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  * efi_print_image_info() - 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  * efi_print_image_infos() - 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 /**
  94  * efi_loader_relocate() - relocate UEFI binary
  95  *
  96  * @rel:                pointer to the relocation table
  97  * @rel_size:           size of the relocation table in bytes
  98  * @efi_reloc:          actual load address of the image
  99  * @pref_address:       preferred load address of the image
 100  * Return:              status code
 101  */
 102 static efi_status_t efi_loader_relocate(const IMAGE_BASE_RELOCATION *rel,
 103                         unsigned long rel_size, void *efi_reloc,
 104                         unsigned long pref_address)
 105 {
 106         unsigned long delta = (unsigned long)efi_reloc - pref_address;
 107         const IMAGE_BASE_RELOCATION *end;
 108         int i;
 109
 110         if (delta == 0)
 111                 return EFI_SUCCESS;
 112
 113         end = (const IMAGE_BASE_RELOCATION *)((const char *)rel + rel_size);
 114         while (rel < end && rel->SizeOfBlock) {
 115                 const uint16_t *relocs = (const uint16_t *)(rel + 1);
 116                 i = (rel->SizeOfBlock - sizeof(*rel)) / sizeof(uint16_t);
 117                 while (i--) {
 118                         uint32_t offset = (uint32_t)(*relocs & 0xfff) +
 119                                           rel->VirtualAddress;
 120                         int type = *relocs >> EFI_PAGE_SHIFT;
 121                         uint64_t *x64 = efi_reloc + offset;
 122                         uint32_t *x32 = efi_reloc + offset;
 123                         uint16_t *x16 = efi_reloc + offset;
 124
 125                         switch (type) {
 126                         case IMAGE_REL_BASED_ABSOLUTE:
 127                                 break;
 128                         case IMAGE_REL_BASED_HIGH:
 129                                 *x16 += ((uint32_t)delta) >> 16;
 130                                 break;
 131                         case IMAGE_REL_BASED_LOW:
 132                                 *x16 += (uint16_t)delta;
 133                                 break;
 134                         case IMAGE_REL_BASED_HIGHLOW:
 135                                 *x32 += (uint32_t)delta;
 136                                 break;
 137                         case IMAGE_REL_BASED_DIR64:
 138                                 *x64 += (uint64_t)delta;
 139                                 break;
 140 #ifdef __riscv
 141                         case IMAGE_REL_BASED_RISCV_HI20:
 142                                 *x32 = ((*x32 & 0xfffff000) + (uint32_t)delta) |
 143                                         (*x32 & 0x00000fff);
 144                                 break;
 145                         case IMAGE_REL_BASED_RISCV_LOW12I:
 146                         case IMAGE_REL_BASED_RISCV_LOW12S:
 147                                 /* We know that we're 4k aligned */
 148                                 if (delta & 0xfff) {
 149                                         printf("Unsupported reloc offset\n");
 150                                         return EFI_LOAD_ERROR;
 151                                 }
 152                                 break;
 153 #endif
 154                         default:
 155                                 printf("Unknown Relocation off %x type %x\n",
 156                                        offset, type);
 157                                 return EFI_LOAD_ERROR;
 158                         }
 159                         relocs++;
 160                 }
 161                 rel = (const IMAGE_BASE_RELOCATION *)relocs;
 162         }
 163         return EFI_SUCCESS;
 164 }
 165
 166 void __weak invalidate_icache_all(void)
 167 {
 168         /* If the system doesn't support icache_all flush, cross our fingers */
 169 }
 170
 171 /**
 172  * efi_set_code_and_data_type() - determine the memory types to be used for code
 173  *                                and data.
 174  *
 175  * @loaded_image_info:  image descriptor
 176  * @image_type:         field Subsystem of the optional header for
 177  *                      Windows specific field
 178  */
 179 static void efi_set_code_and_data_type(
 180                         struct efi_loaded_image *loaded_image_info,
 181                         uint16_t image_type)
 182 {
 183         switch (image_type) {
 184         case IMAGE_SUBSYSTEM_EFI_APPLICATION:
 185                 loaded_image_info->image_code_type = EFI_LOADER_CODE;
 186                 loaded_image_info->image_data_type = EFI_LOADER_DATA;
 187                 break;
 188         case IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER:
 189                 loaded_image_info->image_code_type = EFI_BOOT_SERVICES_CODE;
 190                 loaded_image_info->image_data_type = EFI_BOOT_SERVICES_DATA;
 191                 break;
 192         case IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER:
 193         case IMAGE_SUBSYSTEM_EFI_ROM:
 194                 loaded_image_info->image_code_type = EFI_RUNTIME_SERVICES_CODE;
 195                 loaded_image_info->image_data_type = EFI_RUNTIME_SERVICES_DATA;
 196                 break;
 197         default:
 198                 printf("%s: invalid image type: %u\n", __func__, image_type);
 199                 /* Let's assume it is an application */
 200                 loaded_image_info->image_code_type = EFI_LOADER_CODE;
 201                 loaded_image_info->image_data_type = EFI_LOADER_DATA;
 202                 break;
 203         }
 204 }
 205
 206 /**
 207  * efi_load_pe() - relocate EFI binary
 208  *
 209  * This function loads all sections from a PE binary into a newly reserved
 210  * piece of memory. On success the entry point is returned as handle->entry.
