README.md

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