arch/x86/boot/compressed/eboot.c

   1
   2 /* -----------------------------------------------------------------------
   3  *
   4  *   Copyright 2011 Intel Corporation; author Matt Fleming
   5  *
   6  *   This file is part of the Linux kernel, and is made available under
   7  *   the terms of the GNU General Public License version 2.
   8  *
   9  * ----------------------------------------------------------------------- */
  10
  11 #include <linux/efi.h>
  12 #include <linux/pci.h>
  13
  14 #include <asm/efi.h>
  15 #include <asm/e820/types.h>
  16 #include <asm/setup.h>
  17 #include <asm/desc.h>
  18
  19 #include "../string.h"
  20 #include "eboot.h"
  21
  22 static efi_system_table_t *sys_table;
  23
  24 static struct efi_config *efi_early;
  25
  26 __pure const struct efi_config *__efi_early(void)
  27 {
  28         return efi_early;
  29 }
  30
  31 #define BOOT_SERVICES(bits)                                             \
  32 static void setup_boot_services##bits(struct efi_config *c)             \
  33 {                                                                       \
  34         efi_system_table_##bits##_t *table;                             \
  35                                                                         \
  36         table = (typeof(table))sys_table;                               \
  37                                                                         \
  38         c->runtime_services     = table->runtime;                       \
  39         c->boot_services        = table->boottime;                      \
  40         c->text_output          = table->con_out;                       \
  41 }
  42 BOOT_SERVICES(32);
  43 BOOT_SERVICES(64);
  44
  45 void efi_char16_printk(efi_system_table_t *table, efi_char16_t *str)
  46 {
  47         efi_call_proto(efi_simple_text_output_protocol, output_string,
  48                        efi_early->text_output, str);
  49 }
  50
  51 static efi_status_t
  52 preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
  53 {
  54         struct pci_setup_rom *rom = NULL;
  55         efi_status_t status;
  56         unsigned long size;
  57         uint64_t romsize;
  58         void *romimage;
  59
  60         /*
  61          * Some firmware images contain EFI function pointers at the place where
  62          * the romimage and romsize fields are supposed to be. Typically the EFI
  63          * code is mapped at high addresses, translating to an unrealistically
  64          * large romsize. The UEFI spec limits the size of option ROMs to 16
  65          * MiB so we reject any ROMs over 16 MiB in size to catch this.
  66          */
  67         romimage = (void *)(unsigned long)efi_table_attr(efi_pci_io_protocol,
  68                                                          romimage, pci);
  69         romsize = efi_table_attr(efi_pci_io_protocol, romsize, pci);
  70         if (!romimage || !romsize || romsize > SZ_16M)
  71                 return EFI_INVALID_PARAMETER;
  72
  73         size = romsize + sizeof(*rom);
  74
  75         status = efi_call_early(allocate_pool, EFI_LOADER_DATA, size, &rom);
  76         if (status != EFI_SUCCESS) {
  77                 efi_printk(sys_table, "Failed to allocate memory for 'rom'\n");
  78                 return status;
  79         }
  80
  81         memset(rom, 0, sizeof(*rom));
  82
  83         rom->data.type  = SETUP_PCI;
  84         rom->data.len   = size - sizeof(struct setup_data);
  85         rom->data.next  = 0;
  86         rom->pcilen     = pci->romsize;
  87         *__rom = rom;
  88
  89         status = efi_call_proto(efi_pci_io_protocol, pci.read, pci,
  90                                 EfiPciIoWidthUint16, PCI_VENDOR_ID, 1,
  91                                 &rom->vendor);
  92
  93         if (status != EFI_SUCCESS) {
  94                 efi_printk(sys_table, "Failed to read rom->vendor\n");
  95                 goto free_struct;
  96         }
  97
  98         status = efi_call_proto(efi_pci_io_protocol, pci.read, pci,
  99                                 EfiPciIoWidthUint16, PCI_DEVICE_ID, 1,
 100                                 &rom->devid);
 101
 102         if (status != EFI_SUCCESS) {
 103                 efi_printk(sys_table, "Failed to read rom->devid\n");
 104                 goto free_struct;
 105         }
 106
 107         status = efi_call_proto(efi_pci_io_protocol, get_location, pci,
 108                                 &rom->segment, &rom->bus, &rom->device,
 109                                 &rom->function);
 110
 111         if (status != EFI_SUCCESS)
 112                 goto free_struct;
 113
 114         memcpy(rom->romdata, romimage, romsize);
 115         return status;
 116
 117 free_struct:
 118         efi_call_early(free_pool, rom);
 119         return status;
 120 }
 121
 122 /*
 123  * There's no way to return an informative status from this function,
 124  * because any analysis (and printing of error messages) needs to be
 125  * done directly at the EFI function call-site.
