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 = EFI_DEVICE_PATH_PROTOCOL_GUID;
  16 const efi_guid_t efi_guid_loaded_image = EFI_LOADED_IMAGE_PROTOCOL_GUID;
  17 const efi_guid_t efi_guid_loaded_image_device_path =
  18                 EFI_LOADED_IMAGE_DEVICE_PATH_PROTOCOL_GUID;
  19 const efi_guid_t efi_simple_file_system_protocol_guid =
  20                 EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID;
  21 const efi_guid_t efi_file_info_guid = EFI_FILE_INFO_GUID;
  22
  23 static int machines[] = {
  24 #if defined(__aarch64__)
  25         IMAGE_FILE_MACHINE_ARM64,
  26 #elif defined(__arm__)
  27         IMAGE_FILE_MACHINE_ARM,
  28         IMAGE_FILE_MACHINE_THUMB,
  29         IMAGE_FILE_MACHINE_ARMNT,
  30 #endif
  31
  32 #if defined(__x86_64__)
  33         IMAGE_FILE_MACHINE_AMD64,
  34 #elif defined(__i386__)
  35         IMAGE_FILE_MACHINE_I386,
  36 #endif
  37
  38 #if defined(__riscv) && (__riscv_xlen == 32)
  39         IMAGE_FILE_MACHINE_RISCV32,
  40 #endif
  41
  42 #if defined(__riscv) && (__riscv_xlen == 64)
  43         IMAGE_FILE_MACHINE_RISCV64,
  44 #endif
  45         0 };
  46
  47 /**
  48  * efi_print_image_info() - print information about a loaded image
  49  *
  50  * If the program counter is located within the image the offset to the base
  51  * address is shown.
  52  *
  53  * @obj:        EFI object
  54  * @image:      loaded image
  55  * @pc:         program counter (use NULL to suppress offset output)
  56  * Return:      status code
  57  */
  58 static efi_status_t efi_print_image_info(struct efi_loaded_image_obj *obj,
  59                                          struct efi_loaded_image *image,
  60                                          void *pc)
  61 {
  62         printf("UEFI image");
  63         printf(" [0x%p:0x%p]",
  64                image->image_base, image->image_base + image->image_size - 1);
  65         if (pc && pc >= image->image_base &&
  66             pc < image->image_base + image->image_size)
  67                 printf(" pc=0x%zx", pc - image->image_base);
  68         if (image->file_path)
  69                 printf(" '%pD'", image->file_path);
  70         printf("\n");
  71         return EFI_SUCCESS;
  72 }
  73
  74 /**
  75  * efi_print_image_infos() - print information about all loaded images
  76  *
  77  * @pc:         program counter (use NULL to suppress offset output)
  78  */
  79 void efi_print_image_infos(void *pc)
  80 {
  81         struct efi_object *efiobj;
  82         struct efi_handler *handler;
  83
  84         list_for_each_entry(efiobj, &efi_obj_list, link) {
  85                 list_for_each_entry(handler, &efiobj->protocols, link) {
  86                         if (!guidcmp(handler->guid, &efi_guid_loaded_image)) {
  87                                 efi_print_image_info(
  88                                         (struct efi_loaded_image_obj *)efiobj,
  89                                         handler->protocol_interface, pc);
  90                         }
  91                 }
  92         }
  93 }
  94
  95 /**
  96  * efi_loader_relocate() - relocate UEFI binary
  97  *
  98  * @rel:                pointer to the relocation table
  99  * @rel_size:           size of the relocation table in bytes
 100  * @efi_reloc:          actual load address of the image
 101  * @pref_address:       preferred load address of the image
 102  * Return:              status code
 103  */
 104 static efi_status_t efi_loader_relocate(const IMAGE_BASE_RELOCATION *rel,
 105                         unsigned long rel_size, void *efi_reloc,
 106                         unsigned long pref_address)
 107 {
 108         unsigned long delta = (unsigned long)efi_reloc - pref_address;
 109         const IMAGE_BASE_RELOCATION *end;
 110         int i;
 111
 112         if (delta == 0)
 113                 return EFI_SUCCESS;
 114
 115         end = (const IMAGE_BASE_RELOCATION *)((const char *)rel + rel_size);
 116         while (rel < end && rel->SizeOfBlock) {
 117                 const uint16_t *relocs = (const uint16_t *)(rel + 1);
 118                 i = (rel->SizeOfBlock - sizeof(*rel)) / sizeof(uint16_t);
 119                 while (i--) {
 120                         uint32_t offset = (uint32_t)(*relocs & 0xfff) +
 121                                           rel->VirtualAddress;
