lib/efi_loader/efi_image_loader.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  *  EFI image loader
   4  *
   5  *  based partly on wine code
   6  *
   7  *  Copyright (c) 2016 Alexander Graf
   8  */
   9
  10 #include <common.h>
  11 #include <efi_loader.h>
  12 #include <pe.h>
  13
  14 const efi_guid_t efi_global_variable_guid = EFI_GLOBAL_VARIABLE_GUID;
  15 const efi_guid_t efi_guid_device_path = DEVICE_PATH_GUID;
  16 const efi_guid_t efi_guid_loaded_image = LOADED_IMAGE_GUID;
  17 const efi_guid_t efi_simple_file_system_protocol_guid =
  18                 EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID;
  19 const efi_guid_t efi_file_info_guid = EFI_FILE_INFO_GUID;
  20
  21 static int machines[] = {
  22 #if defined(__aarch64__)
  23         IMAGE_FILE_MACHINE_ARM64,
  24 #elif defined(__arm__)
  25         IMAGE_FILE_MACHINE_ARM,
  26         IMAGE_FILE_MACHINE_THUMB,
  27         IMAGE_FILE_MACHINE_ARMNT,
  28 #endif
  29
  30 #if defined(__x86_64__)
  31         IMAGE_FILE_MACHINE_AMD64,
  32 #elif defined(__i386__)
  33         IMAGE_FILE_MACHINE_I386,
  34 #endif
  35
  36 #if defined(__riscv) && (__riscv_xlen == 32)
  37         IMAGE_FILE_MACHINE_RISCV32,
  38 #endif
  39
  40 #if defined(__riscv) && (__riscv_xlen == 64)
  41         IMAGE_FILE_MACHINE_RISCV64,
  42 #endif
  43         0 };
  44
  45 /*
  46  * Print information about a loaded image.
  47  *
  48  * If the program counter is located within the image the offset to the base
  49  * address is shown.
  50  *
  51  * @obj:        EFI object
  52  * @image:      loaded image
  53  * @pc:         program counter (use NULL to suppress offset output)
  54  * @return:     status code
  55  */
  56 static efi_status_t efi_print_image_info(struct efi_loaded_image_obj *obj,
  57                                          struct efi_loaded_image *image,
  58                                          void *pc)
  59 {
  60         printf("UEFI image");
  61         printf(" [0x%p:0x%p]",
  62                obj->reloc_base, obj->reloc_base + obj->reloc_size - 1);
  63         if (pc && pc >= obj->reloc_base &&
  64             pc < obj->reloc_base + obj->reloc_size)
  65                 printf(" pc=0x%zx", pc - obj->reloc_base);
  66         if (image->file_path)
  67                 printf(" '%pD'", image->file_path);
  68         printf("\n");
  69         return EFI_SUCCESS;
  70 }
  71
  72 /*
  73  * Print information about all loaded images.
  74  *
  75  * @pc:         program counter (use NULL to suppress offset output)
  76  */
  77 void efi_print_image_infos(void *pc)
  78 {
  79         struct efi_object *efiobj;
  80         struct efi_handler *handler;
  81
  82         list_for_each_entry(efiobj, &efi_obj_list, link) {
  83                 list_for_each_entry(handler, &efiobj->protocols, link) {
  84                         if (!guidcmp(handler->guid, &efi_guid_loaded_image)) {
  85                                 efi_print_image_info(
  86                                         (struct efi_loaded_image_obj *)efiobj,
  87                                         handler->protocol_interface, pc);
  88                         }
  89                 }
  90         }
  91 }
  92
  93 static efi_status_t efi_loader_relocate(const IMAGE_BASE_RELOCATION *rel,
  94                         unsigned long rel_size, void *efi_reloc,
  95                         unsigned long pref_address)
  96 {
  97         unsigned long delta = (unsigned long)efi_reloc - pref_address;
  98         const IMAGE_BASE_RELOCATION *end;
  99         int i;
 100
 101         if (delta == 0)
 102                 return EFI_SUCCESS;
 103
 104         end = (const IMAGE_BASE_RELOCATION *)((const char *)rel + rel_size);
 105         while (rel < end - 1 && rel->SizeOfBlock) {
 106                 const uint16_t *relocs = (const uint16_t *)(rel + 1);
 107                 i = (rel->SizeOfBlock - sizeof(*rel)) / sizeof(uint16_t);
 108                 while (i--) {
 109                         uint32_t offset = (uint32_t)(*relocs & 0xfff) +
 110                                           rel->VirtualAddress;
 111                         int type = *relocs >> EFI_PAGE_SHIFT;
