refactor(plat/arm): update NV flags on image load/authentication failure

Erasing the FIP TOC header present in a flash is replaced by updating NV
flags with an error code on image load/authentication failure.
BL1 component uses these NV flags to detect whether a firmware update is
needed or not.
These NV flags get cleared once the firmware update gets completed.

Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: I6232a0db07c89b2373b7b9d28acd37df6203d914
diff --git a/plat/arm/board/fvp/fvp_err.c b/plat/arm/board/fvp/fvp_err.c
index 2928b3a..1f9f0dd 100644
--- a/plat/arm/board/fvp/fvp_err.c
+++ b/plat/arm/board/fvp/fvp_err.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2020, Arm Limited. All rights reserved.
+ * Copyright (c) 2019-2021, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -9,6 +9,7 @@
 #include <common/debug.h>
 #include <drivers/arm/sp805.h>
 #include <drivers/cfi/v2m_flash.h>
+#include <lib/mmio.h>
 #include <plat/arm/common/plat_arm.h>
 #include <platform_def.h>
 
@@ -17,25 +18,8 @@
  */
 __dead2 void plat_arm_error_handler(int err)
 {
-	int ret;
-
-	switch (err) {
-	case -ENOENT:
-	case -EAUTH:
-		/* Image load or authentication error. Erase the ToC */
-		INFO("Erasing FIP ToC from flash...\n");
-		(void)nor_unlock(PLAT_ARM_FLASH_IMAGE_BASE);
-		ret = nor_word_program(PLAT_ARM_FLASH_IMAGE_BASE, 0);
-		if (ret != 0) {
-			ERROR("Cannot erase ToC\n");
-		} else {
-			INFO("Done\n");
-		}
-		break;
-	default:
-		/* Unexpected error */
-		break;
-	}
+	/* Propagate the err code in the NV-flags register */
+	mmio_write_32(V2M_SYS_NVFLAGS_ADDR, (uint32_t)err);
 
 	console_flush();