// SPDX-License-Identifier: GPL-2.0+
/*
 *  EFI image loader
 *
 *  based partly on wine code
 *
 *  Copyright (c) 2016 Alexander Graf
 */

#define LOG_CATEGORY LOGC_EFI

#include <common.h>
#include <cpu_func.h>
#include <efi_loader.h>
#include <log.h>
#include <malloc.h>
#include <pe.h>
#include <sort.h>
#include <crypto/pkcs7_parser.h>
#include <linux/err.h>

const efi_guid_t efi_global_variable_guid = EFI_GLOBAL_VARIABLE_GUID;
const efi_guid_t efi_guid_device_path = EFI_DEVICE_PATH_PROTOCOL_GUID;
const efi_guid_t efi_guid_loaded_image = EFI_LOADED_IMAGE_PROTOCOL_GUID;
const efi_guid_t efi_guid_loaded_image_device_path =
                EFI_LOADED_IMAGE_DEVICE_PATH_PROTOCOL_GUID;
const efi_guid_t efi_simple_file_system_protocol_guid =
                EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID;
const efi_guid_t efi_file_info_guid = EFI_FILE_INFO_GUID;

static int machines[] = {
#if defined(__aarch64__)
        IMAGE_FILE_MACHINE_ARM64,
#elif defined(__arm__)
        IMAGE_FILE_MACHINE_ARM,
        IMAGE_FILE_MACHINE_THUMB,
        IMAGE_FILE_MACHINE_ARMNT,
#endif

#if defined(__x86_64__)
        IMAGE_FILE_MACHINE_AMD64,
#elif defined(__i386__)
        IMAGE_FILE_MACHINE_I386,
#endif

#if defined(__riscv) && (__riscv_xlen == 32)
        IMAGE_FILE_MACHINE_RISCV32,
#endif

#if defined(__riscv) && (__riscv_xlen == 64)
        IMAGE_FILE_MACHINE_RISCV64,
#endif
        0 };

/**
 * efi_print_image_info() - print information about a loaded image
 *
 * If the program counter is located within the image the offset to the base
 * address is shown.
 *
 * @obj:        EFI object
 * @image:      loaded image
 * @pc:         program counter (use NULL to suppress offset output)
 * Return:      status code
 */
static efi_status_t efi_print_image_info(struct efi_loaded_image_obj *obj,
                                         struct efi_loaded_image *image,
                                         void *pc)
{
        printf("UEFI image");
        printf(" [0x%p:0x%p]",
               image->image_base, image->image_base + image->image_size - 1);
        if (pc && pc >= image->image_base &&
            pc < image->image_base + image->image_size)
                printf(" pc=0x%zx", pc - image->image_base);
        if (image->file_path)
                printf(" '%pD'", image->file_path);
        printf("\n");
        return EFI_SUCCESS;
}

/**
 * efi_print_image_infos() - print information about all loaded images
 *
 * @pc:         program counter (use NULL to suppress offset output)
 */
void efi_print_image_infos(void *pc)
{
        struct efi_object *efiobj;
        struct efi_handler *handler;

        list_for_each_entry(efiobj, &efi_obj_list, link) {
                list_for_each_entry(handler, &efiobj->protocols, link) {
                        if (!guidcmp(handler->guid, &efi_guid_loaded_image)) {
                                efi_print_image_info(
                                        (struct efi_loaded_image_obj *)efiobj,
                                        handler->protocol_interface, pc);
                        }
                }
        }
}

/**
 * efi_loader_relocate() - relocate UEFI binary
 *
 * @rel:                pointer to the relocation table
 * @rel_size:           size of the relocation table in bytes
 * @efi_reloc:          actual load address of the image
 * @pref_address:       preferred load address of the image
 * Return:              status code
 */
static efi_status_t efi_loader_relocate(const IMAGE_BASE_RELOCATION *rel,
                        unsigned long rel_size, void *efi_reloc,
                        unsigned long pref_address)
{
        unsigned long delta = (unsigned long)efi_reloc - pref_address;
        const IMAGE_BASE_RELOCATION *end;
        int i;

        if (delta == 0)
                return EFI_SUCCESS;

        end = (const IMAGE_BASE_RELOCATION *)((const char *)rel + rel_size);
        while (rel < end && rel->SizeOfBlock) {
                const uint16_t *relocs = (const uint16_t *)(rel + 1);
                i = (rel->SizeOfBlock - sizeof(*rel)) / sizeof(uint16_t);
                while (i--) {
                        uint32_t offset = (uint32_t)(*relocs & 0xfff) +
                                          rel->VirtualAddress;
                        int type = *relocs >> EFI_PAGE_SHIFT;
                        uint64_t *x64 = efi_reloc + offset;
                        uint32_t *x32 = efi_reloc + offset;
                        uint16_t *x16 = efi_reloc + offset;

