feat(stm32mp1): add support for reading the metadata partition

Add support for reading the FWU metadata partition. The metadata
partition stores information on the current active bank along with
information on all the FWU updatable images on the platform. This
information is then used to identify the image to be booted.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Change-Id: I66bc5ac718c21a49c504e698b5b1f5c4daed2d08
diff --git a/plat/st/common/bl2_io_storage.c b/plat/st/common/bl2_io_storage.c
index 96921e0..e129dfd 100644
--- a/plat/st/common/bl2_io_storage.c
+++ b/plat/st/common/bl2_io_storage.c
@@ -548,4 +548,51 @@
 		image_spec->length = entry->length;
 	}
 }
+
+static int plat_set_image_source(unsigned int image_id,
+				 uintptr_t *handle,
+				 uintptr_t *image_spec,
+				 const char *part_name)
+{
+	struct plat_io_policy *policy;
+	io_block_spec_t *spec;
+	const partition_entry_t *entry = get_partition_entry(part_name);
+
+	if (entry == NULL) {
+		ERROR("Unable to find the %s partition\n", part_name);
+		return -ENOENT;
+	}
+
+	policy = &policies[image_id];
+
+	spec = (io_block_spec_t *)policy->image_spec;
+	spec->offset = entry->start;
+	spec->length = entry->length;
+
+	*image_spec = policy->image_spec;
+	*handle = *policy->dev_handle;
+
+	return 0;
+}
+
+int plat_fwu_set_metadata_image_source(unsigned int image_id,
+				       uintptr_t *handle,
+				       uintptr_t *image_spec)
+{
+	char *part_name;
+
+	assert((image_id == FWU_METADATA_IMAGE_ID) ||
+	       (image_id == BKUP_FWU_METADATA_IMAGE_ID));
+
+	partition_init(GPT_IMAGE_ID);
+
+	if (image_id == FWU_METADATA_IMAGE_ID) {
+		part_name = METADATA_PART_1;
+	} else {
+		part_name = METADATA_PART_2;
+	}
+
+	return plat_set_image_source(image_id, handle, image_spec,
+				     part_name);
+}
 #endif /* (STM32MP_SDMMC || STM32MP_EMMC) && PSA_FWU_SUPPORT */
diff --git a/plat/st/common/stm32mp_fconf_io.c b/plat/st/common/stm32mp_fconf_io.c
index 7ab3b73..ca71958 100644
--- a/plat/st/common/stm32mp_fconf_io.c
+++ b/plat/st/common/stm32mp_fconf_io.c
@@ -27,6 +27,13 @@
 };
 #endif
 
+#if (STM32MP_SDMMC || STM32MP_EMMC) && PSA_FWU_SUPPORT
+io_block_spec_t metadata_block_spec = {
+	.offset = 0,    /* To be filled at runtime */
+	.length = 0,    /* To be filled at runtime */
+};
+#endif /* (STM32MP_SDMMC || STM32MP_EMMC) && PSA_FWU_SUPPORT */
+
 /* By default, STM32 platforms load images from the FIP */
 struct plat_io_policy policies[MAX_NUMBER_IDS] = {
 	[FIP_IMAGE_ID] = {
@@ -43,6 +50,20 @@
 		.check = open_storage
 	},
 #endif
+#if (STM32MP_SDMMC || STM32MP_EMMC) && PSA_FWU_SUPPORT
+	[FWU_METADATA_IMAGE_ID] = {
+		.dev_handle = &storage_dev_handle,
+		.image_spec = (uintptr_t)&metadata_block_spec,
+		.img_type_guid = NULL_GUID,
+		.check = open_storage
+	},
+	[BKUP_FWU_METADATA_IMAGE_ID] = {
+		.dev_handle = &storage_dev_handle,
+		.image_spec = (uintptr_t)&metadata_block_spec,
+		.img_type_guid = NULL_GUID,
+		.check = open_storage
+	},
+#endif /* (STM32MP_SDMMC || STM32MP_EMMC) && PSA_FWU_SUPPORT */
 };
 
 #define FCONF_ST_IO_UUID_NUMBER	U(8)
diff --git a/plat/st/stm32mp1/include/platform_def.h b/plat/st/stm32mp1/include/platform_def.h
index 511a0e2..8ecb4c3 100644
--- a/plat/st/stm32mp1/include/platform_def.h
+++ b/plat/st/stm32mp1/include/platform_def.h
@@ -40,6 +40,9 @@
 #define BL33_BINARY_TYPE		U(0x0)
 #else /* STM32MP_USE_STM32IMAGE */
 #define FIP_IMAGE_NAME			"fip"
+#define METADATA_PART_1			"metadata1"
+#define METADATA_PART_2			"metadata2"
+
 #endif /* STM32MP_USE_STM32IMAGE */
 
 #define STM32MP_PRIMARY_CPU		U(0x0)