refactor(plat/arm): store UUID as a string, rather than ints

NOTE: Breaking change to the way UUIDs are stored in the DT

Currently, UUIDs are stored in the device tree as
sequences of 4 integers. There is a mismatch in endianness
between the way UUIDs are represented in memory and the way
they are parsed from the device tree. As a result, we must either
store the UUIDs in little-endian format in the DT (which means
that they do not match up with their string representations)
or perform endianness conversion after parsing them.

Currently, TF-A chooses the second option, with unwieldy
endianness-conversion taking place after reading a UUID.

To fix this problem, and to make it convenient to copy and
paste UUIDs from other tools, change to store UUIDs in string
format, using a new wrapper function to parse them from the
device tree.

Change-Id: I38bd63c907be14e412f03ef0aab9dcabfba0eaa0
Signed-off-by: David Horstmann <david.horstmann@arm.com>
diff --git a/include/tools_share/uuid.h b/include/tools_share/uuid.h
index a6891d1..2ced3a3 100644
--- a/include/tools_share/uuid.h
+++ b/include/tools_share/uuid.h
@@ -66,7 +66,6 @@
 union uuid_helper_t {
 	struct uuid uuid_struct;
 	struct efi_guid efi_guid;
-	uint32_t word[4];
 };
 
 /* XXX namespace pollution? */
diff --git a/plat/arm/board/fvp/fdts/fvp_tb_fw_config.dts b/plat/arm/board/fvp/fdts/fvp_tb_fw_config.dts
index fe154e9..14ad5f5 100644
--- a/plat/arm/board/fvp/fdts/fvp_tb_fw_config.dts
+++ b/plat/arm/board/fvp/fdts/fvp_tb_fw_config.dts
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, ARM Limited. All rights reserved.
+ * Copyright (c) 2020-2021, ARM Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -48,26 +48,26 @@
 	arm-io_policies {
 		fip-handles {
 			compatible = "arm,io-fip-handle";
-			scp_bl2_uuid = <0x9766fd3d 0x89bee849 0xae5d78a1 0x40608213>;
-			bl31_uuid = <0x47d4086d 0x4cfe9846 0x9b952950 0xcbbd5a00>;
-			bl32_uuid = <0x05d0e189 0x53dc1347 0x8d2b500a 0x4b7a3e38>;
-			bl32_extra1_uuid = <0x0b70c28b 0x2a5a7840 0x9f650a56 0x82738288>;
-			bl32_extra2_uuid = <0x8ea87bb1 0xcfa23f4d 0x85fde7bb 0xa50220d9>;
-			bl33_uuid = <0xd6d0eea7 0xfcead54b 0x97829934 0xf234b6e4>;
-			hw_cfg_uuid = <0x08b8f1d9 0xc9cf9349 0xa9626fbc 0x6b7265cc>;
-			soc_fw_cfg_uuid = <0x9979814b 0x0376fb46 0x8c8e8d26 0x7f7859e0>;
-			tos_fw_cfg_uuid = <0x26257c1a 0xdbc67f47 0x8d96c4c4 0xb0248021>;
-			nt_fw_cfg_uuid = <0x28da9815 0x93e87e44 0xac661aaf 0x801550f9>;
-			t_key_cert_uuid = <0x827ee890 0xf860e411 0xa1b477a7 0x21b4f94c>;
-			scp_fw_key_uuid = <0x024221a1 0xf860e411 0x8d9bf33c 0x0e15a014>;
-			soc_fw_key_uuid = <0x8ab8becc 0xf960e411 0x9ad0eb48 0x22d8dcf8>;
-			tos_fw_key_cert_uuid = <0x9477d603 0xfb60e411 0x85ddb710 0x5b8cee04>;
-			nt_fw_key_cert_uuid = <0x8ad5832a 0xfb60e411 0x8aafdf30 0xbbc49859>;
-			scp_fw_content_cert_uuid = <0x44be6f04 0x5e63e411 0xb28b73d8 0xeaae9656>;
-			soc_fw_content_cert_uuid = <0xe2b20c20 0x5e63e411 0x9ce8abcc 0xf92bb666>;
-			tos_fw_content_cert_uuid = <0xa49f4411 0x5e63e411 0x87283f05 0x722af33d>;
-			nt_fw_content_cert_uuid = <0x8ec4c1f3 0x5d63e411 0xa7a987ee 0x40b23fa7>;
-			sp_content_cert_uuid = <0x776dfd44 0x86974c3b 0x91ebc13e 0x025a2a6f>;
+			scp_bl2_uuid = "9766fd3d-89be-e849-ae5d-78a140608213";
+			bl31_uuid = "47d4086d-4cfe-9846-9b95-2950cbbd5a00";
+			bl32_uuid = "05d0e189-53dc-1347-8d2b-500a4b7a3e38";
+			bl32_extra1_uuid = "0b70c28b-2a5a-7840-9f65-0a5682738288";
+			bl32_extra2_uuid = "8ea87bb1-cfa2-3f4d-85fd-e7bba50220d9";
+			bl33_uuid = "d6d0eea7-fcea-d54b-9782-9934f234b6e4";
+			hw_cfg_uuid = "08b8f1d9-c9cf-9349-a962-6fbc6b7265cc";
+			soc_fw_cfg_uuid = "9979814b-0376-fb46-8c8e-8d267f7859e0";
+			tos_fw_cfg_uuid = "26257c1a-dbc6-7f47-8d96-c4c4b0248021";
+			nt_fw_cfg_uuid = "28da9815-93e8-7e44-ac66-1aaf801550f9";
+			t_key_cert_uuid = "827ee890-f860-e411-a1b4-77a721b4f94c";
+			scp_fw_key_uuid = "024221a1-f860-e411-8d9b-f33c0e15a014";
+			soc_fw_key_uuid = "8ab8becc-f960-e411-9ad0-eb4822d8dcf8";
+			tos_fw_key_cert_uuid = "9477d603-fb60-e411-85dd-b7105b8cee04";
+			nt_fw_key_cert_uuid = "8ad5832a-fb60-e411-8aaf-df30bbc49859";
+			scp_fw_content_cert_uuid = "44be6f04-5e63-e411-b28b-73d8eaae9656";
+			soc_fw_content_cert_uuid = "e2b20c20-5e63-e411-9ce8-abccf92bb666";
+			tos_fw_content_cert_uuid = "a49f4411-5e63-e411-8728-3f05722af33d";
+			nt_fw_content_cert_uuid = "8ec4c1f3-5d63-e411-a7a9-87ee40b23fa7";
+			sp_content_cert_uuid = "776dfd44-8697-4c3b-91eb-c13e025a2a6f";
 		};
 	};
 #endif /* ARM_IO_IN_DTB */
@@ -76,24 +76,24 @@
 		compatible = "arm,sp";
 #ifdef OPTEE_SP_FW_CONFIG
 		op-tee {
-			uuid = <0x486178e0 0xe7f811e3 0xbc5e0002 0xa5d5c51b>;
+			uuid = "486178e0-e7f8-11e3-bc5e-0002a5d5c51b";
 			load-address = <0x6280000>;
 		};
 #else
 		cactus-primary {
-			uuid = <0xb4b5671e 0x4a904fe1 0xb81ffb13 0xdae1dacb>;
+			uuid = "b4b5671e-4a90-4fe1-b81f-fb13dae1dacb";
 			load-address = <0x7000000>;
 			owner = "SiP";
 		};
 