 126  *
 127  * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we
 128  * just didn't find any PCI devices, but there's no way to tell outside
 129  * the context of the call.
 130  */
 131 static void setup_efi_pci(struct boot_params *params)
 132 {
 133         efi_status_t status;
 134         void **pci_handle = NULL;
 135         efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID;
 136         unsigned long size = 0;
 137         unsigned long nr_pci;
 138         struct setup_data *data;
 139         int i;
 140
 141         status = efi_call_early(locate_handle,
 142                                 EFI_LOCATE_BY_PROTOCOL,
 143                                 &pci_proto, NULL, &size, pci_handle);
 144
 145         if (status == EFI_BUFFER_TOO_SMALL) {
 146                 status = efi_call_early(allocate_pool,
 147                                         EFI_LOADER_DATA,
 148                                         size, (void **)&pci_handle);
 149
 150                 if (status != EFI_SUCCESS) {
 151                         efi_printk(sys_table, "Failed to allocate memory for 'pci_handle'\n");
 152                         return;
 153                 }
 154
 155                 status = efi_call_early(locate_handle,
 156                                         EFI_LOCATE_BY_PROTOCOL, &pci_proto,
 157                                         NULL, &size, pci_handle);
 158         }
 159
 160         if (status != EFI_SUCCESS)
 161                 goto free_handle;
 162
 163         data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
 164
 165         while (data && data->next)
 166                 data = (struct setup_data *)(unsigned long)data->next;
 167
 168         nr_pci = size / (efi_is_64bit() ? sizeof(u64) : sizeof(u32));
 169         for (i = 0; i < nr_pci; i++) {
 170                 efi_pci_io_protocol_t *pci = NULL;
 171                 struct pci_setup_rom *rom;
 172
 173                 status = efi_call_early(handle_protocol,
 174                                         efi_is_64bit() ? ((u64 *)pci_handle)[i]
 175                                                        : ((u32 *)pci_handle)[i],
 176                                         &pci_proto, (void **)&pci);
 177                 if (status != EFI_SUCCESS || !pci)
 178                         continue;
 179
 180                 status = preserve_pci_rom_image(pci, &rom);
 181                 if (status != EFI_SUCCESS)
 182                         continue;
 183
 184                 if (data)
 185                         data->next = (unsigned long)rom;
 186                 else
 187                         params->hdr.setup_data = (unsigned long)rom;
 188
 189                 data = (struct setup_data *)rom;
 190         }
 191
 192 free_handle:
 193         efi_call_early(free_pool, pci_handle);
 194 }
 195
 196 static void retrieve_apple_device_properties(struct boot_params *boot_params)
 197 {
 198         efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID;
 199         struct setup_data *data, *new;
 200         efi_status_t status;
 201         u32 size = 0;
 202         void *p;
 203
 204         status = efi_call_early(locate_protocol, &guid, NULL, &p);
 205         if (status != EFI_SUCCESS)
 206                 return;
 207
 208         if (efi_table_attr(apple_properties_protocol, version, p) != 0x10000) {
 209                 efi_printk(sys_table, "Unsupported properties proto version\n");
 210                 return;
 211         }
 212
 213         efi_call_proto(apple_properties_protocol, get_all, p, NULL, &size);
 214         if (!size)
 215                 return;
 216
 217         do {
 218                 status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
 219                                         size + sizeof(struct setup_data), &new);
 220                 if (status != EFI_SUCCESS) {
 221                         efi_printk(sys_table, "Failed to allocate memory for 'properties'\n");
 222                         return;
 223                 }
 224
 225                 status = efi_call_proto(apple_properties_protocol, get_all, p,
 226                                         new->data, &size);
 227
 228                 if (status == EFI_BUFFER_TOO_SMALL)
 229                         efi_call_early(free_pool, new);
 230         } while (status == EFI_BUFFER_TOO_SMALL);
 231
 232         new->type = SETUP_APPLE_PROPERTIES;
 233         new->len  = size;
 234         new->next = 0;
 235
 236         data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data;
 237         if (!data) {
 238                 boot_params->hdr.setup_data = (unsigned long)new;
 239         } else {
 240                 while (data->next)
 241                         data = (struct setup_data *)(unsigned long)data->next;
 242                 data->next = (unsigned long)new;
 243         }
 244 }
 245
 246 static const efi_char16_t apple[] = L"Apple";
 247
 248 static void setup_quirks(struct boot_params *boot_params)
 249 {
 250         efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long)
