1 /* 2 * Copyright (c) 2018-2020, ARM Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #include <assert.h> 8 9 #include <libfdt.h> 10 11 #include <common/fdt_wrappers.h> 12 #include <plat/arm/common/arm_dyn_cfg_helpers.h> 13 #include <plat/arm/common/plat_arm.h> 14 15 #define DTB_PROP_MBEDTLS_HEAP_ADDR "mbedtls_heap_addr" 16 #define DTB_PROP_MBEDTLS_HEAP_SIZE "mbedtls_heap_size" 17 18 /******************************************************************************* 19 * Validate the tb_fw_config is a valid DTB file and returns the node offset 20 * to "arm,tb_fw" property. 21 * Arguments: 22 * void *dtb - pointer to the TB_FW_CONFIG in memory 23 * int *node - Returns the node offset to "arm,tb_fw" property if found. 24 * 25 * Returns 0 on success and -1 on error. 26 ******************************************************************************/ 27 int arm_dyn_tb_fw_cfg_init(void *dtb, int *node) 28 { 29 assert(dtb != NULL); 30 assert(node != NULL); 31 32 /* Check if the pointer to DT is correct */ 33 if (fdt_check_header(dtb) != 0) { 34 WARN("Invalid DTB file passed as TB_FW_CONFIG\n"); 35 return -1; 36 } 37 38 /* Assert the node offset point to "arm,tb_fw" compatible property */ 39 *node = fdt_node_offset_by_compatible(dtb, -1, "arm,tb_fw"); 40 if (*node < 0) { 41 WARN("The compatible property `arm,tb_fw` not found in the config\n"); 42 return -1; 43 } 44 45 VERBOSE("Dyn cfg: Found \"arm,tb_fw\" in the config\n"); 46 return 0; 47 } 48 49 /* 50 * Reads and returns the Mbed TLS shared heap information from the DTB. 51 * This function is supposed to be called *only* when a DTB is present. 52 * This function is supposed to be called only by BL2. 53 * 54 * Returns: 55 * 0 = success 56 * -1 = error. In this case the values of heap_addr, heap_size should be 57 * considered as garbage by the caller. 58 */ 59 int arm_get_dtb_mbedtls_heap_info(void *dtb, void **heap_addr, 60 size_t *heap_size) 61 { 62 int err, dtb_root; 63 64 /* Verify the DTB is valid and get the root node */ 65 err = arm_dyn_tb_fw_cfg_init(dtb, &dtb_root); 66 if (err < 0) { 67 ERROR("Invalid TB_FW_CONFIG. Cannot retrieve Mbed TLS heap information from DTB\n"); 68 return -1; 69 } 70 71 /* Retrieve the Mbed TLS heap details from the DTB */ 72 err = fdtw_read_cells(dtb, dtb_root, 73 DTB_PROP_MBEDTLS_HEAP_ADDR, 2, heap_addr); 74 if (err < 0) { 75 ERROR("Error while reading %s from DTB\n", 76 DTB_PROP_MBEDTLS_HEAP_ADDR); 77 return -1; 78 } 79 err = fdtw_read_cells(dtb, dtb_root, 80 DTB_PROP_MBEDTLS_HEAP_SIZE, 1, heap_size); 81 if (err < 0) { 82 ERROR("Error while reading %s from DTB\n", 83 DTB_PROP_MBEDTLS_HEAP_SIZE); 84 return -1; 85 } 86 return 0; 87 } 88 89 90 /* 91 * This function writes the Mbed TLS heap address and size in the DTB. When it 92 * is called, it is guaranteed that a DTB is available. However it is not 93 * guaranteed that the shared Mbed TLS heap implementation is used. Thus we 94 * return error code from here and it's the responsibility of the caller to 95 * determine the action upon error. 96 * 97 * This function is supposed to be called only by BL1. 98 * 99 * Returns: 100 * 0 = success 101 * 1 = error 102 */ 103 int arm_set_dtb_mbedtls_heap_info(void *dtb, void *heap_addr, size_t heap_size) 104 { 105 int err, dtb_root; 106 107 /* 108 * Verify that the DTB is valid, before attempting to write to it, 109 * and get the DTB root node. 110 */ 111 err = arm_dyn_tb_fw_cfg_init(dtb, &dtb_root); 112 if (err < 0) { 113 ERROR("Invalid TB_FW_CONFIG loaded. Unable to get root node\n"); 114 return -1; 115 } 116 117 /* 118 * Write the heap address and size in the DTB. 119 * 120 * NOTE: The variables heap_addr and heap_size are corrupted 121 * by the "fdtw_write_inplace_cells" function. After the 122 * function calls they must NOT be reused. 123 */ 124 err = fdtw_write_inplace_cells(dtb, dtb_root, 125 DTB_PROP_MBEDTLS_HEAP_ADDR, 2, &heap_addr); 126 if (err < 0) { 127 ERROR("Unable to write DTB property %s\n", 128 DTB_PROP_MBEDTLS_HEAP_ADDR); 129 return -1; 130 } 131 132 err = fdtw_write_inplace_cells(dtb, dtb_root, 133 DTB_PROP_MBEDTLS_HEAP_SIZE, 1, &heap_size); 134 if (err < 0) { 135 ERROR("Unable to write DTB property %s\n", 136 DTB_PROP_MBEDTLS_HEAP_SIZE); 137 return -1; 138 } 139 140 return 0; 141 } 142