I have tried the below flashrom option (code tested) in order to find a right response on my no name VT6421A pci sata card, but no luck. Environment is Freedos in an usb boot sdcard device in a standard PC. Address was from 0xffff0000 to others. The card is found by flashrom at 1106:3249  BDF 02:0b.0 . The card has an Eprom flashable sst39Vf512 at is printed in top of it. Final messages are:
Requested bar is of type rom.
Error:  No suported PCI found.
Error: Program initialization failed.
I managed flashrom to work with my 3C905TX and do it in the same environment as a charm. I know VT6421A hardware is very tricky depending on every pci maker. The final goal is to flash a 64k boot rom ins this card. Any help will be wellcome.
Thanks in advance.
The code tested:
flashrom –p atavia offset=(different address) –V