Details see official OpenWrt instructions.

Usually the following is sufficient:

• sudo apt-get install git-core build-essential libssl-dev libncurses5-dev unzip gawk zlib1g-dev

Additionally, we need quilt to patch the OpenWrt tree with p44b before running make for the first time (which will build quilt), so we just install it:

• sudo apt-get install quilt

1. OpenWrt needs a case sensitive file system, but macOS by default has a case insensitive file system. So OpenWrt needs to be put on a volume with case sensitive file system.

   On macOS before 10.13, you can create a sparse image of ~20GB with Disk Utility.

   With macOS 10.13 and later, the APFS file system allows creating extra volumes without partitioning or reserving any space - this is much better than a disk image (Disk Utility -> Edit -> Add APFS volume...)

2. XCode needs to be installed

3. Some utilities are needed from homebrew

   • install brew as described here
   • brew tap homebrew/dupes
   • brew install coreutils findutils gawk gnu-getopt gnu-tar grep wget quilt xz
   • brew ln gnu-getopt --force

Also see OpenWrt Quick Image Building docs for general info about OpenWrt bootstrap.

Assuming that you've created and mounted a case sensitive volume named CaseSens already (macOS case, for Linux just use any directory of your choice):

cd /Volumes/CaseSens
git clone -o openwrt.org -b openwrt-18.06 https://git.openwrt.org/openwrt/openwrt.git openwrt

Note: this is a script that helps managing differently configured OpenWrt targets on top of an unpolluted OpenWrt original tree.

git clone -o github https://github.com/plan44/p44build.git

Go to the directory where you checked out OpenWrt and p44build (/Volumes/CaseSens on macOS according to the steps above). Then:

cd openwrt
git checkout -b pixelboard v18.06.2

# do NOT change feeds.conf.default - custom changes belong into feeds.conf!
cp feeds.conf.default feeds.conf
echo "src-git plan44 https://github.com/plan44/plan44-feed.git;master" >>feeds.conf
echo "src-git onion https://github.com/OnionIoT/OpenWRT-Packages.git" >>feeds.conf

./scripts/feeds update -a

OpenWrt clones only a shallow (no history) copy of the feed repository. This saves space, but limits git operations (and crashes tools like GitX). The following steps convert the feed into a regular repository:

pushd feeds/plan44
git fetch --unshallow
popd

TARGET_CFG_PACKAGE="plan44/pixelboard-config"
../p44build/p44b init feeds/${TARGET_CFG_PACKAGE}/p44build

./p44b prepare

Note: My standard setup disables any password based login by default, by providing a modified shadow file in files/etc/shadow. If you want the standard OpenWrt default of no initial password, then delete this extra file now:

rm files/etc/shadow

only install (= make ready for OpenWrt to potentially build at all) those packages that were recorded present at last './p44b save':

./p44b instpkg

or just install all packages from all feeds:

./scripts/feeds install -a

1. If python/python3 package is installed, make will try to host-compile it and fail on macOS. As we don't need python at all, just make sure those packages are not installed:

   • ./scripts/feeds uninstall python
   • ./scripts/feeds uninstall python3

2. For pixelboardd, make sure the plan44 version of i2c-tools is installed, not the standard package. The difference is that it does not include python stuff, but installs the needed enhanced i2c-dev.h header plus a copy as lib-i2c-dev.h:

   • ./scripts/feeds uninstall i2c-tools
   • ./scripts/feeds install -p plan44 i2c-tools

# shows all possible targets, currently only Omega2
./p44b target

# select the target
./p44b target pixelboard-omega2

make menuconfig

make
# or, if you have multiple CPU cores you want to use (3, here)
# to speed up things, allow parallelizing jobs:
make -j 3

Note: when doing this for the first time, it takes a looooong time (hours). This is because initial OpenWrt build involves creating the compiler toolchain, and the complete linux kernel and tools. Subsequent builds will be faster.

If everything went well, the OpenWrt build process will have produced a ready-to-flash firmware image in bin/targets/ramips/mt7688. You can now send this to the Omega2 and flash it (of course, to actually get a Pixelboard you'd need to have built the hardware around it)

# specify the IP address of your Omega2 here (for the p44b send and login subcommands)
export TARGET_HOST=192.168.11.86

# copy FW image to the Omega2
./p44b send

# login to the Omega2 (you might want to do that in a separate terminal)
./p44b login

# on the Omega2, flash the new firmware image
cd /tmp
sysupgrade -n pixelboard-*.bin

After that, Omega reboots and is now a Pixelboard controller :-)

./p44b save

This records the precise details of this build into feeds/plan44/pixelboard-config/p44build, in particular the OpenWrt tree's SHA and .config as well as the SHAs of the feeds used. The idea is that this can be committed back into the pixelboard-config package, as kind of a "head" record for this very pixelboard firmware build, and allows to go back to this point later, even if the OpenWrt tree was used to build other firmware images in between (in fact, exactly that is the very purpose of p44b - the ability to work and switch between different firmware projects in a single OpenWrt tree)