diff --git a/src/build.sh b/src/build.sh
new file mode 100755
index 0000000000..c4bd888b97
--- /dev/null
+++ b/src/build.sh
@@ -0,0 +1,83 @@
+#!/bin/sh
+set -e
+
+export TMPDIR="$PWD/tmp"
+mkdir -p "$TMPDIR"
+
+if [ "$1" = debug ]; then
+  out=out/Debug
+  flags="
+    is_debug=true
+    is_component_build=true"
+else
+  out=out/Release
+  flags="
+    is_official_build=true
+    exclude_unwind_tables=true
+    enable_resource_whitelist_generation=false
+    symbol_level=0"
+fi
+
+if which ccache >/dev/null 2>&1; then
+  export CCACHE_SLOPPINESS=time_macros
+  export CCACHE_BASEDIR="$PWD"
+  export CCACHE_CPP2=yes
+  flags="$flags"'
+   cc_wrapper="ccache"'
+elif [ -f "$HOME"/.cargo/bin/sccache* ]; then
+  export PATH="$PATH:$HOME/.cargo/bin"
+  flags="$flags"'
+   cc_wrapper="sccache"'
+fi
+
+flags="$flags"'
+  is_clang=true
+  linux_use_bundled_binutils=false
+  use_sysroot=false
+
+  fatal_linker_warnings=false
+  treat_warnings_as_errors=false
+
+  fieldtrial_testing_like_official_build=true
+
+  use_cups=false
+  use_dbus=false
+  use_gio=false
+  use_platform_icu_alternatives=true
+  use_gtk=false
+  use_system_libdrm=false
+
+  disable_file_support=true
+  enable_websockets=false
+  disable_ftp_support=true
+  use_kerberos=false
+  enable_mdns=false
+  enable_reporting=false
+  include_transport_security_state_preload_list=false
+  rtc_use_pipewire=false
+'
+
+if [ "$(uname)" = Linux ]; then
+  flags="$flags"'
+    use_xkbcommon=false
+    use_ozone=true
+    ozone_auto_platforms=false
+    ozone_platform="headless"
+    ozone_platform_headless=true'
+  . ./get-sysroot.sh
+  sysroot=$(get_sysroot)
+  if [ "$sysroot" ]; then
+      flags="$flags
+        target_sysroot=\"//$sysroot\""
+  fi
+fi
+
+rm -rf "./$out"
+mkdir -p out
+
+python2=$(which python2 2>/dev/null || which python 2>/dev/null)
+export DEPOT_TOOLS_WIN_TOOLCHAIN=0
+
+./gn/out/gn gen "$out" --args="$flags $EXTRA_FLAGS" --script-executable=$python2
+
+ninja -C "$out" naive
diff --git a/src/get-clang.sh b/src/get-clang.sh
new file mode 100755
index 0000000000..28fea1dba7
--- /dev/null
+++ b/src/get-clang.sh
@@ -0,0 +1,76 @@
+#!/bin/sh
+set -ex
+
+ARCH=$(uname)
+case "$ARCH" in
+  MINGW*) ARCH=Windows;;
+  MSYS*) ARCH=Windows;;
+esac
+
+build_sysroot() {
+  ./build/linux/sysroot_scripts/sysroot-creator-sid-naive.sh "BuildSysroot$1"
+}
+
+if [ "$ARCH" = Linux ]; then
+  if [ "$OPENWRT_FLAGS" ]; then
+    ./get-openwrt.sh
+  else
+    eval "$EXTRA_FLAGS"
+    case "$target_cpu" in
+      x64) build_sysroot Amd64;;
+      x86) build_sysroot I386;;
+      arm64) build_sysroot ARM64;;
+      arm) build_sysroot ARM;;
+    esac
+  fi
+fi
+
+# Clang
+python2=$(which python2 2>/dev/null || which python 2>/dev/null)
+CLANG_REVISION=$($python2 tools/clang/scripts/update.py --print-revision)
+CLANG_PATH="clang-$CLANG_REVISION.tgz"
+case "$ARCH" in
+  Linux) clang_url="https://commondatastorage.googleapis.com/chromium-browser-clang/Linux_x64/$CLANG_PATH";;
+  Darwin) clang_url="https://commondatastorage.googleapis.com/chromium-browser-clang/Mac/$CLANG_PATH";;
+  Windows) clang_url="https://commondatastorage.googleapis.com/chromium-browser-clang/Win/$CLANG_PATH";;
+  *) exit 1;;
+esac
+if [ ! -d third_party/llvm-build/Release+Asserts/bin ]; then
+  mkdir -p third_party/llvm-build/Release+Asserts
+  curl "$clang_url" | tar xzf - -C third_party/llvm-build/Release+Asserts
+fi
+
+# AFDO profile (Linux)
