         void *romimage;
  34
  35         /*
  36          * Some firmware images contain EFI function pointers at the place where
  37          * the romimage and romsize fields are supposed to be. Typically the EFI
  38          * code is mapped at high addresses, translating to an unrealistically
  39          * large romsize. The UEFI spec limits the size of option ROMs to 16
  40          * MiB so we reject any ROMs over 16 MiB in size to catch this.
  41          */
  42         romimage = efi_table_attr(pci, romimage);
  43         romsize = efi_table_attr(pci, romsize);
  44         if (!romimage || !romsize || romsize > SZ_16M)
  45                 return EFI_INVALID_PARAMETER;
  46
  47         size = romsize + sizeof(*rom);
  48
  49         status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
  50                              (void **)&rom);
  51         if (status != EFI_SUCCESS) {
  52                 efi_printk("Failed to allocate memory for 'rom'\n");
  53                 return status;
  54         }
  55
  56         memset(rom, 0, sizeof(*rom));
  57
  58         rom->data.type  = SETUP_PCI;
  59         rom->data.len   = size - sizeof(struct setup_data);
  60         rom->data.next  = 0;
  61         rom->pcilen     = pci->romsize;
  62         *__rom = rom;
  63
  64         status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
  65                                 PCI_VENDOR_ID, 1, &rom->vendor);
  66
  67         if (status != EFI_SUCCESS) {
  68                 efi_printk("Failed to read rom->vendor\n");
  69                 goto free_struct;
  70         }
  71
  72         status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
  73                                 PCI_DEVICE_ID, 1, &rom->devid);
  74
  75         if (status != EFI_SUCCESS) {
  76                 efi_printk("Failed to read rom->devid\n");
  77                 goto free_struct;
  78         }
  79
  80         status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus,
  81                                 &rom->device, &rom->function);
  82
  83         if (status != EFI_SUCCESS)
  84                 goto free_struct;
  85
  86         memcpy(rom->romdata, romimage, romsize);
  87         return status;
  88
  89 free_struct:
  90         efi_bs_call(free_pool, rom);
  91         return status;
  92 }
  93
  94 /*
  95  * There's no way to return an informative status from this function,
  96  * because any analysis (and printing of error messages) needs to be
  97  * done directly at the EFI function call-site.
  98  *
  99  * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we
 100  * just didn't find any PCI devices, but there's no way to tell outside
 101  * the context of the call.
 102  */
 103 static void setup_efi_pci(struct boot_params *params)
 104 {
 105         efi_status_t status;
 106         void **pci_handle = NULL;
 107         efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID;
 108         unsigned long size = 0;
 109         struct setup_data *data;
 110         efi_handle_t h;
 111         int i;
 112
 113         status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
 114                              &pci_proto, NULL, &size, pci_handle);
 115
 116         if (status == EFI_BUFFER_TOO_SMALL) {
 117                 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
 118                                      (void **)&pci_handle);
 119
 120                 if (status != EFI_SUCCESS) {
 121                         efi_printk("Failed to allocate memory for 'pci_handle'\n");
 122                         return;
 123                 }
 124
 125                 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
 126                                      &pci_proto, NULL, &size, pci_handle);
 127         }
 128
 129         if (status != EFI_SUCCESS)
 130                 goto free_handle;
 131
 132         data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
 133
 134         while (data && data->next)
 135                 data = (struct setup_data *)(unsigned long)data->next;
 136
 137         for_each_efi_handle(h, pci_handle, size, i) {
 138                 efi_pci_io_protocol_t *pci = NULL;
 139                 struct pci_setup_rom *rom;
 140
 141                 status = efi_bs_call(handle_protocol, h, &pci_proto,
 142                                      (void **)&pci);
 143                 if (status != EFI_SUCCESS || !pci)
 144                         continue;
 145
 146                 status = preserve_pci_rom_image(pci, &rom);
 147                 if (status != EFI_SUCCESS)
 148                         continue;
 149
 150                 if (data)
