feat(arm): add support for loading CONFIG from BL2
This commit introduces a new ARM platform-specific build option called
`ARM_FW_CONFIG_LOAD_ENABLE`. This option enables the loading of the
`fw_config` device tree when resetting to the BL2 scenario.
Additionally, the FW_CONFIG image reference has been added to the
fdts/tbbr_cot_descriptors.dtsi file in order to use in the scenario of
RESET_TO_BL2.
Signed-off-by: Divin Raj <divin.raj@arm.com>
Change-Id: I11de497b7dbb1386ed84d939d6fd2a11856e9e1b
diff --git a/docs/plat/arm/arm-build-options.rst b/docs/plat/arm/arm-build-options.rst
index e1b3ef0..afbb157 100644
--- a/docs/plat/arm/arm-build-options.rst
+++ b/docs/plat/arm/arm-build-options.rst
@@ -16,6 +16,12 @@
should match the frame used by the Non-Secure image (normally the Linux
kernel). Default is true (access to the frame is allowed).
+- ``ARM_FW_CONFIG_LOAD_ENABLE``: Boolean option to enable the loading of
+ FW_CONFIG device trees from the Firmware Image Package (FIP). When enabled,
+ BL2 calls the platform specific function `arm_bl2_el3_plat_config_load`.
+ This function is responsible for loading, parsing, and validating the
+ FW_CONFIG device trees from the FIP. The option depends on RESET_TO_BL2.
+
- ``ARM_DISABLE_TRUSTED_WDOG``: boolean option to disable the Trusted Watchdog.
By default, Arm platforms use a watchdog to trigger a system reset in case
an error is encountered during the boot process (for example, when an image
diff --git a/fdts/tbbr_cot_descriptors.dtsi b/fdts/tbbr_cot_descriptors.dtsi
index b3c0ca7..253297f 100644
--- a/fdts/tbbr_cot_descriptors.dtsi
+++ b/fdts/tbbr_cot_descriptors.dtsi
@@ -195,6 +195,12 @@
hash = <&hw_config_hash>;
};
+ fw_config {
+ image-id = <FW_CONFIG_ID>;
+ parent = <&trusted_boot_fw_cert>;
+ hash = <&fw_config_hash>;
+ };
+
scp_bl2_image {
image-id = <SCP_BL2_IMAGE_ID>;
parent = <&scp_fw_content_cert>;
diff --git a/include/plat/arm/common/plat_arm.h b/include/plat/arm/common/plat_arm.h
index 83a5cd2..c3756bf 100644
--- a/include/plat/arm/common/plat_arm.h
+++ b/include/plat/arm/common/plat_arm.h
@@ -262,6 +262,9 @@
/* BL2 at EL3 functions */
void arm_bl2_el3_early_platform_setup(void);
void arm_bl2_el3_plat_arch_setup(void);
+#if ARM_FW_CONFIG_LOAD_ENABLE
+void arm_bl2_el3_plat_config_load(void);
+#endif /* ARM_FW_CONFIG_LOAD_ENABLE */
/* BL2U utility functions */
void arm_bl2u_early_platform_setup(struct meminfo *mem_layout,
diff --git a/plat/arm/common/arm_bl2_el3_setup.c b/plat/arm/common/arm_bl2_el3_setup.c
index 01e0db0..869830d 100644
--- a/plat/arm/common/arm_bl2_el3_setup.c
+++ b/plat/arm/common/arm_bl2_el3_setup.c
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2017-2023, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2024, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -8,6 +8,8 @@
#include <drivers/generic_delay_timer.h>
#include <drivers/partition/partition.h>
+#include <lib/fconf/fconf.h>
+#include <lib/fconf/fconf_dyn_cfg_getter.h>
#include <plat/arm/common/plat_arm.h>
#include <plat/common/platform.h>
#include <platform_def.h>
@@ -64,6 +66,43 @@
generic_delay_timer_init();
}
+#if ARM_FW_CONFIG_LOAD_ENABLE
+/*************************************************************************************
+ * FW CONFIG load function for BL2 when RESET_TO_BL2=1 && ARM_FW_CONFIG_LOAD_ENABLE=1
+ *************************************************************************************/
+void arm_bl2_el3_plat_config_load(void)
+{
+ int ret;
+ const struct dyn_cfg_dtb_info_t *fw_config_info;
+
+ /* Set global DTB info for fixed fw_config information */
+ set_config_info(PLAT_FW_CONFIG_BASE, ~0UL, PLAT_FW_CONFIG_MAX_SIZE, FW_CONFIG_ID);
+
+ /* Fill the device tree information struct with the info from the config dtb */
+ ret = fconf_load_config(FW_CONFIG_ID);
+ if (ret < 0) {
+ ERROR("Loading of FW_CONFIG failed %d\n", ret);
+ plat_error_handler(ret);
+ }
+
+ /*
+ * FW_CONFIG loaded successfully. Check the FW_CONFIG device tree parsing
+ * is successful.
