From ac32f33d19f8997dd81b55bc5e5dc62fb840cf06 Mon Sep 17 00:00:00 2001
From: Svante Karlsson <svante.karlsson@csi.se>
Date: Tue, 12 Aug 2025 11:03:11 +0200
Subject: [PATCH 1/5] initial arm64 support from prebuilt toolchain

---
 ARM64_USAGE.md                             |  57 ++++++++++
 FORK_USAGE.md                              |  85 +++++++++++++++
 extentions/gcc.bzl                         | 118 +++++++++++++++++----
 platforms/BUILD                            |   9 ++
 rules/gcc.bzl                              |  15 +++
 test/.bazelrc                              |   9 ++
 test/BUILD                                 |   1 +
 test/MODULE.bazel                          |  45 ++++++--
 toolchain/internal/cc_toolchain_config.bzl |  29 ++---
 toolchain/internal/toolchain.BUILD         |   4 +-
 toolchain/third_party/gcc.BUILD.tpl        |  54 ++++++++++
 11 files changed, 381 insertions(+), 45 deletions(-)
 create mode 100644 ARM64_USAGE.md
 create mode 100644 FORK_USAGE.md
 create mode 100644 toolchain/third_party/gcc.BUILD.tpl

diff --git a/ARM64_USAGE.md b/ARM64_USAGE.md
new file mode 100644
index 0000000..7180e19
--- /dev/null
+++ b/ARM64_USAGE.md
@@ -0,0 +1,57 @@
+# ARM64 Support for SCORE Toolchains GCC
+
+## Using ARM64 Toolchain
+
+### In your MODULE.bazel:
+
+```python
+bazel_dep(name = "score_toolchains_gcc", version = "0.5")
+
+gcc = use_extension("@score_toolchains_gcc//extentions:gcc.bzl", "gcc")
+# Default toolchains for x86_64 and aarch64 are automatically configured
+
+use_repo(gcc, "gcc_toolchain_x86_64", "gcc_toolchain_aarch64")
+register_toolchains(
+    "@gcc_toolchain_x86_64//:host_gcc_12",
+    "@gcc_toolchain_aarch64//:host_gcc_12",
+)
+```
+
+### Building for ARM64:
+
+Add to your project's `.bazelrc`:
+```
+# ARM64 build configuration
+build:arm64 --platforms=@score_toolchains_gcc//platforms:aarch64-linux
+build:aarch64 --platforms=@score_toolchains_gcc//platforms:aarch64-linux
+```
+
+Then build with:
+```bash
+# Using the config
+bazel build --config=arm64 //your:target
+# or
+bazel build --config=aarch64 //your:target
+
+# Direct platform specification (without .bazelrc)
+bazel build --platforms=@score_toolchains_gcc//platforms:aarch64-linux //your:target
+```
+
+## Cross-compilation vs Native Compilation
+
+- **Cross-compilation** (x86_64 host → ARM64 target):
+  ```python
+  target_arch = "aarch64",
+  exec_arch = "x86_64",
+  ```
+
+- **Native compilation** (ARM64 host → ARM64 target):
+  ```python
+  target_arch = "aarch64",
+  exec_arch = "aarch64",
+  ```
+
+
+## Example
+
+See the `test/` directory for a complete working example that supports both x86_64 and ARM64 builds.
\ No newline at end of file
diff --git a/FORK_USAGE.md b/FORK_USAGE.md
new file mode 100644
index 0000000..0b06f17
--- /dev/null
+++ b/FORK_USAGE.md
@@ -0,0 +1,85 @@
+# Using the ARM64-enabled Fork
+
+This fork includes:
+- ARM64 (aarch64) platform support
+- Default toolchains pointing to `skarlsson/toolchains_gcc_packages` v0.0.2-pr3
+- Both x86_64 and aarch64 GCC 12 toolchains
+
+Until these changes are merged into the official SCORE toolchains_gcc, you can use this fork locally.
+
+## Step 1: Clone the fork and checkout the ARM64 branch
+
+```bash
+# As a submodule
+git submodule add -b arm64-from-prebuilt https://github.com/skarlsson/toolchains_gcc.git
+
+# Or clone directly
+git clone -b arm64-from-prebuilt https://github.com/skarlsson/toolchains_gcc.git
+```
+
+## Step 2: Configure MODULE.bazel
+
+```python
+module(
+    name = "your_project",
+    version = "0.0.1",
+)
+
+# Declare dependency on the version this fork is based on
+bazel_dep(name = "score_toolchains_gcc", version = "0.5")
+
+# Override with the local fork (e.g., cloned as submodule)
+local_path_override(
+    module_name = "score_toolchains_gcc",
+    path = "path/to/toolchains_gcc",  # Adjust path to where you cloned the fork
+)
+
+# Use the extension - default toolchains are automatically configured
+gcc = use_extension("@score_toolchains_gcc//extentions:gcc.bzl", "gcc")
+
+# Optional: Configure warning flags and features (see test/MODULE.bazel for examples)
+# gcc.warning_flags(...)
+# gcc.extra_features(...)
+
+use_repo(gcc, "gcc_toolchain_x86_64", "gcc_toolchain_aarch64")
+
+# Register toolchains
+register_toolchains(
+    "@gcc_toolchain_x86_64//:host_gcc_12",
+    "@gcc_toolchain_aarch64//:host_gcc_12",
+)
+```
+
+## Step 3: Configure .bazelrc
+
+Add to your project's `.bazelrc`:
+
+```bash
+# ARM64/AArch64 build configurations
+build:arm64 --platforms=@score_toolchains_gcc//platforms:aarch64-linux
+build:aarch64 --platforms=@score_toolchains_gcc//platforms:aarch64-linux
+
+# Optional: explicit x86_64 configuration
+build:x86_64 --platforms=@score_toolchains_gcc//platforms:x86_64-linux
+```
+
+## Step 4: Build
+
+```bash
+# For ARM64
+bazel build --config=arm64 //your:target
+# or
+bazel build --config=aarch64 //your:target
+
+# For x86_64 (default)
+bazel build //your:target
+# or explicitly
+bazel build --config=x86_64 //your:target
+```
+
+## Switching back to official release
+
+Once ARM64 support is merged and published, simply:
+1. Remove the `archive_override` block
+2. Update the version in `bazel_dep` to the new release
+3. Keep your .bazelrc configurations - they'll continue to work!
\ No newline at end of file
diff --git a/extentions/gcc.bzl b/extentions/gcc.bzl
index 9051096..8429e61 100644
--- a/extentions/gcc.bzl
+++ b/extentions/gcc.bzl
@@ -21,49 +21,125 @@ def _gcc_impl(mctx):
         if not mod.is_root:
             fail("Only the root module can use the 'gcc' extension")
 
