luajitpi

LuaJIT + TinyCC on RPi bare metal.

This has only been tested on an RPi B+. The changes to make this run on the RPi2 are probably easy (just the GPIO addresses) but I've not tested this!

Compiling

I built the arm-none-eabi toolchain from source on Linux (lubuntu on x64) using a modified version of the script from https://gist.github.com/cjmeyer/4251208 I used:

• binutils 2.27
• GCC 4.9.4
• newlib 2.4.0
• gdb 7.9

The script I used is included in build_toolchain/ as arm-none-eabi.sh

The Debian arm-none-eabi package may also work, but I haven't tried it yet.

LuaJIT

LuaJIT 2.0.4 compiles easily if you:

modify the Makefile to uncomment the line

    XCFLAGS += -DLUAJIT_USE_SYSMALLOC

(which forces LuaJIT to use the newlib malloc()) and change the BUILDMODE from mixed to static

    BUILDMODE= static
    

then compile with: make HOST_CC="gcc -m32" CROSS="arm-none-eabi-"

To enable dynamic link loading, edit lj_arch.h and adjust the LJ_TARGET_DLOPEN to

#define LJ_TARGET_DLOPEN 1

add edit lj_clib.c and lib_package.c to include "ldl.h" instead of <dlfcn.h>.

Note that luajit itself won't build (because libdl is missing) but this isn't important as libluajit.a will be built succesfully.

TinyCC

I had to modify TCC slightly to make it compile without standard libraries or dynamic link support; see the modified version in tcc/. Note that TCC is distributed under an LGPL license. The modification just add some stubs to tccrun.c, and adjust the Makefile to remove libdl

I used version 0.9.26 of TinyCC.

UART access

I based the UART access on dwelch67's newlib example, but the current version uses the code from rpi-boot.

The bootloader in bootloader/ is a slightly modified version of dwelch67's bootloader07 (it prints dots and flashes the LED during loading, as the images are very large and it is nice to see some progress indication!).