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 static efi_system_table_t *sys_table __efistub_global;
  24 extern const bool efi_is64;
  25 extern u32 image_offset;
  26
  27 __pure efi_system_table_t *efi_system_table(void)
  28 {
  29         return sys_table;
  30 }
  31
  32 __attribute_const__ bool efi_is_64bit(void)
  33 {
  34         if (IS_ENABLED(CONFIG_EFI_MIXED))
  35                 return efi_is64;
  36         return IS_ENABLED(CONFIG_X86_64);
  37 }
  38
  39 static efi_status_t
  40 preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
  41 {
  42         struct pci_setup_rom *rom = NULL;
  43         efi_status_t status;
  44         unsigned long size;
  45         uint64_t romsize;
  46         void *romimage;
  47
  48         /*
  49          * Some firmware images contain EFI function pointers at the place where
  50          * the romimage and romsize fields are supposed to be. Typically the EFI
  51          * code is mapped at high addresses, translating to an unrealistically
  52          * large romsize. The UEFI spec limits the size of option ROMs to 16
  53          * MiB so we reject any ROMs over 16 MiB in size to catch this.
  54          */
  55         romimage = efi_table_attr(pci, romimage);
  56         romsize = efi_table_attr(pci, romsize);
  57         if (!romimage || !romsize || romsize > SZ_16M)
  58                 return EFI_INVALID_PARAMETER;
  59
  60         size = romsize + sizeof(*rom);
  61
  62         status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
  63                              (void **)&rom);
  64         if (status != EFI_SUCCESS) {
  65                 efi_printk("Failed to allocate memory for 'rom'\n");
  66                 return status;
  67         }
  68
  69         memset(rom, 0, sizeof(*rom));
  70
  71         rom->data.type  = SETUP_PCI;
  72         rom->data.len   = size - sizeof(struct setup_data);
  73         rom->data.next  = 0;
  74         rom->pcilen     = pci->romsize;
  75         *__rom = rom;
  76
  77         status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
  78                                 PCI_VENDOR_ID, 1, &rom->vendor);
  79
  80         if (status != EFI_SUCCESS) {
  81                 efi_printk("Failed to read rom->vendor\n");
  82                 goto free_struct;
  83         }
  84
  85         status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
  86                                 PCI_DEVICE_ID, 1, &rom->devid);
  87
  88         if (status != EFI_SUCCESS) {
  89                 efi_printk("Failed to read rom->devid\n");
  90                 goto free_struct;
  91         }
  92
  93         status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus,
  94                                 &rom->device, &rom->function);
  95
  96         if (status != EFI_SUCCESS)
  97                 goto free_struct;
  98
  99         memcpy(rom->romdata, romimage, romsize);
 100         return status;
 101
 102 free_struct:
 103         efi_bs_call(free_pool, rom);
 104         return status;
 105 }
 106
 107 /*
 108  * There's no way to return an informative status from this function,
 109  * because any analysis (and printing of error messages) needs to be
 110  * done directly at the EFI function call-site.
 111  *
 112  * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we
 113  * just didn't find any PCI devices, but there's no way to tell outside
 114  * the context of the call.
