README.md

   1 <p align="center">
   2 <img src="media/microwatt-title.png" alt="Microwatt">
   3 </p>
   4
   5 # Microwatt
   6
   7 A tiny Open POWER ISA softcore written in VHDL 2008. It aims to be simple and easy
   8 to understand.
   9
  10 ## Simulation using ghdl
  11 <p align="center">
  12 <img src="http://neuling.org/microwatt-micropython.gif" alt="MicroPython running on Microwatt"/>
  13 </p>
  14
  15 - Build micropython. If you aren't building on a ppc64le box you
  16   will need a cross compiler. If it isn't available on your distro
  17   grab the powerpc64le-power8 toolchain from https://toolchains.bootlin.com
  18
  19 ```
  20 git clone https://github.com/mikey/micropython
  21 cd micropython
  22 git checkout powerpc
  23 cd ports/powerpc
  24 make -j$(nproc)
  25 cd ../../../
  26 ```
  27
  28 - Microwatt uses ghdl for simulation. Either install this from your
  29   distro or build it. Next build microwatt:
  30
  31 ```
  32 git clone https://github.com/antonblanchard/microwatt
  33 cd microwatt
  34 make
  35 ```
  36
  37 - Link in the micropython image:
  38
  39 ```
  40 ln -s ../micropython/ports/powerpc/build/firmware.bin simple_ram_behavioural.bin
  41 ```
  42
  43 - Now run microwatt, sending debug output to /dev/null:
  44
  45 ```
  46 ./core_tb > /dev/null
  47 ```
  48
  49 ## Synthesis on Xilinx FPGAs using Vivado
  50
  51 - Install Vivado (I'm using the free 2019.1 webpack edition).
  52
  53 - Setup Vivado paths:
  54
  55 ```
  56 source /opt/Xilinx/Vivado/2019.1/settings64.sh
  57 ```
  58
  59 - Install FuseSoC:
  60
  61 ```
  62 pip3 install --user -U fusesoc
  63 ```
  64
  65 - Create a working directory and point FuseSoC at microwatt:
  66
  67 ```
  68 mkdir microwatt-fusesoc
  69 cd microwatt-fusesoc
  70 fusesoc library add microwatt /path/to/microwatt/
  71 ```
  72
  73 - Build using FuseSoC. For hello world (Replace nexys_video with your FPGA board):
  74
  75 ```
  76 fusesoc run --target=nexys_video microwatt --memory_size=8192 --ram_init_file=/path/to/microwatt/fpga/hello_world.hex
  77 ```
  78
  79 - To build micropython (currently requires 1MB of BRAM eg an Artix-7 A200):
  80
  81 ```
  82 fusesoc run --target=nexys_video microwatt
  83 ```
  84
  85 ## Testing
  86
  87 - A simple test suite containing random execution test cases and a couple of
  88   micropython test cases can be run with:
  89
  90 ```
  91 make -j$(nproc) check
  92 ```
  93
  94 ## Issues
  95
  96 This is functional, but very simple. We still have quite a lot to do:
  97
  98 - There are a few instructions still to be implemented
  99 - Need to add caches and bypassing (in progress)
 100 - Need to add supervisor state (in progress)