Recent versions of flashrom support the -p ft2232_spi (or -p ft2232spi in older flashrom revisions) option which allows you to use a FTDI FT2232/FT4232H based device as external SPI programmer.
This is made possible by using libftdi. flashrom autodetects the presence of libftdi headers and enables FT2232/FT4232H support if they are available.
We currently know of the following devices which can be used as SPI programmer together with flashrom:
DLP Design DLP-USB1232H
Sidenote: The module can also be used as JTAG programmer with OpenOCD support.
In order to use the DLP-USB1232H device as SPI programmer you have to setup a small circuit (e.g. on a breadboard). See the schematics for details (you can also download the schematics as PDF for easier printing).
- You must connect/shorten pins 8 and 9, which configures the device to be powered by USB. Without this connection it will not be powered, and thus not be detected by your OS (e.g. it will not appear in the lsusb output).
- You need a 3.3V voltage regulator to convert the 5V from USB to 3.3V, so you can power the 3.3V SPI BIOS chip.
- You can probably use pretty much any 3.3V voltage regulator, e.g. LD33V or LD1117xx. For usage on a breadboard the TO-220 packaging is probably most useful.
- You have to connect two capacitors (e.g. 100nF and 10uF as per datasheets, but using two 10uF capacitors, or even two 47uF capacitors also works in practice) as shown in the schematics, otherwise the voltage regulator will not work correctly and reliably.
- Connect the following pins from the DLP-USB1232H to the SPI BIOS chip:
- 18 (SK) to SCLK
- 16 (DO) to SI
- 2 (DI) to SO
- 5 (CS) to CS#
- The WP# and HOLD# pins should be tied to VCC! If you leave them unconnected you'll likely experience strange issues.
- All GND pins should be connected together (pins 1 and 10 on the DLP-USB1232H, pin 8 on the SPI chip, pin 1 on the voltage regulator).
You have to invoke flashrom with the following parameters:
$ flashrom -p ft2232_spi:type=2232H,port=A
On older flashrom versions the syntax was:
$ flashrom -p ft2232_spi:ft2232_type=2232:port=A
FTDI FT2232H Mini-Module
Where to buy: FTDI
FTDI FT4232H Mini-Module
Where to buy: FTDI
Where to buy: Amontec eShop
More info can be found on on the JTAGkey site.
- You need a 3.3V voltage source - see above for details.
- Connect the following pins from the JTAGkey2 to the SPI BIOS chip:
- 1 (Vref) to VCC
- 5 (MOSI/TDI) to SI
- 7 (CS#/TMS) to CS#
- 9 (CLK/TCK) to SCLK
- 13 (MISO/TDO) to SO
- 20 (GND) to GND
- The WP# and HOLD# pins should be tied to VCC.
The picture on the right-hand side shows the colors on the breakout cable.
The Olimex ARM-USB-TINY (VID:PID 15BA:0004) can be used with flashrom for programming SPI chips. The ARM-USB-TINY-H (15BA:002A), ARM-USB-OCD (15BA:0003) and ARM-USB-OCD-H (15BA:002B) should also work, though they are currently untested.
The following setup can then be used to flash a BIOS chip through SPI.
|Pin (JTAG Name)||SPI/Voltage Source|
|1 (VREF)||VCC (from Voltage Source)|
|2 (VTARGET)||VCC (to SPI target)|
|4 (GND)||GND (from Voltage Source)|
|6 (GND)||GND (to SPI target)|
On the ARM-USB-TINY, VREF and VTARGET are internally connected, and all the GND lines (even numbered pins, from 4 to 20) share the same line as well, so they can be used to split VCC/GND between the voltage source and the target.
The voltage source should provide 3.0V to 3.3V DC but doesn't have to come from USB: it can be as simple as two AA or AAA batteries placed in serial (2 x 1.5V).
You first need to add the
-p ft2232_spi option, and then specify one of
arm-usb-ocd-f for the type. For instance, to use an ARM-USB-TINY, you would use:
$ flashrom -p ft2232_spi:type=arm-usb-tiny