feat(sptool): generate `ARM_BL2_SP_LIST_DTS` file from `sp_layout.json`

TF-A makefile accepts a device-tree snippet to override hardcoded SP
nodes, via the `ARM_BL2_SP_LIST_DTS` variable. However the SPs declared
in `ARM_BL2_SP_LIST_DTS` must be in the same order as they are in the
FIP image, otherwise hash authentication will fail when loaded by BL2.

This patch generates the `ARM_BL2_SP_LIST_DTS` file from the
`sp_layout.json` file. The SPs in the FIP image are also generated from
`sp_layout.json`, so this ensures that there is only one source of truth
for the SP list, removing the possibility to have the lists disagree
with each other.

Signed-off-by: Karl Meakin <karl.meakin@arm.com>
Change-Id: I7d76715135c596605c6a02aad5196d967dfeb1ce
diff --git a/Makefile b/Makefile
index 4b96be1..46b712e 100644
--- a/Makefile
+++ b/Makefile
@@ -139,6 +139,7 @@
 SPTOOLPATH		?=	tools/sptool
 SPTOOL			?=	${SPTOOLPATH}/sptool.py
 SP_MK_GEN		?=	${SPTOOLPATH}/sp_mk_generator.py
+SP_DTS_LIST_FRAGMENT	?=	${BUILD_PLAT}/sp_list_fragment.dts
 
 # Variables for use with ROMLIB
 ROMLIBPATH		?=	lib/romlib
@@ -1542,8 +1543,8 @@
 
 # Add Secure Partition packages
 ifeq (${NEED_SP_PKG},yes)
-$(BUILD_PLAT)/sp_gen.mk: ${SP_MK_GEN} ${SP_LAYOUT_FILE} | ${BUILD_PLAT}
-	${Q}${PYTHON} "$<" "$@" $(filter-out $<,$^) $(BUILD_PLAT) ${COT}
+$(BUILD_PLAT)/sp_gen.mk : ${SP_MK_GEN} ${SP_LAYOUT_FILE} | ${BUILD_PLAT}
+	${PYTHON} "$<" "$@" $(filter-out $<,$^) $(BUILD_PLAT) ${COT} ${SP_DTS_LIST_FRAGMENT}
 sp: $(DTBS) $(BUILD_PLAT)/sp_gen.mk $(SP_PKGS)
 	@${ECHO_BLANK_LINE}
 	@echo "Built SP Images successfully"
diff --git a/tools/sptool/sp_mk_generator.py b/tools/sptool/sp_mk_generator.py
index 4067331..c69e0a7 100644
--- a/tools/sptool/sp_mk_generator.py
+++ b/tools/sptool/sp_mk_generator.py
@@ -1,5 +1,5 @@
 #!/usr/bin/python3
-# Copyright (c) 2020-2022, Arm Limited. All rights reserved.
+# Copyright (c) 2020-2023, Arm Limited. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
@@ -21,6 +21,7 @@
 param2: "SP_LAYOUT_FILE", json file containing platform provided information
 param3: plat out directory
 param4: CoT parameter
+param5: Generated dts file "sp_list_fragment.dts"
 
 Generated "sp_gen.mk" file contains triplet of following information for each
 Secure Partition entry
@@ -112,6 +113,34 @@
     ''' Helper to fetch pm offset from sp_layout.json '''
     return get_offset_from_layout(node["pm"])
 