 115  */
 116 static void setup_efi_pci(struct boot_params *params)
 117 {
 118         efi_status_t status;
 119         void **pci_handle = NULL;
 120         efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID;
 121         unsigned long size = 0;
 122         struct setup_data *data;
 123         efi_handle_t h;
 124         int i;
 125
 126         status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
 127                              &pci_proto, NULL, &size, pci_handle);
 128
 129         if (status == EFI_BUFFER_TOO_SMALL) {
 130                 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
 131                                      (void **)&pci_handle);
 132
 133                 if (status != EFI_SUCCESS) {
 134                         efi_printk("Failed to allocate memory for 'pci_handle'\n");
 135                         return;
 136                 }
 137
 138                 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
 139                                      &pci_proto, NULL, &size, pci_handle);
 140         }
 141
 142         if (status != EFI_SUCCESS)
 143                 goto free_handle;
 144
 145         data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
 146
 147         while (data && data->next)
 148                 data = (struct setup_data *)(unsigned long)data->next;
 149
 150         for_each_efi_handle(h, pci_handle, size, i) {
 151                 efi_pci_io_protocol_t *pci = NULL;
 152                 struct pci_setup_rom *rom;
 153
 154                 status = efi_bs_call(handle_protocol, h, &pci_proto,
 155                                      (void **)&pci);
 156                 if (status != EFI_SUCCESS || !pci)
 157                         continue;
 158
 159                 status = preserve_pci_rom_image(pci, &rom);
 160                 if (status != EFI_SUCCESS)
 161                         continue;
 162
 163                 if (data)
 164                         data->next = (unsigned long)rom;
 165                 else
 166                         params->hdr.setup_data = (unsigned long)rom;
 167
 168                 data = (struct setup_data *)rom;
 169         }
 170
 171 free_handle:
 172         efi_bs_call(free_pool, pci_handle);
 173 }
 174
 175 static void retrieve_apple_device_properties(struct boot_params *boot_params)
 176 {
 177         efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID;
 178         struct setup_data *data, *new;
 179         efi_status_t status;
 180         u32 size = 0;
 181         apple_properties_protocol_t *p;
 182
 183         status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p);
 184         if (status != EFI_SUCCESS)
 185                 return;
 186
 187         if (efi_table_attr(p, version) != 0x10000) {
 188                 efi_printk("Unsupported properties proto version\n");
 189                 return;
 190         }
 191
 192         efi_call_proto(p, get_all, NULL, &size);
 193         if (!size)
 194                 return;
 195
 196         do {
 197                 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
 198                                      size + sizeof(struct setup_data),
 199                                      (void **)&new);
 200                 if (status != EFI_SUCCESS) {
 201                         efi_printk("Failed to allocate memory for 'properties'\n");
 202                         return;
 203                 }
 204
 205                 status = efi_call_proto(p, get_all, new->data, &size);
 206
 207                 if (status == EFI_BUFFER_TOO_SMALL)
 208                         efi_bs_call(free_pool, new);
 209         } while (status == EFI_BUFFER_TOO_SMALL);
 210
 211         new->type = SETUP_APPLE_PROPERTIES;
 212         new->len  = size;
 213         new->next = 0;
 214
 215         data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data;
 216         if (!data) {
 217                 boot_params->hdr.setup_data = (unsigned long)new;
 218         } else {
 219                 while (data->next)
 220                         data = (struct setup_data *)(unsigned long)data->next;
 221                 data->next = (unsigned long)new;
 222         }
 223 }
 224
 225 static const efi_char16_t apple[] = L"Apple";
 226
 227 static void setup_quirks(struct boot_params *boot_params)
 228 {
 229         efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long)
 230                 efi_table_attr(efi_system_table(), fw_vendor);
 231
 232         if (!memcmp(fw_vendor, apple, sizeof(apple))) {
 233                 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES))
 234                         retrieve_apple_device_properties(boot_params);
 235         }
 236 }
 237
 238 /*
 239  * See if we have Universal Graphics Adapter (UGA) protocol
 240  */
 241 static efi_status_t
 242 setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size)
 243 {
 244         efi_status_t status;
 245         u32 width, height;
 246         void **uga_handle = NULL;
 247         efi_uga_draw_protocol_t *uga = NULL, *first_uga;
 248         efi_handle_t handle;
 249         int i;
 250
 251         status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
 252                              (void **)&uga_handle);
 253         if (status != EFI_SUCCESS)
 254                 return status;
 255
 256         status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
 257                              uga_proto, NULL, &size, uga_handle);
 258         if (status != EFI_SUCCESS)
 259                 goto free_handle;
 260
 261         height = 0;
 262         width = 0;
 263
 264         first_uga = NULL;
 265         for_each_efi_handle(handle, uga_handle, size, i) {
 266                 efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
 267                 u32 w, h, depth, refresh;
 268                 void *pciio;
 269
 270                 status = efi_bs_call(handle_protocol, handle, uga_proto,
 271                                      (void **)&uga);
 272                 if (status != EFI_SUCCESS)
 273                         continue;
 274
 275                 pciio = NULL;
 276                 efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio);
 277
 278                 status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh);
 279                 if (status == EFI_SUCCESS && (!first_uga || pciio)) {
 280                         width = w;
 281                         height = h;
 282
 283                         /*
 284                          * Once we've found a UGA supporting PCIIO,
 285                          * don't bother looking any further.
