buildbrain

This repository includes:

• linux-brain, u-boot-brain and boot4u as submodules
• Useful build targets in Makefile
• r3build.toml to watch changes that occur in submodules

Confirmed environments

• Debian 10 (buster) amd64

Getting Started

1. Install dependencies.

   $ sudo apt install build-essential bison flex libncurses5-dev gcc-arm-linux-gnueabihf libssl-dev bc lzop
   $ pip install pyelftools
   

2. Clone this repository with recursive clone enabled.

   $ git clone --recursive git@github.com:brain-hackers/buildbrain.git
   

   • If you've cloned it without --recursive, run following command:

   $ git submodule update --init --recursive
   

Build U-Boot

1. Run make udefconfig to generate .config.

2. Run make ubuild to build whole repository and generate u-boot.bin.

Build and deploy boot4u

1. Run make boot4u

2. Create index.din and copy AppMain.bin

   • mkdir /path/to/your/sd/1st/partition/App/boot4u
   • touch /path/to/your/sd/1st/partition/App/boot4u/index.din
   • cp boot4u/AppMain.bin /path/to/your/sd/1st/partition/App/boot4u/

Build Linux

1. Run make ldefconfig to generate .config.

2. Run make lbuild to generate zImage.

3. Confirm that linux-brain/arch/arm/boot/zImage exists.

Bootstrap Debian 10 (buster)

1. Partition an SD card into two partitions.

   • 1st: FAT32 (vfat), about 100MB
   • 2st: ext4, fill the remaining area

2. Build and copy the Linux kernel.

   • Run make ldefconfig lbuild.
   • Copy /linux-brain/arch/arm/boot/zImage and /linux-brain/arch/arm/boot/dts/imx7ulp-pwh1.dtb into the 1st partition.

3. Run APT cache in background (mandatory): make aptcache.

4. Run make debian.

5. Copy all contents in ./brainux into the 2nd partition.

   • sudo cp -ar ./brainux/* /path/to/your/sd/2nd/partition/
   • Please make sure that all attributes are preserved with -a flag.

Known issues

If you using gcc 10 for host compiler, make ubuild may fail.
To complete build, open u-boot-brain/scripts/dtc/dtc-lexer.lex.c or u-boot-brain/scripts/dtc/dtc-parser.tab.c then comment out YYLTYPE yylloc;

Watch changes in submodules & auto-build

1. Run make setup-dev to prepare a Python venv to watch code changes. Namely;

   • Python 3 venv in env
   • r3build command in the env

2. Run r3build. It'll detect the changes you make and builds the corresponding executable automatically.

What's r3build?

r3build is a smart file watcher that aims to provide hot-reloading feature like Web frontend development.