[u-boot-builder] Adding support for patches and config fragments (#29)

- Bumped to 2022.07
- Updated Readme with usage information and explanations
- Created entry point script which handles patches and fragments

u-boot-builder/Dockerfile

@@ -2,7 +2,7 @@ FROM robotpajamas/gcc-arm-linux-gnueabihf:10.3-2021.07 as builder
 
 LABEL maintainer="[email protected]"
 
-ARG UBOOT_TAG=v2022.04
+ARG UBOOT_TAG=v2022.07
 
 SHELL ["/bin/bash", "-o", "pipefail", "-c"]
 ARG DEBIAN_FRONTEND=non-interactive
@@ -30,4 +30,8 @@ RUN apt-get update \
 USER armothy
 WORKDIR /app
 
-CMD ["bash"]
+COPY docker-entrypoint.sh /
+ENV DEFCONFIG="qemu_arm_defconfig"
+
+ENTRYPOINT ["/docker-entrypoint.sh"]
+CMD ["make"]

u-boot-builder/README.md

@@ -1,17 +1,72 @@
 # u-boot-builder
 
-## TODO
+A development environment containing an ARM gcc toolchain which can build u-boot for ARM devices.
 
-- Notes: Use a volume to host the git repo + changes, so it's not accidentally lost on container removal.
-  Optionally bind mount `ccache`, so that it can be shared across builds or containers - and probably put it in a tmp folder so the OS can manage it.
-- These should probably be re-done with the `--mount` syntax, as it's clearer for documentation purposes. `-v` is a shortcut.
-- Confirm this runs with `Podman` as well.
-- Test by passing in a bash command
-- Show git diff/patch example
+## Usage
+
+Given some input paramters, this container will automatically download u-boot, apply patches, and use configuration fragments to setup and then build u-boot.
+
+Below is the typical, non-interactive build command.
+
+```bash
+docker run --rm \
+  -e DEFCONFIG=am335x_evm_defconfig \
+  -v uboot-2022.07:/app \
+  -v ccache:/ccache \
+  -v $(pwd)/mykconfig.fragment:/u-boot.fragment:ro \
+  -v $(pwd)/mygit.patch:/u-boot.patch:ro \
+  robotpajamas/u-boot-builder:2022.07
+```
+
+- `-e DEFCONFIG=am335x_evm_defconfig` is an environment variable specifying which defconfig to use, it defaults to `qemu_arm_defconfig`.
+- `-v uboot-2022.07:/app` is a named volume to store u-boot sources, and to persist modifications when using this container as a develop environment. Additionally, using a named volume instead of a bind mount skips permission and performance problems on non-Linux host OSes.
+- `-v ccache:/ccache` is a named volume to store `ccache` objects.
+- `-v $(pwd)/mykconfig.fragment:/u-boot.fragment:ro` is an optional volume mapping a `Kconfig` fragment, which is applied via `scripts/kconfig/merge_configs.sh` after making the u-boot defconfig.
+- `-v $(pwd)/mygit.patch:/u-boot.patch:ro` is an optional volume mapping a git patch file, which is applied via `git apply u-boot.patch`.
+
+The `entrypoint` for this container automatically attempts to apply patches, `make` the defconfig, and then apply the configuration fragment on each invocation. The default `cmd` runs `make`.
+
+In order to run this as an interactive container, and to manually run the `make` process - you can use something like the following:
+
+```bash
+docker run --rm -it \
+  -e DEFCONFIG=am335x_evm_defconfig \
+  -v uboot-2022.07:/app \
+  -v ccache:/ccache \
+  robotpajamas/u-boot-builder:2022.07 bash
+```
+
+## Snippets
+
+### Configuration Fragment
+
+```bash
+# mykconfig.fragment
+
+CONFIG_SYS_REDUNDAND_ENVIRONMENT=y
+CONFIG_ENV_SIZE=0x8000
+CONFIG_ENV_OFFSET=0x100000
+CONFIG_ENV_OFFSET_REDUND=0x200000
+```
+
+### Git Patch
 
 ```bash
-docker run --rm -v uboot-2022.04:/app -v ccache:/ccache -it robotpajamas/u-boot-builder:latest bash
+diff --git a/README b/README
+index b7ab6e50..b36b6e99 100644
+--- a/README
++++ b/README
+@@ -1,6 +1,6 @@
+ # SPDX-License-Identifier: GPL-2.0+
+ #
+-# (C) Copyright 2000 - 2013
++# (C) Copyright 2000 - 2022
+ # Wolfgang Denk, DENX Software Engineering, [email protected].
 
-make am335x_evm_defconfig
-make
+ Summary:
 ```
+
+## TODO
+
+- These should probably be re-done with the `--mount` syntax, as it's clearer for documentation purposes. `-v` is a shortcut.
+- Check if `git apply` can be ignored once applied, or if the error can be ignored

u-boot-builder/docker-entrypoint.sh

@@ -0,0 +1,20 @@
+#! /bin/sh
+
+# Working directory is /app (i.e. u-boot directory)
+
+# Apply u-boot fragment to configuration
+if test -f "/u-boot.patch"; then
+    echo "***** Applying patch at /u-boot.patch *****"
+    git apply /u-boot.patch
+fi
+
+echo "***** Making defconfig: ${DEFCONFIG} *****"
+KBUILD_VERBOSE=1 make ${DEFCONFIG}
+
+# Apply u-boot patch, if present
+if test -f "/u-boot.fragment"; then
+    echo "***** Applying fragment at /u-boot.fragment *****"
+    /app/scripts/kconfig/merge_config.sh /app/.config /u-boot.fragment
+fi
+
+exec "$@"