Bazel: Add aarch64 and armv7 cross compilation toolchains

.github/workflows/job_bazel-cross-build.yaml

@@ -0,0 +1,34 @@
+name: Bazel Cross-Compilation Build
+run-name: ${{ github.actor }} is cross-compiling with bazel
+on:
+  workflow_call:
+    inputs:
+      runner:
+        description: 'Which runner to use'
+        required: false
+        default: 'ubuntu-24.04'
+        type: string
+      platform:
+        description: 'Human-readable platform name for display'
+        required: true
+        type: string
+jobs:
+  bazel-cross-build:
+    name: Cross-compile (${{ inputs.platform }})
+    runs-on: ${{ inputs.runner }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4.1.0
+      - name: Mount bazel cache
+        uses: actions/cache@v3
+        with:
+          path: "~/.cache/bazel"
+          key: ${{ runner.os }}-bazel-cross-${{ inputs.platform }}-${{ hashFiles('.bazelversion', '.bazelrc', 'MODULE.bazel', 'third-party/bazel/*') }}
+          restore-keys: |
+            ${{ runner.os }}-bazel-cross-${{ inputs.platform }}-
+            ${{ runner.os }}-bazel-
+      - name: Build all
+        run: >
+          bazelisk build //...
+          --platforms=//third-party/bazel/toolchains:${{ inputs.platform }}
+          --@bazel_tools//tools/test:incompatible_use_default_test_toolchain=false

.github/workflows/on_pr.yaml

@@ -128,3 +128,19 @@ jobs:
     uses: ./.github/workflows/job_bazel-build-test.yaml
     with:
       runner: ${{ inputs.runner || 'ubuntu-24.04' }}
+
+
+  bazel-cross-build:
+    name: Bazel Cross-Build (${{ matrix.platform }})
+    strategy:
+      fail-fast: false
+      matrix:
+        platform:
+          - aarch64-linux-gnu
+          - aarch64-linux-musl
+          - armv7-linux-gnueabihf
+          - armv7-linux-musleabihf
+    uses: ./.github/workflows/job_bazel-cross-build.yaml
+    with:
+      runner: ${{ inputs.runner || 'ubuntu-24.04' }}
+      platform: ${{ matrix.platform }}

MODULE.bazel

@@ -9,7 +9,9 @@ module(
 
 bazel_dep(name = "bazel_features", version = "1.21.0")
 bazel_dep(name = "bazel_skylib", version = "1.7.1")
+
 BOOST_VERSION = "1.87.0"
+
 bazel_dep(name = "boost.asio", version = BOOST_VERSION)
 bazel_dep(name = "boost.process", version = BOOST_VERSION)
 bazel_dep(name = "boost.uuid", version = BOOST_VERSION)
@@ -22,7 +24,7 @@ bazel_dep(name = "fast_float", version = "6.1.6")
 bazel_dep(name = "fmt", version = "12.1.0", repo_name = "com_github_fmtlib_fmt")
 bazel_dep(name = "nlohmann_json", version = "3.12.0.bcr.1", repo_name = "com_github_nlohmann_json")
 bazel_dep(name = "libcap", version = "2.27.bcr.1")
-bazel_dep(name = "openssl", version = "3.3.1.bcr.6")
+bazel_dep(name = "openssl", version = "3.3.1.bcr.9")
 bazel_dep(name = "platforms", version = "0.0.11")
 bazel_dep(name = "pugixml", version = "1.15")
 bazel_dep(name = "rapidyaml", version = "0.10.0")
@@ -35,19 +37,47 @@ bazel_dep(name = "rules_shell", version = "0.6.1")
 bazel_dep(name = "pybind11_bazel", version = "3.0.0")
 bazel_dep(name = "sqlite3", version = "3.51.2")
 