 112                         uint64_t *x64 = efi_reloc + offset;
 113                         uint32_t *x32 = efi_reloc + offset;
 114                         uint16_t *x16 = efi_reloc + offset;
 115
 116                         switch (type) {
 117                         case IMAGE_REL_BASED_ABSOLUTE:
 118                                 break;
 119                         case IMAGE_REL_BASED_HIGH:
 120                                 *x16 += ((uint32_t)delta) >> 16;
 121                                 break;
 122                         case IMAGE_REL_BASED_LOW:
 123                                 *x16 += (uint16_t)delta;
 124                                 break;
 125                         case IMAGE_REL_BASED_HIGHLOW:
 126                                 *x32 += (uint32_t)delta;
 127                                 break;
 128                         case IMAGE_REL_BASED_DIR64:
 129                                 *x64 += (uint64_t)delta;
 130                                 break;
 131 #ifdef __riscv
 132                         case IMAGE_REL_BASED_RISCV_HI20:
 133                                 *x32 = ((*x32 & 0xfffff000) + (uint32_t)delta) |
 134                                         (*x32 & 0x00000fff);
 135                                 break;
 136                         case IMAGE_REL_BASED_RISCV_LOW12I:
 137                         case IMAGE_REL_BASED_RISCV_LOW12S:
 138                                 /* We know that we're 4k aligned */
 139                                 if (delta & 0xfff) {
 140                                         printf("Unsupported reloc offset\n");
 141                                         return EFI_LOAD_ERROR;
 142                                 }
 143                                 break;
 144 #endif
 145                         default:
 146                                 printf("Unknown Relocation off %x type %x\n",
 147                                        offset, type);
 148                                 return EFI_LOAD_ERROR;
 149                         }
 150                         relocs++;
 151                 }
 152                 rel = (const IMAGE_BASE_RELOCATION *)relocs;
 153         }
 154         return EFI_SUCCESS;
 155 }
 156
 157 void __weak invalidate_icache_all(void)
 158 {
 159         /* If the system doesn't support icache_all flush, cross our fingers */
 160 }
 161
 162 /*
 163  * Determine the memory types to be used for code and data.
 164  *
 165  * @loaded_image_info   image descriptor
 166  * @image_type          field Subsystem of the optional header for
 167  *                      Windows specific field
 168  */
 169 static void efi_set_code_and_data_type(
 170                         struct efi_loaded_image *loaded_image_info,
 171                         uint16_t image_type)
 172 {
 173         switch (image_type) {
 174         case IMAGE_SUBSYSTEM_EFI_APPLICATION:
 175                 loaded_image_info->image_code_type = EFI_LOADER_CODE;
 176                 loaded_image_info->image_data_type = EFI_LOADER_DATA;
 177                 break;
 178         case IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER:
 179                 loaded_image_info->image_code_type = EFI_BOOT_SERVICES_CODE;
 180                 loaded_image_info->image_data_type = EFI_BOOT_SERVICES_DATA;
 181                 break;
 182         case IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER:
 183         case IMAGE_SUBSYSTEM_EFI_ROM:
 184                 loaded_image_info->image_code_type = EFI_RUNTIME_SERVICES_CODE;
 185                 loaded_image_info->image_data_type = EFI_RUNTIME_SERVICES_DATA;
 186                 break;
 187         default:
 188                 printf("%s: invalid image type: %u\n", __func__, image_type);
 189                 /* Let's assume it is an application */
 190                 loaded_image_info->image_code_type = EFI_LOADER_CODE;
 191                 loaded_image_info->image_data_type = EFI_LOADER_DATA;
 192                 break;
 193         }
 194 }
 195
 196 /*
 197  * This function loads all sections from a PE binary into a newly reserved
 198  * piece of memory. On successful load it then returns the entry point for
 199  * the binary. Otherwise NULL.