+ */
+ fw_config_info = FCONF_GET_PROPERTY(dyn_cfg, dtb, FW_CONFIG_ID);
+ if (fw_config_info == NULL) {
+ ret = -1;
+ ERROR("Invalid FW_CONFIG address\n");
+ plat_error_handler(ret);
+ }
+ ret = fconf_populate_dtb_registry(fw_config_info->config_addr);
+ if (ret < 0) {
+ ERROR("Parsing of FW_CONFIG failed %d\n", ret);
+ plat_error_handler(ret);
+ }
+}
+#endif /* ARM_FW_CONFIG_LOAD_ENABLE */
+
/*******************************************************************************
* Perform the very early platform specific architectural setup here. At the
* moment this is only initializes the mmu in a quick and dirty way.
diff --git a/plat/arm/common/arm_bl2_setup.c b/plat/arm/common/arm_bl2_setup.c
index b5a7db1..d018a95 100644
--- a/plat/arm/common/arm_bl2_setup.c
+++ b/plat/arm/common/arm_bl2_setup.c
@@ -140,6 +140,9 @@
arm_transfer_list_dyn_cfg_init(secure_tl);
#else
+#if ARM_FW_CONFIG_LOAD_ENABLE
+ arm_bl2_el3_plat_config_load();
+#endif /* ARM_FW_CONFIG_LOAD_ENABLE */
arm_bl2_dyn_cfg_init();
#endif
diff --git a/plat/arm/common/arm_common.mk b/plat/arm/common/arm_common.mk
index 0c9b943..13694b8 100644
--- a/plat/arm/common/arm_common.mk
+++ b/plat/arm/common/arm_common.mk
@@ -164,6 +164,25 @@
ENABLE_PIE := 1
endif
+# On Arm platform, disable ARM_FW_CONFIG_LOAD_ENABLE by default.
+ARM_FW_CONFIG_LOAD_ENABLE := 0
+$(eval $(call assert_boolean,ARM_FW_CONFIG_LOAD_ENABLE))
+$(eval $(call add_define,ARM_FW_CONFIG_LOAD_ENABLE))
+
+# In order to enable ARM_FW_CONFIG_LOAD_ENABLE for the Arm platform, the
+# platform should be reset to BL2 (RESET_TO_BL2=1), and FW_CONFIG must be
+# specified.
+ifeq (${ARM_FW_CONFIG_LOAD_ENABLE},1)
+ ifneq (${RESET_TO_BL2},1)
+ $(error RESET_TO_BL2 must be enabled when ARM_FW_CONFIG_LOAD_ENABLE \
+ is enabled)
+ endif
+ ifeq (${FW_CONFIG},)
+ $(error FW_CONFIG must be specified when ARM_FW_CONFIG_LOAD_ENABLE \
+ is enabled)
+ endif
+endif
+
# Disable GPT parser support, use FIP image by default
ARM_GPT_SUPPORT := 0
$(eval $(call assert_boolean,ARM_GPT_SUPPORT))