tests: subsys: secure_storage: Erase flash before write once test

tests/subsys/secure_storage/psa/its/src/main.c

@@ -4,7 +4,62 @@
 #include <zephyr/ztest.h>
 #include <psa/internal_trusted_storage.h>
 
+#include <zephyr/types.h>
+#include <zephyr/storage/flash_map.h>
+#include <zephyr/drivers/flash.h>
+
 /* The flash must be erased after this test suite is run for the write-once entry test to pass. */
+
+#if !defined(CONFIG_BUILD_WITH_TFM) && defined(CONFIG_FLASH_PAGE_LAYOUT)
+
+#define MAX_NUM_PAGES 2
+static const struct device *const fdev = DEVICE_DT_GET(DT_CHOSEN(zephyr_flash_controller));
+
+#define FLASH_ERASE_END_ADDR                                                                       \
+	(FIXED_PARTITION_OFFSET(storage_partition) + FIXED_PARTITION_SIZE(storage_partition))
+
+static int erase_flash(void)
+{
+	int rc;
+	off_t address = FIXED_PARTITION_OFFSET(storage_partition);
+	struct flash_pages_info page_info;
+
+	while (address < FLASH_ERASE_END_ADDR) {
+		rc = flash_get_page_info_by_offs(fdev, address, &page_info);
+		if (rc < 0) {
+			return rc;
+		}
+
+#if defined(CONFIG_FLASH_HAS_NO_EXPLICIT_ERASE)
+		/* Lacking an explicit erase, just write all ones to the pages */
+		uint8_t empty[page_info.size];
+
+		memset(empty, 0xff, page_info.size);
+
+		TC_PRINT("Setting %d at %ld to 0xff\n", page_info.size, page_info.start_offset);
+		rc = flash_write(fdev, page_info.start_offset, empty, page_info.size);
+		if (rc < 0) {
+			return rc;
+		}
+#else
+		TC_PRINT("Erasing %d at %ld\n", page_info.size, page_info.start_offset);
+		rc = flash_erase(fdev, page_info.start_offset, page_info.size);
+		if (rc < 0) {
+			return rc;
+		}
+#endif
+
+		address += page_info.size;
+	}
+
+	return 0;
+}
+
+/* Low priority to ensure we run after any flash drivers are initialized */
+SYS_INIT(erase_flash, POST_KERNEL, 100);
+
+#endif
+
 ZTEST_SUITE(secure_storage_psa_its, NULL, NULL, NULL, NULL, NULL);
 
 #ifdef CONFIG_SECURE_STORAGE