 200  */
 201 void *efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
 202                   struct efi_loaded_image *loaded_image_info)
 203 {
 204         IMAGE_NT_HEADERS32 *nt;
 205         IMAGE_DOS_HEADER *dos;
 206         IMAGE_SECTION_HEADER *sections;
 207         int num_sections;
 208         void *efi_reloc;
 209         int i;
 210         const IMAGE_BASE_RELOCATION *rel;
 211         unsigned long rel_size;
 212         int rel_idx = IMAGE_DIRECTORY_ENTRY_BASERELOC;
 213         void *entry;
 214         uint64_t image_base;
 215         uint64_t image_size;
 216         unsigned long virt_size = 0;
 217         int supported = 0;
 218
 219         dos = efi;
 220         if (dos->e_magic != IMAGE_DOS_SIGNATURE) {
 221                 printf("%s: Invalid DOS Signature\n", __func__);
 222                 return NULL;
 223         }
 224
 225         nt = (void *) ((char *)efi + dos->e_lfanew);
 226         if (nt->Signature != IMAGE_NT_SIGNATURE) {
 227                 printf("%s: Invalid NT Signature\n", __func__);
 228                 return NULL;
 229         }
 230
 231         for (i = 0; machines[i]; i++)
 232                 if (machines[i] == nt->FileHeader.Machine) {
 233                         supported = 1;
 234                         break;
 235                 }
 236
 237         if (!supported) {
 238                 printf("%s: Machine type 0x%04x is not supported\n",
 239                        __func__, nt->FileHeader.Machine);
 240                 return NULL;
 241         }
 242
 243         /* Calculate upper virtual address boundary */
 244         num_sections = nt->FileHeader.NumberOfSections;
 245         sections = (void *)&nt->OptionalHeader +
 246                             nt->FileHeader.SizeOfOptionalHeader;
 247
 248         for (i = num_sections - 1; i >= 0; i--) {
 249                 IMAGE_SECTION_HEADER *sec = &sections[i];
 250                 virt_size = max_t(unsigned long, virt_size,
 251                                   sec->VirtualAddress + sec->Misc.VirtualSize);
 252         }
 253
 254         /* Read 32/64bit specific header bits */
 255         if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) {
 256                 IMAGE_NT_HEADERS64 *nt64 = (void *)nt;
 257                 IMAGE_OPTIONAL_HEADER64 *opt = &nt64->OptionalHeader;
 258                 image_base = opt->ImageBase;
 259                 image_size = opt->SizeOfImage;
 260                 efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
 261                 efi_reloc = efi_alloc(virt_size,
 262                                       loaded_image_info->image_code_type);
 263                 if (!efi_reloc) {
 264                         printf("%s: Could not allocate %lu bytes\n",
 265                                __func__, virt_size);
 266                         return NULL;
 267                 }
 268                 entry = efi_reloc + opt->AddressOfEntryPoint;
 269                 rel_size = opt->DataDirectory[rel_idx].Size;
 270                 rel = efi_reloc + opt->DataDirectory[rel_idx].VirtualAddress;
 271                 virt_size = ALIGN(virt_size, opt->SectionAlignment);
 272         } else if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
 273                 IMAGE_OPTIONAL_HEADER32 *opt = &nt->OptionalHeader;
 274                 image_base = opt->ImageBase;
 275                 image_size = opt->SizeOfImage;
 276                 efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
 277                 efi_reloc = efi_alloc(virt_size,
 278                                       loaded_image_info->image_code_type);
 279                 if (!efi_reloc) {
 280                         printf("%s: Could not allocate %lu bytes\n",
 281                                __func__, virt_size);
 282                         return NULL;
 283                 }
 284                 entry = efi_reloc + opt->AddressOfEntryPoint;
 285                 rel_size = opt->DataDirectory[rel_idx].Size;
 286                 rel = efi_reloc + opt->DataDirectory[rel_idx].VirtualAddress;
 287                 virt_size = ALIGN(virt_size, opt->SectionAlignment);
 288         } else {
 289                 printf("%s: Invalid optional header magic %x\n", __func__,
 290                        nt->OptionalHeader.Magic);
 291                 return NULL;
 292         }
 293
 294         /* Load sections into RAM */
 295         for (i = num_sections - 1; i >= 0; i--) {
 296                 IMAGE_SECTION_HEADER *sec = &sections[i];
 297                 memset(efi_reloc + sec->VirtualAddress, 0,
 298                        sec->Misc.VirtualSize);
 299                 memcpy(efi_reloc + sec->VirtualAddress,
 300                        efi + sec->PointerToRawData,
 301                        sec->SizeOfRawData);
 302         }
 303
 304         /* Run through relocations */
 305         if (efi_loader_relocate(rel, rel_size, efi_reloc,
 306                                 (unsigned long)image_base) != EFI_SUCCESS) {
 307                 efi_free_pages((uintptr_t) efi_reloc,
 308                                (virt_size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT);
 309                 return NULL;
 310         }
 311
 312         /* Flush cache */
 313         flush_cache((ulong)efi_reloc,
 314                     ALIGN(virt_size, EFI_CACHELINE_SIZE));
 315         invalidate_icache_all();
 316
 317         /* Populate the loaded image interface bits */
 318         loaded_image_info->image_base = efi;
 319         loaded_image_info->image_size = image_size;
 320         handle->reloc_base = efi_reloc;
 321         handle->reloc_size = virt_size;
 322
 323         return entry;
 324 }