 		cactus-secondary {
-			uuid = <0xd1582309 0xf02347b9 0x827c4464 0xf5578fc8>;
+			uuid = "d1582309-f023-47b9-827c-4464f5578fc8";
 			load-address = <0x7100000>;
 			owner = "Plat";
 		};
 
 		cactus-tertiary {
-			uuid = <0x79b55c73 0x1d8c44b9 0x859361e1 0x770ad8d2>;
+			uuid = "79b55c73-1d8c-44b9-8593-61e1770ad8d2";
 			load-address = <0x7200000>;
 		};
 #endif
diff --git a/plat/arm/common/arm_common.mk b/plat/arm/common/arm_common.mk
index 232d562..2ae26da 100644
--- a/plat/arm/common/arm_common.mk
+++ b/plat/arm/common/arm_common.mk
@@ -222,7 +222,8 @@
 
 DYN_CFG_SOURCES		+=	plat/arm/common/arm_dyn_cfg.c		\
 				plat/arm/common/arm_dyn_cfg_helpers.c	\
-				common/fdt_wrappers.c
+				common/fdt_wrappers.c			\
+				common/uuid.c
 
 BL1_SOURCES		+=	${DYN_CFG_SOURCES}
 BL2_SOURCES		+=	${DYN_CFG_SOURCES}
@@ -302,6 +303,7 @@
 ifeq (${SPD},spmd)
 BL31_SOURCES		+=	plat/common/plat_spmd_manifest.c	\
 				common/fdt_wrappers.c			\
+				common/uuid.c				\
 				${LIBFDT_SRCS}
 
 endif
diff --git a/plat/arm/common/fconf/arm_fconf_io.c b/plat/arm/common/fconf/arm_fconf_io.c
index 48286c2..2880238 100644
--- a/plat/arm/common/fconf/arm_fconf_io.c
+++ b/plat/arm/common/fconf/arm_fconf_io.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
  */
@@ -249,7 +249,6 @@
 {
 	int err, node;
 	unsigned int i;
-	unsigned int j;
 
 	union uuid_helper_t uuid_helper;
 	io_uuid_spec_t *uuid_ptr;
@@ -268,26 +267,26 @@
 	/* Locate the uuid cells and read the value for all the load info uuid */
 	for (i = 0; i < FCONF_ARM_IO_UUID_NUMBER; i++) {
 		uuid_ptr = pool_alloc(&fconf_arm_uuids_pool);
-		err = fdt_read_uint32_array(dtb, node, load_info[i].name,
-					    4, uuid_helper.word);
+		err = fdtw_read_uuid(dtb, node, load_info[i].name, 16,
+				     (uint8_t *)&uuid_helper);
 		if (err < 0) {
 			WARN("FCONF: Read cell failed for %s\n", load_info[i].name);
 			return err;
 		}
 