-    toolchain_info = None
-    features = []
-    warning_flags = None
+    toolchains = []
+    features_by_name = {}
+    warning_flags_by_name = {}
 
     for mod in mctx.modules:
         for tag in mod.tags.toolchain:
-            toolchain_info = {
+            toolchains.append({
                 "name": tag.name,
                 "url": tag.url,
                 "strip_prefix": tag.strip_prefix,
                 "sha256": tag.sha256,
-            }
+                "target_arch": tag.target_arch,
+                "exec_arch": tag.exec_arch,
+            })
 
         for tag in mod.tags.extra_features:
+            name = tag.name
+            if name not in features_by_name:
+                features_by_name[name] = []
             for feature in tag.features:
-                features.append(feature)
+                features_by_name[name].append(feature)
 
         for tag in mod.tags.warning_flags:
-            warning_flags = {
-                "minimal_warnings":tag.minimal_warnings,
-                "strict_warnings":tag.strict_warnings,
-                "treat_warnings_as_errors":tag.treat_warnings_as_errors
+            name = tag.name
+            warning_flags_by_name[name] = {
+                "minimal_warnings": tag.minimal_warnings,
+                "strict_warnings": tag.strict_warnings,
+                "treat_warnings_as_errors": tag.treat_warnings_as_errors
             }
 
-    if toolchain_info:
+    # If no toolchains specified, use defaults
+    if not toolchains:
+        # Default toolchains from skarlsson/toolchains_gcc_packages
+        toolchains = [
+            {
+                "name": "gcc_toolchain_x86_64",
+                "url": "https://github.com/skarlsson/toolchains_gcc_packages/releases/download/v0.0.2-pr3/x86_64-unknown-linux-gnu_gcc12.tar.gz",
+                "sha256": "ede0289c89a633f6f0b7fa5079a1fbc912e9a8607d01a792e3d78f4939d4e96a",
+                "strip_prefix": "x86_64-unknown-linux-gnu",
+                "target_arch": "x86_64",
+                "exec_arch": "x86_64",
+            },
+            {
+                "name": "gcc_toolchain_aarch64",
+                "url": "https://github.com/skarlsson/toolchains_gcc_packages/releases/download/v0.0.2-pr3/aarch64-unknown-linux-gnu_gcc12.tar.gz",
+                "sha256": "cd9fcac29bea3dd7e52724166491a10e152f58188c9f25568e6f50b6c38f6dc3",
+                "strip_prefix": "aarch64-unknown-linux-gnu",
+                "target_arch": "aarch64",
+                "exec_arch": "x86_64",
+            },
+        ]
+
+    for toolchain_info in toolchains:
+        name = toolchain_info["name"]
+        target_arch = toolchain_info["target_arch"]
+        
+        # Determine target triple based on architecture
+        target_triple = "%s-unknown-linux-gnu" % target_arch
+        
         http_archive(
-            name = "%s_gcc" % toolchain_info["name"],
+            name = "%s_gcc" % name,
             urls = [toolchain_info["url"]],
-            build_file = "@score_toolchains_gcc//toolchain/third_party:gcc.BUILD",
+            build_file_content = """
+# Generated BUILD file for gcc toolchain
+package(default_visibility = ["//visibility:public"])
+
+filegroup(
+    name = "all_files",
+    srcs = glob(["*/**/*"]),
+)
+
+filegroup(
+    name = "bin",
+    srcs = ["bin"],
+)
+
+filegroup(
+    name = "ar",
+    srcs = ["bin/{triple}-ar"],
+)
+
+filegroup(
+    name = "gcc",
+    srcs = ["bin/{triple}-gcc"],
+)
+
+filegroup(
+    name = "gcov",
+    srcs = ["bin/{triple}-gcov"],
+)
+
+filegroup(
+    name = "gpp",
+    srcs = ["bin/{triple}-g++"],
+)
+
+filegroup(
+    name = "strip",
+    srcs = ["bin/{triple}-strip"],
+)
+
+filegroup(
+    name = "sysroot_dir",
+    srcs = ["{triple}/sysroot"],
+)
+""".format(triple = target_triple),
             sha256 = toolchain_info["sha256"],
             strip_prefix = toolchain_info["strip_prefix"],
         )
 
