Squash commits for public release

build/config/BUILDCONFIG.gn

@@ -0,0 +1,70 @@
+declare_args() {
+  # Common
+  debug_build = true
+  optimize = true
+  host = "gnu"
+  llvm_bin_path = ""
+  device_type = "desktop"
+  target_arch = ""
+  target_board = ""
+
+  # Kernel Flags
+  kernel_symbols = true
+  kernel_preempt = true
+
+  # Userland
+  userland_symbols = true
+  compile_tests = true
+  objc_support = false
+  test_method = "none"
+}
+
+if (target_arch == "") {
+  # target_cpu is deprecated, but not fully deleted.
+  if (target_cpu != "") {
+    target_arch = target_cpu
+  } else {
+    target_arch = "x86"
+  }
+}
+if (target_arch == "arm") {
+  target_arch = "arm32"
+}
+if (target_arch == "aarch64") {
+  target_arch = "arm64"
+}
+if (device_type == "m") {
+  device_type = "mobile"
+}
+if (device_type == "d") {
+  device_type = "desktop"
+}
+
+if (target_arch == "x86") {
+  target_board = "i386"
+}
+if (target_arch == "x86_64") {
+  target_board = "x86_64"
+}
+if (target_arch == "arm32") {
+  # Currently we support only vexpress-a15.
+  target_board = "vexpress-a15"
+}
+if (target_arch == "arm64") {
+  if (target_board == "") {
+    target_board = "qemu_virt"
+  }
+}
+if (target_arch == "riscv64") {
+  target_board = "riscv64"
+}
+
+if (host == "gnu") {
+  set_default_toolchain("//toolchains:gnu-cross-compiler")
+}
+
+if (host == "llvm") {
+  objc_support = true
+  llvm_bin_path = getenv("LLVM_BIN_PATH")
+  set_default_toolchain("//toolchains:llvm-cross-compiler")
+}