                        switch (type) {
                        case IMAGE_REL_BASED_ABSOLUTE:
                                break;
                        case IMAGE_REL_BASED_HIGH:
                                *x16 += ((uint32_t)delta) >> 16;
                                break;
                        case IMAGE_REL_BASED_LOW:
                                *x16 += (uint16_t)delta;
                                break;
                        case IMAGE_REL_BASED_HIGHLOW:
                                *x32 += (uint32_t)delta;
                                break;
                        case IMAGE_REL_BASED_DIR64:
                                *x64 += (uint64_t)delta;
                                break;
#ifdef __riscv
                        case IMAGE_REL_BASED_RISCV_HI20:
                                *x32 = ((*x32 & 0xfffff000) + (uint32_t)delta) |
                                        (*x32 & 0x00000fff);
                                break;
                        case IMAGE_REL_BASED_RISCV_LOW12I:
                        case IMAGE_REL_BASED_RISCV_LOW12S:
                                /* We know that we're 4k aligned */
                                if (delta & 0xfff) {
                                        log_err("Unsupported reloc offset\n");
                                        return EFI_LOAD_ERROR;
                                }
                                break;
#endif
                        default:
                                log_err("Unknown Relocation off %x type %x\n",
                                        offset, type);
                                return EFI_LOAD_ERROR;
                        }
                        relocs++;
                }
                rel = (const IMAGE_BASE_RELOCATION *)relocs;
        }
        return EFI_SUCCESS;
}

void __weak invalidate_icache_all(void)
{
        /* If the system doesn't support icache_all flush, cross our fingers */
}

/**
 * efi_set_code_and_data_type() - determine the memory types to be used for code
 *                                and data.
 *
 * @loaded_image_info:  image descriptor
 * @image_type:         field Subsystem of the optional header for
 *                      Windows specific field
 */
static void efi_set_code_and_data_type(
                        struct efi_loaded_image *loaded_image_info,
                        uint16_t image_type)
{
        switch (image_type) {
        case IMAGE_SUBSYSTEM_EFI_APPLICATION:
                loaded_image_info->image_code_type = EFI_LOADER_CODE;
                loaded_image_info->image_data_type = EFI_LOADER_DATA;
                break;
        case IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER:
                loaded_image_info->image_code_type = EFI_BOOT_SERVICES_CODE;
                loaded_image_info->image_data_type = EFI_BOOT_SERVICES_DATA;
                break;
        case IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER:
        case IMAGE_SUBSYSTEM_EFI_ROM:
                loaded_image_info->image_code_type = EFI_RUNTIME_SERVICES_CODE;
                loaded_image_info->image_data_type = EFI_RUNTIME_SERVICES_DATA;
                break;
        default:
                log_err("invalid image type: %u\n", image_type);
                /* Let's assume it is an application */
                loaded_image_info->image_code_type = EFI_LOADER_CODE;
                loaded_image_info->image_data_type = EFI_LOADER_DATA;
                break;
        }
}

#ifdef CONFIG_EFI_SECURE_BOOT
/**
 * cmp_pe_section() - compare virtual addresses of two PE image sections
 * @arg1:       pointer to pointer to first section header
 * @arg2:       pointer to pointer to second section header
 *
 * Compare the virtual addresses of two sections of an portable executable.
 * The arguments are defined as const void * to allow usage with qsort().
 *
 * Return:      -1 if the virtual address of arg1 is less than that of arg2,
 *              0 if the virtual addresses are equal, 1 if the virtual address
 *              of arg1 is greater than that of arg2.
 */
static int cmp_pe_section(const void *arg1, const void *arg2)
{
        const IMAGE_SECTION_HEADER *section1, *section2;

        section1 = *((const IMAGE_SECTION_HEADER **)arg1);
        section2 = *((const IMAGE_SECTION_HEADER **)arg2);

        if (section1->VirtualAddress < section2->VirtualAddress)
                return -1;
        else if (section1->VirtualAddress == section2->VirtualAddress)
                return 0;
        else
                return 1;
}