 251                 efi_table_attr(efi_system_table, fw_vendor, sys_table);
 252
 253         if (!memcmp(fw_vendor, apple, sizeof(apple))) {
 254                 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES))
 255                         retrieve_apple_device_properties(boot_params);
 256         }
 257 }
 258
 259 /*
 260  * See if we have Universal Graphics Adapter (UGA) protocol
 261  */
 262 static efi_status_t
 263 setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size)
 264 {
 265         efi_status_t status;
 266         u32 width, height;
 267         void **uga_handle = NULL;
 268         efi_uga_draw_protocol_t *uga = NULL, *first_uga;
 269         unsigned long nr_ugas;
 270         int i;
 271
 272         status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
 273                                 size, (void **)&uga_handle);
 274         if (status != EFI_SUCCESS)
 275                 return status;
 276
 277         status = efi_call_early(locate_handle,
 278                                 EFI_LOCATE_BY_PROTOCOL,
 279                                 uga_proto, NULL, &size, uga_handle);
 280         if (status != EFI_SUCCESS)
 281                 goto free_handle;
 282
 283         height = 0;
 284         width = 0;
 285
 286         first_uga = NULL;
 287         nr_ugas = size / (efi_is_64bit() ? sizeof(u64) : sizeof(u32));
 288         for (i = 0; i < nr_ugas; i++) {
 289                 efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
 290                 u32 w, h, depth, refresh;
 291                 void *pciio;
 292                 unsigned long handle = efi_is_64bit() ? ((u64 *)uga_handle)[i]
 293                                                       : ((u32 *)uga_handle)[i];
 294
 295                 status = efi_call_early(handle_protocol, handle,
 296                                         uga_proto, (void **)&uga);
 297                 if (status != EFI_SUCCESS)
 298                         continue;
 299
 300                 pciio = NULL;
 301                 efi_call_early(handle_protocol, handle, &pciio_proto, &pciio);
 302
 303                 status = efi_call_proto(efi_uga_draw_protocol, get_mode, uga,
 304                                         &w, &h, &depth, &refresh);
 305                 if (status == EFI_SUCCESS && (!first_uga || pciio)) {
 306                         width = w;
 307                         height = h;
 308
 309                         /*
 310                          * Once we've found a UGA supporting PCIIO,
 311                          * don't bother looking any further.
 312                          */
 313                         if (pciio)
 314                                 break;
 315
 316                         first_uga = uga;
 317                 }
 318         }
 319
 320         if (!width && !height)
 321                 goto free_handle;
 322
 323         /* EFI framebuffer */
 324         si->orig_video_isVGA    = VIDEO_TYPE_EFI;
 325
 326         si->lfb_depth           = 32;
 327         si->lfb_width           = width;
 328         si->lfb_height          = height;
 329
 330         si->red_size            = 8;
 331         si->red_pos             = 16;
 332         si->green_size          = 8;
 333         si->green_pos           = 8;
 334         si->blue_size           = 8;
 335         si->blue_pos            = 0;
 336         si->rsvd_size           = 8;
 337         si->rsvd_pos            = 24;
 338
 339 free_handle:
 340         efi_call_early(free_pool, uga_handle);
 341
 342         return status;
 343 }
 344
 345 void setup_graphics(struct boot_params *boot_params)
 346 {
 347         efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
 348         struct screen_info *si;
 349         efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
 350         efi_status_t status;
 351         unsigned long size;
 352         void **gop_handle = NULL;
 353         void **uga_handle = NULL;
 354
 355         si = &boot_params->screen_info;
 356         memset(si, 0, sizeof(*si));
 357
 358         size = 0;
 359         status = efi_call_early(locate_handle,
 360                                 EFI_LOCATE_BY_PROTOCOL,
 361                                 &graphics_proto, NULL, &size, gop_handle);
 362         if (status == EFI_BUFFER_TOO_SMALL)
 363                 status = efi_setup_gop(NULL, si, &graphics_proto, size);
 364
 365         if (status != EFI_SUCCESS) {
 366                 size = 0;
 367                 status = efi_call_early(locate_handle,
 368                                         EFI_LOCATE_BY_PROTOCOL,
 369                                         &uga_proto, NULL, &size, uga_handle);
 370                 if (status == EFI_BUFFER_TOO_SMALL)
 371                         setup_uga(si, &uga_proto, size);
 372         }
 373 }
 374
 375 /*
 376  * Because the x86 boot code expects to be passed a boot_params we
 377  * need to create one ourselves (usually the bootloader would create
 378  * one for us).
