+<p align="center">
+<img src="media/microwatt-title.png" alt="Microwatt">
+</p>
+
# Microwatt
A tiny Open POWER ISA softcore written in VHDL 2008. It aims to be simple and easy
to understand.
-## Simulation
+## Simulation using ghdl
+<p align="center">
+<img src="http://neuling.org/microwatt-micropython.gif" alt="MicroPython running on Microwatt"/>
+</p>
+
+You can try out Microwatt/Micropython without hardware by using the ghdl simulator. If you want to build directly for a hardware target board, see below.
- 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
+ grab the powerpc64le-power8 toolchain from https://toolchains.bootlin.com.
+ You may need to set the CROSS_COMPILE environment variable
+ to the prefix used for your cross compilers. The default is
+ powerpc64le-linux-gnu-.
```
-git clone https://github.com/mikey/micropython
+git clone https://github.com/micropython/micropython.git
cd micropython
-git checkout powerpc
cd ports/powerpc
make -j$(nproc)
cd ../../../
```
+ A prebuilt micropython image is also available in the micropython/ directory.
+
- Microwatt uses ghdl for simulation. Either install this from your
- distro or build it. Next build microwatt:
+ distro or build it. Microwatt requires ghdl to be built with the LLVM
+ or gcc backend, which not all distros do (Fedora does, Debian/Ubuntu
+ appears not to). ghdl with the LLVM backend is likely easier to build.
+
+ If building ghdl from scratch is too much for you, the microwatt Makefile
+ supports using Docker or Podman.
+
+- Next build microwatt:
```
git clone https://github.com/antonblanchard/microwatt
cd microwatt
make
+```
+
+ To build using Docker:
+```
+make DOCKER=1
+```
+
+ and to build using Podman:
+
+```
+make PODMAN=1
```
- Link in the micropython image:
```
-ln -s ../micropython/ports/powerpc/build/firmware.bin simple_ram_behavioural.bin
+ln -s ../micropython/ports/powerpc/build/firmware.bin main_ram.bin
+```
+
+ Or if you were using the pre-built image:
+
+```
+ln -s micropython/firmware.bin main_ram.bin
```
- Now run microwatt, sending debug output to /dev/null:
./core_tb > /dev/null
```
+## Synthesis on Xilinx FPGAs using Vivado
+
+- Install Vivado (I'm using the free 2019.1 webpack edition).
+
+- Setup Vivado paths:
+
+```
+source /opt/Xilinx/Vivado/2019.1/settings64.sh
+```
+
+- Install FuseSoC:
+
+```
+pip3 install --user -U fusesoc
+```
+Fedora users can get FuseSoC package via
+```
+sudo dnf copr enable sharkcz/danny
+sudo dnf install fusesoc
+```
+
+- Create a working directory and point FuseSoC at microwatt:
+
+```
+mkdir microwatt-fusesoc
+cd microwatt-fusesoc
+fusesoc library add microwatt /path/to/microwatt/
+```
+
+- Build using FuseSoC. For hello world (Replace nexys_video with your FPGA board such as --target=arty_a7-100):
+
+```
+fusesoc run --target=nexys_video microwatt --memory_size=16384 --ram_init_file=/path/to/microwatt/fpga/hello_world.hex
+```
+You should then be able to see output via the serial port of the board (/dev/ttyUSB1, 115200 for example assuming standard clock speeds). There is a know bug where initial output may not be sent - try the reset (not programming button) on your board if you don't see anything.
+
+- To build micropython (currently requires 1MB of BRAM eg an Artix-7 A200):
+
+```
+fusesoc run --target=nexys_video microwatt
+```
+
## Testing
- A simple test suite containing random execution test cases and a couple of
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)
projects / microwatt.git / blobdiff