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/*
* Copyright (c) 2018-2020, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <assert.h>
#include <string.h>
#include <libfdt.h>
#include <platform_def.h>
#include <common/debug.h>
#include <common/desc_image_load.h>
#include <common/tbbr/tbbr_img_def.h>
#if TRUSTED_BOARD_BOOT
#include <drivers/auth/mbedtls/mbedtls_config.h>
#if MEASURED_BOOT
#include <drivers/auth/crypto_mod.h>
#include <mbedtls/md.h>
#endif
#endif
#include <lib/fconf/fconf.h>
#include <lib/fconf/fconf_dyn_cfg_getter.h>
#include <lib/fconf/fconf_tbbr_getter.h>
#include <plat/arm/common/arm_dyn_cfg_helpers.h>
#include <plat/arm/common/plat_arm.h>
#if TRUSTED_BOARD_BOOT
static void *mbedtls_heap_addr;
static size_t mbedtls_heap_size;
/*
* This function is the implementation of the shared Mbed TLS heap between
* BL1 and BL2 for Arm platforms. The shared heap address is passed from BL1
* to BL2 with a pointer. This pointer resides inside the TB_FW_CONFIG file
* which is a DTB.
*
* This function is placed inside an #if directive for the below reasons:
* - To allocate space for the Mbed TLS heap --only if-- Trusted Board Boot
* is enabled.
* - This implementation requires the DTB to be present so that BL1 has a
* mechanism to pass the pointer to BL2.
*/
int arm_get_mbedtls_heap(void **heap_addr, size_t *heap_size)
{
assert(heap_addr != NULL);
assert(heap_size != NULL);
#if defined(IMAGE_BL1) || BL2_AT_EL3
/* If in BL1 or BL2_AT_EL3 define a heap */
static unsigned char heap[TF_MBEDTLS_HEAP_SIZE];
*heap_addr = heap;
*heap_size = sizeof(heap);
mbedtls_heap_addr = heap;
mbedtls_heap_size = sizeof(heap);
#elif defined(IMAGE_BL2)
/* If in BL2, retrieve the already allocated heap's info from DTB */
*heap_addr = FCONF_GET_PROPERTY(tbbr, dyn_config, mbedtls_heap_addr);
*heap_size = FCONF_GET_PROPERTY(tbbr, dyn_config, mbedtls_heap_size);
#endif
return 0;
}
/*
* Puts the shared Mbed TLS heap information to the DTB.
* Executed only from BL1.
*/
void arm_bl1_set_mbedtls_heap(void)
{
int err;
uintptr_t tb_fw_cfg_dtb;
const struct dyn_cfg_dtb_info_t *tb_fw_config_info;
/*
* If tb_fw_cfg_dtb==NULL then DTB is not present for the current
* platform. As such, we don't attempt to write to the DTB at all.
*
* If mbedtls_heap_addr==NULL, then it means we are using the default
* heap implementation. As such, BL2 will have its own heap for sure
* and hence there is no need to pass any information to the DTB.
*
* In the latter case, if we still wanted to write in the DTB the heap
* information, we would need to call plat_get_mbedtls_heap to retrieve
* the default heap's address and size.
*/
tb_fw_config_info = FCONF_GET_PROPERTY(dyn_cfg, dtb, TB_FW_CONFIG_ID);
assert(tb_fw_config_info != NULL);
tb_fw_cfg_dtb = tb_fw_config_info->config_addr;
if ((tb_fw_cfg_dtb != 0UL) && (mbedtls_heap_addr != NULL)) {
/* As libfdt uses void *, we can't avoid this cast */
void *dtb = (void *)tb_fw_cfg_dtb;
err = arm_set_dtb_mbedtls_heap_info(dtb,
mbedtls_heap_addr, mbedtls_heap_size);
if (err < 0) {
ERROR("%swrite shared Mbed TLS heap information%s",
"BL1: unable to ", " to DTB\n");
panic();
}
#if !MEASURED_BOOT
/*
* Ensure that the info written to the DTB is visible to other
* images. It's critical because BL2 won't be able to proceed
* without the heap info.
*
* In MEASURED_BOOT case flushing is done in
* arm_bl1_set_bl2_hash() function which is called after heap
* information is written in the DTB.
*/
flush_dcache_range(tb_fw_cfg_dtb, fdt_totalsize(dtb));
#endif /* !MEASURED_BOOT */
}
}
#if MEASURED_BOOT
/*
* Calculates and writes BL2 hash data to TB_FW_CONFIG DTB.
* Executed only from BL1.
