Merge changes from topic "fwu-refactor" into integration

* changes:
  refactor(plat/arm): use mmio* functions to read/write NVFLAGS registers
  refactor(plat/arm): mark the flash region as read-only
  refactor(plat/arm): update NV flags on image load/authentication failure

plat/arm/board/fvp/fvp_bl1_setup.c

 /*
- * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
 #include <assert.h>
+#include <errno.h>
 
 #include <bl1/bl1.h>
 #include <common/tbbr/tbbr_img_def.h>
 #include <drivers/arm/smmu_v3.h>
 #include <drivers/arm/sp805.h>
+#include <lib/mmio.h>
 #include <plat/arm/common/arm_config.h>
 #include <plat/arm/common/plat_arm.h>
 #include <plat/arm/common/arm_def.h>
@@ -61,6 +63,12 @@ void bl1_platform_setup(void)
 
 __dead2 void bl1_plat_fwu_done(void *client_cookie, void *reserved)
 {
+	uint32_t nv_flags = mmio_read_32(V2M_SYS_NVFLAGS_ADDR);
+
+	/* Clear the NV flags register. */
+	mmio_write_32((V2M_SYSREGS_BASE + V2M_SYS_NVFLAGSCLR),
+		      nv_flags);
+
 	/* Setup the watchdog to reset the system as soon as possible */
 	sp805_refresh(ARM_SP805_TWDG_BASE, 1U);
 
@@ -124,3 +132,15 @@ int bl1_plat_handle_post_image_load(unsigned int image_id)
 	return 0;
 }
 #endif /* MEASURED_BOOT */
+
+/*******************************************************************************
+ * The following function checks if Firmware update is needed by checking error
+ * reported in NV flag.
+ ******************************************************************************/
+bool plat_arm_bl1_fwu_needed(void)
+{
+	int32_t nv_flags = (int32_t)mmio_read_32(V2M_SYS_NVFLAGS_ADDR);
+
+	/* if image load/authentication failed */
+	return ((nv_flags == -EAUTH) || (nv_flags == -ENOENT));
+}

plat/arm/board/fvp/fvp_common.c

@@ -72,14 +72,11 @@ arm_config_t arm_config;
  * Table of memory regions for various BL stages to map using the MMU.
  * This doesn't include Trusted SRAM as setup_page_tables() already takes care
  * of mapping it.
- *
- * The flash needs to be mapped as writable in order to erase the FIP's Table of
- * Contents in case of unrecoverable error (see plat_error_handler()).
  */
 #ifdef IMAGE_BL1
 const mmap_region_t plat_arm_mmap[] = {
 	ARM_MAP_SHARED_RAM,
-	V2M_MAP_FLASH0_RW,
+	V2M_MAP_FLASH0_RO,
 	V2M_MAP_IOFPGA,
 	MAP_DEVICE0,
 #if FVP_INTERCONNECT_DRIVER == FVP_CCN

plat/arm/board/fvp/fvp_err.c

 /*
- * 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();
 

plat/arm/board/juno/juno_bl1_setup.c

 /*
- * Copyright (c) 2015-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -62,11 +62,11 @@ static int is_watchdog_reset(void)
  ******************************************************************************/
 bool plat_arm_bl1_fwu_needed(void)
 {
-	const int32_t *nv_flags_ptr = (const int32_t *)V2M_SYS_NVFLAGS_ADDR;
+	int32_t nv_flags = (int32_t)mmio_read_32(V2M_SYS_NVFLAGS_ADDR);
 
 	/* Check if TOC is invalid or watchdog reset happened. */
-	return (!arm_io_is_toc_valid() || (((*nv_flags_ptr == -EAUTH) ||
-		(*nv_flags_ptr == -ENOENT)) && is_watchdog_reset()));
+	return (!arm_io_is_toc_valid() || (((nv_flags == -EAUTH) ||
+		(nv_flags == -ENOENT)) && is_watchdog_reset()));
 }
 
 /*******************************************************************************
@@ -86,13 +86,11 @@ void bl1_plat_set_ep_info(unsigned int image_id,
  ******************************************************************************/
 __dead2 void bl1_plat_fwu_done(void *client_cookie, void *reserved)
 {
-	unsigned int *nv_flags_clr = (unsigned int *)
-			(V2M_SYSREGS_BASE + V2M_SYS_NVFLAGSCLR);
-	unsigned int *nv_flags_ptr = (unsigned int *)
-			(V2M_SYSREGS_BASE + V2M_SYS_NVFLAGS);
+	uint32_t nv_flags = mmio_read_32(V2M_SYS_NVFLAGS_ADDR);
 
 	/* Clear the NV flags register. */
-	*nv_flags_clr = *nv_flags_ptr;
+	mmio_write_32((V2M_SYSREGS_BASE + V2M_SYS_NVFLAGSCLR),
+		      nv_flags);
 
 	/* Setup the watchdog to reset the system as soon as possible */
 	sp805_refresh(ARM_SP805_TWDG_BASE, 1U);

plat/arm/board/juno/juno_err.c

 /*
- * Copyright (c) 2015-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -16,10 +16,8 @@
  */
 void __dead2 plat_arm_error_handler(int err)
 {
-	uint32_t *flags_ptr = (uint32_t *)V2M_SYS_NVFLAGS_ADDR;
-
 	/* Propagate the err code in the NV-flags register */
-	*flags_ptr = err;
+	mmio_write_32(V2M_SYS_NVFLAGS_ADDR, (uint32_t)err);
 
 	/* Setup the watchdog to reset the system as soon as possible */
 	sp805_refresh(ARM_SP805_TWDG_BASE, 1U);