         gcc_toolchain(
-            name = toolchain_info["name"],
-            gcc_repo = "%s_gcc" % toolchain_info["name"],
-            extra_features = features,
-            warning_flags = warning_flags,
+            name = name,
+            gcc_repo = "%s_gcc" % name,
+            extra_features = features_by_name.get(name, []),
+            warning_flags = warning_flags_by_name.get(name, None),
+            target_arch = toolchain_info["target_arch"],
+            exec_arch = toolchain_info["exec_arch"],
         )
 
-    else:
-        fail("Cannot create gcc toolchain repository, some info is missing!")
-
 gcc = module_extension(
     implementation = _gcc_impl,
     tag_classes = {
@@ -73,6 +149,8 @@ gcc = module_extension(
                 "url": attr.string(doc = "Url to the toolchain package."),
                 "strip_prefix": attr.string(doc = "Strip prefix from toolchain package.", default=""),
                 "sha256": attr.string(doc = "Checksum of the package"),
+                "target_arch": attr.string(doc = "Target architecture (x86_64 or aarch64)", default="x86_64"),
+                "exec_arch": attr.string(doc = "Execution architecture (x86_64 or aarch64)", default="x86_64"),
             },
         ),
         "warning_flags": tag_class(
diff --git a/platforms/BUILD b/platforms/BUILD
index f8803bb..59859c4 100644
--- a/platforms/BUILD
+++ b/platforms/BUILD
@@ -19,3 +19,12 @@ platform(
     ],
     visibility = ["//visibility:public"],
 )
+
+platform(
+    name = "aarch64-linux",
+    constraint_values = [
+        "@platforms//cpu:aarch64",
+        "@platforms//os:linux",
+    ],
+    visibility = ["//visibility:public"],
+)
diff --git a/rules/gcc.bzl b/rules/gcc.bzl
index 224aa53..41a069e 100644
--- a/rules/gcc.bzl
+++ b/rules/gcc.bzl
@@ -37,12 +37,23 @@ def _impl(rctx):
         rctx (repository_ctx): The Bazel repository context, providing access to attributes
             and methods for creating repository rules.
     """
+    # Map architecture names to platform CPU values
+    arch_map = {
+        "x86_64": "x86_64",
+        "aarch64": "aarch64",
+    }
+    
+    # Determine target system name based on architecture
+    target_system = "%s-linux" % rctx.attr.target_arch
+    
     rctx.template(
         "BUILD",
         rctx.attr._cc_tolchain_build,
         {
             "%{gcc_repo}": rctx.attr.gcc_repo,
             "%{tc_name}": "host_gcc_12",
+            "%{exec_cpu}": arch_map.get(rctx.attr.exec_arch, "x86_64"),
+            "%{target_cpu}": arch_map.get(rctx.attr.target_arch, "x86_64"),
         },
     )
     minimal_warnings = "[]"
@@ -73,6 +84,8 @@ def _impl(rctx):
             "%{treat_warnings_as_errors_switch}": "True" if "treat_warnings_as_errors" in rctx.attr.extra_features else "False",
             "%{third_party_warnings_flags}": third_party_warnings,
             "%{third_party_warnings_switch}": "True" if "third_party_warnings" in rctx.attr.extra_features else "False",
+            "%{target_cpu}": rctx.attr.target_arch,
+            "%{target_system}": target_system,
         },
     )
 