*/
void arm_bl1_set_bl2_hash(const image_desc_t *image_desc)
{
unsigned char hash_data[MBEDTLS_MD_MAX_SIZE];
const image_info_t image_info = image_desc->image_info;
uintptr_t tb_fw_cfg_dtb;
int err;
const struct dyn_cfg_dtb_info_t *tb_fw_config_info;
tb_fw_config_info = FCONF_GET_PROPERTY(dyn_cfg, dtb, TB_FW_CONFIG_ID);
assert(tb_fw_config_info != NULL);
tb_fw_cfg_dtb = tb_fw_config_info->config_addr;
/*
* If tb_fw_cfg_dtb==NULL then DTB is not present for the current
* platform. As such, we cannot write to the DTB at all and pass
* measured data.
*/
if (tb_fw_cfg_dtb == 0UL) {
panic();
}
/* Calculate hash */
err = crypto_mod_calc_hash(MBEDTLS_MD_ID,
(void *)image_info.image_base,
image_info.image_size, hash_data);
if (err != 0) {
ERROR("%scalculate%s\n", "BL1: unable to ",
" BL2 hash");
panic();
}
err = arm_set_bl2_hash_info((void *)tb_fw_cfg_dtb, hash_data);
if (err < 0) {
ERROR("%swrite%sdata%s\n", "BL1: unable to ",
" BL2 hash ", "to DTB\n");
panic();
}
/*
* Ensure that the info written to the DTB is visible to other
* images. It's critical because BL2 won't be able to proceed
* without the heap info and its hash data.
*/
flush_dcache_range(tb_fw_cfg_dtb, fdt_totalsize((void *)tb_fw_cfg_dtb));
}
/*
* Reads TCG_DIGEST_SIZE bytes of BL2 hash data from the DTB.
* Executed only from BL2.
*/
void arm_bl2_get_hash(void *data)
{
const void *bl2_hash;
assert(data != NULL);
/* Retrieve TCG_DIGEST_SIZE bytes of BL2 hash data from the DTB */
bl2_hash = FCONF_GET_PROPERTY(tbbr, dyn_config, bl2_hash_data);
(void)memcpy(data, bl2_hash, TCG_DIGEST_SIZE);
}
#endif /* MEASURED_BOOT */
#endif /* TRUSTED_BOARD_BOOT */
/*
* BL2 utility function to initialize dynamic configuration specified by
* FW_CONFIG. Populate the bl_mem_params_node_t of other FW_CONFIGs if
* specified in FW_CONFIG.
*/
void arm_bl2_dyn_cfg_init(void)
{
unsigned int i;
bl_mem_params_node_t *cfg_mem_params = NULL;
uintptr_t image_base;
uint32_t image_size;
const unsigned int config_ids[] = {
HW_CONFIG_ID,
SOC_FW_CONFIG_ID,
NT_FW_CONFIG_ID,
#if defined(SPD_tspd) || defined(SPD_spmd)
/* tos_fw_config is only present for TSPD/SPMD */
TOS_FW_CONFIG_ID
#endif
};
const struct dyn_cfg_dtb_info_t *dtb_info;
/* Iterate through all the fw config IDs */
for (i = 0; i < ARRAY_SIZE(config_ids); i++) {
/* Get the config load address and size from TB_FW_CONFIG */
cfg_mem_params = get_bl_mem_params_node(config_ids[i]);
if (cfg_mem_params == NULL) {
VERBOSE("%sHW_CONFIG in bl_mem_params_node\n",
"Couldn't find ");
continue;
}
dtb_info = FCONF_GET_PROPERTY(dyn_cfg, dtb, config_ids[i]);
if (dtb_info == NULL) {
VERBOSE("%sconfig_id %d load info in TB_FW_CONFIG\n",
"Couldn't find ", config_ids[i]);
continue;
}
image_base = dtb_info->config_addr;
image_size = dtb_info->config_max_size;
/*
* Do some runtime checks on the load addresses of soc_fw_config,
* tos_fw_config, nt_fw_config. This is not a comprehensive check
* of all invalid addresses but to prevent trivial porting errors.
*/
if (config_ids[i] != HW_CONFIG_ID) {
if (check_uptr_overflow(image_base, image_size)) {
continue;
}
#ifdef BL31_BASE
/* Ensure the configs don't overlap with BL31 */
if ((image_base >= BL31_BASE) &&
(image_base <= BL31_LIMIT)) {
continue;
}
#endif
/* Ensure the configs are loaded in a valid address */
if (image_base < ARM_BL_RAM_BASE) {
continue;
}
#ifdef BL32_BASE
/*
* If BL32 is present, ensure that the configs don't
* overlap with it.
*/
if ((image_base >= BL32_BASE) &&
(image_base <= BL32_LIMIT)) {
continue;
}
#endif
}
cfg_mem_params->image_info.image_base = image_base;
cfg_mem_params->image_info.image_max_size = (uint32_t)image_size;
/*
* Remove the IMAGE_ATTRIB_SKIP_LOADING attribute from
* HW_CONFIG or FW_CONFIG nodes
*/
cfg_mem_params->image_info.h.attr &= ~IMAGE_ATTRIB_SKIP_LOADING;
}
}