| /* |
| * Copyright (c) 2013-2021, Arm Limited and Contributors. All rights reserved. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| |
| #include <assert.h> |
| #include <errno.h> |
| #include <string.h> |
| |
| #include <arch.h> |
| #include <arch_features.h> |
| #include <arch_helpers.h> |
| #include <common/bl_common.h> |
| #include <common/debug.h> |
| #include <drivers/auth/auth_mod.h> |
| #include <drivers/io/io_storage.h> |
| #include <lib/utils.h> |
| #include <lib/xlat_tables/xlat_tables_defs.h> |
| #include <plat/common/platform.h> |
| |
| #if TRUSTED_BOARD_BOOT |
| # ifdef DYN_DISABLE_AUTH |
| static int disable_auth; |
| |
| /****************************************************************************** |
| * API to dynamically disable authentication. Only meant for development |
| * systems. This is only invoked if DYN_DISABLE_AUTH is defined. |
| *****************************************************************************/ |
| void dyn_disable_auth(void) |
| { |
| INFO("Disabling authentication of images dynamically\n"); |
| disable_auth = 1; |
| } |
| # endif /* DYN_DISABLE_AUTH */ |
| |
| /****************************************************************************** |
| * Function to determine whether the authentication is disabled dynamically. |
| *****************************************************************************/ |
| static int dyn_is_auth_disabled(void) |
| { |
| # ifdef DYN_DISABLE_AUTH |
| return disable_auth; |
| # else |
| return 0; |
| # endif |
| } |
| #endif /* TRUSTED_BOARD_BOOT */ |
| |
| uintptr_t page_align(uintptr_t value, unsigned dir) |
| { |
| /* Round up the limit to the next page boundary */ |
| if ((value & PAGE_SIZE_MASK) != 0U) { |
| value &= ~PAGE_SIZE_MASK; |
| if (dir == UP) |
| value += PAGE_SIZE; |
| } |
| |
| return value; |
| } |
| |
| /******************************************************************************* |
| * Internal function to load an image at a specific address given |
| * an image ID and extents of free memory. |
| * |
| * If the load is successful then the image information is updated. |
| * |
| * Returns 0 on success, a negative error code otherwise. |
| ******************************************************************************/ |
| static int load_image(unsigned int image_id, image_info_t *image_data) |
| { |
| uintptr_t dev_handle; |
| uintptr_t image_handle; |
| uintptr_t image_spec; |
| uintptr_t image_base; |
| size_t image_size; |
| size_t bytes_read; |
| int io_result; |
| |
| assert(image_data != NULL); |
| assert(image_data->h.version >= VERSION_2); |
| |
| image_base = image_data->image_base; |
| |
| /* Obtain a reference to the image by querying the platform layer */ |
| io_result = plat_get_image_source(image_id, &dev_handle, &image_spec); |
| if (io_result != 0) { |
| WARN("Failed to obtain reference to image id=%u (%i)\n", |
| image_id, io_result); |
| return io_result; |
| } |
| |
| /* Attempt to access the image */ |
| io_result = io_open(dev_handle, image_spec, &image_handle); |
| if (io_result != 0) { |
| WARN("Failed to access image id=%u (%i)\n", |
| image_id, io_result); |
| return io_result; |
| } |
| |
| INFO("Loading image id=%u at address 0x%lx\n", image_id, image_base); |
| |
| /* Find the size of the image */ |
| io_result = io_size(image_handle, &image_size); |
| if ((io_result != 0) || (image_size == 0U)) { |
| WARN("Failed to determine the size of the image id=%u (%i)\n", |
| image_id, io_result); |
| goto exit; |
| } |
| |
| /* Check that the image size to load is within limit */ |
| if (image_size > image_data->image_max_size) { |
| WARN("Image id=%u size out of bounds\n", image_id); |
| io_result = -EFBIG; |
| goto exit; |
| } |
| |
| /* |
| * image_data->image_max_size is a uint32_t so image_size will always |
| * fit in image_data->image_size. |
| */ |
| image_data->image_size = (uint32_t)image_size; |
| |
| /* We have enough space so load the image now */ |
| /* TODO: Consider whether to try to recover/retry a partially successful read */ |
| io_result = io_read(image_handle, image_base, image_size, &bytes_read); |
| if ((io_result != 0) || (bytes_read < image_size)) { |
| WARN("Failed to load image id=%u (%i)\n", image_id, io_result); |
| goto exit; |
| } |
| |
| INFO("Image id=%u loaded: 0x%lx - 0x%lx\n", image_id, image_base, |
| (uintptr_t)(image_base + image_size)); |
| |
| exit: |
| (void)io_close(image_handle); |
| /* Ignore improbable/unrecoverable error in 'close' */ |
| |
| /* TODO: Consider maintaining open device connection from this bootloader stage */ |
| (void)io_dev_close(dev_handle); |