 286                          */
 287                         if (pciio)
 288                                 break;
 289
 290                         first_uga = uga;
 291                 }
 292         }
 293
 294         if (!width && !height)
 295                 goto free_handle;
 296
 297         /* EFI framebuffer */
 298         si->orig_video_isVGA    = VIDEO_TYPE_EFI;
 299
 300         si->lfb_depth           = 32;
 301         si->lfb_width           = width;
 302         si->lfb_height          = height;
 303
 304         si->red_size            = 8;
 305         si->red_pos             = 16;
 306         si->green_size          = 8;
 307         si->green_pos           = 8;
 308         si->blue_size           = 8;
 309         si->blue_pos            = 0;
 310         si->rsvd_size           = 8;
 311         si->rsvd_pos            = 24;
 312
 313 free_handle:
 314         efi_bs_call(free_pool, uga_handle);
 315
 316         return status;
 317 }
 318
 319 static void setup_graphics(struct boot_params *boot_params)
 320 {
 321         efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
 322         struct screen_info *si;
 323         efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
 324         efi_status_t status;
 325         unsigned long size;
 326         void **gop_handle = NULL;
 327         void **uga_handle = NULL;
 328
 329         si = &boot_params->screen_info;
 330         memset(si, 0, sizeof(*si));
 331
 332         size = 0;
 333         status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
 334                              &graphics_proto, NULL, &size, gop_handle);
 335         if (status == EFI_BUFFER_TOO_SMALL)
 336                 status = efi_setup_gop(si, &graphics_proto, size);
 337
 338         if (status != EFI_SUCCESS) {
 339                 size = 0;
 340                 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
 341                                      &uga_proto, NULL, &size, uga_handle);
 342                 if (status == EFI_BUFFER_TOO_SMALL)
 343                         setup_uga(si, &uga_proto, size);
 344         }
 345 }
 346
 347
 348 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)
 349 {
 350         efi_bs_call(exit, handle, status, 0, NULL);
 351         for(;;)
 352                 asm("hlt");
 353 }
 354
 355 void startup_32(struct boot_params *boot_params);
 356
 357 void __noreturn efi_stub_entry(efi_handle_t handle,
 358                                efi_system_table_t *sys_table_arg,
 359                                struct boot_params *boot_params);
 360
 361 /*
 362  * Because the x86 boot code expects to be passed a boot_params we
 363  * need to create one ourselves (usually the bootloader would create
 364  * one for us).
 365  */
 366 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 367                                    efi_system_table_t *sys_table_arg)
 368 {
 369         struct boot_params *boot_params;
 370         struct setup_header *hdr;
 371         efi_loaded_image_t *image;
 372         void *image_base;
 373         efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
 374         int options_size = 0;
 375         efi_status_t status;
 376         char *cmdline_ptr;
 377         unsigned long ramdisk_addr;
 378         unsigned long ramdisk_size;
 379
 380         sys_table = sys_table_arg;
 381
 382         /* Check if we were booted by the EFI firmware */
 383         if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
 384                 efi_exit(handle, EFI_INVALID_PARAMETER);
 385
 386         status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image);
 387         if (status != EFI_SUCCESS) {
 388                 efi_printk("Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
 389                 efi_exit(handle, status);
 390         }
 391
 392         image_base = efi_table_attr(image, image_base);
 393         image_offset = (void *)startup_32 - image_base;
 394
 395         status = efi_allocate_pages(0x4000, (unsigned long *)&boot_params, ULONG_MAX);
 396         if (status != EFI_SUCCESS) {
 397                 efi_printk("Failed to allocate lowmem for boot params\n");
 398                 efi_exit(handle, status);
 399         }
 400
 401         memset(boot_params, 0x0, 0x4000);
 402
 403         hdr = &boot_params->hdr;
 404
 405         /* Copy the second sector to boot_params */
 406         memcpy(&hdr->jump, image_base + 512, 512);
 407
 408         /*
 409          * Fill out some of the header fields ourselves because the
 410          * EFI firmware loader doesn't load the first sector.