/**
 * efi_image_parse() - parse a PE image
 * @efi:        Pointer to image
 * @len:        Size of @efi
 * @regp:       Pointer to a list of regions
 * @auth:       Pointer to a pointer to authentication data in PE
 * @auth_len:   Size of @auth
 *
 * Parse image binary in PE32(+) format, assuming that sanity of PE image
 * has been checked by a caller.
 * On success, an address of authentication data in @efi and its size will
 * be returned in @auth and @auth_len, respectively.
 *
 * Return:      true on success, false on error
 */
bool efi_image_parse(void *efi, size_t len, struct efi_image_regions **regp,
                     WIN_CERTIFICATE **auth, size_t *auth_len)
{
        struct efi_image_regions *regs;
        IMAGE_DOS_HEADER *dos;
        IMAGE_NT_HEADERS32 *nt;
        IMAGE_SECTION_HEADER *sections, **sorted;
        int num_regions, num_sections, i;
        int ctidx = IMAGE_DIRECTORY_ENTRY_SECURITY;
        u32 align, size, authsz, authoff;
        size_t bytes_hashed;

        dos = (void *)efi;
        nt = (void *)(efi + dos->e_lfanew);
        authoff = 0;
        authsz = 0;

        /*
         * Count maximum number of regions to be digested.
         * We don't have to have an exact number here.
         * See efi_image_region_add()'s in parsing below.
         */
        num_regions = 3; /* for header */
        num_regions += nt->FileHeader.NumberOfSections;
        num_regions++; /* for extra */

        regs = calloc(sizeof(*regs) + sizeof(struct image_region) * num_regions,
                      1);
        if (!regs)
                goto err;
        regs->max = num_regions;

        /*
         * Collect data regions for hash calculation
         * 1. File headers
         */
        if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) {
                IMAGE_NT_HEADERS64 *nt64 = (void *)nt;
                IMAGE_OPTIONAL_HEADER64 *opt = &nt64->OptionalHeader;

                /* Skip CheckSum */
                efi_image_region_add(regs, efi, &opt->CheckSum, 0);
                if (nt64->OptionalHeader.NumberOfRvaAndSizes <= ctidx) {
                        efi_image_region_add(regs,
                                             &opt->Subsystem,
                                             efi + opt->SizeOfHeaders, 0);
                } else {
                        /* Skip Certificates Table */
                        efi_image_region_add(regs,
                                             &opt->Subsystem,
                                             &opt->DataDirectory[ctidx], 0);
                        efi_image_region_add(regs,
                                             &opt->DataDirectory[ctidx] + 1,
                                             efi + opt->SizeOfHeaders, 0);

                        authoff = opt->DataDirectory[ctidx].VirtualAddress;
                        authsz = opt->DataDirectory[ctidx].Size;
                }

                bytes_hashed = opt->SizeOfHeaders;
                align = opt->FileAlignment;
        } else if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
                IMAGE_OPTIONAL_HEADER32 *opt = &nt->OptionalHeader;

                /* Skip CheckSum */
                efi_image_region_add(regs, efi, &opt->CheckSum, 0);
                if (nt->OptionalHeader.NumberOfRvaAndSizes <= ctidx) {
                        efi_image_region_add(regs,
                                             &opt->Subsystem,
                                             efi + opt->SizeOfHeaders, 0);
                } else {
                        /* Skip Certificates Table */
                        efi_image_region_add(regs, &opt->Subsystem,
                                             &opt->DataDirectory[ctidx], 0);
                        efi_image_region_add(regs,
                                             &opt->DataDirectory[ctidx] + 1,
                                             efi + opt->SizeOfHeaders, 0);

                        authoff = opt->DataDirectory[ctidx].VirtualAddress;
                        authsz = opt->DataDirectory[ctidx].Size;
                }

                bytes_hashed = opt->SizeOfHeaders;
                align = opt->FileAlignment;
        } else {
                EFI_PRINT("%s: Invalid optional header magic %x\n", __func__,
                          nt->OptionalHeader.Magic);
                goto err;
        }

        /* 2. Sections */
        num_sections = nt->FileHeader.NumberOfSections;
        sections = (void *)((uint8_t *)&nt->OptionalHeader +
                            nt->FileHeader.SizeOfOptionalHeader);
        sorted = calloc(sizeof(IMAGE_SECTION_HEADER *), num_sections);
        if (!sorted) {
                EFI_PRINT("%s: Out of memory\n", __func__);
                goto err;
        }