+single_version_override(
+    module_name = "boost.context",
+    patches = ["//third-party/bazel/patches:boost.context.patch"],
+)
+
+###############################################################################
+# C R O S S - C O M P I L A T I O N   T O O L C H A I N S
+###############################################################################
+
+# Module extension for cross-compilation toolchain repositories
+cross_toolchains = use_extension("//third-party/bazel/toolchains:extensions.bzl", "toolchains")
+use_repo(
+    cross_toolchains,
+    "cc_toolchain_aarch64-linux-gnu-x86_64-linux",
+    "cc_toolchain_aarch64-linux-musl-x86_64-linux",
+    "cc_toolchain_armv7-linux-gnu-x86_64-linux",
+    "cc_toolchain_armv7-linux-musl-x86_64-linux",
+)
+
+register_toolchains("@cc_toolchain_aarch64-linux-gnu-x86_64-linux//:aarch64-linux-glibc_toolchain_toolchain")
+
+register_toolchains("@cc_toolchain_aarch64-linux-musl-x86_64-linux//:aarch64-linux-musl_toolchain_toolchain")
+
+register_toolchains("@cc_toolchain_armv7-linux-musl-x86_64-linux//:armv7-linux-musl_toolchain_toolchain")
+
+register_toolchains("@cc_toolchain_armv7-linux-gnu-x86_64-linux//:armv7-linux-gnu_toolchain_toolchain")
+
 ###############################################################################
 # N O N   M O D U L E
 ###############################################################################
 
 deps = use_extension("//third-party/bazel:extension.bzl", "deps")
 use_repo(
     deps,
-    "sigslot",
     "com_github_HowardHinnant_date",
+    "com_github_LiamBindle_mqtt-c",
     "com_github_pboettch_json-schema-validator",
     "com_github_warmcatt_libwebsockets",
-    "com_github_LiamBindle_mqtt-c",
+    "openssl_source",
     "pybind11_json",
+    "sigslot",
 )
 
 ###############################################################################
@@ -56,19 +86,17 @@ use_repo(
 
 python = use_extension("@rules_python//python/extensions:python.bzl", "python")
 python.toolchain(
-    python_version = "3.10",
     is_default = True,
+    python_version = "3.10",
 )
-
 use_repo(python, "python_3_10")
 
 pip_deps = use_extension("@rules_python//python/extensions:pip.bzl", "pip")
 pip_deps.parse(
-    python_version = "3.10",
     hub_name = "everest-testing_pip_deps",
+    python_version = "3.10",
     requirements_lock = "//applications/utils:requirements-bazel.txt",
 )
-
 use_repo(pip_deps, "everest-testing_pip_deps")
 
 ###############################################################################
@@ -79,15 +107,50 @@ RUST_EDITION = "2021"
 
 RUST_VERSION = "1.86.0"
 
+RUST_EXTRA_TARGET_TRIPLES = {
+    "armv7-unknown-linux-musleabihf": [
+        "@platforms//os:linux",
+        "@platforms//cpu:armv7",
+        "@everest-core//third-party/bazel/toolchains:musl",
+    ],
+    "armv7-unknown-linux-gnueabihf": [
+        "@platforms//os:linux",
+        "@platforms//cpu:armv7",
+        "@everest-core//third-party/bazel/toolchains:gnu",
+    ],
+    "aarch64-unknown-linux-musl": [
+        "@platforms//os:linux",
+        "@platforms//cpu:aarch64",
+        "@everest-core//third-party/bazel/toolchains:musl",
+    ],
+    "aarch64-unknown-linux-gnu": [
+        "@platforms//os:linux",
+        "@platforms//cpu:aarch64",
+        "@everest-core//third-party/bazel/toolchains:gnu",
+    ],
+}
+
 rust = use_extension("@rules_rust//rust:extensions.bzl", "rust")
 rust.toolchain(
     edition = RUST_EDITION,
-    extra_target_triples = [
-        "aarch64-unknown-linux-gnu",
-        "x86_64-unknown-linux-gnu",
+    versions = [
+        RUST_VERSION,
+        "nightly/2026-02-09",
     ],
-    versions = [RUST_VERSION],
 )
+
+[
+    rust.repository_set(
+        name = "rust_{}_repository_set_x86_64-unknown-linux-gnu".format(target_triple.replace("-", "_")),
+        edition = RUST_EDITION,
+        exec_triple = "x86_64-unknown-linux-gnu",
+        target_compatible_with = target_compatible_with,
+        target_triple = target_triple,
+        versions = [RUST_VERSION],
+    )
+    for (target_triple, target_compatible_with) in RUST_EXTRA_TARGET_TRIPLES.items()
+]
+
 use_repo(rust, "rust_toolchains")
 
