fconf: Add dynamic config DTBs info as property

This patch introduces a better separation between the trusted-boot
related properties, and the dynamic configuration DTBs loading
information.

The dynamic configuration DTBs properties are moved to a new node:
`dtb-registry`. All the sub-nodes present will be provided to the
dynamic config framework to be loaded. The node currently only contains
the already defined configuration DTBs, but can be extended for future
features if necessary.
The dynamic config framework is modified to use the abstraction provided
by the fconf framework, instead of directly accessing the DTBs.

The trusted-boot properties are kept under the "arm,tb_fw" compatible
string, but in a separate `tb_fw-config` node.
The `tb_fw-config` property of the `dtb-registry` node simply points
to the load address of `fw_config`, as the `tb_fw-config` is currently
part of the same DTB.

Change-Id: Iceb6c4c2cb92b692b6e28dbdc9fb060f1c46de82
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>

3 files changed, 98 insertions, 2 deletions

diff --git a/lib/fconf/fconf.c b/lib/fconf/fconf.c
index 2ca1bdc77..a6da56b00 100644
--- a/lib/fconf/fconf.c
+++ b/lib/fconf/fconf.c
@@ -18,7 +18,7 @@ struct fconf_dtb_info_t fconf_dtb_info;
 void fconf_load_config(void)
 {
 	int err;
-
+	/* fconf FW_CONFIG and TB_FW_CONFIG are currently the same DTB */
 	image_info_t arm_tb_fw_info = {
 		.h.type = (uint8_t)PARAM_IMAGE_BINARY,
 		.h.version = (uint8_t)VERSION_2,
diff --git a/lib/fconf/fconf.mk b/lib/fconf/fconf.mk
index 0813c73cc..703196949 100644
--- a/lib/fconf/fconf.mk
+++ b/lib/fconf/fconf.mk
@@ -5,7 +5,8 @@
 #
 
 # Add Firmware Configuration files
-FCONF_SOURCES		:=	lib/fconf/fconf.c
+FCONF_SOURCES		:=	lib/fconf/fconf.c				\
+				lib/fconf/fconf_dyn_cfg_getter.c
 
 BL1_SOURCES		+=	${FCONF_SOURCES}
 BL2_SOURCES		+=	${FCONF_SOURCES}
diff --git a/lib/fconf/fconf_dyn_cfg_getter.c b/lib/fconf/fconf_dyn_cfg_getter.c
new file mode 100644
index 000000000..d313a5618
--- /dev/null
+++ b/lib/fconf/fconf_dyn_cfg_getter.c
@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2019-2020, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+
+#include <common/debug.h>
+#include <common/fdt_wrappers.h>
+#include <lib/fconf/fconf_dyn_cfg_getter.h>
+#include <lib/object_pool.h>
+#include <libfdt.h>
+
+/* We currently use TB_FW, SOC_FW, TOS_FW, NS_fw and HW configs  */
+#define MAX_DTB_INFO	U(5)
+
+static struct dyn_cfg_dtb_info_t dtb_infos[MAX_DTB_INFO];
+static OBJECT_POOL_ARRAY(dtb_info_pool, dtb_infos);
+
+struct dyn_cfg_dtb_info_t *dyn_cfg_dtb_info_getter(unsigned int config_id)
+{
+	unsigned int index;
+	struct dyn_cfg_dtb_info_t *info;
+
+	/* Positions index to the proper config-id */
+	for (index = 0; index < MAX_DTB_INFO; index++) {
+		if (dtb_infos[index].config_id == config_id) {
+			info = &dtb_infos[index];
+			break;
+		}
+	}
+
+	if (index == MAX_DTB_INFO) {
+		WARN("FCONF: Invalid config id %u\n", config_id);
+		info = NULL;
+	}
+
+	return info;
+}
+
+int fconf_populate_dtb_registry(uintptr_t config)
+{
+	int rc;
+	int node, child;
+	struct dyn_cfg_dtb_info_t *dtb_info;
+
+	/* As libfdt use void *, we can't avoid this cast */
+	const void *dtb = (void *)config;
+
+	/* Find the node offset point to "arm,dyn_cfg-dtb_registry" compatible property */
+	const char *compatible_str = "arm,dyn_cfg-dtb_registry";
+	node = fdt_node_offset_by_compatible(dtb, -1, compatible_str);
+	if (node < 0) {
+		ERROR("FCONF: Can't find %s compatible in dtb\n", compatible_str);
+		return node;
+	}
+
+	fdt_for_each_subnode(child, dtb, node) {
+		dtb_info = pool_alloc(&dtb_info_pool);
+
+		/* Read configuration dtb information */
+		rc = fdtw_read_cells(dtb, child, "load-address", 2, &dtb_info->config_addr);
+		if (rc < 0) {
+			ERROR("FCONF: Incomplete configuration property in dtb-registry.\n");
+			return rc;
+		}
+
+		rc = fdtw_read_cells(dtb, child, "max-size", 1, &dtb_info->config_max_size);
+		if (rc < 0) {
+			ERROR("FCONF: Incomplete configuration property in dtb-registry.\n");
+			return rc;
+		}
+
+		rc = fdtw_read_cells(dtb, child, "id", 1, &dtb_info->config_id);
+		if (rc < 0) {
+			ERROR("FCONF: Incomplete configuration property in dtb-registry.\n");
+			return rc;
+		}
+
+		VERBOSE("FCONF: dyn_cfg.dtb_registry cell found with:\n");
+		VERBOSE("\tload-address = %lx\n", dtb_info->config_addr);
+		VERBOSE("\tmax-size = 0x%zx\n", dtb_info->config_max_size);
+		VERBOSE("\tconfig-id = %u\n", dtb_info->config_id);
+	}
+
+	if ((child < 0) && (child != -FDT_ERR_NOTFOUND)) {
+		ERROR("%d: fdt_for_each_subnode(): %d\n", __LINE__, node);
+		return child;
+	}
+
+	return 0;
+}
+
+FCONF_REGISTER_POPULATOR(dyn_cfg, fconf_populate_dtb_registry);