Reduce the size of a probed flash for broken HW
Nicolas Pitre
nico at cam.org
Mon Apr 24 11:07:38 EDT 2006
On Mon, 24 Apr 2006, Franck Bui-Huu wrote:
> [discussed with Vitaly Wool on IRC]
>
> My hardware has some problem to access my onboard flashes specially
> the last 64Ko of them. So I need a way to restrict access to these areas.
>
> Several solutions comes in mind:
>
> - In the mapping driver, try to modify the mtd_info and cfi_info
> setup by the MTD probing functions to reduce the detected
> size. This solution is really hackish since it modifies internal
> structures of the MTD layer that the mapping driver is not
> supposed to be aware of. I just did this in my driver:
>
> *mtd = do_map_probe("xxx_probe", map);
> while ((*mtd)->size > 32Mo - 64Ko)
> (*mtd)->size -= (*mtd)->erasesize;
>
> and it seems to work fine...
I think that is indeed the easiest solution. Just keep it to your map
driver and clearly label it with a big comment explaining why you do so.
I don't think you need to modify the cfi_info at all.
Nicolas
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