        /*
         * Make sure the section list is in ascending order.
         */
        for (i = 0; i < num_sections; i++)
                sorted[i] = &sections[i];
        qsort(sorted, num_sections, sizeof(sorted[0]), cmp_pe_section);

        for (i = 0; i < num_sections; i++) {
                if (!sorted[i]->SizeOfRawData)
                        continue;

                size = (sorted[i]->SizeOfRawData + align - 1) & ~(align - 1);
                efi_image_region_add(regs, efi + sorted[i]->PointerToRawData,
                                     efi + sorted[i]->PointerToRawData + size,
                                     0);
                EFI_PRINT("section[%d](%s): raw: 0x%x-0x%x, virt: %x-%x\n",
                          i, sorted[i]->Name,
                          sorted[i]->PointerToRawData,
                          sorted[i]->PointerToRawData + size,
                          sorted[i]->VirtualAddress,
                          sorted[i]->VirtualAddress
                            + sorted[i]->Misc.VirtualSize);

                bytes_hashed += size;
        }
        free(sorted);

        /* 3. Extra data excluding Certificates Table */
        if (bytes_hashed + authsz < len) {
                EFI_PRINT("extra data for hash: %zu\n",
                          len - (bytes_hashed + authsz));
                efi_image_region_add(regs, efi + bytes_hashed,
                                     efi + len - authsz, 0);
        }

        /* Return Certificates Table */
        if (authsz) {
                if (len < authoff + authsz) {
                        EFI_PRINT("%s: Size for auth too large: %u >= %zu\n",
                                  __func__, authsz, len - authoff);
                        goto err;
                }
                if (authsz < sizeof(*auth)) {
                        EFI_PRINT("%s: Size for auth too small: %u < %zu\n",
                                  __func__, authsz, sizeof(*auth));
                        goto err;
                }
                *auth = efi + authoff;
                *auth_len = authsz;
                EFI_PRINT("WIN_CERTIFICATE: 0x%x, size: 0x%x\n", authoff,
                          authsz);
        } else {
                *auth = NULL;
                *auth_len = 0;
        }

        *regp = regs;

        return true;

err:
        free(regs);

        return false;
}

/**
 * efi_image_unsigned_authenticate() - authenticate unsigned image with
 * SHA256 hash
 * @regs:       List of regions to be verified
 *
 * If an image is not signed, it doesn't have a signature. In this case,
 * its message digest is calculated and it will be compared with one of
 * hash values stored in signature databases.
 *
 * Return:      true if authenticated, false if not
 */
static bool efi_image_unsigned_authenticate(struct efi_image_regions *regs)
{
        struct efi_signature_store *db = NULL, *dbx = NULL;
        bool ret = false;

        dbx = efi_sigstore_parse_sigdb(L"dbx");
        if (!dbx) {
                EFI_PRINT("Getting signature database(dbx) failed\n");
                goto out;
        }

        db = efi_sigstore_parse_sigdb(L"db");
        if (!db) {
                EFI_PRINT("Getting signature database(db) failed\n");
                goto out;
        }

        /* try black-list first */
        if (efi_signature_lookup_digest(regs, dbx)) {
                EFI_PRINT("Image is not signed and its digest found in \"dbx\"\n");
                goto out;
        }

        /* try white-list */
        if (efi_signature_lookup_digest(regs, db))
                ret = true;
        else
                EFI_PRINT("Image is not signed and its digest not found in \"db\" or \"dbx\"\n");

out:
        efi_sigstore_free(db);
        efi_sigstore_free(dbx);

        return ret;
}

/**
 * efi_image_authenticate() - verify a signature of signed image
 * @efi:        Pointer to image
 * @efi_size:   Size of @efi
 *
 * A signed image should have its signature stored in a table of its PE header.
 * So if an image is signed and only if if its signature is verified using
 * signature databases, an image is authenticated.
 * If an image is not signed, its validity is checked by using
 * efi_image_unsigned_authenticated().
 * TODO:
 * When AuditMode==0, if the image's signature is not found in
 * the authorized database, or is found in the forbidden database,
 * the image will not be started and instead, information about it
 * will be placed in this table.
 * When AuditMode==1, an EFI_IMAGE_EXECUTION_INFO element is created
 * in the EFI_IMAGE_EXECUTION_INFO_TABLE for every certificate found
 * in the certificate table of every image that is validated.
 *
 * Return:      true if authenticated, false if not
 */
static bool efi_image_authenticate(void *efi, size_t efi_size)
{
        struct efi_image_regions *regs = NULL;
        WIN_CERTIFICATE *wincerts = NULL, *wincert;
        size_t wincerts_len;
        struct pkcs7_message *msg = NULL;
        struct efi_signature_store *db = NULL, *dbx = NULL;
        void *new_efi = NULL;
        u8 *auth, *wincerts_end;
        size_t new_efi_size, auth_size;
        bool ret = false;

