[EXAMPLES] better examples (#23)

* [EXAMPLES] better examples * [EXAMPLES] fix tools
hexdae · Nov 17, 2023 · fb31092 · fb31092
1 parent adf6841
commit fb31092
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Showing 14 changed files with 142 additions and 5 deletions.
diff --git a/MODULE.bazel b/MODULE.bazel
@@ -4,10 +4,6 @@ module(
     compatibility_level = 1,
 )
 
-# INTERNAL
-bazel_dep(name = "aspect_bazel_lib", version = "2.0.0", dev_dependency = True)
-bazel_dep(name = "bazel_skylib", version = "1.5.0", dev_dependency = True)
-
 arm_none_eabi = use_extension("@arm_none_eabi//:extensions.bzl", "arm_none_eabi")
 arm_none_eabi.toolchain(version = "9.2.1")
 use_repo(
@@ -18,4 +14,16 @@ use_repo(
     "arm_none_eabi_windows_x86_64",
 )
 
-register_toolchains("@arm_none_eabi//toolchain:all")
+# DEV ONLY (not needed for release)
+bazel_dep(name = "aspect_bazel_lib", version = "2.0.0", dev_dependency = True)
+bazel_dep(name = "bazel_skylib", version = "1.5.0", dev_dependency = True)
+
+register_toolchains(
+    "@arm_none_eabi//toolchain:all",
+    dev_dependency = True,
+)
+
+register_toolchains(
+    "@arm_none_eabi//examples/custom/toolchain:all",
+    dev_dependency = True,
+)
diff --git a/examples/README.md b/examples/README.md
@@ -0,0 +1,3 @@
+# Examples
+
+These examples can be used to understand the different features of this toolchain
diff --git a/examples/custom/BUILD b/examples/custom/BUILD
@@ -0,0 +1,27 @@
+# project/BUILD.bazel
+
+load("@rules_cc//cc:defs.bzl", "cc_binary")
+load("@aspect_bazel_lib//lib:transitions.bzl", "platform_transition_filegroup")
+
+cc_binary(
+    name = "binary",
+    srcs = ["main.c"],
+    linkopts = [
+        "-Wl,-entry=main",
+    ],
+    target_compatible_with = [
+        "@platforms//os:none",
+    ],
+)
+
+platform_transition_filegroup(
+    name = "cortex_m3_elf",
+    srcs = [":binary"],
+    target_platform = "//examples/custom/platform:cortex_m3",
+)
+
+platform_transition_filegroup(
+    name = "cortex_m4_elf",
+    srcs = [":binary"],
+    target_platform = "//examples/custom/platform:cortex_m4",
+)
diff --git a/examples/custom/README.md b/examples/custom/README.md
@@ -0,0 +1,5 @@
+# Custom toolchain example
+
+This example shows how to create a custom toolchain with different CPUs based
+on custom constraint values. The toolchain has different flags for each CPU and
+is applied to all dependencies.
diff --git a/examples/custom/cpu/BUILD b/examples/custom/cpu/BUILD
@@ -0,0 +1,15 @@
+constraint_setting(
+    name = "arm_none_eabi_cpu",
+)
+
+constraint_value(
+    name = "cortex_m3",
+    constraint_setting = "arm_none_eabi_cpu",
+    visibility = ["//visibility:public"],
+)
+
+constraint_value(
+    name = "cortex_m4",
+    constraint_setting = "arm_none_eabi_cpu",
+    visibility = ["//visibility:public"],
+)
diff --git a/examples/custom/main.c b/examples/custom/main.c
@@ -0,0 +1,11 @@
+// The simplest possible main function
+
+int main()
+{
+    return 0;
+}
+
+extern void _start()
+{
+    main();
+}
diff --git a/examples/custom/platform/BUILD b/examples/custom/platform/BUILD
@@ -0,0 +1,18 @@
+
+platform(
+    name = "cortex_m4",
+    constraint_values = [
+        "@platforms//os:none",
+        "//examples/custom/cpu:cortex_m4"
+    ],
+    visibility = ["//visibility:public"],
+)
+
+platform(
+    name = "cortex_m3",
+    constraint_values = [
+        "@platforms//os:none",
+        "//examples/custom/cpu:cortex_m3"
+    ],
+    visibility = ["//visibility:public"],
+)
diff --git a/examples/custom/toolchain/BUILD b/examples/custom/toolchain/BUILD
@@ -0,0 +1,43 @@
+load("@arm_none_eabi//toolchain:toolchain.bzl", "arm_none_eabi_toolchain")
+
+arm_none_eabi_toolchain(
+    name = "cortex_m3_toolchain",
+    target_compatible_with = [
+        "@platforms//os:none",
+        "//examples/custom/cpu:cortex_m3"
+    ],
+    copts = [
+        "-mcpu=cortex-m3",
+        "-mthumb",
+        "-mfloat-abi=hard",
+        "-mfpu=fpv4-sp-d16",
+    ],
+    linkopts = [
+        "-mcpu=cortex-m3",
+        "-mthumb",
+        "-mfloat-abi=hard",
+        "-mfpu=fpv4-sp-d16",
+        "-nostartfiles",
+    ],
+)
+
+arm_none_eabi_toolchain(
+    name = "cortex_m4_toolchain",
+    target_compatible_with = [
+        "@platforms//os:none",
+        "//examples/custom/cpu:cortex_m4"
+    ],
+    copts = [
+        "-mcpu=cortex-m4",
+        "-mthumb",
+        "-mfloat-abi=hard",
+        "-mfpu=fpv4-sp-d16",
+    ],
+    linkopts = [
+        "-mcpu=cortex-m4",
+        "-mthumb",
+        "-mfloat-abi=hard",
+        "-mfpu=fpv4-sp-d16",
+        "-nostartfiles",
+    ],
+)
diff --git a/examples/cc/BUILD → examples/simple/BUILD b/examples/cc/BUILD → examples/simple/BUILD
diff --git a/examples/cc/includes/library.h → examples/simple/includes/library.h b/examples/cc/includes/library.h → examples/simple/includes/library.h
diff --git a/examples/cc/source/library.cpp → examples/simple/source/library.cpp b/examples/cc/source/library.cpp → examples/simple/source/library.cpp
diff --git a/examples/cc/source/main.cpp → examples/simple/source/main.cpp b/examples/cc/source/main.cpp → examples/simple/source/main.cpp
diff --git a/examples/gdb/BUILD → examples/tools/BUILD b/examples/gdb/BUILD → examples/tools/BUILD
@@ -6,3 +6,10 @@ native_binary(
     out = "gdb",
     visibility = ["//visibility:public"],
 )
+
+native_binary(
+    name = "readelf",
+    src = "@arm_none_eabi//:readelf",
+    out = "readelf",
+    visibility = ["//visibility:public"],
+)
diff --git a/examples/tools/README.md b/examples/tools/README.md
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,3 @@
		# Examples

		These examples can be used to understand the different features of this toolchain