 379  *
 380  * The caller is responsible for filling out ->code32_start in the
 381  * returned boot_params.
 382  */
 383 struct boot_params *make_boot_params(struct efi_config *c)
 384 {
 385         struct boot_params *boot_params;
 386         struct apm_bios_info *bi;
 387         struct setup_header *hdr;
 388         efi_loaded_image_t *image;
 389         void *options, *handle;
 390         efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
 391         int options_size = 0;
 392         efi_status_t status;
 393         char *cmdline_ptr;
 394         u16 *s2;
 395         u8 *s1;
 396         int i;
 397         unsigned long ramdisk_addr;
 398         unsigned long ramdisk_size;
 399
 400         efi_early = c;
 401         sys_table = (efi_system_table_t *)(unsigned long)efi_early->table;
 402         handle = (void *)(unsigned long)efi_early->image_handle;
 403
 404         /* Check if we were booted by the EFI firmware */
 405         if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
 406                 return NULL;
 407
 408         if (efi_is_64bit())
 409                 setup_boot_services64(efi_early);
 410         else
 411                 setup_boot_services32(efi_early);
 412
 413         status = efi_call_early(handle_protocol, handle,
 414                                 &proto, (void *)&image);
 415         if (status != EFI_SUCCESS) {
 416                 efi_printk(sys_table, "Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
 417                 return NULL;
 418         }
 419
 420         status = efi_low_alloc(sys_table, 0x4000, 1,
 421                                (unsigned long *)&boot_params);
 422         if (status != EFI_SUCCESS) {
 423                 efi_printk(sys_table, "Failed to allocate lowmem for boot params\n");
 424                 return NULL;
 425         }
 426
 427         memset(boot_params, 0x0, 0x4000);
 428
 429         hdr = &boot_params->hdr;
 430         bi = &boot_params->apm_bios_info;
 431
 432         /* Copy the second sector to boot_params */
 433         memcpy(&hdr->jump, image->image_base + 512, 512);
 434
 435         /*
 436          * Fill out some of the header fields ourselves because the
 437          * EFI firmware loader doesn't load the first sector.
 438          */
 439         hdr->root_flags = 1;
 440         hdr->vid_mode   = 0xffff;
 441         hdr->boot_flag  = 0xAA55;
 442
 443         hdr->type_of_loader = 0x21;
 444
 445         /* Convert unicode cmdline to ascii */
 446         cmdline_ptr = efi_convert_cmdline(sys_table, image, &options_size);
 447         if (!cmdline_ptr)
 448                 goto fail;
 449
 450         hdr->cmd_line_ptr = (unsigned long)cmdline_ptr;
 451         /* Fill in upper bits of command line address, NOP on 32 bit  */
 452         boot_params->ext_cmd_line_ptr = (u64)(unsigned long)cmdline_ptr >> 32;
 453
 454         hdr->ramdisk_image = 0;
 455         hdr->ramdisk_size = 0;
 456
 457         /* Clear APM BIOS info */
 458         memset(bi, 0, sizeof(*bi));
 459
 460         status = efi_parse_options(cmdline_ptr);
 461         if (status != EFI_SUCCESS)
 462                 goto fail2;
 463
 464         status = handle_cmdline_files(sys_table, image,
 465                                       (char *)(unsigned long)hdr->cmd_line_ptr,
 466                                       "initrd=", hdr->initrd_addr_max,
 467                                       &ramdisk_addr, &ramdisk_size);
 468
 469         if (status != EFI_SUCCESS &&
 470             hdr->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G) {
 471                 efi_printk(sys_table, "Trying to load files to higher address\n");
 472                 status = handle_cmdline_files(sys_table, image,
 473                                       (char *)(unsigned long)hdr->cmd_line_ptr,
 474                                       "initrd=", -1UL,
 475                                       &ramdisk_addr, &ramdisk_size);
 476         }
 477
 478         if (status != EFI_SUCCESS)
 479                 goto fail2;
 480         hdr->ramdisk_image = ramdisk_addr & 0xffffffff;
 481         hdr->ramdisk_size  = ramdisk_size & 0xffffffff;
 482         boot_params->ext_ramdisk_image = (u64)ramdisk_addr >> 32;
 483         boot_params->ext_ramdisk_size  = (u64)ramdisk_size >> 32;
 484
 485         return boot_params;
 486
 487 fail2:
 488         efi_free(sys_table, options_size, hdr->cmd_line_ptr);
 489 fail:
 490         efi_free(sys_table, 0x4000, (unsigned long)boot_params);
 491
 492         return NULL;
 493 }
 494
 495 static void add_e820ext(struct boot_params *params,
 496                         struct setup_data *e820ext, u32 nr_entries)
