1 files changed, 231 insertions, 0 deletions
diff --git a/plat/arm/common/arm_dyn_cfg.c b/plat/arm/common/arm_dyn_cfg.c
new file mode 100644
index 0000000..c88621e
--- /dev/null
+++ b/plat/arm/common/arm_dyn_cfg.c
@@ -0,0 +1,231 @@
+/*
+ * Copyright (c) 2018-2022, 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 CRYPTO_SUPPORT
+#include MBEDTLS_CONFIG_FILE
+#endif /* CRYPTO_SUPPORT */
+#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 CRYPTO_SUPPORT
+
+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 || defined(IMAGE_BL31)
+
+	/* 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 a 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 */
+	}
+}
+#endif /* CRYPTO_SUPPORT */
+
+/*
+ * 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;
+	unsigned int error_config_id = MAX_IMAGE_IDS;
+	const unsigned int config_ids[] = {
+			HW_CONFIG_ID,
+			SOC_FW_CONFIG_ID,
+			NT_FW_CONFIG_ID,
+			TOS_FW_CONFIG_ID
+	};
+
+	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 */
+		cfg_mem_params = get_bl_mem_params_node(config_ids[i]);
+		if (cfg_mem_params == NULL) {
+			VERBOSE("%sconfig_id = %d in bl_mem_params_node\n",
+				"Couldn't find ", config_ids[i]);
+			continue;
+		}
+
+		dtb_info = FCONF_GET_PROPERTY(dyn_cfg, dtb, config_ids[i]);
+		if (dtb_info == NULL) {
+			VERBOSE("%sconfig_id %d load info in 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)) {
+				VERBOSE("%s=%d as its %s is overflowing uptr\n",
+					"skip loading of firmware config",
+					config_ids[i],
+					"load-address");
+				error_config_id = config_ids[i];
+				continue;
+			}
+#ifdef	BL31_BASE
+			/* Ensure the configs don't overlap with BL31 */
+			if ((image_base >= BL31_BASE) &&
+			    (image_base <= BL31_LIMIT)) {
+				VERBOSE("%s=%d as its %s is overlapping BL31\n",
+					"skip loading of firmware config",
+					config_ids[i],
+					"load-address");
+				error_config_id = config_ids[i];
+				continue;
+			}
+#endif
+			/* Ensure the configs are loaded in a valid address */
+			if (image_base < ARM_BL_RAM_BASE) {
+				VERBOSE("%s=%d as its %s is invalid\n",
+					"skip loading of firmware config",
+					config_ids[i],
+					"load-address");
+				error_config_id = config_ids[i];
+				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)) {
+				VERBOSE("%s=%d as its %s is overlapping BL32\n",
+					"skip loading of firmware config",
+					config_ids[i],
+					"load-address");
+				error_config_id = config_ids[i];
+				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;
+	}
+
+	if (error_config_id != MAX_IMAGE_IDS) {
+		ERROR("Invalid config file %u\n", error_config_id);
+		panic();
+	}
+}