 122                         int type = *relocs >> EFI_PAGE_SHIFT;
 123                         uint64_t *x64 = efi_reloc + offset;
 124                         uint32_t *x32 = efi_reloc + offset;
 125                         uint16_t *x16 = efi_reloc + offset;
 126
 127                         switch (type) {
 128                         case IMAGE_REL_BASED_ABSOLUTE:
 129                                 break;
 130                         case IMAGE_REL_BASED_HIGH:
 131                                 *x16 += ((uint32_t)delta) >> 16;
 132                                 break;
 133                         case IMAGE_REL_BASED_LOW:
 134                                 *x16 += (uint16_t)delta;
 135                                 break;
 136                         case IMAGE_REL_BASED_HIGHLOW:
 137                                 *x32 += (uint32_t)delta;
 138                                 break;
 139                         case IMAGE_REL_BASED_DIR64:
 140                                 *x64 += (uint64_t)delta;
 141                                 break;
 142 #ifdef __riscv
 143                         case IMAGE_REL_BASED_RISCV_HI20:
 144                                 *x32 = ((*x32 & 0xfffff000) + (uint32_t)delta) |
 145                                         (*x32 & 0x00000fff);
 146                                 break;
 147                         case IMAGE_REL_BASED_RISCV_LOW12I:
 148                         case IMAGE_REL_BASED_RISCV_LOW12S:
 149                                 /* We know that we're 4k aligned */
 150                                 if (delta & 0xfff) {
 151                                         printf("Unsupported reloc offset\n");
 152                                         return EFI_LOAD_ERROR;
 153                                 }
 154                                 break;
 155 #endif
 156                         default:
 157                                 printf("Unknown Relocation off %x type %x\n",
 158                                        offset, type);
 159                                 return EFI_LOAD_ERROR;
 160                         }
 161                         relocs++;
 162                 }
 163                 rel = (const IMAGE_BASE_RELOCATION *)relocs;
 164         }
 165         return EFI_SUCCESS;
 166 }
 167
 168 void __weak invalidate_icache_all(void)
 169 {
 170         /* If the system doesn't support icache_all flush, cross our fingers */
 171 }
 172
 173 /**
 174  * efi_set_code_and_data_type() - determine the memory types to be used for code
 175  *                                and data.
 176  *
 177  * @loaded_image_info:  image descriptor
 178  * @image_type:         field Subsystem of the optional header for
 179  *                      Windows specific field
 180  */
 181 static void efi_set_code_and_data_type(
 182                         struct efi_loaded_image *loaded_image_info,
 183                         uint16_t image_type)
 184 {
 185         switch (image_type) {
 186         case IMAGE_SUBSYSTEM_EFI_APPLICATION:
 187                 loaded_image_info->image_code_type = EFI_LOADER_CODE;
 188                 loaded_image_info->image_data_type = EFI_LOADER_DATA;
 189                 break;
 190         case IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER:
 191                 loaded_image_info->image_code_type = EFI_BOOT_SERVICES_CODE;
 192                 loaded_image_info->image_data_type = EFI_BOOT_SERVICES_DATA;
 193                 break;
 194         case IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER:
 195         case IMAGE_SUBSYSTEM_EFI_ROM:
 196                 loaded_image_info->image_code_type = EFI_RUNTIME_SERVICES_CODE;
 197                 loaded_image_info->image_data_type = EFI_RUNTIME_SERVICES_DATA;
 198                 break;
 199         default:
 200                 printf("%s: invalid image type: %u\n", __func__, image_type);
 201                 /* Let's assume it is an application */
 202                 loaded_image_info->image_code_type = EFI_LOADER_CODE;
 203                 loaded_image_info->image_data_type = EFI_LOADER_DATA;
 204                 break;
 205         }
 206 }
 207
 208 /**
 209  * efi_load_pe() - relocate EFI binary
 210  *
 211  * This function loads all sections from a PE binary into a newly reserved
 212  * piece of memory. On success the entry point is returned as handle->entry.