 497 {
 498         struct setup_data *data;
 499         efi_status_t status;
 500         unsigned long size;
 501
 502         e820ext->type = SETUP_E820_EXT;
 503         e820ext->len  = nr_entries * sizeof(struct boot_e820_entry);
 504         e820ext->next = 0;
 505
 506         data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
 507
 508         while (data && data->next)
 509                 data = (struct setup_data *)(unsigned long)data->next;
 510
 511         if (data)
 512                 data->next = (unsigned long)e820ext;
 513         else
 514                 params->hdr.setup_data = (unsigned long)e820ext;
 515 }
 516
 517 static efi_status_t
 518 setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size)
 519 {
 520         struct boot_e820_entry *entry = params->e820_table;
 521         struct efi_info *efi = &params->efi_info;
 522         struct boot_e820_entry *prev = NULL;
 523         u32 nr_entries;
 524         u32 nr_desc;
 525         int i;
 526
 527         nr_entries = 0;
 528         nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;
 529
 530         for (i = 0; i < nr_desc; i++) {
 531                 efi_memory_desc_t *d;
 532                 unsigned int e820_type = 0;
 533                 unsigned long m = efi->efi_memmap;
 534
 535 #ifdef CONFIG_X86_64
 536                 m |= (u64)efi->efi_memmap_hi << 32;
 537 #endif
 538
 539                 d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i);
 540                 switch (d->type) {
 541                 case EFI_RESERVED_TYPE:
 542                 case EFI_RUNTIME_SERVICES_CODE:
 543                 case EFI_RUNTIME_SERVICES_DATA:
 544                 case EFI_MEMORY_MAPPED_IO:
 545                 case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
 546                 case EFI_PAL_CODE:
 547                         e820_type = E820_TYPE_RESERVED;
 548                         break;
 549
 550                 case EFI_UNUSABLE_MEMORY:
 551                         e820_type = E820_TYPE_UNUSABLE;
 552                         break;
 553
 554                 case EFI_ACPI_RECLAIM_MEMORY:
 555                         e820_type = E820_TYPE_ACPI;
 556                         break;
 557
 558                 case EFI_LOADER_CODE:
 559                 case EFI_LOADER_DATA:
 560                 case EFI_BOOT_SERVICES_CODE:
 561                 case EFI_BOOT_SERVICES_DATA:
 562                 case EFI_CONVENTIONAL_MEMORY:
 563                         e820_type = E820_TYPE_RAM;
 564                         break;
 565
 566                 case EFI_ACPI_MEMORY_NVS:
 567                         e820_type = E820_TYPE_NVS;
 568                         break;
 569
 570                 case EFI_PERSISTENT_MEMORY:
 571                         e820_type = E820_TYPE_PMEM;
 572                         break;
 573
 574                 default:
 575                         continue;
 576                 }
 577
 578                 /* Merge adjacent mappings */
 579                 if (prev && prev->type == e820_type &&
 580                     (prev->addr + prev->size) == d->phys_addr) {
 581                         prev->size += d->num_pages << 12;
 582                         continue;
 583                 }
 584
 585                 if (nr_entries == ARRAY_SIZE(params->e820_table)) {
 586                         u32 need = (nr_desc - i) * sizeof(struct e820_entry) +
 587                                    sizeof(struct setup_data);
 588
 589                         if (!e820ext || e820ext_size < need)
 590                                 return EFI_BUFFER_TOO_SMALL;
 591
 592                         /* boot_params map full, switch to e820 extended */
 593                         entry = (struct boot_e820_entry *)e820ext->data;
 594                 }
 595
 596                 entry->addr = d->phys_addr;
 597                 entry->size = d->num_pages << PAGE_SHIFT;
 598                 entry->type = e820_type;
 599                 prev = entry++;
 600                 nr_entries++;
 601         }
 602
 603         if (nr_entries > ARRAY_SIZE(params->e820_table)) {
 604                 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table);
 605
 606                 add_e820ext(params, e820ext, nr_e820ext);
 607                 nr_entries -= nr_e820ext;
 608         }
 609
 610         params->e820_entries = (u8)nr_entries;
 611
 612         return EFI_SUCCESS;
 613 }
 614
 615 static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
 616                                   u32 *e820ext_size)
 617 {
 618         efi_status_t status;
 619         unsigned long size;
 620
 621         size = sizeof(struct setup_data) +
