Pronounced "
Kernel-lua" (as one word), capitalized as a noun.Luaby itself has a capitalL: http://www.lua.org/about.html#name.
Kernelua is a Rasberry Pi kernel written in C that allows running Lua as the operating system of a device. The primary goal is to run ComputerCraft's CraftOS on real hardware (ideally in a Pocket Computer enclosure).
This project is based on the valvers.com tutorial, check it out: https://www.valvers.com/open-software/raspberry-pi/bare-metal-programming-in-c-part-1.
It also makes use of USPi, a bare-metal USB driver for the RPi 1-3: https://github.com/rsta2/uspi (very cool).
Kernelua is not ready for production use yet, so to run it you must create a bootable SD card image manually.
The SD card must contain bootcode.bin, fixup.dat, and start.elf from the Rasberry Pi repo: https://github.com/raspberrypi/firmware, and the kernel.img created by building this project (output in build/bin, see #Compiling below).
Additionally, I had to add a config.txt with the following contents to fix some weird margins with my display:
disable_overscan=1
The firmware will still properly boot without this file present, at least on my RPi3B+, it just caused the display to appear blurry which completly ruined the point of using an 8x8 pixel font.
Kernelua is built using GNU make (unlike the tutorial which uses Cmake), so compiling is about as simple as running make.
However, you must first download the ARM compiler from the Arm website: https://developer.arm.com/tools-and-software/open-source-software/developer-tools/gnu-toolchain/gnu-rm/downloads and extract it to compiler/gcc-arm-none-eabi-VERSION/.
I only own a Rasberry Pi 3B+, and currently the build system only sets the proper flags for this model. If you have a different model, uhh look at the makefile and have fun :) Also if u use VS Code add the flags to the C/C++ extension settings so it doesn't yell at you.