suit: Workaround for IPUC caches search before initialization

The IPUC cache was being searched for URI-s before it has been
initialized (before the first pull into the IPUC).

This led to issues - if only some images were already fetched and
the update was interrupted, the suit-processor would detect they
are already present in the cache. However, when pulling the
first missing image, the IPUC cache with the detected images
was erased leading to update failure.

Signed-off-by: Artur Hadasz <[email protected]>

Author: ahasztag

subsys/suit/cache/src/suit_dfu_cache_helpers.c

@@ -15,8 +15,34 @@
 #include "suit_ram_sink.h"
 #include "zcbor_noncanonical_decode.h"
 
+#ifdef CONFIG_FLASH_IPUC
+#include <drivers/flash/flash_ipuc.h>
+#endif /* CONFIG_FLASH_IPUC */
+
 LOG_MODULE_REGISTER(dfu_cache_helpers, CONFIG_SUIT_LOG_LEVEL);
 
+#ifdef CONFIG_FLASH_IPUC
+/* This function returns true if the given cache pool is an IPUC-based cache
+ * but is not initialized yet.
+ */
+static bool is_cache_ipuc_uninitialized(struct dfu_cache_pool *cache_pool)
+{
+	uintptr_t ipuc_address;
+	size_t ipuc_size;
+	bool ipuc_possible =
+		flash_cache_ipuc_check((uintptr_t)cache_pool->address, &ipuc_address, &ipuc_size);
+
+	if (ipuc_possible) {
+		if (flash_ipuc_find((uintptr_t)cache_pool->address, cache_pool->size, &ipuc_address,
+				    &ipuc_size) == NULL) {
+			return true;
+		}
+	}
+
+	return false;
+}
+#endif /* CONFIG_FLASH_IPUC */
+
 suit_plat_err_t suit_dfu_cache_partition_slot_foreach(struct dfu_cache_pool *cache_pool,
 						      partition_slot_foreach_cb cb, void *ctx)
 {
@@ -49,6 +75,12 @@ suit_plat_err_t suit_dfu_cache_partition_slot_foreach(struct dfu_cache_pool *cac
 			break;
 		}
 
+#ifdef CONFIG_FLASH_IPUC
+		if (is_cache_ipuc_uninitialized(cache_pool)) {
+			return SUIT_PLAT_ERR_CBOR_DECODING;
+		}
+#endif /* CONFIG_FLASH_IPUC */
+
 		err = suit_dfu_cache_memcpy(partition_header_storage, current_address, read_size);
 
 		if (err != SUIT_PLAT_SUCCESS) {
@@ -168,6 +200,12 @@ suit_plat_err_t suit_dfu_cache_partition_is_empty(struct dfu_cache_pool *cache_p
 	const size_t chunk_size = sizeof(buffer);
 	suit_plat_err_t ret = SUIT_PLAT_SUCCESS;
 
+#ifdef CONFIG_FLASH_IPUC
+	if (is_cache_ipuc_uninitialized(cache_pool)) {
+		return SUIT_PLAT_SUCCESS;
+	}
+#endif /* CONFIG_FLASH_IPUC */
+
 	while (remaining > 0) {
 		size_t read_size = MIN(chunk_size, remaining);