 622                 sizeof(struct e820_entry) * nr_desc;
 623
 624         if (*e820ext) {
 625                 efi_call_early(free_pool, *e820ext);
 626                 *e820ext = NULL;
 627                 *e820ext_size = 0;
 628         }
 629
 630         status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
 631                                 size, (void **)e820ext);
 632         if (status == EFI_SUCCESS)
 633                 *e820ext_size = size;
 634
 635         return status;
 636 }
 637
 638 static efi_status_t allocate_e820(struct boot_params *params,
 639                                   struct setup_data **e820ext,
 640                                   u32 *e820ext_size)
 641 {
 642         unsigned long map_size, desc_size, buff_size;
 643         struct efi_boot_memmap boot_map;
 644         efi_memory_desc_t *map;
 645         efi_status_t status;
 646         __u32 nr_desc;
 647
 648         boot_map.map            = &map;
 649         boot_map.map_size       = &map_size;
 650         boot_map.desc_size      = &desc_size;
 651         boot_map.desc_ver       = NULL;
 652         boot_map.key_ptr        = NULL;
 653         boot_map.buff_size      = &buff_size;
 654
 655         status = efi_get_memory_map(sys_table, &boot_map);
 656         if (status != EFI_SUCCESS)
 657                 return status;
 658
 659         nr_desc = buff_size / desc_size;
 660
 661         if (nr_desc > ARRAY_SIZE(params->e820_table)) {
 662                 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table);
 663
 664                 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
 665                 if (status != EFI_SUCCESS)
 666                         return status;
 667         }
 668
 669         return EFI_SUCCESS;
 670 }
 671
 672 struct exit_boot_struct {
 673         struct boot_params      *boot_params;
 674         struct efi_info         *efi;
 675 };
 676
 677 static efi_status_t exit_boot_func(efi_system_table_t *sys_table_arg,
 678                                    struct efi_boot_memmap *map,
 679                                    void *priv)
 680 {
 681         const char *signature;
 682         __u32 nr_desc;
 683         efi_status_t status;
 684         struct exit_boot_struct *p = priv;
 685
 686         signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE
 687                                    : EFI32_LOADER_SIGNATURE;
 688         memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
 689
 690         p->efi->efi_systab              = (unsigned long)sys_table_arg;
 691         p->efi->efi_memdesc_size        = *map->desc_size;
 692         p->efi->efi_memdesc_version     = *map->desc_ver;
 693         p->efi->efi_memmap              = (unsigned long)*map->map;
 694         p->efi->efi_memmap_size         = *map->map_size;
 695
 696 #ifdef CONFIG_X86_64
 697         p->efi->efi_systab_hi           = (unsigned long)sys_table_arg >> 32;
 698         p->efi->efi_memmap_hi           = (unsigned long)*map->map >> 32;
 699 #endif
 700
 701         return EFI_SUCCESS;
 702 }
 703
 704 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
 705 {
 706         unsigned long map_sz, key, desc_size, buff_size;
 707         efi_memory_desc_t *mem_map;
 708         struct setup_data *e820ext = NULL;
 709         __u32 e820ext_size = 0;
 710         efi_status_t status;
 711         __u32 desc_version;
 712         struct efi_boot_memmap map;
 713         struct exit_boot_struct priv;
 714
 715         map.map                 = &mem_map;
 716         map.map_size            = &map_sz;
 717         map.desc_size           = &desc_size;
 718         map.desc_ver            = &desc_version;
 719         map.key_ptr             = &key;
 720         map.buff_size           = &buff_size;
 721         priv.boot_params        = boot_params;
 722         priv.efi                = &boot_params->efi_info;
 723
 724         status = allocate_e820(boot_params, &e820ext, &e820ext_size);
 725         if (status != EFI_SUCCESS)
 726                 return status;
 727
 728         /* Might as well exit boot services now */
 729         status = efi_exit_boot_services(sys_table, handle, &map, &priv,
 730                                         exit_boot_func);
 731         if (status != EFI_SUCCESS)
 732                 return status;
 733
 734         /* Historic? */
 735         boot_params->alt_mem_k  = 32 * 1024;
 736
 737         status = setup_e820(boot_params, e820ext, e820ext_size);
 738         if (status != EFI_SUCCESS)
 739                 return status;
 740
 741         return EFI_SUCCESS;
 742 }
 743
 744 /*
 745  * On success we return a pointer to a boot_params structure, and NULL
 746  * on failure.