 411          */
 412         hdr->root_flags = 1;
 413         hdr->vid_mode   = 0xffff;
 414         hdr->boot_flag  = 0xAA55;
 415
 416         hdr->type_of_loader = 0x21;
 417
 418         /* Convert unicode cmdline to ascii */
 419         cmdline_ptr = efi_convert_cmdline(image, &options_size, ULONG_MAX);
 420         if (!cmdline_ptr)
 421                 goto fail;
 422
 423         hdr->cmd_line_ptr = (unsigned long)cmdline_ptr;
 424         /* Fill in upper bits of command line address, NOP on 32 bit  */
 425         boot_params->ext_cmd_line_ptr = (u64)(unsigned long)cmdline_ptr >> 32;
 426
 427         hdr->ramdisk_image = 0;
 428         hdr->ramdisk_size = 0;
 429
 430         if (efi_is_native()) {
 431                 status = efi_parse_options(cmdline_ptr);
 432                 if (status != EFI_SUCCESS)
 433                         goto fail2;
 434
 435                 if (!noinitrd()) {
 436                         status = efi_load_initrd(image, &ramdisk_addr,
 437                                                  &ramdisk_size,
 438                                                  hdr->initrd_addr_max,
 439                                                  ULONG_MAX);
 440                         if (status != EFI_SUCCESS)
 441                                 goto fail2;
 442                         hdr->ramdisk_image = ramdisk_addr & 0xffffffff;
 443                         hdr->ramdisk_size  = ramdisk_size & 0xffffffff;
 444                         boot_params->ext_ramdisk_image = (u64)ramdisk_addr >> 32;
 445                         boot_params->ext_ramdisk_size  = (u64)ramdisk_size >> 32;
 446                 }
 447         }
 448
 449         efi_stub_entry(handle, sys_table, boot_params);
 450         /* not reached */
 451
 452 fail2:
 453         efi_free(options_size, (unsigned long)cmdline_ptr);
 454 fail:
 455         efi_free(0x4000, (unsigned long)boot_params);
 456
 457         efi_exit(handle, status);
 458 }
 459
 460 static void add_e820ext(struct boot_params *params,
 461                         struct setup_data *e820ext, u32 nr_entries)
 462 {
 463         struct setup_data *data;
 464
 465         e820ext->type = SETUP_E820_EXT;
 466         e820ext->len  = nr_entries * sizeof(struct boot_e820_entry);
 467         e820ext->next = 0;
 468
 469         data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
 470
 471         while (data && data->next)
 472                 data = (struct setup_data *)(unsigned long)data->next;
 473
 474         if (data)
 475                 data->next = (unsigned long)e820ext;
 476         else
 477                 params->hdr.setup_data = (unsigned long)e820ext;
 478 }
 479
 480 static efi_status_t
 481 setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size)
 482 {
 483         struct boot_e820_entry *entry = params->e820_table;
 484         struct efi_info *efi = &params->efi_info;
 485         struct boot_e820_entry *prev = NULL;
 486         u32 nr_entries;
 487         u32 nr_desc;
 488         int i;
 489
 490         nr_entries = 0;
 491         nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;
 492
 493         for (i = 0; i < nr_desc; i++) {
 494                 efi_memory_desc_t *d;
 495                 unsigned int e820_type = 0;
 496                 unsigned long m = efi->efi_memmap;
 497
 498 #ifdef CONFIG_X86_64
 499                 m |= (u64)efi->efi_memmap_hi << 32;
 500 #endif
 501
 502                 d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i);
 503                 switch (d->type) {
 504                 case EFI_RESERVED_TYPE:
 505                 case EFI_RUNTIME_SERVICES_CODE:
 506                 case EFI_RUNTIME_SERVICES_DATA:
 507                 case EFI_MEMORY_MAPPED_IO:
 508                 case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
 509                 case EFI_PAL_CODE:
 510                         e820_type = E820_TYPE_RESERVED;
 511                         break;
 512
 513                 case EFI_UNUSABLE_MEMORY:
 514                         e820_type = E820_TYPE_UNUSABLE;
 515                         break;
 516
 517                 case EFI_ACPI_RECLAIM_MEMORY:
 518                         e820_type = E820_TYPE_ACPI;
 519                         break;
 520
 521                 case EFI_LOADER_CODE:
 522                 case EFI_LOADER_DATA:
