$ sudo flashrom --programmer ch341a_spi -w build/coreboot.rom 
flashrom v0.9.9-r1954 on Linux 4.9.0-8-amd64 (x86_64)
flashrom is free software, get the source code at https://flashrom.org

Calibrating delay loop... OK.
Found Winbond flash chip "W25Q32.V" (4096 kB, SPI) on ch341a_spi.
Reading old flash chip contents... done.
Erasing and writing flash chip... Erase/write done.
Verifying flash... VERIFIED.
$