 747  */
 748 struct boot_params *
 749 efi_main(struct efi_config *c, struct boot_params *boot_params)
 750 {
 751         struct desc_ptr *gdt = NULL;
 752         efi_loaded_image_t *image;
 753         struct setup_header *hdr = &boot_params->hdr;
 754         efi_status_t status;
 755         struct desc_struct *desc;
 756         void *handle;
 757         efi_system_table_t *_table;
 758         unsigned long cmdline_paddr;
 759
 760         efi_early = c;
 761
 762         _table = (efi_system_table_t *)(unsigned long)efi_early->table;
 763         handle = (void *)(unsigned long)efi_early->image_handle;
 764
 765         sys_table = _table;
 766
 767         /* Check if we were booted by the EFI firmware */
 768         if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
 769                 goto fail;
 770
 771         if (efi_is_64bit())
 772                 setup_boot_services64(efi_early);
 773         else
 774                 setup_boot_services32(efi_early);
 775
 776         /*
 777          * make_boot_params() may have been called before efi_main(), in which
 778          * case this is the second time we parse the cmdline. This is ok,
 779          * parsing the cmdline multiple times does not have side-effects.
 780          */
 781         cmdline_paddr = ((u64)hdr->cmd_line_ptr |
 782                          ((u64)boot_params->ext_cmd_line_ptr << 32));
 783         efi_parse_options((char *)cmdline_paddr);
 784
 785         /*
 786          * If the boot loader gave us a value for secure_boot then we use that,
 787          * otherwise we ask the BIOS.
 788          */
 789         if (boot_params->secure_boot == efi_secureboot_mode_unset)
 790                 boot_params->secure_boot = efi_get_secureboot(sys_table);
 791
 792         /* Ask the firmware to clear memory on unclean shutdown */
 793         efi_enable_reset_attack_mitigation(sys_table);
 794         efi_retrieve_tpm2_eventlog(sys_table);
 795
 796         setup_graphics(boot_params);
 797
 798         setup_efi_pci(boot_params);
 799
 800         setup_quirks(boot_params);
 801
 802         status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
 803                                 sizeof(*gdt), (void **)&gdt);
 804         if (status != EFI_SUCCESS) {
 805                 efi_printk(sys_table, "Failed to allocate memory for 'gdt' structure\n");
 806                 goto fail;
 807         }
 808
 809         gdt->size = 0x800;
 810         status = efi_low_alloc(sys_table, gdt->size, 8,
 811                            (unsigned long *)&gdt->address);
 812         if (status != EFI_SUCCESS) {
 813                 efi_printk(sys_table, "Failed to allocate memory for 'gdt'\n");
 814                 goto fail;
 815         }
 816
 817         /*
 818          * If the kernel isn't already loaded at the preferred load
 819          * address, relocate it.