 523                 case EFI_BOOT_SERVICES_CODE:
 524                 case EFI_BOOT_SERVICES_DATA:
 525                 case EFI_CONVENTIONAL_MEMORY:
 526                         if (efi_soft_reserve_enabled() &&
 527                             (d->attribute & EFI_MEMORY_SP))
 528                                 e820_type = E820_TYPE_SOFT_RESERVED;
 529                         else
 530                                 e820_type = E820_TYPE_RAM;
 531                         break;
 532
 533                 case EFI_ACPI_MEMORY_NVS:
 534                         e820_type = E820_TYPE_NVS;
 535                         break;
 536
 537                 case EFI_PERSISTENT_MEMORY:
 538                         e820_type = E820_TYPE_PMEM;
 539                         break;
 540
 541                 default:
 542                         continue;
 543                 }
 544
 545                 /* Merge adjacent mappings */
 546                 if (prev && prev->type == e820_type &&
 547                     (prev->addr + prev->size) == d->phys_addr) {
 548                         prev->size += d->num_pages << 12;
 549                         continue;
 550                 }
 551
 552                 if (nr_entries == ARRAY_SIZE(params->e820_table)) {
 553                         u32 need = (nr_desc - i) * sizeof(struct e820_entry) +
 554                                    sizeof(struct setup_data);
 555
 556                         if (!e820ext || e820ext_size < need)
 557                                 return EFI_BUFFER_TOO_SMALL;
 558
 559                         /* boot_params map full, switch to e820 extended */
 560                         entry = (struct boot_e820_entry *)e820ext->data;
 561                 }
 562
 563                 entry->addr = d->phys_addr;
 564                 entry->size = d->num_pages << PAGE_SHIFT;
 565                 entry->type = e820_type;
 566                 prev = entry++;
 567                 nr_entries++;
 568         }
 569
 570         if (nr_entries > ARRAY_SIZE(params->e820_table)) {
 571                 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table);
 572
 573                 add_e820ext(params, e820ext, nr_e820ext);
 574                 nr_entries -= nr_e820ext;
 575         }
 576
 577         params->e820_entries = (u8)nr_entries;
 578
 579         return EFI_SUCCESS;
 580 }
 581
 582 static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
 583                                   u32 *e820ext_size)
 584 {
 585         efi_status_t status;
 586         unsigned long size;
 587
 588         size = sizeof(struct setup_data) +
 589                 sizeof(struct e820_entry) * nr_desc;
 590
 591         if (*e820ext) {
 592                 efi_bs_call(free_pool, *e820ext);
 593                 *e820ext = NULL;
 594                 *e820ext_size = 0;
 595         }
 596
 597         status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
 598                              (void **)e820ext);
 599         if (status == EFI_SUCCESS)
 600                 *e820ext_size = size;
 601
 602         return status;
 603 }
 604
 605 static efi_status_t allocate_e820(struct boot_params *params,
 606                                   struct setup_data **e820ext,
 607                                   u32 *e820ext_size)
 608 {
 609         unsigned long map_size, desc_size, buff_size;
 610         struct efi_boot_memmap boot_map;
 611         efi_memory_desc_t *map;
 612         efi_status_t status;
 613         __u32 nr_desc;
 614
 615         boot_map.map            = &map;
 616         boot_map.map_size       = &map_size;
 617         boot_map.desc_size      = &desc_size;
 618         boot_map.desc_ver       = NULL;
 619         boot_map.key_ptr        = NULL;
 620         boot_map.buff_size      = &buff_size;
 621
 622         status = efi_get_memory_map(&boot_map);
 623         if (status != EFI_SUCCESS)
 624                 return status;
 625
 626         nr_desc = buff_size / desc_size;
 627
 628         if (nr_desc > ARRAY_SIZE(params->e820_table)) {
 629                 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table);
 630
 631                 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
 632                 if (status != EFI_SUCCESS)
 633                         return status;
 634         }
