RetroBSD is an embedded version of 2.11BSD for PIC32 micro-controllers.

First we need to fetch a working cross-compiler. RetroBSD supports this one in Linux.

cd /usr/local
wget https://github.com/downloads/jasonkajita/chipKIT-cxx/pic32-tools-chipKIT-cxx-master-Linux32-image-20120720.zip
unzip pic32-tools-chipKIT-cxx-master-Linux32-image-20120720.zip

Now we fetch the RetroBSD source from GitHUB.

mkdir -p /embedded
cd /embedded
git clone https://github.com/RetroBSD/retrobsd.git
cd retrobsd

In this example we will configure RetroBSD for the SDXL board.

First select the SDXL.

sed -i 's/(MAX32)/(SDXL)/' Makefile

Now we will enable two UARTS. Edit the following file,

vi sys/pic32/sdxl/Makefile

and add the following within the DEFS section, save the file.

DEFS += -DUART1_BAUD=115200
DEFS += -DUART1_ENABLED=YES
DEFS += -DUART2_BAUD=115200
DEFS += -DUART2_ENABLED=YES

Now edit the kernel configuration to enable the devices.

vi sys/pic32/sdxl/SDXL

Add the following options to enable the UARTS.

# tty0
device uart1 baud=115200
# tty1
device uart2 baud=115200

Building will create the unix boot image and the SDcard image for the system.

make cleanall
make

Hold the PROG button and toggle RESET. We will use Pickle pload to install the kernel.

pload program /dev/ttyACM0 sys/pic32/sdxl/unix.hex 24
Total: 157004
Time: 0:08.45s