+if [ "$ARCH" = Linux -a ! -f chrome/android/profiles/afdo.prof ]; then
+  AFDO_PATH=$(cat chrome/android/profiles/newest.txt)
+  afdo_url="https://storage.googleapis.com/chromeos-prebuilt/afdo-job/llvm/$AFDO_PATH"
+  curl "$afdo_url" | bzip2 -cd >chrome/android/profiles/afdo.prof
+fi
+
+# dsymutil (Mac)
+if [ "$ARCH" = Darwin ]; then
+  mkdir -p tools/clang/dsymutil
+  DSYMUTIL_PATH="dsymutil-$CLANG_REVISION.tgz"
+  dsymutil_url="http://commondatastorage.googleapis.com/chromium-browser-clang-staging/Mac/$DSYMUTIL_PATH"
+  curl "$dsymutil_url" | tar xzf - -C tools/clang/dsymutil
+fi
+
+# sccache (Windows)
+if [ "$ARCH" = Windows ]; then
+  sccache_url="https://github.com/mozilla/sccache/releases/download/0.2.8/sccache-0.2.8-x86_64-pc-windows-msvc.tar.gz"
+  mkdir -p ~/.cargo/bin
+  curl -L "$sccache_url" | tar xzf - --strip=1 -C ~/.cargo/bin
+fi
+
+# gn
+if [ ! -f gn/out/gn ]; then
+  GN_VERSION=$(grep "'gn_version':" buildtools/DEPS | cut -d"'" -f4)
+  mkdir -p gn/out
+  cd gn/out
+  case "$ARCH" in
+    Linux) curl -L "https://chrome-infra-packages.appspot.com/dl/gn/gn/linux-amd64/+/$GN_VERSION" -o gn.zip;;
+    Darwin) curl -L "https://chrome-infra-packages.appspot.com/dl/gn/gn/mac-amd64/+/$GN_VERSION" -o gn.zip;;
+    Windows) curl -L "https://chrome-infra-packages.appspot.com/dl/gn/gn/windows-amd64/+/$GN_VERSION" -o gn.zip;;
+  esac
+  unzip gn.zip
+fi
diff --git a/src/get-openwrt.sh b/src/get-openwrt.sh
new file mode 100755
index 0000000000..4378e7bc38
--- /dev/null
+++ b/src/get-openwrt.sh
@@ -0,0 +1,47 @@
+#!/bin/sh
+
+set -ex
+
+eval "$OPENWRT_FLAGS"
+
+sysroot=$PWD/out/sysroot-build/openwrt/$release/$arch
+if [ -d $sysroot/lib ]; then
+  exit 0
+fi
+mkdir -p $sysroot
+
+SDK_PATH=openwrt-sdk-$release-$target-${subtarget}_gcc-${gcc_ver}_musl.Linux-x86_64
+SDK_URL=https://downloads.openwrt.org/releases/$release/targets/$target/$subtarget/$SDK_PATH.tar.xz
+rm -rf $SDK_PATH
+curl $SDK_URL | tar xJf -
+cd $SDK_PATH
+./scripts/feeds update base packages
+./scripts/feeds install libnss
+make defconfig
+for flag in ALL_NONSHARED ALL_KMODS ALL SIGNED_PACKAGES; do
+  sed -i "s/CONFIG_$flag=y/# CONFIG_$flag is not set/" .config
+done
+make oldconfig
+make
+full_root=staging_dir/toolchain-*_gcc-${gcc_ver}_musl
+cp -r staging_dir/target-*_musl/usr $full_root
+echo '
+./include
+./lib/*.o
+./lib/gcc/*/libgcc.a
+./lib/libatomic.so*
+./lib/libc.so
+./lib/libdl.a
+./lib/ld-*
+./lib/libgcc_s.*
+./lib/libm.a
+./lib/libpthread.a
+./lib/libresolv.a
+./lib/librt.a
+./usr
+*.ld.bin
+' >include.txt
+tar cf - -C $full_root --hard-dereference . | tar xf - -C $sysroot --wildcards --wildcards-match-slash -T include.txt
+rm include.txt
+cd $sysroot/*-openwrt-linux-musl/bin
+mv .ld.bin ld
diff --git a/src/get-sysroot.sh b/src/get-sysroot.sh
new file mode 100644
index 0000000000..1970e3d415
--- /dev/null
+++ b/src/get-sysroot.sh
@@ -0,0 +1,21 @@
+get_sysroot() {
+  if [ "$OPENWRT_FLAGS" ]; then
+     eval "$OPENWRT_FLAGS"
+     echo "out/sysroot-build/openwrt/$release/$arch"
+     return
+  fi
+  eval "$EXTRA_FLAGS"
+  if [ ! "$target_sysroot" ]; then
+    local sysroot_type
+    case "$target_cpu" in
+      x64) sysroot_type=amd64;;
+      x86) sysroot_type=i386;;
+      arm64) sysroot_type=arm64;;
+      arm) sysroot_type=arm;;
+      mipsel) sysroot_type=mips;;
+    esac
+    if [ "$sysroot_type" ]; then
+      echo "out/sysroot-build/sid/sid_${sysroot_type}_staging"
+    fi
+  fi
+}