Tag Archives: fpga

OpenRISC: Making the stack 100% free

Posted on June 21, 2011 1 comment

OpenRISC is the flagship project of the OpenCores community. This project aims to develop a series of general purpose open source RISC CPU architectures.

The OpenRISC 1200 (OR1200) is a synthesizable CPU core that runs on FPGAs from a broad number of vendors, and is currently being used in a number of successful industrial projects. This CPU is an open source implementation (LGPL) of the OpenRISC 1000 RISC architecture.

These days the project has reached an important milestone: they have submitted their patches for review to the Linux kernel mailing list and hopefully they will get it merged, so Linux will officially support the OpenRISC architecture.

This are exciting news!

If you have a FPGA board you can load it with the OpenRISC softcore and execute Linux on it (demo video).

But if you don’t have one, then you can try the nice OpenRISC emulator: its easy and funny.
Here is a link to the detailed howto, and here is my cheat sheet:

sudo apt-get install build-essential libmpc-dev lzop git-core
sudo apt-get build-dep gcc-4.4
mkdir ~/openrisc
cd ~/openrisc
git clone git://openrisc.net/jonas/or1ksim-svn
cd or1ksim-svn
./configure && make && sudo make install
cd ~/openrisc
git clone git://openrisc.net/jonas/toolchain
cd toolchain
git submodule update --init
# go for a coffee
export PATH=~/openrisc/toolchain/bin:$PATH
make PREFIX=~/openrisc/toolchain
cd linux
make ARCH=openrisc defconfig
make CROSS_COMPILE=or32-linux-
# go for a tea
sim -f arch/openrisc/or1ksim.cfg vmlinux

And voila! You are running a 100% free system, from the CPU to the Operating System, including the Wishbone bus :)

# cat /proc/cpuinfo
cpu                     : OpenRISC-18
revision                : 1
dcache size             : 8192 kB
dcache block size       : 16 bytes
icache size             : 8192 kB
icache block size       : 16 bytes
immu                    : 64 entries, 1 ways
dmmu                    : 64 entries, 1 ways
bogomips                : 40.00

As the OpenRISC 1000 is now considered stable, the OpenCores project is trying to build a cost-efficient ASIC with this design to get improved performance. They launched a call for donations in 2011 with the aim to produce the first ASIC in Q1 2012.

I am willing to get one of this!

The open-source methodology is here to stay, just take a look at the success story behind Linux/Android, and all the great benefits that open-source offers. We now need to take the next step with open-source hardware development, meaning to actually create “true” open-source Semiconductor components in order to stay competitive, and to make sure that smaller companies can compete with large Semiconductor giants. So please join us and help us rewrite the history books for hardware development…