@@ -82,6 +95,8 @@ gcc_toolchain = repository_rule(
         "gcc_repo": attr.string(doc="The URL of the GCC binary package."),
         "extra_features": attr.string_list(doc="A list of extra features to enable in the toolchain."),
         "warning_flags": attr.string_list_dict(doc="A dictionary mapping warning categories to lists of warning flags."),
+        "target_arch": attr.string(default="x86_64", doc="Target architecture (x86_64 or aarch64)."),
+        "exec_arch": attr.string(default="x86_64", doc="Execution architecture (x86_64 or aarch64)."),
         "_cc_toolchain_config_bzl": attr.label(
             default = "@score_toolchains_gcc//toolchain/internal:cc_toolchain_config.bzl",
             doc = "Path to the cc_toolchain_config.bzl template file.",
diff --git a/test/.bazelrc b/test/.bazelrc
index 126f7c3..2fb7978 100644
--- a/test/.bazelrc
+++ b/test/.bazelrc
@@ -17,3 +17,12 @@ common --registry=https://bcr.bazel.build
 build:x86_64-linux --incompatible_strict_action_env
 build:x86_64-linux --platforms=@score_toolchains_gcc//platforms:x86_64-linux
 build:x86_64-linux --sandbox_writable_path=/var/tmp
+
+# ARM64/AArch64 configurations
+build:arm64 --incompatible_strict_action_env
+build:arm64 --platforms=@score_toolchains_gcc//platforms:aarch64-linux
+build:arm64 --sandbox_writable_path=/var/tmp
+
+build:aarch64 --incompatible_strict_action_env
+build:aarch64 --platforms=@score_toolchains_gcc//platforms:aarch64-linux
+build:aarch64 --sandbox_writable_path=/var/tmp
diff --git a/test/BUILD b/test/BUILD
index 63402bb..54af413 100644
--- a/test/BUILD
+++ b/test/BUILD
@@ -19,4 +19,5 @@ cc_binary(
 cc_binary(
     name = "main_pthread_cpp",
     srcs = ["main_pthread.cpp"],
+    features = ["use_pthread"],
 )
diff --git a/test/MODULE.bazel b/test/MODULE.bazel
index 2da31e3..7e9b59e 100644
--- a/test/MODULE.bazel
+++ b/test/MODULE.bazel
@@ -24,21 +24,46 @@ local_path_override(
 )
 
 gcc = use_extension("@score_toolchains_gcc//extentions:gcc.bzl", "gcc")
-gcc.toolchain(
-    url = "https://github.com/eclipse-score/toolchains_gcc_packages/releases/download/0.0.1/x86_64-unknown-linux-gnu_gcc12.tar.gz",
-    sha256 = "457f5f20f57528033cb840d708b507050d711ae93e009388847e113b11bf3600",
-    strip_prefix = "x86_64-unknown-linux-gnu",
+
+# Use default toolchains - no configuration needed!
+# The defaults already include x86_64 and aarch64 toolchains
+
+# Add warning flags for both toolchains
+gcc.warning_flags(
+    name = "gcc_toolchain_x86_64",
+    minimal_warnings = ["-Wall", "-Wno-error=deprecated-declarations"],
+    strict_warnings = ["-Wextra", "-Wpedantic"],
+    treat_warnings_as_errors = ["-Werror"],
+)
+
+gcc.warning_flags(
+    name = "gcc_toolchain_aarch64",
+    minimal_warnings = ["-Wall", "-Wno-error=deprecated-declarations"],
+    strict_warnings = ["-Wextra", "-Wpedantic"],
+    treat_warnings_as_errors = ["-Werror"],
+)
+
+# Enable extra features for both toolchains
+gcc.extra_features(
+    name = "gcc_toolchain_x86_64",
+    features = [
+        "minimal_warnings",
+        "treat_warnings_as_errors",
+    ],
 )
+
 gcc.extra_features(
+    name = "gcc_toolchain_aarch64",
     features = [
         "minimal_warnings",
         "treat_warnings_as_errors",
     ],
 )
-gcc.warning_flags(
-    minimal_warnings = ["-Wall", "-Wno-error=deprecated-declarations"],
-    strict_warnings = ["-Wextra", "-Wpedantic"],
-    treat_warnings_as_errors = ["-Werror"],
+
+use_repo(gcc, "gcc_toolchain_x86_64", "gcc_toolchain_aarch64")
+
+# Register both toolchains
+register_toolchains(
+    "@gcc_toolchain_x86_64//:host_gcc_12",
+    "@gcc_toolchain_aarch64//:host_gcc_12",
 )
-use_repo(gcc, "gcc_toolchain", "gcc_toolchain_gcc")
-register_toolchains("@gcc_toolchain//:host_gcc_12")
diff --git a/toolchain/internal/cc_toolchain_config.bzl b/toolchain/internal/cc_toolchain_config.bzl
index 3ded6c0..1b55b69 100644
--- a/toolchain/internal/cc_toolchain_config.bzl
+++ b/toolchain/internal/cc_toolchain_config.bzl
@@ -149,20 +149,23 @@ def _impl(ctx):
         ],
     )
 
