Skip to content


Subversion checkout URL

You can clone with
Download ZIP
Distributed FPGA Number Crunching for the Masses
Verilog Python VHDL
Branch: master

Fetching latest commit…

Cannot retrieve the latest commit at this time

Failed to load latest commit information.


A very quick&dirty guide to brute force DES:

1. Build xc3sprog.
2. Make sure that xc3sprog -j finds your FPGA board.
   - I tend to like FTDI JTAG cables. If you use something else, you might
     have to add support into xc3sprog's python wrapper.
3. Install "crunchy" python library
   - cd src/crunchy; python install
4. Use "build_design" to build a bitstream for your board:
   - python Dance2048 descrack \
5. initialize project:
   - python descrack init descrack WORKUNIT_BITS=38
   - python descrack adduser username password
   - python descrack add_pattern 0 3237433300000000
     (add more patterns if you like)
6. run server:
   - python descrack
7. run client:
   - PYTHONPATH=../xc3sprog/ python descrack \
       NR_CORES=6,WORKUNIT_BITS=38,NR_RESULTS=16 Dance2048 http://localhost:8880 \
       username password --productid=0x6011 --instances=9 --bitstream=dance2048_6_16_38.bit
     "product id" here is the usb PID of m FTDI cable. 

A more descriptive guide of what the tools do:

== xc3sprog == 

xc3sprog is a branch of the well-known xc3sprog that's used a backend method
to talk to the FPGA. There is a very simple python wrapper around it that
allows to do three things:

1. Chain enumeration
2. Programming bitstreams
3. Talking with USER chains

== ==

build_design builds a bitstream based on the

- board description,
- project HDL code,
- parameters for the project.

A sample invokation would be

python Dance2048 descrack NR_CORES=6,WORKUNIT_BITS=38,NR_PATTERNS=16

which would build the "descrack" project for a "Dance2048" board with the


A project will pass these parameters to the HDL, and usually use
"generics"/"parameters" to configure the HDL code. In this case, the
descrack project is told to use 6 DES cores (per FPGA), a workunit size of
38 bits, and match up to 16 patterns.

== ==

Command-line interface to the server. A running project uses a
sqlite-backed database to store information, like the state of the
workunits and meta-information (users, per-project configuration like match 

Supported commands are:

"results" - shows results
"adduser" - adds a user (client)
"users" - lists users
"status" - get project status (short for "progress", "pending", "results")
"pending" - shows workunits that have been allocated, but not completed
"expire --seconds 3600" - expires workunits that have been allocated >=
  3600s ago
"init <project> <parameters>" - initializes a runtime-project based on
  the named project, with the given parameters. Some parameters are global
  (for descrack for example WORKUNIT_BITS), some are per-client (NR_CORES)
  and don't need to be given here (obviously, since they might differ per

for descrack: (yes, this is not abstracted very well yet)
"add_pattern 0 0011223344556677" - add a pattern to search for

== ==

runs a http server (on port 8880) that's used by the client. You have to
initialize the project first using the cli, but you can do changes (expire
workunits, add users) while having the server running. Obviously adding
patterns would be a bad idea.

== ==

The actual code that talks to the FPGA (with, the python wrapper
around xc3sprog). 

sample invokation:
PYTHONPATH=../xc3sprog/ python descrack \
  NR_CORES=6,WORKUNIT_BITS=38,NR_RESULTS=16 Dance2048 http://localhost:8880 \
  username password --productid=0x6011 --instances=9 --bitstream=dance2048_6_16_38.bit

"descrack" is the project to run on. It must match with the server's name of
the database.

"NR_CORES..." are the parameters that have to BOTH match the actual
bitstream, *and* the server. No validation is done (yet).

"Dance2048" is the board that's used. 

"http://localhost:8880" is the URL of the server.

"username password" is the (very weak) authentication with the server. Don't
rely on it!

"--productid=0x6011" sets the USB product ID for an FTDI cable. This is
obviously specific to your JTAG cable. "" currently assumes FTDI
cables, but that can be fixed.

"--instances" sets the number of boards that are within one chain. They all
need to be of the same type.

"--bitstream" specifies the generated bitstream that has been generated with

Something went wrong with that request. Please try again.