        EFI_PRINT("%s: Enter, %d\n", __func__, ret);

        if (!efi_secure_boot_enabled())
                return true;

        /*
         * Size must be 8-byte aligned and the trailing bytes must be
         * zero'ed. Otherwise hash value may be incorrect.
         */
        if (efi_size & 0x7) {
                new_efi_size = (efi_size + 0x7) & ~0x7ULL;
                new_efi = calloc(new_efi_size, 1);
                if (!new_efi)
                        return false;
                memcpy(new_efi, efi, efi_size);
                efi = new_efi;
                efi_size = new_efi_size;
        }

        if (!efi_image_parse(efi, efi_size, &regs, &wincerts,
                             &wincerts_len)) {
                EFI_PRINT("Parsing PE executable image failed\n");
                goto err;
        }

        if (!wincerts) {
                /* The image is not signed */
                ret = efi_image_unsigned_authenticate(regs);

                goto err;
        }

        /*
         * verify signature using db and dbx
         */
        db = efi_sigstore_parse_sigdb(L"db");
        if (!db) {
                EFI_PRINT("Getting signature database(db) failed\n");
                goto err;
        }

        dbx = efi_sigstore_parse_sigdb(L"dbx");
        if (!dbx) {
                EFI_PRINT("Getting signature database(dbx) failed\n");
                goto err;
        }

        if (efi_signature_lookup_digest(regs, dbx)) {
                EFI_PRINT("Image's digest was found in \"dbx\"\n");
                goto err;
        }

        /*
         * go through WIN_CERTIFICATE list
         * NOTE:
         * We may have multiple signatures either as WIN_CERTIFICATE's
         * in PE header, or as pkcs7 SignerInfo's in SignedData.
         * So the verification policy here is:
         *   - Success if, at least, one of signatures is verified
         *   - unless signature is rejected explicitly with its digest.
         */

        for (wincert = wincerts, wincerts_end = (u8 *)wincerts + wincerts_len;
             (u8 *)wincert < wincerts_end;
             wincert = (WIN_CERTIFICATE *)
                        ((u8 *)wincert + ALIGN(wincert->dwLength, 8))) {
                if ((u8 *)wincert + sizeof(*wincert) >= wincerts_end)
                        break;

                if (wincert->dwLength <= sizeof(*wincert)) {
                        EFI_PRINT("dwLength too small: %u < %zu\n",
                                  wincert->dwLength, sizeof(*wincert));
                        continue;
                }

                EFI_PRINT("WIN_CERTIFICATE_TYPE: 0x%x\n",
                          wincert->wCertificateType);

                auth = (u8 *)wincert + sizeof(*wincert);
                auth_size = wincert->dwLength - sizeof(*wincert);
                if (wincert->wCertificateType == WIN_CERT_TYPE_EFI_GUID) {
                        if (auth + sizeof(efi_guid_t) >= wincerts_end)
                                break;

                        if (auth_size <= sizeof(efi_guid_t)) {
                                EFI_PRINT("dwLength too small: %u < %zu\n",
                                          wincert->dwLength, sizeof(*wincert));
                                continue;
                        }
                        if (guidcmp(auth, &efi_guid_cert_type_pkcs7)) {
                                EFI_PRINT("Certificate type not supported: %pUl\n",
                                          auth);
                                continue;
                        }

                        auth += sizeof(efi_guid_t);
                        auth_size -= sizeof(efi_guid_t);
                } else if (wincert->wCertificateType
                                != WIN_CERT_TYPE_PKCS_SIGNED_DATA) {
                        EFI_PRINT("Certificate type not supported\n");
                        continue;
                }

                msg = pkcs7_parse_message(auth, auth_size);
                if (IS_ERR(msg)) {
                        EFI_PRINT("Parsing image's signature failed\n");
                        msg = NULL;
                        continue;
                }