 151                         data->next = (unsigned long)rom;
 152                 else
 153                         params->hdr.setup_data = (unsigned long)rom;
 154
 155                 data = (struct setup_data *)rom;
 156         }
 157
 158 free_handle:
 159         efi_bs_call(free_pool, pci_handle);
 160 }
 161
 162 static void retrieve_apple_device_properties(struct boot_params *boot_params)
 163 {
 164         efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID;
 165         struct setup_data *data, *new;
 166         efi_status_t status;
 167         u32 size = 0;
 168         apple_properties_protocol_t *p;
 169
 170         status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p);
 171         if (status != EFI_SUCCESS)
 172                 return;
 173
 174         if (efi_table_attr(p, version) != 0x10000) {
 175                 efi_printk("Unsupported properties proto version\n");
 176                 return;
 177         }
 178
 179         efi_call_proto(p, get_all, NULL, &size);
 180         if (!size)
 181                 return;
 182
 183         do {
 184                 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
 185                                      size + sizeof(struct setup_data),
 186                                      (void **)&new);
 187                 if (status != EFI_SUCCESS) {
 188                         efi_printk("Failed to allocate memory for 'properties'\n");
 189                         return;
 190                 }
 191
 192                 status = efi_call_proto(p, get_all, new->data, &size);
 193
 194                 if (status == EFI_BUFFER_TOO_SMALL)
 195                         efi_bs_call(free_pool, new);
 196         } while (status == EFI_BUFFER_TOO_SMALL);
 197
 198         new->type = SETUP_APPLE_PROPERTIES;
 199         new->len  = size;
 200         new->next = 0;
 201
 202         data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data;
 203         if (!data) {
 204                 boot_params->hdr.setup_data = (unsigned long)new;
 205         } else {
 206                 while (data->next)
 207                         data = (struct setup_data *)(unsigned long)data->next;
 208                 data->next = (unsigned long)new;
 209         }
 210 }
 211
 212 static const efi_char16_t apple[] = L"Apple";
 213
 214 static void setup_quirks(struct boot_params *boot_params)
 215 {
 216         efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long)
 217                 efi_table_attr(efi_system_table, fw_vendor);
 218
 219         if (!memcmp(fw_vendor, apple, sizeof(apple))) {
 220                 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES))
 221                         retrieve_apple_device_properties(boot_params);
 222         }
 223 }
 224
 225 /*
 226  * See if we have Universal Graphics Adapter (UGA) protocol
 227  */
 228 static efi_status_t
 229 setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size)
 230 {
 231         efi_status_t status;
 232         u32 width, height;
 233         void **uga_handle = NULL;
 234         efi_uga_draw_protocol_t *uga = NULL, *first_uga;
 235         efi_handle_t handle;
 236         int i;
 237
 238         status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
 239                              (void **)&uga_handle);
 240         if (status != EFI_SUCCESS)
 241                 return status;
 242
 243         status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
 244                              uga_proto, NULL, &size, uga_handle);
 245         if (status != EFI_SUCCESS)
 246                 goto free_handle;
 247
 248         height = 0;
 249         width = 0;
 250
 251         first_uga = NULL;
 252         for_each_efi_handle(handle, uga_handle, size, i) {
 253                 efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
 254                 u32 w, h, depth, refresh;
 255                 void *pciio;
 256
 257                 status = efi_bs_call(handle_protocol, handle, uga_proto,
 258                                      (void **)&uga);
 259                 if (status != EFI_SUCCESS)
 260                         continue;
 261
 262                 pciio = NULL;
 263                 efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio);
 264
 265                 status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh);
 266                 if (status == EFI_SUCCESS && (!first_uga || pciio)) {
 267                         width = w;
 268                         height = h;
 269
 270                         /*
 271                          * Once we've found a UGA supporting PCIIO,
 272                          * don't bother looking any further.