 820          */
 821         if (hdr->pref_address != hdr->code32_start) {
 822                 unsigned long bzimage_addr = hdr->code32_start;
 823                 status = efi_relocate_kernel(sys_table, &bzimage_addr,
 824                                              hdr->init_size, hdr->init_size,
 825                                              hdr->pref_address,
 826                                              hdr->kernel_alignment);
 827                 if (status != EFI_SUCCESS) {
 828                         efi_printk(sys_table, "efi_relocate_kernel() failed!\n");
 829                         goto fail;
 830                 }
 831
 832                 hdr->pref_address = hdr->code32_start;
 833                 hdr->code32_start = bzimage_addr;
 834         }
 835
 836         status = exit_boot(boot_params, handle);
 837         if (status != EFI_SUCCESS) {
 838                 efi_printk(sys_table, "exit_boot() failed!\n");
 839                 goto fail;
 840         }
 841
 842         memset((char *)gdt->address, 0x0, gdt->size);
 843         desc = (struct desc_struct *)gdt->address;
 844
 845         /* The first GDT is a dummy. */
 846         desc++;
 847
 848         if (IS_ENABLED(CONFIG_X86_64)) {
 849                 /* __KERNEL32_CS */
 850                 desc->limit0    = 0xffff;
 851                 desc->base0     = 0x0000;
 852                 desc->base1     = 0x0000;
 853                 desc->type      = SEG_TYPE_CODE | SEG_TYPE_EXEC_READ;
 854                 desc->s         = DESC_TYPE_CODE_DATA;
 855                 desc->dpl       = 0;
 856                 desc->p         = 1;
 857                 desc->limit1    = 0xf;
 858                 desc->avl       = 0;
 859                 desc->l         = 0;
 860                 desc->d         = SEG_OP_SIZE_32BIT;
 861                 desc->g         = SEG_GRANULARITY_4KB;
 862                 desc->base2     = 0x00;
 863
 864                 desc++;
 865         } else {
 866                 /* Second entry is unused on 32-bit */
 867                 desc++;
 868         }
 869
 870         /* __KERNEL_CS */
 871         desc->limit0    = 0xffff;
 872         desc->base0     = 0x0000;
 873         desc->base1     = 0x0000;
 874         desc->type      = SEG_TYPE_CODE | SEG_TYPE_EXEC_READ;
 875         desc->s         = DESC_TYPE_CODE_DATA;
 876         desc->dpl       = 0;
 877         desc->p         = 1;
 878         desc->limit1    = 0xf;
 879         desc->avl       = 0;
 880
 881         if (IS_ENABLED(CONFIG_X86_64)) {
 882                 desc->l = 1;
 883                 desc->d = 0;
 884         } else {
 885                 desc->l = 0;
 886                 desc->d = SEG_OP_SIZE_32BIT;
 887         }
 888         desc->g         = SEG_GRANULARITY_4KB;
 889         desc->base2     = 0x00;
 890         desc++;
 891
 892         /* __KERNEL_DS */
 893         desc->limit0    = 0xffff;
 894         desc->base0     = 0x0000;
 895         desc->base1     = 0x0000;
 896         desc->type      = SEG_TYPE_DATA | SEG_TYPE_READ_WRITE;
 897         desc->s         = DESC_TYPE_CODE_DATA;
 898         desc->dpl       = 0;
 899         desc->p         = 1;
 900         desc->limit1    = 0xf;
 901         desc->avl       = 0;
 902         desc->l         = 0;
 903         desc->d         = SEG_OP_SIZE_32BIT;
 904         desc->g         = SEG_GRANULARITY_4KB;
 905         desc->base2     = 0x00;
 906         desc++;
 907
 908         if (IS_ENABLED(CONFIG_X86_64)) {
 909                 /* Task segment value */
 910                 desc->limit0    = 0x0000;
 911                 desc->base0     = 0x0000;
 912                 desc->base1     = 0x0000;
 913                 desc->type      = SEG_TYPE_TSS;
 914                 desc->s         = 0;
 915                 desc->dpl       = 0;
 916                 desc->p         = 1;
 917                 desc->limit1    = 0x0;
 918                 desc->avl       = 0;
 919                 desc->l         = 0;
 920                 desc->d         = 0;
 921                 desc->g         = SEG_GRANULARITY_4KB;
 922                 desc->base2     = 0x00;
 923                 desc++;
 924         }
 925
 926         asm volatile("cli");
 927         asm volatile ("lgdt %0" : : "m" (*gdt));
 928
 929         return boot_params;
 930 fail:
 931         efi_printk(sys_table, "efi_main() failed!\n");
 932
 933         return NULL;
 934 }