 register_toolchains("@rust_toolchains//:all")
@@ -103,17 +166,21 @@ everest_core_crate_index.from_cargo(
         "@everest-core//modules/Examples/RustExamples/RsExample:Cargo.toml",
         "@everest-core//modules/Examples/RustExamples/RsExampleUser:Cargo.toml",
     ],
+    supported_platform_triples = [
+        "x86_64-unknown-linux-gnu",
+        "aarch64-unknown-linux-gnu",
+        "armv7-unknown-linux-gnueabihf",
+    ],
 )
 everest_core_crate_index.annotation(
     crate = "everestrs",
-    repositories = ["everest_core_crate_index"],
     crate_features = ["build_bazel"],
+    repositories = ["everest_core_crate_index"],
     deps = [
-        "//lib/everest/framework/everestrs/everestrs-build",
         "//lib/everest/framework/everestrs/everestrs",
+        "//lib/everest/framework/everestrs/everestrs-build",
     ],
 )
-
 use_repo(
     everest_core_crate_index,
     "everest_core_crate_index",
@@ -132,8 +199,12 @@ everest_framework_crate_index.from_cargo(
         "//lib/everest/framework/everestrs/everestrs:Cargo.toml",
         "//lib/everest/framework/everestrs/everestrs-build:Cargo.toml",
     ],
+    supported_platform_triples = [
+        "x86_64-unknown-linux-gnu",
+        "aarch64-unknown-linux-gnu",
+        "armv7-unknown-linux-gnueabihf",
+    ],
 )
-
 use_repo(
     everest_framework_crate_index,
     "everest_framework_crate_index",
@@ -147,7 +218,6 @@ everest_framework_validate_crate_index.from_cargo(
         "//lib/everest/framework/bazel/validate:Cargo.toml",
     ],
 )
-
 use_repo(
     everest_framework_validate_crate_index,
     "everest_framework_validate_crate_index",

applications/utils/BUILD.bazel

@@ -1,6 +1,7 @@
 load("@bazel_skylib//rules:diff_test.bzl", "diff_test")
 load("@bazel_skylib//rules:write_file.bzl", "write_file")
 load("@rules_shell//shell:sh_binary.bzl", "sh_binary")
+load("//third-party/bazel/toolchains:defs.bzl", "CROSS_PYTHON_INCOMPATIBLE")
 
 write_file(
     name = "gen_update",
@@ -23,4 +24,5 @@ diff_test(
     failure_message = "Please run `bazel run //:vendor_requirements` to update the vendored requirements.bzl file.",
     file1 = "@everest-testing_pip_deps//:requirements.bzl",
     file2 = ":requirements.bzl",
+    target_compatible_with = CROSS_PYTHON_INCOMPATIBLE,
 )

applications/utils/ev-dev-tools/BUILD.bazel

@@ -1,5 +1,6 @@
 load("//applications/utils:requirements.bzl", "requirement")
 load("@rules_python//python:defs.bzl", "py_binary", "py_library")
+load("//third-party/bazel/toolchains:defs.bzl", "CROSS_PYTHON_INCOMPATIBLE")
 
 exports_files(
     ["BUILD.bazel"],
@@ -9,6 +10,7 @@ py_library(
     name = "lib",
     srcs = glob(["src/ev_cli/*.py"]),
     imports = ["src"],
+    target_compatible_with = CROSS_PYTHON_INCOMPATIBLE,
     deps = [
         requirement("jinja2"),
         requirement("jsonschema"),
@@ -24,5 +26,6 @@ py_binary(
     legacy_create_init = False,
     main = "src/ev_cli/ev.py",
     visibility = ["//visibility:public"],
+    target_compatible_with = CROSS_PYTHON_INCOMPATIBLE,
     deps = [":lib"],
 )

applications/utils/everest-testing/BUILD.bazel

@@ -1,5 +1,6 @@
 load("//applications/utils:requirements.bzl", "requirement")
 load("@rules_python//python:defs.bzl", "py_library")
+load("//third-party/bazel/toolchains:defs.bzl", "CROSS_PYTHON_INCOMPATIBLE")
 
 exports_files(
     ["BUILD.bazel"],
@@ -10,6 +11,7 @@ py_library(
     srcs = glob(["src/**/*.py"]),
     imports = ["src"],
     visibility = ["//visibility:public"],
+    target_compatible_with = CROSS_PYTHON_INCOMPATIBLE,
     deps = [
         requirement("pytest"),
         requirement("pytest-asyncio"),

lib/everest/evse_security/BUILD.bazel

@@ -31,7 +31,7 @@ cc_library(
         ":cert_rehash",
         "//lib/everest/framework:framework",
         "//lib/everest/timer:libtimer",
-        "@openssl//:crypto",
-        "@openssl//:ssl",
+        "//third-party/bazel/openssl:crypto",
+        "//third-party/bazel/openssl:ssl",
     ],
 )