Hi list,
Seeing that my beloved i440BX platform will not support enough memory to run Windows 10, and with 7 EOLed, its days are numbered even though I enjoyed working on a blob-free platform.
I am now setting myself up for porting coreboot to my P8Z77-M board, where a close cousin is already in the tree.
First, I need a 8MB SPI flash chip. I picked up a two W25Q64JVSSIM from Digikey and some adapter as well since they don't carry any in DIP form anymore. :( I mounted one and it seems to physically work. It wasn't supported in flashrom yet, so I sent a patch there as well [1], flagged as untested, because an issue I'll get to later, and my reason for this email.
Next, I need a SPI flash programmer. I'm trying to avoid making major purchases. The most handy thing I have is a 5V Arduino Mega 2560 r3, so I loaded frser-duino on it, and HoodLoader2 on its 16u2 for the fast USB. I also picked up a level shifter module [2] because the chips are 3.3V. When I wired up everything on a breadboard with the board's original chip it reads fine and I was actually able to save a backup of its contents. Of course I then wanted to build something that I can just plug the chip in and go, as I will need to use it quite often.
I wired the level shifter and a DIP socket on a XBee shield (because it has a 3.3V regulator and a proto area), but it's not detecting the chip. I then reverted to the breadboard, this time using 3 resistor dividers for level shifting because the level shifter's legs are now soldered on the shield.
I read the (still virgin) chip 3 times, and saw the read bytes periodically goes to 0x00 instead of being all 0xff, as expected from an unprogrammed chip. The connection is not working right.
What else can I try? If I can't get this serprog-on-an-arduino setup working, what is my next best setup I can use?
[1] https://review.coreboot.org/c/flashrom/+/38578 [2] https://www.velleman.eu/products/view/?id=435578