+    # Architecture-specific compile flags
+    arch_flag_sets = []
+    if "%{target_cpu}" == "x86_64":
+        arch_flag_sets.append(flag_set(
+            actions = all_compile_actions,
+            flag_groups = [
+                flag_group(
+                    flags = ["-m64"],
+                ),
+            ],
+        ))
+    # For aarch64, no specific architecture flag is needed
+    
     default_compile_flags_feature = feature(
         name = "default_compile_flags",
         enabled = True,
-        flag_sets = [
-            flag_set(
-                actions = all_compile_actions,
-                flag_groups = [
-                    flag_group(
-                        flags = [
-                            "-m64",
-                        ],
-                    ),
-                ],
-            ),
+        flag_sets = arch_flag_sets + [
             flag_set(
                 actions = all_cpp_compile_actions,
                 flag_groups = [
@@ -383,8 +386,8 @@ def _impl(ctx):
         features =  features,
         action_configs = action_configs,
         host_system_name = "local",
-        target_system_name = "x86_64-linux",
-        target_cpu = "x86_64",
+        target_system_name = "%{target_system}",
+        target_cpu = "%{target_cpu}",
         target_libc = "unknown",
         toolchain_identifier = toolchain_full_name,
         tool_paths = tool_paths,
diff --git a/toolchain/internal/toolchain.BUILD b/toolchain/internal/toolchain.BUILD
index b873303..b76cf2d 100644
--- a/toolchain/internal/toolchain.BUILD
+++ b/toolchain/internal/toolchain.BUILD
@@ -48,11 +48,11 @@ cc_toolchain(
 toolchain(
     name = "%{tc_name}",
     exec_compatible_with = [
-        "@platforms//cpu:x86_64",
+        "@platforms//cpu:%{exec_cpu}",
         "@platforms//os:linux",
     ],
     target_compatible_with = [
-        "@platforms//cpu:x86_64",
+        "@platforms//cpu:%{target_cpu}",
         "@platforms//os:linux",
     ],
     toolchain = ":cc_toolchain",
diff --git a/toolchain/third_party/gcc.BUILD.tpl b/toolchain/third_party/gcc.BUILD.tpl
new file mode 100644
index 0000000..5d64eb3
--- /dev/null
+++ b/toolchain/third_party/gcc.BUILD.tpl
@@ -0,0 +1,54 @@
+# *******************************************************************************
+# Copyright (c) 2025 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# This program and the accompanying materials are made available under the
+# terms of the Apache License Version 2.0 which is available at
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# SPDX-License-Identifier: Apache-2.0
+# *******************************************************************************
+
+package(default_visibility = ["//visibility:public"])
+
+filegroup(
+    name = "all_files",
+    srcs = glob(["*/**/*"]),
+)
+
+filegroup(
+    name = "bin",
+    srcs = ["bin"],
+)
+
+filegroup(
+    name = "ar",
+    srcs = ["bin/%{target_triple}-ar"],
+)
+
+filegroup(
+    name = "gcc",
+    srcs = ["bin/%{target_triple}-gcc"],
+)
+
+filegroup(
+    name = "gcov",
+    srcs = ["bin/%{target_triple}-gcov"],
+)
+
+filegroup(
+    name = "gpp",
+    srcs = ["bin/%{target_triple}-g++"],
+)
+
+filegroup(
+    name = "strip",
+    srcs = ["bin/%{target_triple}-strip"],
+)
+
+filegroup(
+    name = "sysroot_dir",
+    srcs = ["%{target_triple}/sysroot"],
+)
\ No newline at end of file

From 1ac2ff1ce09da8c673694e32169941981018c21f Mon Sep 17 00:00:00 2001
From: Svante Karlsson <svante.karlsson@csi.se>
Date: Thu, 11 Sep 2025 08:36:33 +0200
Subject: [PATCH 2/5] point to official release

---
 extentions/gcc.bzl | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/extentions/gcc.bzl b/extentions/gcc.bzl
index 8429e61..a2ef3f1 100644
--- a/extentions/gcc.bzl
+++ b/extentions/gcc.bzl
@@ -53,20 +53,19 @@ def _gcc_impl(mctx):
 
     # If no toolchains specified, use defaults
     if not toolchains:
-        # Default toolchains from skarlsson/toolchains_gcc_packages
         toolchains = [
             {
                 "name": "gcc_toolchain_x86_64",
-                "url": "https://github.com/skarlsson/toolchains_gcc_packages/releases/download/v0.0.2-pr3/x86_64-unknown-linux-gnu_gcc12.tar.gz",
-                "sha256": "ede0289c89a633f6f0b7fa5079a1fbc912e9a8607d01a792e3d78f4939d4e96a",
+                "url": "https://github.com/eclipse-score/toolchains_gcc_packages/releases/download/v0.0.3/x86_64-unknown-linux-gnu_gcc12.tar.gz",
+                "sha256": "8fa85c2a93a6bef1cf866fa658495a2416dfeec692e4246063b791abf18da083",
                 "strip_prefix": "x86_64-unknown-linux-gnu",
                 "target_arch": "x86_64",
                 "exec_arch": "x86_64",
             },
             {
                 "name": "gcc_toolchain_aarch64",
-                "url": "https://github.com/skarlsson/toolchains_gcc_packages/releases/download/v0.0.2-pr3/aarch64-unknown-linux-gnu_gcc12.tar.gz",
-                "sha256": "cd9fcac29bea3dd7e52724166491a10e152f58188c9f25568e6f50b6c38f6dc3",
+                "url": "https://github.com/eclipse-score/toolchains_gcc_packages/releases/download/v0.0.3/aarch64-unknown-linux-gnu_gcc12.tar.gz",
+                "sha256": "57153340625581b199408391b895c84651382d3edd4c60fadbf0399f9dad21e1",
                 "strip_prefix": "aarch64-unknown-linux-gnu",
                 "target_arch": "aarch64",
                 "exec_arch": "x86_64",