+def get_uuid(sp_layout, sp, args :dict):
+    ''' Helper to fetch uuid from pm file listed in sp_layout.json'''
+    if "uuid" in sp_layout[sp]:
+        # Extract the UUID from the JSON file if the SP entry has a 'uuid' field
+        uuid_std = uuid.UUID(sp_layout[sp]['uuid'])
+    else:
+        with open(get_sp_manifest_full_path(sp_layout[sp], args), "r") as pm_f:
+            uuid_lines = [l for l in pm_f if 'uuid' in l]
+        assert(len(uuid_lines) == 1)
+        # The uuid field in SP manifest is the little endian representation
+        # mapped to arguments as described in SMCCC section 5.3.
+        # Convert each unsigned integer value to a big endian representation
+        # required by fiptool.
+        uuid_parsed = re.findall("0x([0-9a-f]+)", uuid_lines[0])
+        y = list(map(bytearray.fromhex, uuid_parsed))
+        z = [int.from_bytes(i, byteorder='little', signed=False) for i in y]
+        uuid_std = uuid.UUID(f'{z[0]:08x}{z[1]:08x}{z[2]:08x}{z[3]:08x}')
+    return uuid_std
+
+def get_load_address(sp_layout, sp, args :dict):
+    ''' Helper to fetch load-address from pm file listed in sp_layout.json'''
+    with open(get_sp_manifest_full_path(sp_layout[sp], args), "r") as pm_f:
+        load_address_lines = [l for l in pm_f if 'load-address' in l]
+    assert(len(load_address_lines) == 1)
+    load_address_parsed = re.search("(0x[0-9a-f]+)", load_address_lines[0])
+    return load_address_parsed.group(0)
+
+
 @SpSetupActions.sp_action(global_action=True)
 def check_max_sps(sp_layout, _, args :dict):
     ''' Check validate the maximum number of SPs is respected. '''
@@ -195,37 +224,53 @@
 @SpSetupActions.sp_action
 def gen_fiptool_args(sp_layout, sp, args :dict):
     ''' Generate arguments for the FIP Tool. '''
-    if "uuid" in sp_layout[sp]:
-        # Extract the UUID from the JSON file if the SP entry has a 'uuid' field
-        uuid_std = uuid.UUID(sp_layout[sp]['uuid'])
-    else:
-        with open(get_sp_manifest_full_path(sp_layout[sp], args), "r") as pm_f:
-            uuid_lines = [l for l in pm_f if 'uuid' in l]
-        assert(len(uuid_lines) == 1)
-        # The uuid field in SP manifest is the little endian representation
-        # mapped to arguments as described in SMCCC section 5.3.
-        # Convert each unsigned integer value to a big endian representation
-        # required by fiptool.
-        uuid_parsed = re.findall("0x([0-9a-f]+)", uuid_lines[0])
-        y = list(map(bytearray.fromhex, uuid_parsed))
-        z = [int.from_bytes(i, byteorder='little', signed=False) for i in y]
-        uuid_std = uuid.UUID(f'{z[0]:08x}{z[1]:08x}{z[2]:08x}{z[3]:08x}')
+    uuid_std = get_uuid(sp_layout, sp, args)
     write_to_sp_mk_gen(f"FIP_ARGS += --blob uuid={str(uuid_std)},file={get_sp_pkg(sp, args)}\n", args)
     return args
 
+@SpSetupActions.sp_action
+def gen_fconf_fragment(sp_layout, sp, args: dict):
+    ''' Generate the fconf fragment file'''
+    with open(args["fconf_fragment"], "a") as f:
+        uuid = get_uuid(sp_layout, sp, args)
+        owner = "Plat" if sp_layout[sp].get("owner") == "Plat" else "SiP"
+
+        if "physical-load-address" in sp_layout[sp].keys():
+            load_address = sp_layout[sp]["physical-load-address"]
+        else:
+            load_address = get_load_address(sp_layout, sp, args)
+
+        f.write(
+f'''\
+{sp} {{
+    uuid = "{uuid}";
+    load-address = <{load_address}>;
+    owner = "{owner}";
+}};
+
+''')
+    return args
+
 def init_sp_actions(sys):
-    sp_layout_file = os.path.abspath(sys.argv[2])
-    with open(sp_layout_file) as json_file:
-        sp_layout = json.load(json_file)
     # Initialize arguments for the SP actions framework
     args = {}
     args["sp_gen_mk"] = os.path.abspath(sys.argv[1])
+    sp_layout_file = os.path.abspath(sys.argv[2])
     args["sp_layout_dir"] = os.path.dirname(sp_layout_file)
     args["out_dir"] = os.path.abspath(sys.argv[3])
     args["dualroot"] = sys.argv[4] == "dualroot"
+    args["fconf_fragment"] = os.path.abspath(sys.argv[5])
+
+
+    with open(sp_layout_file) as json_file:
+        sp_layout = json.load(json_file)
     #Clear content of file "sp_gen.mk".
     with open(args["sp_gen_mk"], "w"):
         None
+    #Clear content of file "fconf_fragment".
+    with open(args["fconf_fragment"], "w"):
+        None
+
     return args, sp_layout
 
 if __name__ == "__main__":