 273                          */
 274                         if (pciio)
 275                                 break;
 276
 277                         first_uga = uga;
 278                 }
 279         }
 280
 281         if (!width && !height)
 282                 goto free_handle;
 283
 284         /* EFI framebuffer */
 285         si->orig_video_isVGA    = VIDEO_TYPE_EFI;
 286
 287         si->lfb_depth           = 32;
 288         si->lfb_width           = width;
 289         si->lfb_height          = height;
 290
 291         si->red_size            = 8;
 292         si->red_pos             = 16;
 293         si->green_size          = 8;
 294         si->green_pos           = 8;
 295         si->blue_size           = 8;
 296         si->blue_pos            = 0;
 297         si->rsvd_size           = 8;
 298         si->rsvd_pos            = 24;
 299
 300 free_handle:
 301         efi_bs_call(free_pool, uga_handle);
 302
 303         return status;
 304 }
 305
 306 static void setup_graphics(struct boot_params *boot_params)
 307 {
 308         efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
 309         struct screen_info *si;
 310         efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
 311         efi_status_t status;
 312         unsigned long size;
 313         void **gop_handle = NULL;
 314         void **uga_handle = NULL;
 315
 316         si = &boot_params->screen_info;
 317         memset(si, 0, sizeof(*si));
 318
 319         size = 0;
 320         status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
 321                              &graphics_proto, NULL, &size, gop_handle);
 322         if (status == EFI_BUFFER_TOO_SMALL)
 323                 status = efi_setup_gop(si, &graphics_proto, size);
 324
 325         if (status != EFI_SUCCESS) {
 326                 size = 0;
 327                 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
 328                                      &uga_proto, NULL, &size, uga_handle);
 329                 if (status == EFI_BUFFER_TOO_SMALL)
 330                         setup_uga(si, &uga_proto, size);
 331         }
 332 }
 333
 334
 335 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)
 336 {
 337         efi_bs_call(exit, handle, status, 0, NULL);
 338         for(;;)
 339                 asm("hlt");
 340 }
 341
 342 void startup_32(struct boot_params *boot_params);
 343
 344 void __noreturn efi_stub_entry(efi_handle_t handle,
 345                                efi_system_table_t *sys_table_arg,
 346                                struct boot_params *boot_params);
 347
 348 /*
 349  * Because the x86 boot code expects to be passed a boot_params we
 350  * need to create one ourselves (usually the bootloader would create
 351  * one for us).
 352  */
 353 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 354                                    efi_system_table_t *sys_table_arg)
 355 {
 356         struct boot_params *boot_params;
 357         struct setup_header *hdr;
 358         efi_loaded_image_t *image;
 359         void *image_base;
 360         efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
 361         int options_size = 0;
 362         efi_status_t status;
 363         char *cmdline_ptr;
 364         unsigned long ramdisk_addr;
 365         unsigned long ramdisk_size;
 366
 367         efi_system_table = sys_table_arg;
 368
 369         /* Check if we were booted by the EFI firmware */
 370         if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
 371                 efi_exit(handle, EFI_INVALID_PARAMETER);
 372
 373         status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image);
 374         if (status != EFI_SUCCESS) {
 375                 efi_printk("Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
 376                 efi_exit(handle, status);
 377         }
 378
 379         image_base = efi_table_attr(image, image_base);
 380         image_offset = (void *)startup_32 - image_base;
 381
 382         status = efi_allocate_pages(sizeof(struct boot_params),
 383                                     (unsigned long *)&boot_params, ULONG_MAX);
 384         if (status != EFI_SUCCESS) {
 385                 efi_printk("Failed to allocate lowmem for boot params\n");
 386                 efi_exit(handle, status);
 387         }
 388
 389         memset(boot_params, 0x0, sizeof(struct boot_params));
 390
 391         hdr = &boot_params->hdr;
 392
 393         /* Copy the second sector to boot_params */
 394         memcpy(&hdr->jump, image_base + 512, 512);
 395
 396         /*
 397          * Fill out some of the header fields ourselves because the
 398          * EFI firmware loader doesn't load the first sector.