                /*
                 * NOTE:
                 * UEFI specification defines two signature types possible
                 * in signature database:
                 * a. x509 certificate, where a signature in image is
                 *    a message digest encrypted by RSA public key
                 *    (EFI_CERT_X509_GUID)
                 * b. bare hash value of message digest
                 *    (EFI_CERT_SHAxxx_GUID)
                 *
                 * efi_signature_verify() handles case (a), while
                 * efi_signature_lookup_digest() handles case (b).
                 *
                 * There is a third type:
                 * c. message digest of a certificate
                 *    (EFI_CERT_X509_SHAAxxx_GUID)
                 * This type of signature is used only in revocation list
                 * (dbx) and handled as part of efi_signatgure_verify().
                 */
                /* try black-list first */
                if (efi_signature_verify_one(regs, msg, dbx)) {
                        EFI_PRINT("Signature was rejected by \"dbx\"\n");
                        continue;
                }

                if (!efi_signature_check_signers(msg, dbx)) {
                        EFI_PRINT("Signer(s) in \"dbx\"\n");
                        continue;
                }

                /* try white-list */
                if (efi_signature_verify(regs, msg, db, dbx)) {
                        ret = true;
                        break;
                }

                EFI_PRINT("Signature was not verified by \"db\"\n");

                if (efi_signature_lookup_digest(regs, db)) {
                        ret = true;
                        break;
                }

                EFI_PRINT("Image's digest was not found in \"db\" or \"dbx\"\n");
        }

err:
        efi_sigstore_free(db);
        efi_sigstore_free(dbx);
        pkcs7_free_message(msg);
        free(regs);
        free(new_efi);

        EFI_PRINT("%s: Exit, %d\n", __func__, ret);
        return ret;
}
#else
static bool efi_image_authenticate(void *efi, size_t efi_size)
{
        return true;
}
#endif /* CONFIG_EFI_SECURE_BOOT */

/**
 * efi_load_pe() - relocate EFI binary
 *
 * This function loads all sections from a PE binary into a newly reserved
 * piece of memory. On success the entry point is returned as handle->entry.
 *
 * @handle:             loaded image handle
 * @efi:                pointer to the EFI binary
 * @efi_size:           size of @efi binary
 * @loaded_image_info:  loaded image protocol
 * Return:              status code
 */
efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle,
                         void *efi, size_t efi_size,
                         struct efi_loaded_image *loaded_image_info)
{
        IMAGE_NT_HEADERS32 *nt;
        IMAGE_DOS_HEADER *dos;
        IMAGE_SECTION_HEADER *sections;
        int num_sections;
        void *efi_reloc;
        int i;
        const IMAGE_BASE_RELOCATION *rel;
        unsigned long rel_size;
        int rel_idx = IMAGE_DIRECTORY_ENTRY_BASERELOC;
        uint64_t image_base;
        unsigned long virt_size = 0;
        int supported = 0;
        efi_status_t ret;

        /* Sanity check for a file header */
        if (efi_size < sizeof(*dos)) {
                log_err("Truncated DOS Header\n");
                ret = EFI_LOAD_ERROR;
                goto err;
        }

        dos = efi;
        if (dos->e_magic != IMAGE_DOS_SIGNATURE) {
                log_err("Invalid DOS Signature\n");
                ret = EFI_LOAD_ERROR;
                goto err;
        }

        /*
         * Check if the image section header fits into the file. Knowing that at
         * least one section header follows we only need to check for the length
         * of the 64bit header which is longer than the 32bit header.
         */
        if (efi_size < dos->e_lfanew + sizeof(IMAGE_NT_HEADERS64)) {
                log_err("Invalid offset for Extended Header\n");
                ret = EFI_LOAD_ERROR;
                goto err;
        }

        nt = (void *) ((char *)efi + dos->e_lfanew);
        if (nt->Signature != IMAGE_NT_SIGNATURE) {
                log_err("Invalid NT Signature\n");
                ret = EFI_LOAD_ERROR;
                goto err;
        }

        for (i = 0; machines[i]; i++)
                if (machines[i] == nt->FileHeader.Machine) {
                        supported = 1;
                        break;
                }

        if (!supported) {
                log_err("Machine type 0x%04x is not supported\n",
                        nt->FileHeader.Machine);
                ret = EFI_LOAD_ERROR;
                goto err;
        }

        num_sections = nt->FileHeader.NumberOfSections;
        sections = (void *)&nt->OptionalHeader +
                            nt->FileHeader.SizeOfOptionalHeader;

        if (efi_size < ((void *)sections + sizeof(sections[0]) * num_sections
                        - efi)) {
                log_err("Invalid number of sections: %d\n", num_sections);
                ret = EFI_LOAD_ERROR;
                goto err;
        }