 211  *
 212  * @handle:             loaded image handle
 213  * @efi:                pointer to the EFI binary
 214  * @loaded_image_info:  loaded image protocol
 215  * Return:              status code
 216  */
 217 efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
 218                          struct efi_loaded_image *loaded_image_info)
 219 {
 220         IMAGE_NT_HEADERS32 *nt;
 221         IMAGE_DOS_HEADER *dos;
 222         IMAGE_SECTION_HEADER *sections;
 223         int num_sections;
 224         void *efi_reloc;
 225         int i;
 226         const IMAGE_BASE_RELOCATION *rel;
 227         unsigned long rel_size;
 228         int rel_idx = IMAGE_DIRECTORY_ENTRY_BASERELOC;
 229         uint64_t image_base;
 230         uint64_t image_size;
 231         unsigned long virt_size = 0;
 232         int supported = 0;
 233
 234         dos = efi;
 235         if (dos->e_magic != IMAGE_DOS_SIGNATURE) {
 236                 printf("%s: Invalid DOS Signature\n", __func__);
 237                 return EFI_LOAD_ERROR;
 238         }
 239
 240         nt = (void *) ((char *)efi + dos->e_lfanew);
 241         if (nt->Signature != IMAGE_NT_SIGNATURE) {
 242                 printf("%s: Invalid NT Signature\n", __func__);
 243                 return EFI_LOAD_ERROR;
 244         }
 245
 246         for (i = 0; machines[i]; i++)
 247                 if (machines[i] == nt->FileHeader.Machine) {
 248                         supported = 1;
 249                         break;
 250                 }
 251
 252         if (!supported) {
 253                 printf("%s: Machine type 0x%04x is not supported\n",
 254                        __func__, nt->FileHeader.Machine);
 255                 return EFI_LOAD_ERROR;
 256         }
 257
 258         /* Calculate upper virtual address boundary */
 259         num_sections = nt->FileHeader.NumberOfSections;
 260         sections = (void *)&nt->OptionalHeader +
 261                             nt->FileHeader.SizeOfOptionalHeader;
 262
 263         for (i = num_sections - 1; i >= 0; i--) {
 264                 IMAGE_SECTION_HEADER *sec = &sections[i];
 265                 virt_size = max_t(unsigned long, virt_size,
 266                                   sec->VirtualAddress + sec->Misc.VirtualSize);
 267         }
 268
 269         /* Read 32/64bit specific header bits */
 270         if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) {
 271                 IMAGE_NT_HEADERS64 *nt64 = (void *)nt;
 272                 IMAGE_OPTIONAL_HEADER64 *opt = &nt64->OptionalHeader;
 273                 image_base = opt->ImageBase;
 274                 image_size = opt->SizeOfImage;
 275                 efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
 276                 efi_reloc = efi_alloc(virt_size,
 277                                       loaded_image_info->image_code_type);
 278                 if (!efi_reloc) {
 279                         printf("%s: Could not allocate %lu bytes\n",
 280                                __func__, virt_size);
 281                         return EFI_OUT_OF_RESOURCES;
 282                 }
 283                 handle->entry = efi_reloc + opt->AddressOfEntryPoint;
 284                 rel_size = opt->DataDirectory[rel_idx].Size;
 285                 rel = efi_reloc + opt->DataDirectory[rel_idx].VirtualAddress;
 286                 virt_size = ALIGN(virt_size, opt->SectionAlignment);
 287         } else if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
 288                 IMAGE_OPTIONAL_HEADER32 *opt = &nt->OptionalHeader;
 289                 image_base = opt->ImageBase;
 290                 image_size = opt->SizeOfImage;
 291                 efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
 292                 efi_reloc = efi_alloc(virt_size,
 293                                       loaded_image_info->image_code_type);
 294                 if (!efi_reloc) {
 295                         printf("%s: Could not allocate %lu bytes\n",
 296                                __func__, virt_size);
 297                         return EFI_OUT_OF_RESOURCES;
 298                 }
 299                 handle->entry = efi_reloc + opt->AddressOfEntryPoint;
 300                 rel_size = opt->DataDirectory[rel_idx].Size;
 301                 rel = efi_reloc + opt->DataDirectory[rel_idx].VirtualAddress;
 302                 virt_size = ALIGN(virt_size, opt->SectionAlignment);
 303         } else {
 304                 printf("%s: Invalid optional header magic %x\n", __func__,
 305                        nt->OptionalHeader.Magic);
 306                 return EFI_LOAD_ERROR;
 307         }
 308
 309         /* Load sections into RAM */
 310         for (i = num_sections - 1; i >= 0; i--) {
 311                 IMAGE_SECTION_HEADER *sec = &sections[i];
 312                 memset(efi_reloc + sec->VirtualAddress, 0,
 313                        sec->Misc.VirtualSize);
 314                 memcpy(efi_reloc + sec->VirtualAddress,
 315                        efi + sec->PointerToRawData,
 316                        sec->SizeOfRawData);
 317         }
 318
 319         /* Run through relocations */
 320         if (efi_loader_relocate(rel, rel_size, efi_reloc,
 321                                 (unsigned long)image_base) != EFI_SUCCESS) {
 322                 efi_free_pages((uintptr_t) efi_reloc,
 323                                (virt_size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT);
 324                 return EFI_LOAD_ERROR;
 325         }
 326
 327         /* Flush cache */
 328         flush_cache((ulong)efi_reloc,
 329                     ALIGN(virt_size, EFI_CACHELINE_SIZE));
 330         invalidate_icache_all();
 331
 332         /* Populate the loaded image interface bits */
 333         loaded_image_info->image_base = efi;
 334         loaded_image_info->image_size = image_size;
 335         handle->reloc_base = efi_reloc;
 336         handle->reloc_size = virt_size;
 337
 338         return EFI_SUCCESS;
 339 }