 399          */
 400         hdr->root_flags = 1;
 401         hdr->vid_mode   = 0xffff;
 402         hdr->boot_flag  = 0xAA55;
 403
 404         hdr->type_of_loader = 0x21;
 405
 406         /* Convert unicode cmdline to ascii */
 407         cmdline_ptr = efi_convert_cmdline(image, &options_size, ULONG_MAX);
 408         if (!cmdline_ptr)
 409                 goto fail;
 410
 411         hdr->cmd_line_ptr = (unsigned long)cmdline_ptr;
 412         /* Fill in upper bits of command line address, NOP on 32 bit  */
 413         boot_params->ext_cmd_line_ptr = (u64)(unsigned long)cmdline_ptr >> 32;
 414
 415         hdr->ramdisk_image = 0;
 416         hdr->ramdisk_size = 0;
 417
 418         if (efi_is_native()) {
 419                 status = efi_parse_options(cmdline_ptr);
 420                 if (status != EFI_SUCCESS)
 421                         goto fail2;
 422
 423                 if (!efi_noinitrd) {
 424                         status = efi_load_initrd(image, &ramdisk_addr,
 425                                                  &ramdisk_size,
 426                                                  hdr->initrd_addr_max,
 427                                                  ULONG_MAX);
 428                         if (status != EFI_SUCCESS)
 429                                 goto fail2;
 430                         hdr->ramdisk_image = ramdisk_addr & 0xffffffff;
 431                         hdr->ramdisk_size  = ramdisk_size & 0xffffffff;
 432                         boot_params->ext_ramdisk_image = (u64)ramdisk_addr >> 32;
 433                         boot_params->ext_ramdisk_size  = (u64)ramdisk_size >> 32;
 434                 }
 435         }
 436
 437         efi_stub_entry(handle, sys_table_arg, boot_params);
 438         /* not reached */
 439
 440 fail2:
 441         efi_free(options_size, (unsigned long)cmdline_ptr);
 442 fail:
 443         efi_free(sizeof(struct boot_params), (unsigned long)boot_params);
 444
 445         efi_exit(handle, status);
 446 }
 447
 448 static void add_e820ext(struct boot_params *params,
 449                         struct setup_data *e820ext, u32 nr_entries)
 450 {
 451         struct setup_data *data;
 452
 453         e820ext->type = SETUP_E820_EXT;
 454         e820ext->len  = nr_entries * sizeof(struct boot_e820_entry);
 455         e820ext->next = 0;
 456
 457         data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
 458
 459         while (data && data->next)
 460                 data = (struct setup_data *)(unsigned long)data->next;
 461
 462         if (data)
 463                 data->next = (unsigned long)e820ext;
 464         else
 465                 params->hdr.setup_data = (unsigned long)e820ext;
 466 }
 467
 468 static efi_status_t
 469 setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size)
 470 {
 471         struct boot_e820_entry *entry = params->e820_table;
 472         struct efi_info *efi = &params->efi_info;
 473         struct boot_e820_entry *prev = NULL;
 474         u32 nr_entries;
 475         u32 nr_desc;
 476         int i;
 477
 478         nr_entries = 0;
 479         nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;
 480
 481         for (i = 0; i < nr_desc; i++) {
 482                 efi_memory_desc_t *d;
 483                 unsigned int e820_type = 0;
 484                 unsigned long m = efi->efi_memmap;
 485
 486 #ifdef CONFIG_X86_64
 487                 m |= (u64)efi->efi_memmap_hi << 32;
 488 #endif
 489
 490                 d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i);
 491                 switch (d->type) {
 492                 case EFI_RESERVED_TYPE:
 493                 case EFI_RUNTIME_SERVICES_CODE:
 494                 case EFI_RUNTIME_SERVICES_DATA:
 495                 case EFI_MEMORY_MAPPED_IO:
 496                 case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
 497                 case EFI_PAL_CODE:
 498                         e820_type = E820_TYPE_RESERVED;
 499                         break;
 500
 501                 case EFI_UNUSABLE_MEMORY:
 502                         e820_type = E820_TYPE_UNUSABLE;
 503                         break;
 504
 505                 case EFI_ACPI_RECLAIM_MEMORY:
 506                         e820_type = E820_TYPE_ACPI;
 507                         break;
 508
 509                 case EFI_LOADER_CODE:
 510                 case EFI_LOADER_DATA:
 511                 case EFI_BOOT_SERVICES_CODE:
 512                 case EFI_BOOT_SERVICES_DATA:
 513                 case EFI_CONVENTIONAL_MEMORY:
 514                         if (efi_soft_reserve_enabled() &&