        /* Authenticate an image */
        if (efi_image_authenticate(efi, efi_size)) {
                handle->auth_status = EFI_IMAGE_AUTH_PASSED;
        } else {
                handle->auth_status = EFI_IMAGE_AUTH_FAILED;
                log_err("Image not authenticated\n");
        }

        /* Calculate upper virtual address boundary */
        for (i = num_sections - 1; i >= 0; i--) {
                IMAGE_SECTION_HEADER *sec = &sections[i];
                virt_size = max_t(unsigned long, virt_size,
                                  sec->VirtualAddress + sec->Misc.VirtualSize);
        }

        /* Read 32/64bit specific header bits */
        if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) {
                IMAGE_NT_HEADERS64 *nt64 = (void *)nt;
                IMAGE_OPTIONAL_HEADER64 *opt = &nt64->OptionalHeader;
                image_base = opt->ImageBase;
                efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
                handle->image_type = opt->Subsystem;
                efi_reloc = efi_alloc(virt_size,
                                      loaded_image_info->image_code_type);
                if (!efi_reloc) {
                        log_err("Out of memory\n");
                        ret = EFI_OUT_OF_RESOURCES;
                        goto err;
                }
                handle->entry = efi_reloc + opt->AddressOfEntryPoint;
                rel_size = opt->DataDirectory[rel_idx].Size;
                rel = efi_reloc + opt->DataDirectory[rel_idx].VirtualAddress;
                virt_size = ALIGN(virt_size, opt->SectionAlignment);
        } else if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
                IMAGE_OPTIONAL_HEADER32 *opt = &nt->OptionalHeader;
                image_base = opt->ImageBase;
                efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
                handle->image_type = opt->Subsystem;
                efi_reloc = efi_alloc(virt_size,
                                      loaded_image_info->image_code_type);
                if (!efi_reloc) {
                        log_err("Out of memory\n");
                        ret = EFI_OUT_OF_RESOURCES;
                        goto err;
                }
                handle->entry = efi_reloc + opt->AddressOfEntryPoint;
                rel_size = opt->DataDirectory[rel_idx].Size;
                rel = efi_reloc + opt->DataDirectory[rel_idx].VirtualAddress;
                virt_size = ALIGN(virt_size, opt->SectionAlignment);
        } else {
                log_err("Invalid optional header magic %x\n",
                        nt->OptionalHeader.Magic);
                ret = EFI_LOAD_ERROR;
                goto err;
        }

        /* Copy PE headers */
        memcpy(efi_reloc, efi,
               sizeof(*dos)
                 + sizeof(*nt)
                 + nt->FileHeader.SizeOfOptionalHeader
                 + num_sections * sizeof(IMAGE_SECTION_HEADER));

        /* Load sections into RAM */
        for (i = num_sections - 1; i >= 0; i--) {
                IMAGE_SECTION_HEADER *sec = &sections[i];
                memset(efi_reloc + sec->VirtualAddress, 0,
                       sec->Misc.VirtualSize);
                memcpy(efi_reloc + sec->VirtualAddress,
                       efi + sec->PointerToRawData,
                       sec->SizeOfRawData);
        }

        /* Run through relocations */
        if (efi_loader_relocate(rel, rel_size, efi_reloc,
                                (unsigned long)image_base) != EFI_SUCCESS) {
                efi_free_pages((uintptr_t) efi_reloc,
                               (virt_size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT);
                ret = EFI_LOAD_ERROR;
                goto err;
        }

        /* Flush cache */
        flush_cache((ulong)efi_reloc,
                    ALIGN(virt_size, EFI_CACHELINE_SIZE));
        invalidate_icache_all();

        /* Populate the loaded image interface bits */
        loaded_image_info->image_base = efi_reloc;
        loaded_image_info->image_size = virt_size;

        if (handle->auth_status == EFI_IMAGE_AUTH_PASSED)
                return EFI_SUCCESS;
        else
                return EFI_SECURITY_VIOLATION;

err:
        return ret;
}