cgminer already supports HashFast ASICs.
New version: 3.7.0, 4th November, 2013
New drivers, lots of code updates, new features, lots of bugfixes, major upgrade.
Human readable changelog:
- Driver for Hashfast ASIC hardware.
- Merge hashfast driver
Drivers are on github.
https://github.com/ckolivas/cgminer/blob/master/driver-hashfast.c