From ad5d4b8dec6379d8df1a54c3b094c887e0aba2b3 Mon Sep 17 00:00:00 2001
From: Svante Karlsson <svante.karlsson@csi.se>
Date: Thu, 11 Sep 2025 09:22:52 +0200
Subject: [PATCH 3/5] cleanup

---
 FORK_USAGE.md  | 85 --------------------------------------------------
 test/README.md |  7 +++++
 2 files changed, 7 insertions(+), 85 deletions(-)
 delete mode 100644 FORK_USAGE.md

diff --git a/FORK_USAGE.md b/FORK_USAGE.md
deleted file mode 100644
index 0b06f17..0000000
--- a/FORK_USAGE.md
+++ /dev/null
@@ -1,85 +0,0 @@
-# Using the ARM64-enabled Fork
-
-This fork includes:
-- ARM64 (aarch64) platform support
-- Default toolchains pointing to `skarlsson/toolchains_gcc_packages` v0.0.2-pr3
-- Both x86_64 and aarch64 GCC 12 toolchains
-
-Until these changes are merged into the official SCORE toolchains_gcc, you can use this fork locally.
-
-## Step 1: Clone the fork and checkout the ARM64 branch
-
-```bash
-# As a submodule
-git submodule add -b arm64-from-prebuilt https://github.com/skarlsson/toolchains_gcc.git
-
-# Or clone directly
-git clone -b arm64-from-prebuilt https://github.com/skarlsson/toolchains_gcc.git
-```
-
-## Step 2: Configure MODULE.bazel
-
-```python
-module(
-    name = "your_project",
-    version = "0.0.1",
-)
-
-# Declare dependency on the version this fork is based on
-bazel_dep(name = "score_toolchains_gcc", version = "0.5")
-
-# Override with the local fork (e.g., cloned as submodule)
-local_path_override(
-    module_name = "score_toolchains_gcc",
-    path = "path/to/toolchains_gcc",  # Adjust path to where you cloned the fork
-)
-
-# Use the extension - default toolchains are automatically configured
-gcc = use_extension("@score_toolchains_gcc//extentions:gcc.bzl", "gcc")
-
-# Optional: Configure warning flags and features (see test/MODULE.bazel for examples)
-# gcc.warning_flags(...)
-# gcc.extra_features(...)
-
-use_repo(gcc, "gcc_toolchain_x86_64", "gcc_toolchain_aarch64")
-
-# Register toolchains
-register_toolchains(
-    "@gcc_toolchain_x86_64//:host_gcc_12",
-    "@gcc_toolchain_aarch64//:host_gcc_12",
-)
-```
-
-## Step 3: Configure .bazelrc
-
-Add to your project's `.bazelrc`:
-
-```bash
-# ARM64/AArch64 build configurations
-build:arm64 --platforms=@score_toolchains_gcc//platforms:aarch64-linux
-build:aarch64 --platforms=@score_toolchains_gcc//platforms:aarch64-linux
-
-# Optional: explicit x86_64 configuration
-build:x86_64 --platforms=@score_toolchains_gcc//platforms:x86_64-linux
-```
-
-## Step 4: Build
-
-```bash
-# For ARM64
-bazel build --config=arm64 //your:target
-# or
-bazel build --config=aarch64 //your:target
-
-# For x86_64 (default)
-bazel build //your:target
-# or explicitly
-bazel build --config=x86_64 //your:target
-```
-
-## Switching back to official release
-
-Once ARM64 support is merged and published, simply:
-1. Remove the `archive_override` block
-2. Update the version in `bazel_dep` to the new release
-3. Keep your .bazelrc configurations - they'll continue to work!
\ No newline at end of file
diff --git a/test/README.md b/test/README.md
index 285865c..eb0cae3 100644
--- a/test/README.md
+++ b/test/README.md
@@ -6,6 +6,13 @@
 bazel build //:main_cpp
 ```
 
+### Building code arm64 gcc toolchain
+```bash
+bazel build --config=arm64 //:main_cpp
+#or 
+bazel build --config=aarch64 //:main_cpp
+```
+
 ### Building code with host gcc toolchain and enabled pthread
 
 ```bash

From 9431de7071f75bc52ea470e54a53810dd673fdf5 Mon Sep 17 00:00:00 2001
From: Svante Karlsson <svante.karlsson@csi.se>
Date: Thu, 11 Sep 2025 09:36:01 +0200
Subject: [PATCH 4/5] cleanup

---
 ARM64_USAGE.md | 25 ++++---------------------
 1 file changed, 4 insertions(+), 21 deletions(-)

diff --git a/ARM64_USAGE.md b/ARM64_USAGE.md
index 7180e19..477a72c 100644
--- a/ARM64_USAGE.md
+++ b/ARM64_USAGE.md
@@ -1,11 +1,9 @@
-# ARM64 Support for SCORE Toolchains GCC
-
-## Using ARM64 Toolchain
+## Using aarch64/arm64 toolchain
 
