arch/x86/boot/compressed/eboot.c

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