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

First we create the file system image on a micro SD card. 4GB is ample.

dd if=sdcard.img of=/dev/sdc bs=4M

Next, Hold the PROG button and toggle RESET on the SDXL board to enter the boot laoder. 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