defmodule Mix.Tasks.Firmware.Patch do
use Mix.Task
import Mix.Nerves.Utils
alias Nerves.Utils.Shell
alias Mix.Nerves.Preflight
@shortdoc "Build a firmware patch"
@fwup_semver "~> 1.6 or ~> 1.6.0-dev"
@moduledoc """
Generate a firmware patch from a source and target firmware and output a new
firmware file with the patch contents. The source firmware file
This requires fwup >= 1.6.0
## Command line options
* `--source` - (Optional) The path to the .fw file used as the source.
Defaults to the last firmware built.
* `--target` - (Optional) The path to the .fw file used as the target.
Defaults to generating a new firmware without overwriting the source.
* `--output` - (Optional) The path to the .fw file used to write the patch
firmware. Defaults to `Nerves.Env.firmware_path/1`
"""
@switches [source: :string, target: :string, output: :string]
@impl true
def run(args) do
work_dir = Path.join(Nerves.Env.images_path(), "patch")
File.rm_rf!(work_dir)
File.mkdir_p!(work_dir)
config = Mix.Project.config()
{opts, _, _} = OptionParser.parse(args, switches: @switches)
Preflight.ensure_fwup_version!("fwup", @fwup_semver)
source = (opts[:source] || Nerves.Env.firmware_path(config)) |> Path.expand()
unless File.exists?(source) do
Mix.raise("""
Source firmware #{source} does not exist.
Please pass --source /path/source.fw or run `mix firmware`.
""")
end
source_stats = File.stat!(source)
target = (opts[:target] || mix_target_firmware(work_dir)) |> Path.expand()
output = (opts[:output] || Path.join(Nerves.Env.images_path(), "patch.fw")) |> Path.expand()
Shell.info("""
Generating patch firmware
""")
target_stats = File.stat!(target)
source_work_dir = Path.join(work_dir, "source")
target_work_dir = Path.join(work_dir, "target")
output_work_dir = Path.join(work_dir, "output")
File.mkdir_p!(source_work_dir)
File.mkdir_p!(target_work_dir)
File.mkdir_p!(Path.join(output_work_dir, "data"))
{_, 0} = shell("unzip", ["-qq", source, "-d", source_work_dir])
{_, 0} = shell("unzip", ["-qq", target, "-d", target_work_dir])
source_rootfs = Path.join([source_work_dir, "data", "rootfs.img"])
target_rootfs = Path.join([target_work_dir, "data", "rootfs.img"])
out_rootfs = Path.join([output_work_dir, "data", "rootfs.img"])
{_, 0} = shell("xdelta3", ["-A", "-S", "-f", "-s", source_rootfs, target_rootfs, out_rootfs])
File.mkdir_p!(Path.dirname(output))
File.cp!(target, output)
{_, 0} = shell("zip", ["-qq", output, "data/rootfs.img"], cd: output_work_dir)
output_stats = File.stat!(output)
{source_meta, 0} = System.cmd("fwup", ["-m", "-i", source])
{target_meta, 0} = System.cmd("fwup", ["-m", "-i", target])
[source_uuid | _] = String.split(source_meta, "meta-uuid=") |> Enum.reverse()
[target_uuid | _] = String.split(target_meta, "meta-uuid=") |> Enum.reverse()
source_uuid = String.trim(source_uuid, "\"")
target_uuid = String.trim(target_uuid, "\"")
File.rm_rf!(work_dir)
Shell.success("""
Finished generating patch firmware
Source
#{source}
uuid: #{source_uuid}
size: #{source_stats.size} bytes
Target
#{target}
uuid: #{target_uuid}
size: #{target_stats.size} bytes
Patch
#{output}
size: #{output_stats.size} bytes
""")
end
defp mix_target_firmware(work_dir) do
Shell.info("Generating new target firmware")
out_fw = Path.join(work_dir, "target.fw")
Mix.Tasks.Firmware.run(["--output", out_fw])
out_fw
end
end