Re: [PATCH] powerpc: Add support to access the flash on SLOF based systems

On Monday 12 January 2009, Martyn Welch wrote:

Adrian Reber wrote:

quoted

The reason why I did not use mtd is that part of the flash is used by
the firmware image and I do not know if that works with mtd, if only a
part of the flash can be used. SLOF does also a "CRC" check over the
firmware image, so that image must have valid SLOF "CRC". The flash is
a direct mapped flash, but the size of the firmware can vary.

It can. MTD can create "partitions" within the flash, for an example
see lines 84-110 of arch/powerpc/bootdts/sbc8641d.dts (http://tinyurl.com/7k2kym) 

Partitions can also be labeled as read-only, I guess the CRC could be
checked from userspace as necessary. 

Murali has also done a modified firmware for experiments in the past where
he added the device tree entry for the flash on a PxCAB. As I recall, he did
not see any problems with that.

	Arnd <><