[U-Boot-Users] "stacked" memory mapped flash assisted with GPIOs

Haavard Skinnemoen
2008-01-21T12:00:06Z

On Sun, 20 Jan 2008 05:56:08 -0500
Mike Frysinger <vapier@gentoo.org> wrote:

> - have memory display / flash write commands toggle the GPIO lines
> * pros: user interface is transparent and not confusing by making it seem
> like 1 flash exists (think software raid 0). able to use 1 write command and
> the lower layers will automatically split it across multiple flashes. should
> work with multiple types of flashes.
> * cons: requires modification to cmd_mem.c and cfi_flash.c.

Wouldn't it be enough to just modify the blackfin-specific implementation
of map_physmem() and unmap_physmem()? Just use some of the physical
address bits to toggle the necessary GPIO lines and return a suitable
pointer into the 4MB memory window.

Haavard