| /* Ignore improbable/unrecoverable error in 'dev_close' */ |
| |
| return io_result; |
| } |
| |
| /* |
| * Load an image and flush it out to main memory so that it can be executed |
| * later by any CPU, regardless of cache and MMU state. |
| */ |
| static int load_image_flush(unsigned int image_id, |
| image_info_t *image_data) |
| { |
| int rc; |
| |
| rc = load_image(image_id, image_data); |
| if (rc == 0) { |
| flush_dcache_range(image_data->image_base, |
| image_data->image_size); |
| } |
| |
| return rc; |
| } |
| |
| |
| #if TRUSTED_BOARD_BOOT |
| /* |
| * This function uses recursion to authenticate the parent images up to the root |
| * of trust. |
| */ |
| static int load_auth_image_recursive(unsigned int image_id, |
| image_info_t *image_data, |
| int is_parent_image) |
| { |
| int rc; |
| unsigned int parent_id; |
| |
| /* Use recursion to authenticate parent images */ |
| rc = auth_mod_get_parent_id(image_id, &parent_id); |
| if (rc == 0) { |
| rc = load_auth_image_recursive(parent_id, image_data, 1); |
| if (rc != 0) { |
| return rc; |
| } |
| } |
| |
| /* Load the image */ |
| rc = load_image(image_id, image_data); |
| if (rc != 0) { |
| return rc; |
| } |
| |
| /* Authenticate it */ |
| rc = auth_mod_verify_img(image_id, |
| (void *)image_data->image_base, |
| image_data->image_size); |
| if (rc != 0) { |
| /* Authentication error, zero memory and flush it right away. */ |
| zero_normalmem((void *)image_data->image_base, |
| image_data->image_size); |
| flush_dcache_range(image_data->image_base, |
| image_data->image_size); |
| return -EAUTH; |
| } |
| |
| if (is_parent_image == 0) { |
| /* |
| * Measure the image. |
| * We do not measure its parents because these only play a role |
| * in authentication, which is orthogonal to measured boot. |
| * |
| * TODO: Change this code if we change our minds about measuring |
| * certificates. |
| */ |
| rc = plat_mboot_measure_image(image_id, image_data); |
| if (rc != 0) { |
| return rc; |
| } |
| |
| /* |
| * Flush the image to main memory so that it can be executed |
| * later by any CPU, regardless of cache and MMU state. This |
| * is only needed for child images, not for the parents |
| * (certificates). |
| */ |
| flush_dcache_range(image_data->image_base, |
| image_data->image_size); |
| } |
| |
| return 0; |
| } |
| #endif /* TRUSTED_BOARD_BOOT */ |
| |
| static int load_auth_image_internal(unsigned int image_id, |
| image_info_t *image_data) |
| { |
| #if TRUSTED_BOARD_BOOT |
| if (dyn_is_auth_disabled() == 0) { |
| return load_auth_image_recursive(image_id, image_data, 0); |
| } |
| #endif |
| |
| return load_image_flush(image_id, image_data); |
| } |
| |
| /******************************************************************************* |
| * Generic function to load and authenticate an image. The image is actually |
| * loaded by calling the 'load_image()' function. Therefore, it returns the |
| * same error codes if the loading operation failed, or -EAUTH if the |
| * authentication failed. In addition, this function uses recursion to |
| * authenticate the parent images up to the root of trust (if TBB is enabled). |
| ******************************************************************************/ |
| int load_auth_image(unsigned int image_id, image_info_t *image_data) |
| { |
| int err; |
| |
| /* |
| * All firmware banks should be part of the same non-volatile storage as per |
| * PSA FWU specification, hence don't check for any alternate boot source |
| * when PSA FWU is enabled. |
| */ |
| #if PSA_FWU_SUPPORT |
| err = load_auth_image_internal(image_id, image_data); |
| #else |
| do { |
| err = load_auth_image_internal(image_id, image_data); |
| } while ((err != 0) && (plat_try_next_boot_source() != 0)); |
| #endif /* PSA_FWU_SUPPORT */ |
| |
| return err; |
| } |
| |
| /******************************************************************************* |
| * Print the content of an entry_point_info_t structure. |
| ******************************************************************************/ |
| void print_entry_point_info(const entry_point_info_t *ep_info) |
| { |
| INFO("Entry point address = 0x%lx\n", ep_info->pc); |
| INFO("SPSR = 0x%x\n", ep_info->spsr); |
| |
| #define PRINT_IMAGE_ARG(n) \ |
| VERBOSE("Argument #" #n " = 0x%llx\n", \ |
| (unsigned long long) ep_info->args.arg##n) |
| |
| PRINT_IMAGE_ARG(0); |
| PRINT_IMAGE_ARG(1); |
| PRINT_IMAGE_ARG(2); |
| PRINT_IMAGE_ARG(3); |
| #ifdef __aarch64__ |
| PRINT_IMAGE_ARG(4); |
| PRINT_IMAGE_ARG(5); |
| PRINT_IMAGE_ARG(6); |
| PRINT_IMAGE_ARG(7); |
| #endif |
| #undef PRINT_IMAGE_ARG |
| } |