 515                             (d->attribute & EFI_MEMORY_SP))
 516                                 e820_type = E820_TYPE_SOFT_RESERVED;
 517                         else
 518                                 e820_type = E820_TYPE_RAM;
 519                         break;
 520
 521                 case EFI_ACPI_MEMORY_NVS:
 522                         e820_type = E820_TYPE_NVS;
 523                         break;
 524
 525                 case EFI_PERSISTENT_MEMORY:
 526                         e820_type = E820_TYPE_PMEM;
 527                         break;
 528
 529                 default:
 530                         continue;
 531                 }
 532
 533                 /* Merge adjacent mappings */
 534                 if (prev && prev->type == e820_type &&
 535                     (prev->addr + prev->size) == d->phys_addr) {
 536                         prev->size += d->num_pages << 12;
 537                         continue;
 538                 }
 539
 540                 if (nr_entries == ARRAY_SIZE(params->e820_table)) {
 541                         u32 need = (nr_desc - i) * sizeof(struct e820_entry) +
 542                                    sizeof(struct setup_data);
 543
 544                         if (!e820ext || e820ext_size < need)
 545                                 return EFI_BUFFER_TOO_SMALL;
 546
 547                         /* boot_params map full, switch to e820 extended */
 548                         entry = (struct boot_e820_entry *)e820ext->data;
 549                 }
 550
 551                 entry->addr = d->phys_addr;
 552                 entry->size = d->num_pages << PAGE_SHIFT;
 553                 entry->type = e820_type;
 554                 prev = entry++;
 555                 nr_entries++;
 556         }
 557
 558         if (nr_entries > ARRAY_SIZE(params->e820_table)) {
 559                 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table);
 560
 561                 add_e820ext(params, e820ext, nr_e820ext);
 562                 nr_entries -= nr_e820ext;
 563         }
 564
 565         params->e820_entries = (u8)nr_entries;
 566
 567         return EFI_SUCCESS;
 568 }
 569
 570 static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
 571                                   u32 *e820ext_size)
 572 {
 573         efi_status_t status;
 574         unsigned long size;
 575
 576         size = sizeof(struct setup_data) +
 577                 sizeof(struct e820_entry) * nr_desc;
 578
 579         if (*e820ext) {
 580                 efi_bs_call(free_pool, *e820ext);
 581                 *e820ext = NULL;
 582                 *e820ext_size = 0;
 583         }
 584
 585         status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
 586                              (void **)e820ext);
 587         if (status == EFI_SUCCESS)
 588                 *e820ext_size = size;
 589
 590         return status;
 591 }
 592
 593 static efi_status_t allocate_e820(struct boot_params *params,
 594                                   struct setup_data **e820ext,
 595                                   u32 *e820ext_size)
 596 {
 597         unsigned long map_size, desc_size, buff_size;
 598         struct efi_boot_memmap boot_map;
 599         efi_memory_desc_t *map;
 600         efi_status_t status;
 601         __u32 nr_desc;
 602
 603         boot_map.map            = &map;
 604         boot_map.map_size       = &map_size;
 605         boot_map.desc_size      = &desc_size;
 606         boot_map.desc_ver       = NULL;
 607         boot_map.key_ptr        = NULL;
 608         boot_map.buff_size      = &buff_size;
 609
 610         status = efi_get_memory_map(&boot_map);
 611         if (status != EFI_SUCCESS)
 612                 return status;
 613
 614         nr_desc = buff_size / desc_size;
 615
 616         if (nr_desc > ARRAY_SIZE(params->e820_table)) {
 617                 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table);
 618
 619                 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
 620                 if (status != EFI_SUCCESS)
 621                         return status;
 622         }
 623
 624         return EFI_SUCCESS;
 625 }
 626
 627 struct exit_boot_struct {
 628         struct boot_params      *boot_params;
 629         struct efi_info         *efi;
 630 };
 631
 632 static efi_status_t exit_boot_func(struct efi_boot_memmap *map,
 633                                    void *priv)
 634 {
 635         const char *signature;
 636         struct exit_boot_struct *p = priv;
 637
 638         signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE
