Build system setup macOS

Tested with macOS 10.15.7, Xcode 12.1 build 12A7403.
Tested with macOS 11.6, Xcode 13.0 build 13A233, arm64 kernel.

Install brew and Xcode.

We will be using a sparsebundle to allow us to have a case sensitive filesystem.

The size that you provide will be the max size of the volume for working with OpenWrt

hdiutil create -size 20g -type SPARSE -fs "Case-sensitive HFS+" -volname OpenWrt OpenWrt.sparseimage
hdiutil attach OpenWrt.sparseimage

Change to the OpenWrt volume and create the necessary directories

cd /Volumes/OpenWrt

Install the necessary packages with brew

brew install coreutils findutils gawk grep gnu-getopt gnu-tar wget diffutils git-extras quilt make ncurses pkg-config

Create a file called env.sh in /Volumes/OpenWrt This is to allow the utilities we just installed to be used instead of the macOS provided ones.

For x86_64 Apple hardware:

PATH="/usr/local/opt/make/libexec/gnubin:$PATH"
PATH="/usr/local/opt/gnu-getopt/bin:$PATH"
PATH="/usr/local/opt/gettext/bin:$PATH"
PATH="/usr/local/opt/coreutils/bin:$PATH"
PATH="/usr/local/opt/findutils/libexec/gnubin:$PATH"
export PATH

For arm64 (Apple Silicon(M1)) Apple hardware:

PATH="/opt/homebrew/opt/make/libexec/gnubin:$PATH"
PATH="/opt/homebrew/opt/gnu-getopt/bin:$PATH"
PATH="/opt/homebrew/opt/gettext/bin:$PATH"
PATH="/opt/homebrew/opt/coreutils/bin:$PATH"
PATH="/opt/homebrew/opt/findutils/libexec/gnubin:$PATH"
export PATH

Check homebrew offical page if you need more information related to PATH variable

When developing do source /Volumes/OpenWrt/env.sh to set up the path variable. This leaves your system in a clean state without symlinking.

Now proceed normally.