 635
 636         return EFI_SUCCESS;
 637 }
 638
 639 struct exit_boot_struct {
 640         struct boot_params      *boot_params;
 641         struct efi_info         *efi;
 642 };
 643
 644 static efi_status_t exit_boot_func(struct efi_boot_memmap *map,
 645                                    void *priv)
 646 {
 647         const char *signature;
 648         struct exit_boot_struct *p = priv;
 649
 650         signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE
 651                                    : EFI32_LOADER_SIGNATURE;
 652         memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
 653
 654         p->efi->efi_systab              = (unsigned long)efi_system_table();
 655         p->efi->efi_memdesc_size        = *map->desc_size;
 656         p->efi->efi_memdesc_version     = *map->desc_ver;
 657         p->efi->efi_memmap              = (unsigned long)*map->map;
 658         p->efi->efi_memmap_size         = *map->map_size;
 659
 660 #ifdef CONFIG_X86_64
 661         p->efi->efi_systab_hi           = (unsigned long)efi_system_table() >> 32;
 662         p->efi->efi_memmap_hi           = (unsigned long)*map->map >> 32;
 663 #endif
 664
 665         return EFI_SUCCESS;
 666 }
 667
 668 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
 669 {
 670         unsigned long map_sz, key, desc_size, buff_size;
 671         efi_memory_desc_t *mem_map;
 672         struct setup_data *e820ext = NULL;
 673         __u32 e820ext_size = 0;
 674         efi_status_t status;
 675         __u32 desc_version;
 676         struct efi_boot_memmap map;
 677         struct exit_boot_struct priv;
 678
 679         map.map                 = &mem_map;
 680         map.map_size            = &map_sz;
 681         map.desc_size           = &desc_size;
 682         map.desc_ver            = &desc_version;
 683         map.key_ptr             = &key;
 684         map.buff_size           = &buff_size;
 685         priv.boot_params        = boot_params;
 686         priv.efi                = &boot_params->efi_info;
 687
 688         status = allocate_e820(boot_params, &e820ext, &e820ext_size);
 689         if (status != EFI_SUCCESS)
 690                 return status;
 691
 692         /* Might as well exit boot services now */
 693         status = efi_exit_boot_services(handle, &map, &priv, exit_boot_func);
 694         if (status != EFI_SUCCESS)
 695                 return status;
 696
 697         /* Historic? */
 698         boot_params->alt_mem_k  = 32 * 1024;
 699
 700         status = setup_e820(boot_params, e820ext, e820ext_size);
 701         if (status != EFI_SUCCESS)
 702                 return status;
 703
 704         return EFI_SUCCESS;
 705 }
 706
 707 /*
 708  * On success, we return the address of startup_32, which has potentially been
 709  * relocated by efi_relocate_kernel.
 710  * On failure, we exit to the firmware via efi_exit instead of returning.
 711  */
 712 unsigned long efi_main(efi_handle_t handle,
 713                              efi_system_table_t *sys_table_arg,
 714                              struct boot_params *boot_params)
 715 {
 716         unsigned long bzimage_addr = (unsigned long)startup_32;
 717         unsigned long buffer_start, buffer_end;
 718         struct setup_header *hdr = &boot_params->hdr;
 719         efi_status_t status;
 720         unsigned long cmdline_paddr;
 721
 722         sys_table = sys_table_arg;
 723
 724         /* Check if we were booted by the EFI firmware */
 725         if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
 726                 efi_exit(handle, EFI_INVALID_PARAMETER);
 727
 728         /*
 729          * If the kernel isn't already loaded at a suitable address,
 730          * relocate it.
 731          *
 732          * It must be loaded above LOAD_PHYSICAL_ADDR.
 733          *
 734          * The maximum address for 64-bit is 1 << 46 for 4-level paging. This
 735          * is defined as the macro MAXMEM, but unfortunately that is not a
 736          * compile-time constant if 5-level paging is configured, so we instead
 737          * define our own macro for use here.
 738          *
 739          * For 32-bit, the maximum address is complicated to figure out, for
 740          * now use KERNEL_IMAGE_SIZE, which will be 512MiB, the same as what
 741          * KASLR uses.