 ### In your MODULE.bazel:
 
 ```python
-bazel_dep(name = "score_toolchains_gcc", version = "0.5")
+bazel_dep(name = "score_toolchains_gcc", version = "0.0.7")
 
 gcc = use_extension("@score_toolchains_gcc//extentions:gcc.bzl", "gcc")
 # Default toolchains for x86_64 and aarch64 are automatically configured
@@ -17,7 +15,7 @@ register_toolchains(
 )
 ```
 
-### Building for ARM64:
+### Building for arm64:
 
 Add to your project's `.bazelrc`:
 ```
@@ -37,21 +35,6 @@ bazel build --config=aarch64 //your:target
 bazel build --platforms=@score_toolchains_gcc//platforms:aarch64-linux //your:target
 ```
 
-## Cross-compilation vs Native Compilation
-
-- **Cross-compilation** (x86_64 host → ARM64 target):
-  ```python
-  target_arch = "aarch64",
-  exec_arch = "x86_64",
-  ```
-
-- **Native compilation** (ARM64 host → ARM64 target):
-  ```python
-  target_arch = "aarch64",
-  exec_arch = "aarch64",
-  ```
-
-
 ## Example
 
-See the `test/` directory for a complete working example that supports both x86_64 and ARM64 builds.
\ No newline at end of file
+See the `test/` directory for a complete working example that supports both x86_64 and aarch64 builds.

From 1b04c71ba145f35b3866ec9e214b1bfe399a7142 Mon Sep 17 00:00:00 2001
From: Svante Karlsson <svante.karlsson@csi.se>
Date: Thu, 11 Sep 2025 16:21:31 +0200
Subject: [PATCH 5/5] Removed redundant arch_map - The mapping was 1:1 and
 served no purpose Added build_file override capability - Allows custom BUILD
 files for non-standard GCC structures Removed unused template files - Cleaned
 up the toolchain/third_party directory

---
 extentions/gcc.bzl                  | 29 ++++++++++++----
 rules/gcc.bzl                       | 10 ++----
 toolchain/third_party/BUILD         | 16 ---------
 toolchain/third_party/gcc.BUILD     | 54 -----------------------------
 toolchain/third_party/gcc.BUILD.tpl | 54 -----------------------------
 5 files changed, 24 insertions(+), 139 deletions(-)
 delete mode 100644 toolchain/third_party/BUILD
 delete mode 100644 toolchain/third_party/gcc.BUILD
 delete mode 100644 toolchain/third_party/gcc.BUILD.tpl

diff --git a/extentions/gcc.bzl b/extentions/gcc.bzl
index a2ef3f1..ddc1375 100644
--- a/extentions/gcc.bzl
+++ b/extentions/gcc.bzl
@@ -34,6 +34,7 @@ def _gcc_impl(mctx):
                 "sha256": tag.sha256,
                 "target_arch": tag.target_arch,
                 "exec_arch": tag.exec_arch,
+                "build_file": tag.build_file,
             })
 
         for tag in mod.tags.extra_features:
@@ -61,6 +62,7 @@ def _gcc_impl(mctx):
                 "strip_prefix": "x86_64-unknown-linux-gnu",
                 "target_arch": "x86_64",
                 "exec_arch": "x86_64",
+                "build_file": None,
             },
             {
                 "name": "gcc_toolchain_aarch64",
@@ -69,6 +71,7 @@ def _gcc_impl(mctx):
                 "strip_prefix": "aarch64-unknown-linux-gnu",
                 "target_arch": "aarch64",
                 "exec_arch": "x86_64",
+                "build_file": None,
             },
         ]
 
@@ -79,10 +82,21 @@ def _gcc_impl(mctx):
         # Determine target triple based on architecture
         target_triple = "%s-unknown-linux-gnu" % target_arch
         
-        http_archive(
-            name = "%s_gcc" % name,
-            urls = [toolchain_info["url"]],
-            build_file_content = """
+        if toolchain_info.get("build_file"):
+            # Use custom build_file if provided
+            http_archive(
+                name = "%s_gcc" % name,
+                urls = [toolchain_info["url"]],
+                build_file = toolchain_info["build_file"],
+                sha256 = toolchain_info["sha256"],
+                strip_prefix = toolchain_info["strip_prefix"],
+            )
+        else:
+            # Use default BUILD file content
+            http_archive(
+                name = "%s_gcc" % name,
+                urls = [toolchain_info["url"]],
+                build_file_content = """
 # Generated BUILD file for gcc toolchain
 package(default_visibility = ["//visibility:public"])
 
