On Tue, 1 Jan 2013 05:03:55 -0500 Brian Salcedo bsalcedo@gmx.us wrote:
When working with some flash chips using the Bus Pirate programmer, the use of the Bus Pirate's on-board pull-up resistors is sometimes necessary.
Use of said pull-up resistors requires the user to apply a voltage to the VPU pin of the Bus Pirate, and then command it to use them.
Included is a patch to initialize the Bus Pirate's pull-up resistors with a 'pullups=1' at the command line:
e.g. flashrom -p buspirate_spi:dev=/dev/buspirate,pullups=1
Here is a link to information pertaining to what this patch does. http://dangerousprototypes.com/docs/SPI_(binary)#0100wxyz_-_Configure_periph...
Currently, flashrom sends 0x4b, which does not set the "pull-ups" bit high. Optionally sending 0x4f instead will enable them.
There were quite some problems with the patch, but they have (hopefully) been fixed by me and tested by Brian. I have committed the result in r1641. Thanks Brian for your contribution!