Port of GNU GCC and Binutils for the TI PRU I/O processor.

Introduction

This is an unofficial GCC/Binutils port for the PRU I/O CPU core that is present in TI Sitara AM33xx SoCs. Older PRU core versions are not supported.

The release is ready for cautious usage. A simulator is used to execute the GCC C regression test suite. Results for this release are:

# of expected passes           81497
# of unexpected failures       31
# of unexpected successes      1
# of expected failures	       97
# of unsupported tests	       1974

There are several examples to get started:

Assorted small examples: https://github.com/dinuxbg/pru-gcc-examples
GCC port of the TI PRU training: https://github.com/dinuxbg/pru-software-support-package . Make sure to read ReadMe-GCC.txt.

Bug reports should be filed in https://github.com/dinuxbg/gnupru/issues . For general questions please use http://beagleboard.org/Community/Forums .

This project has no relation to the TI PRU C compiler. ABI differences between GCC PRU and TI PRU C are tracked in https://github.com/dinuxbg/gnupru/wiki

Building

The toolchain is published as a series of patches inside the patches subdirectory. The build scripts are tested on a Debian host, but should work on any recent distro.

You'll need some prerequisites. For a Debian host:

sudo apt-get install build-essential libmpfr-dev libgmp-dev libmpc-dev texinfo libncurses5-dev bison flex

Then it should be a simple matter of:

export PREFIX=$HOME/bin/pru-gcc   # Define where to install the toolchain
./download-and-patch.sh           # Download and patch the sources
./build.sh                        # Build

Creating Debian Packages From Scratch

There are experimental scripts for packaging binutils and gcc+newlib.

Installing the prerequisites:

sudo apt-get install dh-autoreconf libgmp-dev libmpfr-dev libmpc-dev libzip-dev

Building and packaging:

./download-and-patch.sh           # Download and patch the sources
./package-binutils.sh
sudo dpkg -i packaging/binutils-pru*.deb
./package-gcc-newlib.sh
sudo dpkg -i packaging/gcc-pru*.deb

Testing the output:

pru-as --version
pru-gcc --version

Acknowledgements

GCC/Binutils Nios2 port was taken as a base for the PRU port.

TODO

A few long term tasks:

Need to review the GCC function prologue handling. Current code is a direct copy of the Nios2 code. It should be correct but is not efficient for PRU.
Investigate feasibility of "packed" register support in GCC. PRU port may have to be rewritten to use "virtual" 8-bit registers in order to allow more efficient variable packing.

ursfassler / gnupru