@@ -126,9 +140,9 @@ filegroup(
     srcs = ["{triple}/sysroot"],
 )
 """.format(triple = target_triple),
-            sha256 = toolchain_info["sha256"],
-            strip_prefix = toolchain_info["strip_prefix"],
-        )
+                sha256 = toolchain_info["sha256"],
+                strip_prefix = toolchain_info["strip_prefix"],
+            )
 
         gcc_toolchain(
             name = name,
@@ -150,6 +164,7 @@ gcc = module_extension(
                 "sha256": attr.string(doc = "Checksum of the package"),
                 "target_arch": attr.string(doc = "Target architecture (x86_64 or aarch64)", default="x86_64"),
                 "exec_arch": attr.string(doc = "Execution architecture (x86_64 or aarch64)", default="x86_64"),
+                "build_file": attr.label(doc = "Label of custom BUILD file for the toolchain. If not provided, uses default generated content.", mandatory=False),
             },
         ),
         "warning_flags": tag_class(
diff --git a/rules/gcc.bzl b/rules/gcc.bzl
index 41a069e..22fd64f 100644
--- a/rules/gcc.bzl
+++ b/rules/gcc.bzl
@@ -37,12 +37,6 @@ def _impl(rctx):
         rctx (repository_ctx): The Bazel repository context, providing access to attributes
             and methods for creating repository rules.
     """
-    # Map architecture names to platform CPU values
-    arch_map = {
-        "x86_64": "x86_64",
-        "aarch64": "aarch64",
-    }
-    
     # Determine target system name based on architecture
     target_system = "%s-linux" % rctx.attr.target_arch
     
@@ -52,8 +46,8 @@ def _impl(rctx):
         {
             "%{gcc_repo}": rctx.attr.gcc_repo,
             "%{tc_name}": "host_gcc_12",
-            "%{exec_cpu}": arch_map.get(rctx.attr.exec_arch, "x86_64"),
-            "%{target_cpu}": arch_map.get(rctx.attr.target_arch, "x86_64"),
+            "%{exec_cpu}": rctx.attr.exec_arch,
+            "%{target_cpu}": rctx.attr.target_arch,
         },
     )
     minimal_warnings = "[]"
diff --git a/toolchain/third_party/BUILD b/toolchain/third_party/BUILD
deleted file mode 100644
index 6e19dcb..0000000
--- a/toolchain/third_party/BUILD
+++ /dev/null
@@ -1,16 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2025 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-
-exports_files([
-    "gcc.BUILD",
-])
diff --git a/toolchain/third_party/gcc.BUILD b/toolchain/third_party/gcc.BUILD
deleted file mode 100644
index a38799a..0000000
--- a/toolchain/third_party/gcc.BUILD
+++ /dev/null
@@ -1,54 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2025 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-
-package(default_visibility = ["//visibility:public"])
-
-filegroup(
-    name = "all_files",
-    srcs = glob(["*/**/*"]),
-)
-
-filegroup(
-    name = "bin",
-    srcs = ["bin"],
-)
-
-filegroup(
-    name = "ar",
-    srcs = ["bin/x86_64-unknown-linux-gnu-ar"],
-)
-
-filegroup(
-    name = "gcc",
-    srcs = ["bin/x86_64-unknown-linux-gnu-gcc"],
-)
-
-filegroup(
-    name = "gcov",
-    srcs = ["bin/x86_64-unknown-linux-gnu-gcov"],
-)
-
-filegroup(
-    name = "gpp",
-    srcs = ["bin/x86_64-unknown-linux-gnu-g++"],
-)
-
-filegroup(
-    name = "strip",
-    srcs = ["bin/x86_64-unknown-linux-gnu-strip"],
-)
-
-filegroup(
-    name = "sysroot_dir",
-    srcs = ["x86_64-unknown-linux-gnu/sysroot"],
-)
diff --git a/toolchain/third_party/gcc.BUILD.tpl b/toolchain/third_party/gcc.BUILD.tpl
deleted file mode 100644
index 5d64eb3..0000000
--- a/toolchain/third_party/gcc.BUILD.tpl
+++ /dev/null
@@ -1,54 +0,0 @@
-# *******************************************************************************
-# Copyright (c) 2025 Contributors to the Eclipse Foundation
-#
-# See the NOTICE file(s) distributed with this work for additional
-# information regarding copyright ownership.
-#
-# This program and the accompanying materials are made available under the
-# terms of the Apache License Version 2.0 which is available at
-# https://www.apache.org/licenses/LICENSE-2.0
-#
-# SPDX-License-Identifier: Apache-2.0
-# *******************************************************************************
-
-package(default_visibility = ["//visibility:public"])
-
-filegroup(
-    name = "all_files",
-    srcs = glob(["*/**/*"]),
-)
-
-filegroup(
-    name = "bin",
-    srcs = ["bin"],
-)
-
-filegroup(
-    name = "ar",
-    srcs = ["bin/%{target_triple}-ar"],
-)
-
-filegroup(
-    name = "gcc",
-    srcs = ["bin/%{target_triple}-gcc"],
-)
-
-filegroup(
-    name = "gcov",
-    srcs = ["bin/%{target_triple}-gcov"],
-)
-
-filegroup(
-    name = "gpp",
-    srcs = ["bin/%{target_triple}-g++"],
-)
-
-filegroup(
-    name = "strip",
-    srcs = ["bin/%{target_triple}-strip"],
-)
-
-filegroup(
-    name = "sysroot_dir",
-    srcs = ["%{target_triple}/sysroot"],
-)
\ No newline at end of file