2 <img src="media/microwatt-title.png" alt="Microwatt">
7 A tiny Open POWER ISA softcore written in VHDL 2008. It aims to be simple and easy
10 ## Simulation using ghdl
12 <img src="http://neuling.org/microwatt-micropython.gif" alt="MicroPython running on Microwatt"/>
15 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.
17 - Build micropython. If you aren't building on a ppc64le box you
18 will need a cross compiler. If it isn't available on your distro
19 grab the powerpc64le-power8 toolchain from https://toolchains.bootlin.com.
20 You may need to set the CROSS_COMPILE environment variable
21 to the prefix used for your cross compilers. The default is
22 powerpc64le-linux-gnu-.
25 git clone https://github.com/micropython/micropython.git
32 A prebuilt micropython image is also available in the micropython/ directory.
34 - Microwatt uses ghdl for simulation. Either install this from your
35 distro or build it. Microwatt requires ghdl to be built with the LLVM
36 or gcc backend, which not all distros do (Fedora does, Debian/Ubuntu
37 appears not to). ghdl with the LLVM backend is likely easier to build.
39 If building ghdl from scratch is too much for you, the microwatt Makefile
40 supports using Docker or Podman.
42 - Next build microwatt:
45 git clone https://github.com/antonblanchard/microwatt
50 To build using Docker:
55 and to build using Podman:
61 - Link in the micropython image:
64 ln -s ../micropython/ports/powerpc/build/firmware.bin main_ram.bin
67 Or if you were using the pre-built image:
70 ln -s micropython/firmware.bin main_ram.bin
73 - Now run microwatt, sending debug output to /dev/null:
79 ## Synthesis on Xilinx FPGAs using Vivado
81 - Install Vivado (I'm using the free 2019.1 webpack edition).
86 source /opt/Xilinx/Vivado/2019.1/settings64.sh
92 pip3 install --user -U fusesoc
94 Fedora users can get FuseSoC package via
96 sudo dnf copr enable sharkcz/danny
97 sudo dnf install fusesoc
100 - Create a working directory and point FuseSoC at microwatt:
103 mkdir microwatt-fusesoc
105 fusesoc library add microwatt /path/to/microwatt/
108 - Build using FuseSoC. For hello world (Replace nexys_video with your FPGA board such as --target=arty_a7-100):
111 fusesoc run --target=nexys_video microwatt --memory_size=16384 --ram_init_file=/path/to/microwatt/fpga/hello_world.hex
113 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.
115 - To build micropython (currently requires 1MB of BRAM eg an Artix-7 A200):
118 fusesoc run --target=nexys_video microwatt
123 - A simple test suite containing random execution test cases and a couple of
124 micropython test cases can be run with:
127 make -j$(nproc) check
132 This is functional, but very simple. We still have quite a lot to do:
134 - There are a few instructions still to be implemented
135 - Need to add caches and bypassing (in progress)
136 - Need to add supervisor state (in progress)