fwu: add helper to get image GUID by type and bank index

Introduce fwu_mdata_get_image_guid() to retrieve a specific image GUID
from the FWU metadata based on the bank index and image type GUID.

This allows identifying the correct partition in multi-bank (A/B)
scenarios, ensuring the correct image is targeted depending on the
current bank.

Signed-off-by: Dario Binacchi <[email protected]>
Reviewed-by: Simon Glass <[email protected]>
Acked-by: Ilias Apalodimas <[email protected]>

2 files changed, 44 insertions, 0 deletions

diff --git a/include/fwu.h b/include/fwu.h
index 9cee8fb085c..68a51fb4296 100644
--- a/include/fwu.h
+++ b/include/fwu.h
@@ -397,6 +397,17 @@ void fwu_populate_mdata_image_info(struct fwu_data *data);
 int fwu_get_mdata_size(uint32_t *mdata_size);
 
 /**
+ * fwu_mdata_get_image_guid() - Get image GUID for a type and bank
+ * @image_guid: Pointer to be filled with the found image GUID
+ * @image_type_guid: Pointer to the image type GUID to search for
+ * @bank_index: Index of the bank
+ *
+ * Return: 0 if OK, -ve on error
+ */
+int fwu_mdata_get_image_guid(efi_guid_t *image_guid,
+			     const efi_guid_t *image_type_guid, u32 bank_index);
+
+/**
  * fwu_state_machine_updates() - Update FWU state of the platform
  * @state: FWU bank state
  * @update_index: Bank number to which images have been updated
diff --git a/lib/fwu_updates/fwu.c b/lib/fwu_updates/fwu.c
index e82600a29a4..2b11e5da061 100644
--- a/lib/fwu_updates/fwu.c
+++ b/lib/fwu_updates/fwu.c
@@ -244,6 +244,39 @@ int fwu_sync_mdata(struct fwu_mdata *mdata, int part)
 }
 
 /**
+ * fwu_mdata_get_image_guid() - Get image GUID for a type and bank
+ * @image_guid: Pointer to be filled with the found image GUID
+ * @image_type_guid: Pointer to the image type GUID to search for
+ * @bank_index: Index of the bank
+ *
+ * Return: 0 if OK, -ve on error
+ */
+int fwu_mdata_get_image_guid(efi_guid_t *image_guid,
+			     const efi_guid_t *image_type_guid, u32 bank_index)
+{
+	struct fwu_data *data = &g_fwu_data;
+	struct fwu_image_entry *image;
+	int i;
+
+	if (bank_index >= data->num_banks)
+		return -EINVAL;
+
+	for (i = 0; i < data->num_images; i++) {
+		image = &data->fwu_images[i];
+
+		if (!guidcmp(image_type_guid, &image->image_type_guid)) {
+			struct fwu_image_bank_info *bank;
+
+			bank = &image->img_bank_info[bank_index];
+			guidcpy(image_guid, &bank->image_guid);
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
+
+/**
  * fwu_mdata_copies_allocate() - Allocate memory for metadata
  * @mdata_size: Size of the metadata structure
  *