So, after realizing that the MX25L256 was the wrong chip, I've obtained a few of the correct chips (MX25L12845EMI-10G). These are detected by flashrom, but writes are failing.
Erase/write done. Verifying flash... FAILED at 0x00000002! Expected=0x55, Found=0x75, failed byte count from 0x00000000-0x00ffffff: 0x3e5cb3 Your flash chip is in an unknown state. Please report this on IRC at chat.freenode.net (channel #flashrom) or mail flashrom@flashrom.org, thanks!
This is using a raspberry pi as a programmer, and:
./flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=32000 -w ../flashrom/ipmi/SMT_313.bin -o debug1
-rw-r--r-- 1 root root 16777216 Jan 2 19:10 ../flashrom/ipmi/SMT_313.bin
Any suggestions here? -o debug1 is attached