sudo flashrom -p ft2232_spi:type=arm-usb-ocd-h,port=A,divisor=8 -c MT25QU256 -w
image.img

flashrom is free software, get the source code at https://flashrom.org

Using clock_gettime for delay loops (clk_id: 1, resolution: 1ns).
Found Micron flash chip "MT25QU256" (32768 kB, SPI) on ft2232_spi.
===
This flash part has status UNTESTED for operations: PROBE READ ERASE WRITE
The test status of this chip may have been updated in the latest development
version of flashrom. If you are running the latest development version,
please email a report to flashrom@flashrom.org if any of the above
operations
work correctly for you with this flash chip. Please include the flashrom log
file for all operations you tested (see the man page for details), and
mention
which mainboard or programmer you tested in the subject line.
Thanks for your help!
Reading old flash chip contents... done.
Erasing and writing flash chip... Erase/write done.
Verifying flash... FAILED at 0x00001000! Expected=0x00, Found=0xff,
failed byte count from 0x00000000-0x01ffffff: 0x250e23
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!