Introduction
 fpgatools is a toolchain to program field-programmable gate arrays
 (FPGAs). The only supported chip at this time is the xc6slx9, a
 7 USD 45nm-generation fpga with 5720 6-input LUTs, block ram and
 multiply-accumulate devices.

 *) maximize chip performance
 *) fast development cycles
 *) independent toolchain that only depends on other free software
 *) reconfigure on-chip
 *) include get-started tools such as jtag, debugging, parts data
    and designs for prototyping hardware
 *) design flow that includes asic manufacturing
 *) lightweight C implementation without GUI
 *) supported platform: Linux
 *) license: public domain

FAQ
 todo

Libraries

- libfpga-cores      reusable cores
- libfpga-stdlib     standard design elements on top of libfpga-control
- libfpga-control    programmatic access to libfpga-model
- libfpga-model      memory-only representation of an FPGA
- libfpga-floorplan  reads and writes .fp floorplan files
- libfpga-bit        reads and writes .bit bitstream files

Design Utilities

- hello_world        outputs an AND gate floorplan to stdout
- blinking_led       outputs blinking led design to stdout
- new_fp             creates empty .fp floorplan file
- fp2bit             converts .fp floorplan into .bit bitstream
- bit2fp             converts .bit bitstream into .fp floorplan
- draw_svg_tiles     draws a simple .svg showing tile types

fpgatools Development Utilities

- autotest           test suite
- sort_seq           sorts line-based text file by sequence numbers in strings
- merge_seq          merges a pre-sorted text file into wire sequences
- pair2net           reads the first two words per line and builds nets
- hstrrep            high-speed hashed array based search and replace util

Profiling

~# time ./hello_world
~# perf record ./hello_world
~# perf annotate
~# perf report

Design Principles

- small independent command line utilities, no GUI
- plain C, no C++
- simple Makefiles
- text-based file formats
- automatic test suite
- public domain software

TODO (as of January, 2013)

short-term (1 month):
* example: counter (including clock, jtag)
* support xc6slx9-ftg256

mid-term (6 months):
* example: j1 soc
* llvm backend
* maybe fp2bit should natively write ieee1532 and separate tools convert
  from ieee1532 to .bit and other formats
* configuration of bram and macc blocks, bram initialization data
* more cases in logic block configuration
* autotest: fix bugs in lut_encoding, logic_cfg, routing_sw, io_sw tests
* autotest: protect stderr of diff executable in autotest log
* 3 Debian packages: libfpga, libfpga-doc, fpgatools
* support chips other than xc6slx9, maybe an ftg256 or fgg484-packaged
  xc6 or the xc7a100
* write standard design elements for libfpga-stdlib library
* several places might benefit from a bison parser:
  - switchbox description into bit parser/generator (bit_frames.c)
  - inter-tile wire connections (model_conns.c)
  - configure devices and route wires

cleanup (whenever convenient):
* use tile flags instead of tile names
* model connections and switches together rather than separately
* describe more wire names/meanings with integers instead of strings
* move all part-specific static data into xc_info()

long-term (>6 months):
* auto-crc calculation in .bit file
* MCB switches and connections
* support lm32 or openrisc core, either via libfpga or iverilog backend
* ipv6 or vnc in hardware?
* iverilog fpga backend
* design fpga core that uses high-speed icap/reconfig to process data

ChangeLog

2012-12-20
* Second design verified: blinking_led is a clocked design where the clock
  increments a counter and the highest bit of the counter drives a LED.

2012-09-24
* First design verified: hello_world is an unclocked AND gate design
  which was verified in a xc6slx9.

2012-08-20
* Beginning of full fidelity circle with model, floorplan, conversion
  between floorplan and binary configuration formats.

2012-06-03
* Project started.