You probably came here trying to find a small (minutes to hours) and easy task where you can get your hands dirty and get results immediately.
If you're a flashrom newbie, this page is for you.
Add timing info to flash chip definitions (mostly done)
Go through the list of flash chips in flashchips.c inside the flashrom source. For each chip (except SPI chips), read through the data sheets and add a comment to the flash chip definition which contains the timing information in microseconds(!) for the probe sequence.
This will make probing a lot more reliable.
Every annotated chip helps.
Add new flash chip definitions
We have a few dozen chip IDs listed in flash.h, but not in flashchips.c. Find them, dig up the data sheets and add chip definitions for them to flashchips.c. You can use similar flash chips as a guideline.
This will reduce the number of undetected chips.
Every added chip broadens flashrom support.
Please see the Board Testing HOWTO.
Add the bus type to flashrom flash chip definitions
Go through the list of flash chips in flashchips.c inside the flashrom source. Look for chip definitions which have .bustype = CHIP_BUSTYPE_NONSPI and look at their data sheets. Read the data sheets and try to figure out the flash bus they use (Parallel/LPC/FWH/SPI). Change the bustype field to CHIP_BUSTYPE_PARALLEL etc. and post a patch to the list.
This will make probing faster and more reliable.
Even a single updated chip helps.
Flashrom#Communication_bus_protocol has a writeup on how to figure out the bus type.