 213  *
 214  * @handle:             loaded image handle
 215  * @efi:                pointer to the EFI binary
 216  * @loaded_image_info:  loaded image protocol
 217  * Return:              status code
 218  */
 219 efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
 220                          struct efi_loaded_image *loaded_image_info)
 221 {
 222         IMAGE_NT_HEADERS32 *nt;
 223         IMAGE_DOS_HEADER *dos;
 224         IMAGE_SECTION_HEADER *sections;
 225         int num_sections;
 226         void *efi_reloc;
 227         int i;
 228         const IMAGE_BASE_RELOCATION *rel;
 229         unsigned long rel_size;
 230         int rel_idx = IMAGE_DIRECTORY_ENTRY_BASERELOC;
 231         uint64_t image_base;
 232         unsigned long virt_size = 0;
 233         int supported = 0;
 234
 235         dos = efi;
 236         if (dos->e_magic != IMAGE_DOS_SIGNATURE) {
 237                 printf("%s: Invalid DOS Signature\n", __func__);
 238                 return EFI_LOAD_ERROR;
 239         }
 240
 241         nt = (void *) ((char *)efi + dos->e_lfanew);
 242         if (nt->Signature != IMAGE_NT_SIGNATURE) {
 243                 printf("%s: Invalid NT Signature\n", __func__);
 244                 return EFI_LOAD_ERROR;
 245         }
 246
 247         for (i = 0; machines[i]; i++)
 248                 if (machines[i] == nt->FileHeader.Machine) {
 249                         supported = 1;
 250                         break;
 251                 }
 252
 253         if (!supported) {
 254                 printf("%s: Machine type 0x%04x is not supported\n",
 255                        __func__, nt->FileHeader.Machine);
 256                 return EFI_LOAD_ERROR;
 257         }
 258
 259         /* Calculate upper virtual address boundary */
 260         num_sections = nt->FileHeader.NumberOfSections;
 261         sections = (void *)&nt->OptionalHeader +
 262                             nt->FileHeader.SizeOfOptionalHeader;
 263
 264         for (i = num_sections - 1; i >= 0; i--) {
 265                 IMAGE_SECTION_HEADER *sec = &sections[i];
 266                 virt_size = max_t(unsigned long, virt_size,
 267                                   sec->VirtualAddress + sec->Misc.VirtualSize);
 268         }
 269
 270         /* Read 32/64bit specific header bits */
 271         if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) {
 272                 IMAGE_NT_HEADERS64 *nt64 = (void *)nt;
 273                 IMAGE_OPTIONAL_HEADER64 *opt = &nt64->OptionalHeader;
 274                 image_base = opt->ImageBase;
 275                 efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
 276                 handle->image_type = 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 EFI_OUT_OF_RESOURCES;
 283                 }
 284                 handle->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 if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
 289                 IMAGE_OPTIONAL_HEADER32 *opt = &nt->OptionalHeader;
 290                 image_base = opt->ImageBase;
 291                 efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
 292                 handle->image_type = opt->Subsystem;
 293                 efi_reloc = efi_alloc(virt_size,
 294                                       loaded_image_info->image_code_type);
 295                 if (!efi_reloc) {
 296                         printf("%s: Could not allocate %lu bytes\n",
 297                                __func__, virt_size);
 298                         return EFI_OUT_OF_RESOURCES;
 299                 }
 300                 handle->entry = efi_reloc + opt->AddressOfEntryPoint;
 301                 rel_size = opt->DataDirectory[rel_idx].Size;
 302                 rel = efi_reloc + opt->DataDirectory[rel_idx].VirtualAddress;
 303                 virt_size = ALIGN(virt_size, opt->SectionAlignment);
 304         } else {
 305                 printf("%s: Invalid optional header magic %x\n", __func__,
 306                        nt->OptionalHeader.Magic);
 307                 return EFI_LOAD_ERROR;
 308         }
 309
 310         /* Copy PE headers */
 311         memcpy(efi_reloc, efi, sizeof(*dos) + sizeof(*nt)
 312                + nt->FileHeader.SizeOfOptionalHeader
 313                + num_sections * sizeof(IMAGE_SECTION_HEADER));
 314
 315         /* Load sections into RAM */
 316         for (i = num_sections - 1; i >= 0; i--) {
 317                 IMAGE_SECTION_HEADER *sec = &sections[i];
 318                 memset(efi_reloc + sec->VirtualAddress, 0,
 319                        sec->Misc.VirtualSize);
 320                 memcpy(efi_reloc + sec->VirtualAddress,
 321                        efi + sec->PointerToRawData,
 322                        sec->SizeOfRawData);
 323         }
 324
 325         /* Run through relocations */
 326         if (efi_loader_relocate(rel, rel_size, efi_reloc,
 327                                 (unsigned long)image_base) != EFI_SUCCESS) {
 328                 efi_free_pages((uintptr_t) efi_reloc,
 329                                (virt_size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT);
 330                 return EFI_LOAD_ERROR;
 331         }
 332
 333         /* Flush cache */
 334         flush_cache((ulong)efi_reloc,
 335                     ALIGN(virt_size, EFI_CACHELINE_SIZE));
 336         invalidate_icache_all();
 337
 338         /* Populate the loaded image interface bits */
 339         loaded_image_info->image_base = efi_reloc;
 340         loaded_image_info->image_size = virt_size;
 341
 342         return EFI_SUCCESS;
 343 }