[flashrom] flashrom external programming with different usb high speed converter

[Carl-Daniel Hailfinger]

Hi Matthias,

On 03.05.2010 19:16, Matthias Olescher wrote:
> as I can see are you using one port of an FT2232H for the SPI programming. Unfortunatly for germans, the chip and the converter board is only aviable from Digikey. Is it also possible to only use full speed with FT232 or even low Speed and V-USB?
>   

To get reliable and reasonably fast (minutes) SPI programming, we need a
chip which can speak SPI natively.
FT2232C, FT2232D, FT2232L should work with small changes in the FT2232H
flashrom driver if libftdi supports them. Please check that the hardware
supports 3.3V input/output because 5V will fry your flash chip.
FT232* variants seem to lack a SPI engine and could work in bitbang
mode, but this means you'd have to wait for hours to read/write a flash
chip. Not fun.


> If high speed is necessary, can the program be changed that it works with http://www-user.tu-chemnitz.de/~heha/bastelecke/Rund%20um%20den%20PC/USB2LPT/ul-17.htm.en ?
>   

As long as you can get those chips to speak SPI without bitbanging from
the host, it should work. Of course you have to make sure input/output
voltage can be set to 3.3V (lower voltages may be required for some
chips, but 3.3V is the most common variant).

If you send me some hardware which speaks SPI and doesn't require
soldering, I can try to implement a flashrom driver for it (on the
condition that programming docs are available without NDA).

In general, if the hardware has some sort of microprocessor and a few
GPIOs, it can do SPI in software if a preconfigured SPI mode does not
exist. All that flashrom requires is a way to either send/receive SPI
communication with the chip or some bitbanging interface (but bitbanging
from the host is slooooooooow).

Regards,
Carl-Daniel

-- 
http://www.hailfinger.org/