Basic Information

Dump Flash

Bus Pirate + flashrom

Note that even if the PINOUT of the Pirate Bus indicates pins for MOSI and MISO to connect to SPI however some SPIs may indicate pins as DI and DO. MOSI -> DI, MISO -> DO
In Windows or Linux you can use the program flashrom to dump the content of the flash memory running something like:
# In this command we are indicating:
# -VV Verbose
# -c <chip> The chip (if you know it better, if not, don'tindicate it and the program might be able to find it)
# -p <programmer> In this case how to contact th chip via the Bus Pirate
# -r <file> Image to save in the filesystem
flashrom -VV -c "W25Q64.V" -p buspirate_spi:dev=COM3 -r flash_content.img