 639                                    : EFI32_LOADER_SIGNATURE;
 640         memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
 641
 642         p->efi->efi_systab              = (unsigned long)efi_system_table;
 643         p->efi->efi_memdesc_size        = *map->desc_size;
 644         p->efi->efi_memdesc_version     = *map->desc_ver;
 645         p->efi->efi_memmap              = (unsigned long)*map->map;
 646         p->efi->efi_memmap_size         = *map->map_size;
 647
 648 #ifdef CONFIG_X86_64
 649         p->efi->efi_systab_hi           = (unsigned long)efi_system_table >> 32;
 650         p->efi->efi_memmap_hi           = (unsigned long)*map->map >> 32;
 651 #endif
 652
 653         return EFI_SUCCESS;
 654 }
 655
 656 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
 657 {
 658         unsigned long map_sz, key, desc_size, buff_size;
 659         efi_memory_desc_t *mem_map;
 660         struct setup_data *e820ext = NULL;
 661         __u32 e820ext_size = 0;
 662         efi_status_t status;
 663         __u32 desc_version;
 664         struct efi_boot_memmap map;
 665         struct exit_boot_struct priv;
 666
 667         map.map                 = &mem_map;
 668         map.map_size            = &map_sz;
 669         map.desc_size           = &desc_size;
 670         map.desc_ver            = &desc_version;
 671         map.key_ptr             = &key;
 672         map.buff_size           = &buff_size;
 673         priv.boot_params        = boot_params;
 674         priv.efi                = &boot_params->efi_info;
 675
 676         status = allocate_e820(boot_params, &e820ext, &e820ext_size);
 677         if (status != EFI_SUCCESS)
 678                 return status;
 679
 680         /* Might as well exit boot services now */
 681         status = efi_exit_boot_services(handle, &map, &priv, exit_boot_func);
 682         if (status != EFI_SUCCESS)
 683                 return status;
 684
 685         /* Historic? */
 686         boot_params->alt_mem_k  = 32 * 1024;
 687
 688         status = setup_e820(boot_params, e820ext, e820ext_size);
 689         if (status != EFI_SUCCESS)
 690                 return status;
 691
 692         return EFI_SUCCESS;
 693 }
 694
 695 /*
 696  * On success, we return the address of startup_32, which has potentially been
 697  * relocated by efi_relocate_kernel.
 698  * On failure, we exit to the firmware via efi_exit instead of returning.
 699  */
 700 unsigned long efi_main(efi_handle_t handle,
 701                              efi_system_table_t *sys_table_arg,
 702                              struct boot_params *boot_params)
 703 {
 704         unsigned long bzimage_addr = (unsigned long)startup_32;
 705         unsigned long buffer_start, buffer_end;
 706         struct setup_header *hdr = &boot_params->hdr;
 707         efi_status_t status;
 708         unsigned long cmdline_paddr;
 709
 710         efi_system_table = sys_table_arg;
 711
 712         /* Check if we were booted by the EFI firmware */
 713         if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
 714                 efi_exit(handle, EFI_INVALID_PARAMETER);
 715
 716         /*
 717          * If the kernel isn't already loaded at a suitable address,
 718          * relocate it.
 719          *
 720          * It must be loaded above LOAD_PHYSICAL_ADDR.
 721          *
 722          * The maximum address for 64-bit is 1 << 46 for 4-level paging. This
 723          * is defined as the macro MAXMEM, but unfortunately that is not a
 724          * compile-time constant if 5-level paging is configured, so we instead
 725          * define our own macro for use here.
 726          *
 727          * For 32-bit, the maximum address is complicated to figure out, for
 728          * now use KERNEL_IMAGE_SIZE, which will be 512MiB, the same as what
 729          * KASLR uses.
 730          *
 731          * Also relocate it if image_offset is zero, i.e. the kernel wasn't
 732          * loaded by LoadImage, but rather by a bootloader that called the
 733          * handover entry. The reason we must always relocate in this case is
 734          * to handle the case of systemd-boot booting a unified kernel image,
 735          * which is a PE executable that contains the bzImage and an initrd as
 736          * COFF sections. The initrd section is placed after the bzImage
 737          * without ensuring that there are at least init_size bytes available
 738          * for the bzImage, and thus the compressed kernel's startup code may
 739          * overwrite the initrd unless it is moved out of the way.