-		/* Convert uuid from big endian to little endian */
-		for (j = 0U; j < 4U; j++) {
-			uuid_helper.word[j] =
-				((uuid_helper.word[j] >> 24U) & 0xff) |
-				((uuid_helper.word[j] << 8U) & 0xff0000) |
-				((uuid_helper.word[j] >> 8U) & 0xff00) |
-				((uuid_helper.word[j] << 24U) & 0xff000000);
-		}
-
-		VERBOSE("FCONF: arm-io_policies.%s cell found with value = 0x%x 0x%x 0x%x 0x%x\n",
+		VERBOSE("FCONF: arm-io_policies.%s cell found with value = "
+			"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x\n",
 			load_info[i].name,
-			uuid_helper.word[0], uuid_helper.word[1],
-			uuid_helper.word[2], uuid_helper.word[3]);
+			uuid_helper.uuid_struct.time_low[0], uuid_helper.uuid_struct.time_low[1],
+			uuid_helper.uuid_struct.time_low[2], uuid_helper.uuid_struct.time_low[3],
+			uuid_helper.uuid_struct.time_mid[0], uuid_helper.uuid_struct.time_mid[1],
+			uuid_helper.uuid_struct.time_hi_and_version[0],
+			uuid_helper.uuid_struct.time_hi_and_version[1],
+			uuid_helper.uuid_struct.clock_seq_hi_and_reserved,
+			uuid_helper.uuid_struct.clock_seq_low,
+			uuid_helper.uuid_struct.node[0], uuid_helper.uuid_struct.node[1],
+			uuid_helper.uuid_struct.node[2], uuid_helper.uuid_struct.node[3],
+			uuid_helper.uuid_struct.node[4], uuid_helper.uuid_struct.node[5]);
 
 		uuid_ptr->uuid = uuid_helper.uuid_struct;
 		policies[load_info[i].image_id].image_spec = (uintptr_t)uuid_ptr;
diff --git a/plat/arm/common/fconf/arm_fconf_sp.c b/plat/arm/common/fconf/arm_fconf_sp.c
index 7950e7f..552393c 100644
--- a/plat/arm/common/fconf/arm_fconf_sp.c
+++ b/plat/arm/common/fconf/arm_fconf_sp.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2020-2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -37,7 +37,6 @@
 	const unsigned int plat_start = SP_PKG5_ID;
 	unsigned int plat_index = plat_start;
 	const unsigned int plat_end = plat_start + MAX_SP_IDS / 2;
-	unsigned int j;
 
 	/* As libfdt use void *, we can't avoid this cast */
 	const void *dtb = (void *)config;
@@ -59,29 +58,28 @@
 		}
 
 		/* Read UUID */
-		err = fdt_read_uint32_array(dtb, sp_node, "uuid", 4,
-					    uuid_helper.word);
+		err = fdtw_read_uuid(dtb, sp_node, "uuid", 16,
+				     (uint8_t *)&uuid_helper);
 		if (err < 0) {
 			ERROR("FCONF: cannot read SP uuid\n");
 			return -1;
 		}
 
-		/* Convert uuid from big endian to little endian */
-		for (j = 0U; j < 4U; j++) {
-			uuid_helper.word[j] =
-				((uuid_helper.word[j] >> 24U) & 0xff) |
-				((uuid_helper.word[j] << 8U) & 0xff0000) |
-				((uuid_helper.word[j] >> 8U) & 0xff00) |
-				((uuid_helper.word[j] << 24U) & 0xff000000);
-		}
-
 		arm_sp.uuids[index] = uuid_helper;
-		VERBOSE("FCONF: %s UUID %x-%x-%x-%x load_addr=%lx\n",
+		VERBOSE("FCONF: %s UUID"
+			" %02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x"
+			" load_addr=%lx\n",
 			__func__,
-			uuid_helper.word[0],
-			uuid_helper.word[1],
-			uuid_helper.word[2],
-			uuid_helper.word[3],
+			uuid_helper.uuid_struct.time_low[0], uuid_helper.uuid_struct.time_low[1],
+			uuid_helper.uuid_struct.time_low[2], uuid_helper.uuid_struct.time_low[3],
+			uuid_helper.uuid_struct.time_mid[0], uuid_helper.uuid_struct.time_mid[1],
+			uuid_helper.uuid_struct.time_hi_and_version[0],
+			uuid_helper.uuid_struct.time_hi_and_version[1],
+			uuid_helper.uuid_struct.clock_seq_hi_and_reserved,
+			uuid_helper.uuid_struct.clock_seq_low,
+			uuid_helper.uuid_struct.node[0], uuid_helper.uuid_struct.node[1],
+			uuid_helper.uuid_struct.node[2], uuid_helper.uuid_struct.node[3],
+			uuid_helper.uuid_struct.node[4], uuid_helper.uuid_struct.node[5],
 			arm_sp.load_addr[index]);
 
 		/* Read Load address */