CGEN, the Cpu tools GENerator
CGEN (pronounced seejen) is a framework for developing
generators of CPU-related tools such as assemblers, disassemblers and
simulators. It specifies a description language for describing the
architecture and organization of a CPU without reference to any
particular application. Additional applications can be written within
the framework. CGEN is written in Scheme and can be run under the GNU
interpreter. It is placed under a free software license.
- May, 2019: Moving to GIT
Yeah it's been a while. But some folks are still building and using
CGEN, so we've made it easier.
- October 18, 2009: CGEN 1.1 is released
Yeah, it's been awhile. But we're not gone, and CGEN is still under
active development. This release includes several new ports:
cris, Fujitsu FRV, Ubicom ip2k, iq2000, lm32, m32c, mep, mt, openrisc,
sh/sh64, xc16x, xstormy16.
It also contains generators for more applications: cpu docs,
GCC intrinsics, the CPU component of the SID simulator.
Read the NEWS file for more details on what's
included in 1.1.
- July 28, 2000: CGEN 1.0 is released
This is the first release of CGEN. It includes the most important
applications, including the assembler, disassembler and simulator
generators. A handful of CPU descriptions are also included: ARM7T,
Intel i960, IA-32, Renesas M32R/D, Fujitsu FR-30, SPARC and more.
A snapshot of the CGEN manual is
available as hypertext.
The self-service CGEN Faq-O-Matic pages is
available for adding your questions and answers.
See the wiki here.
If you are not doing active development on CGEN, you should get the
release. The FTP server is often very busy, see one of the mirror sites if you're having trouble
You can access the development source tree a couple of different ways.
- Anonymous GIT read-only access
git clone git://sourceware.org/cgen.git
- Read-only web-based GIT access
You can browse the source code using the gitweb
Bug reports and patches
If you would like to report a bug in CGEN, please send an email to
the mailing list.
Patches must be approved and will be checked into the source tree by
the maintainers. All patches must conform to the GNU Coding Standards
and be accompanied by a ChangeLog
entry. Please send patches to the
There are three mailing lists related to CGEN:
You can use this form to subscribe or unsubscribe to the above mailing
A mailing list for discussion of all issues related to development,
CVS commit messages are automatically sent to this list so that
people can track changes. Don't send messages to this list.
Problem reports (PRs) and PR activities are sent to this list by the
bug tracking system
CGEN is written in Scheme (and justifiably!). Many folks are new to
Scheme and some are new to functional programming. Rather than try to
keep an up-to-date collection of references, the Guile
includes such a
already. Many universities teach Scheme as an introductory
programming language, so a search on the World Wide Web should turn up
lots of tutorial material, if that's what you're looking for.
A couple of excellent books on Scheme are:
CGEN uses the Guile Scheme implementation.
The Guile home page is here.
CGEN currently supports Guile 1.6.8, and 1.8.5.
Perhaps this section can become a collection of links to CPU
vendors' reference documentation. Please send suggestions and
amendments to the mailing list.
The GCC project reading list
contains a good list.
CGEN Generated Documentation
These pages are generated from the cpu description files.