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

Table Of Contents

• Introduction
• Examples
• Getting The Cross Toolchain
  • Installing On Beagleboard Debian
  • Prebuilt Tarballs
  • Building Using Crosstool-ng
  • Building From Sources
• Acknowledgements

Introduction

This is a collection of documentation and build scripts for the GNU toolchain targeting the PRU I/O CPU. PRU cores present in TI Sitara AM33xx and later SoCs are supported.

Support for older PRU core versions is not planned.

A simulator is used to execute the GCC C regression test suite. Results are posted daily to https://gcc.gnu.org/pipermail/gcc-testresults/ .

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

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

Examples

There are several examples to get started:

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

Getting The Cross Toolchain

Several methods to acquire the PRU cross toolchain are listed below, ordered by most convenient first.

Installing On Beagleboard Debian

If you are running a Beagleboard Debian Image, then installation is simple:

sudo apt-get update
sudo apt-get install gcc-pru gnuprumcu

Prebuilt Tarballs

Latest releases provide prebuilt tarballs for several hosts: amd64 Linux, armhf Linux, Windows. Simply download, untar and use them when:

• You want to cross-compile PRU firmware from amd64 Linux or Windows host.
• You are using an armhf distribution other than Beagleboard Debian Image.

Note for maintainers: These prebuilt release tarballs are prepared using the build-crosstool-ng.sh script.

Building Using Crosstool-ng

Recently crosstool-ng acquired pru support. Provided you build top-of-tree crosstool-ng, you should be able to:

$ ct-ng pru
$ ct-ng build
$ PATH=$HOME/x-tools/pru-elf/bin:$PATH

Building From Sources

The custom build scripts are should work on any recent Linux distro. They are intended to be simple enough, so that they can act as a documentation how to cross-compile a toolchain. They intentionally lack some features:

• Downloaded source tarballs are not verified.
• Host binaries are not stripped, leading to bigger host executables sizes. Target firmware size is not affected, though!
• Code complexity is kept at only about 100 lines of simple BASH statements.

Users may find that Beagleboard Debian Packages, or prebuilt releases or crosstool-ng are instead more suitable for production.

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 texinfo

Alternatively, for a Fedora host:

sudo dnf install @development-tools g++ mpfr-devel gmp-devel libmpc-devel texinfo texinfo-tex texlive-cm-super* texlive-ec ncurses-devel bison flex

Then it should be a simple matter of:

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

Acknowledgements

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