A tiny Open POWER ISA softcore written in VHDL 2008

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Anton Blanchard 37fe8b954c Add a few more FPGA related files Add a temporary gcc patch to remove hardware divide instructions. Also add a firmware.hex file built with a gcc with the above patch. Right now micropython assumes 1MB of BRAM, which limits the FPGAs we can run on. We should be able to cut it down somewhat. Signed-off-by: Anton Blanchard <anton@linux.ibm.com>		6 years ago
fpga	Add a few more FPGA related files	6 years ago
scripts	Initial import of microwatt	6 years ago
tests	Initial import of microwatt	6 years ago
.gitignore	Initial import of microwatt	6 years ago
LICENSE	Initial import of microwatt	6 years ago
Makefile	Initial import of microwatt	6 years ago
README.md	Initial import of microwatt	6 years ago
common.vhdl	Initial import of microwatt	6 years ago
core.vhdl	Initial import of microwatt	6 years ago
core_tb.vhdl	Initial import of microwatt	6 years ago
cr_file.vhdl	Initial import of microwatt	6 years ago
crhelpers.vhdl	Initial import of microwatt	6 years ago
decode1.vhdl	Initial import of microwatt	6 years ago
decode2.vhdl	Initial import of microwatt	6 years ago
decode_types.vhdl	Initial import of microwatt	6 years ago
execute1.vhdl	Initial import of microwatt	6 years ago
execute2.vhdl	Initial import of microwatt	6 years ago
fetch1.vhdl	Initial import of microwatt	6 years ago
fetch2.vhdl	Initial import of microwatt	6 years ago
glibc_random.vhdl	Initial import of microwatt	6 years ago
glibc_random_helpers.vhdl	Initial import of microwatt	6 years ago
helpers.vhdl	Initial import of microwatt	6 years ago
loadstore1.vhdl	Initial import of microwatt	6 years ago
loadstore2.vhdl	Initial import of microwatt	6 years ago
multiply.vhdl	Initial import of microwatt	6 years ago
multiply_tb.vhdl	Initial import of microwatt	6 years ago
ppc_fx_insns.vhdl	Initial import of microwatt	6 years ago
register_file.vhdl	Initial import of microwatt	6 years ago
sim_console.vhdl	Initial import of microwatt	6 years ago
sim_console_c.c	Initial import of microwatt	6 years ago
simple_ram_behavioural.vhdl	Initial import of microwatt	6 years ago
simple_ram_behavioural_helpers.vhdl	Initial import of microwatt	6 years ago
simple_ram_behavioural_helpers_c.c	Initial import of microwatt	6 years ago
simple_ram_behavioural_tb.bin	Initial import of microwatt	6 years ago
simple_ram_behavioural_tb.vhdl	Initial import of microwatt	6 years ago
wishbone_arbiter.vhdl	Initial import of microwatt	6 years ago
wishbone_types.vhdl	Initial import of microwatt	6 years ago
writeback.vhdl	Initial import of microwatt	6 years ago

README.md

Microwatt

A tiny Open POWER ISA softcore written in VHDL 2008. It aims to be simple and easy to understand.

Simulation

Build micropython. If you aren't building on a ppc64le box you will need a cross compiler. If it isn't available on your distro grab the powerpc64le-power8 toolchain from https://toolchains.bootlin.com

git clone https://github.com/mikey/micropython
cd micropython
git checkout powerpc
cd ports/powerpc
make -j$(nproc)
cd ../../../

Microwatt uses ghdl for simulation. Either install this from your distro or build it. Next build microwatt:

git clone https://github.com/antonblanchard/microwatt
cd microwatt
make

Link in the micropython image:

ln -s ../micropython/ports/powerpc/build/firmware.bin simple_ram_behavioural.bin

Now run microwatt, sending debug output to /dev/null:

./core_tb > /dev/null

Testing

A simple test suite containing random execution test cases and a couple of micropython test cases can be run with:

make -j$(nproc) check

Issues

This is functional, but very simple. We still have quite a lot to do:

Need to implement a simple non pipelined divide
There are a few instructions still to be implemented
Need to add caches and bypassing (in progress)
Need to add supervisor state (in progress)