feat(tc): populate HW_CONFIG in BL31

BL2 passes FW_CONFIG to BL31 which contains information
about different DTBs present. BL31 then uses FW_CONFIG
to get the base address of HW_CONFIG and populate fconf.

Signed-off-by: Usama Arif <usama.arif@arm.com>
Change-Id: I0b4fc83e6e0a0b9401f692516654eb9a3b037616
diff --git a/plat/arm/board/tc/tc_bl2_setup.c b/plat/arm/board/tc/tc_bl2_setup.c
new file mode 100644
index 0000000..74ef569
--- /dev/null
+++ b/plat/arm/board/tc/tc_bl2_setup.c
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2021, ARM Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+
+#include <common/bl_common.h>
+#include <common/desc_image_load.h>
+#include <lib/fconf/fconf.h>
+#include <lib/fconf/fconf_dyn_cfg_getter.h>
+
+#include <plat/arm/common/plat_arm.h>
+
+/*******************************************************************************
+ * This function returns the list of executable images
+ ******************************************************************************/
+struct bl_params *plat_get_next_bl_params(void)
+{
+	struct bl_params *arm_bl_params = arm_get_next_bl_params();
+
+	const struct dyn_cfg_dtb_info_t *fw_config_info;
+	bl_mem_params_node_t *param_node;
+	uintptr_t fw_config_base = 0U;
+	entry_point_info_t *ep_info;
+
+	/* Get BL31 image node */
+	param_node = get_bl_mem_params_node(BL31_IMAGE_ID);
+	assert(param_node != NULL);
+
+	/* Get fw_config load address */
+	fw_config_info = FCONF_GET_PROPERTY(dyn_cfg, dtb, FW_CONFIG_ID);
+	assert(fw_config_info != NULL);
+
+	fw_config_base = fw_config_info->config_addr;
+	assert(fw_config_base != 0U);
+
+	/*
+	 * Get the entry point info of BL31 image and override
+	 * arg1 of entry point info with fw_config base address
+	 */
+	ep_info = &param_node->ep_info;
+	ep_info->args.arg1 = (uint32_t)fw_config_base;
+
+	return arm_bl_params;
+}