 742          *
 743          * Also relocate it if image_offset is zero, i.e. the kernel wasn't
 744          * loaded by LoadImage, but rather by a bootloader that called the
 745          * handover entry. The reason we must always relocate in this case is
 746          * to handle the case of systemd-boot booting a unified kernel image,
 747          * which is a PE executable that contains the bzImage and an initrd as
 748          * COFF sections. The initrd section is placed after the bzImage
 749          * without ensuring that there are at least init_size bytes available
 750          * for the bzImage, and thus the compressed kernel's startup code may
 751          * overwrite the initrd unless it is moved out of the way.
 752          */
 753
 754         buffer_start = ALIGN(bzimage_addr - image_offset,
 755                              hdr->kernel_alignment);
 756         buffer_end = buffer_start + hdr->init_size;
 757
 758         if ((buffer_start < LOAD_PHYSICAL_ADDR)                              ||
 759             (IS_ENABLED(CONFIG_X86_32) && buffer_end > KERNEL_IMAGE_SIZE)    ||
 760             (IS_ENABLED(CONFIG_X86_64) && buffer_end > MAXMEM_X86_64_4LEVEL) ||
 761             (image_offset == 0)) {
 762                 status = efi_relocate_kernel(&bzimage_addr,
 763                                              hdr->init_size, hdr->init_size,
 764                                              hdr->pref_address,
 765                                              hdr->kernel_alignment,
 766                                              LOAD_PHYSICAL_ADDR);
 767                 if (status != EFI_SUCCESS) {
 768                         efi_printk("efi_relocate_kernel() failed!\n");
 769                         goto fail;
 770                 }
 771                 /*
 772                  * Now that we've copied the kernel elsewhere, we no longer
 773                  * have a set up block before startup_32(), so reset image_offset
 774                  * to zero in case it was set earlier.
 775                  */
 776                 image_offset = 0;
 777         }
 778
 779         /*
 780          * efi_pe_entry() may have been called before efi_main(), in which
 781          * case this is the second time we parse the cmdline. This is ok,
 782          * parsing the cmdline multiple times does not have side-effects.
 783          */
 784         cmdline_paddr = ((u64)hdr->cmd_line_ptr |
 785                          ((u64)boot_params->ext_cmd_line_ptr << 32));
 786         efi_parse_options((char *)cmdline_paddr);
 787
 788         /*
 789          * At this point, an initrd may already have been loaded, either by
 790          * the bootloader and passed via bootparams, or loaded from a initrd=
 791          * command line option by efi_pe_entry() above. In either case, we
 792          * permit an initrd loaded from the LINUX_EFI_INITRD_MEDIA_GUID device
 793          * path to supersede it.
 794          */
 795         if (!noinitrd()) {
 796                 unsigned long addr, size;
 797
 798                 status = efi_load_initrd_dev_path(&addr, &size, ULONG_MAX);
 799                 if (status == EFI_SUCCESS) {
 800                         hdr->ramdisk_image              = (u32)addr;
 801                         hdr->ramdisk_size               = (u32)size;
 802                         boot_params->ext_ramdisk_image  = (u64)addr >> 32;
 803                         boot_params->ext_ramdisk_size   = (u64)size >> 32;
 804                 } else if (status != EFI_NOT_FOUND) {
 805                         efi_printk("efi_load_initrd_dev_path() failed!\n");
 806                         goto fail;
 807                 }
 808         }
 809
 810         /*
 811          * If the boot loader gave us a value for secure_boot then we use that,
 812          * otherwise we ask the BIOS.
 813          */
 814         if (boot_params->secure_boot == efi_secureboot_mode_unset)
 815                 boot_params->secure_boot = efi_get_secureboot();
 816
 817         /* Ask the firmware to clear memory on unclean shutdown */
 818         efi_enable_reset_attack_mitigation();
 819
 820         efi_random_get_seed();
 821
 822         efi_retrieve_tpm2_eventlog();
 823
 824         setup_graphics(boot_params);
 825
 826         setup_efi_pci(boot_params);
 827
 828         setup_quirks(boot_params);
 829
 830         status = exit_boot(boot_params, handle);
 831         if (status != EFI_SUCCESS) {
 832                 efi_printk("exit_boot() failed!\n");
 833                 goto fail;
 834         }
 835
 836         return bzimage_addr;
 837 fail:
 838         efi_printk("efi_main() failed!\n");
 839
 840         efi_exit(handle, status);
 841 }