Build Skia for a bare-bones embedded Linux system.

platform_tools/barelinux/bin/arm64_download

+#!/bin/sh
+
+# Copyright 2014 Google Inc.
+#
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+
+usage() {
+    cat >&2 <<EOF
+arm64_download - this script downloads the Linaro's ARMv8 Aarch64
+toolchain and minimal embedded Linux system as well as ARM's
+foundation model.  The required files are mirrored on Google Cloud.
+
+If the files are already located in the working directory, the
+download can be skipped if the checksums match.
+
+The script then starts a emulated Arm64 Linux system in the
+background.  After the boot is complete, you can SSH into the system
+at port 8022 via user@localhost.  The SSH key will be downloaded into
+the working directery as well.
+
+Requires gsutil, xz, tar, and gunzip.
+
+Usage:
+  $0 WORKING_DIRECTORY
+  ssh-add WORKING_DIRECTORY/key
+  ...wait...
+  ssh -p 8022 user@localhost
+EOF
+    return 1
+}
+
+try() {
+    # print an error on nonzero return code
+    "$@"
+    local ret=$?
+    if [ $ret != 0 ] ; then
+        echo "'$@' failed and returned ${ret}." >&2
+        return $ret
+    fi
+}
+
+gsutil_check_get() {
+    local gurl="$1"
+    local file="$2"
+    if ! [ -f "$file" ] || \
+        [ "$(gsutil stat "$gurl" | sed -n 's/\W*Hash (md5):\W*//p')" \
+        != "$(md5sum < "$file" | sed 's/\W*-//')" ] ; then
+        try gsutil cp "$gurl" "$file" || return
+    fi
+}
+
+download_compiler() {
+    local working_dir="$1"
+    local location="$2"
+    local toolchain="$3"
+
+    try cd "$working_dir" || return
+
+    try gsutil_check_get "gs://${location}/${toolchain}.tar.xz" \
+        "${working_dir}/${toolchain}.tar.xz" || return
+    (
+        cd "$working_dir"
+        xz --decompress --stdout < "${toolchain}.tar.xz" | tar xf -
+    )
+    local dir="${working_dir}/${toolchain}"
+    try test -d "$dir" || return
+    try test -x "${dir}/bin/aarch64-linux-gnu-gcc" || return
+    try test -x "${dir}/bin/aarch64-linux-gnu-g++" || return
+}
+
+download_runtime() {
+    local working_dir="$1"
+    local location="$2"
+    local firmware="$3"
+    local compressed_rootfs="$4"
+    local compressed_foundation_model="$5"
+    local keyfile="$6"
+
+    try gsutil_check_get "gs://${location}/${firmware}" \
+        "${working_dir}/firmware" || return
+
+    try gsutil_check_get "gs://${location}/${compressed_rootfs}" \
+        "${working_dir}/${compressed_rootfs}" || return
+
+    try xz --decompress --stdout \
+            < "${working_dir}/${compressed_rootfs}" \
+            > "${working_dir}/rootfs" || return
+    try test -f "${working_dir}/rootfs" || return
+
+    try gsutil_check_get "gs://${location}/${compressed_foundation_model}" \
+        "${working_dir}/${compressed_foundation_model}" || return
+    (
+        try cd "$working_dir" || return
+        try gunzip -c "$compressed_foundation_model" | try tar xf - || return
+        try test -d "Foundation_v8pkg" || return  #  Assert.
+    )
+
+    try gsutil_check_get "gs://${location}/${keyfile}" \
+        "${working_dir}/key" || return
+    chmod go= "${working_dir}/key"
+}
+
+start_arm64_image() {
+    local working_dir="$1"
+    local foundation_dir="${working_dir}/Foundation_v8pkg"
+    local foundation="${foundation_dir}/models/Linux64_GCC-4.1/Foundation_v8"
+    local firmware="${working_dir}/firmware"
+    local rootfs="${working_dir}/rootfs"
+
+    try test -d "$foundation_dir" || return
+    try test -x "$foundation" || return
+    try test -f "$firmware" || return
+    try test -f "$rootfs" || return
+
+    for PID in $(ps -o 'pid=' -C 'Foundation_v8') ; do
+        kill $PID
+    done
+
+    DISPLAY='' nohup \
+    "$foundation" \
+        --image="${firmware}" \
+        --cores=4 \
+        --block-device="${rootfs}" \
+        --network="nat" \
+        --network-nat-subnet="192.168.31.0/24" \
+        --network-nat-ports="8022=22" \
+        > /dev/null 2>&1 &
+    echo 'Listening to SSH on port 8022.'
+}
+
+arm64_download() {
+    local working_directory="$1"
+    local location="chromium-skia-gm/arm64env"
+    try mkdir -p "$working_directory" || return
+
+    try download_compiler \
+        "$working_directory" \
+        "$location" \
+        'gcc-linaro-aarch64-linux-gnu-4.8-2013.12_linux' \
+         || return
+
+    local rootfs='vexpress64-openembedded_lamp-armv8-gcc-4.8_20131215-557'
+    try download_runtime \
+        "$working_directory" \
+        "$location" \
+        'img-foundation.axf' \
+        "${rootfs}.img.CLEAN_AND_CONFIGURED.xz" \
+        'FM000-KT-00035-r0p8-52rel06.tgz' \
+        'CLEAN_AND_CONFIGURED_key' \
+        || return
+
+    try start_arm64_image \
+        "$working_directory" \
+        || return
+
+}
+
+for command in gsutil xz tar gunzip; do
+    try command -v "$command" > /dev/null || usage || exit
+done
+
+if [ -z "$1" ] ; then
+    usage || exit
+fi
+try arm64_download "$1" || exit