 740          */
 741
 742         buffer_start = ALIGN(bzimage_addr - image_offset,
 743                              hdr->kernel_alignment);
 744         buffer_end = buffer_start + hdr->init_size;
 745
 746         if ((buffer_start < LOAD_PHYSICAL_ADDR)                              ||
 747             (IS_ENABLED(CONFIG_X86_32) && buffer_end > KERNEL_IMAGE_SIZE)    ||
 748             (IS_ENABLED(CONFIG_X86_64) && buffer_end > MAXMEM_X86_64_4LEVEL) ||
 749             (image_offset == 0)) {
 750                 status = efi_relocate_kernel(&bzimage_addr,
 751                                              hdr->init_size, hdr->init_size,
 752                                              hdr->pref_address,
 753                                              hdr->kernel_alignment,
 754                                              LOAD_PHYSICAL_ADDR);
 755                 if (status != EFI_SUCCESS) {
 756                         efi_printk("efi_relocate_kernel() failed!\n");
 757                         goto fail;
 758                 }
 759                 /*
 760                  * Now that we've copied the kernel elsewhere, we no longer
 761                  * have a set up block before startup_32(), so reset image_offset
 762                  * to zero in case it was set earlier.
 763                  */
 764                 image_offset = 0;
 765         }
 766
 767         /*
 768          * efi_pe_entry() may have been called before efi_main(), in which
 769          * case this is the second time we parse the cmdline. This is ok,
 770          * parsing the cmdline multiple times does not have side-effects.
 771          */
 772         cmdline_paddr = ((u64)hdr->cmd_line_ptr |
 773                          ((u64)boot_params->ext_cmd_line_ptr << 32));
 774         efi_parse_options((char *)cmdline_paddr);
 775
 776         /*
 777          * At this point, an initrd may already have been loaded, either by
 778          * the bootloader and passed via bootparams, or loaded from a initrd=
 779          * command line option by efi_pe_entry() above. In either case, we
 780          * permit an initrd loaded from the LINUX_EFI_INITRD_MEDIA_GUID device
 781          * path to supersede it.
 782          */
 783         if (!efi_noinitrd) {
 784                 unsigned long addr, size;
 785
 786                 status = efi_load_initrd_dev_path(&addr, &size, ULONG_MAX);
 787                 if (status == EFI_SUCCESS) {
 788                         hdr->ramdisk_image              = (u32)addr;
 789                         hdr->ramdisk_size               = (u32)size;
 790                         boot_params->ext_ramdisk_image  = (u64)addr >> 32;
 791                         boot_params->ext_ramdisk_size   = (u64)size >> 32;
 792                 } else if (status != EFI_NOT_FOUND) {
 793                         efi_printk("efi_load_initrd_dev_path() failed!\n");
 794                         goto fail;
 795                 }
 796         }
 797
 798         /*
 799          * If the boot loader gave us a value for secure_boot then we use that,
 800          * otherwise we ask the BIOS.
 801          */
 802         if (boot_params->secure_boot == efi_secureboot_mode_unset)
 803                 boot_params->secure_boot = efi_get_secureboot();
 804
 805         /* Ask the firmware to clear memory on unclean shutdown */
 806         efi_enable_reset_attack_mitigation();
 807
 808         efi_random_get_seed();
 809
 810         efi_retrieve_tpm2_eventlog();
 811
 812         setup_graphics(boot_params);
 813
 814         setup_efi_pci(boot_params);
 815
 816         setup_quirks(boot_params);
 817
 818         status = exit_boot(boot_params, handle);
 819         if (status != EFI_SUCCESS) {
 820                 efi_printk("exit_boot() failed!\n");
 821                 goto fail;
 822         }
 823
 824         return bzimage_addr;
 825 fail:
 826         efi_printk("efi_main() failed!\n");
 827
 828         efi_exit(handle, status);
 829 }