[U-Boot] [PATCH 3/3] avr32: Add simple paging support

[Andreas Bießmann]

Dear Håvard Skinnemoen,

I have tested the simple TLB implementation on our own hardware and it
does work with CFI driver.
Thanks a lot for introducing this, we had to wait so long ...

Am 02.08.2010 14:06, schrieb Haavard Skinnemoen:
> Use the MMU hardware to set up 1:1 mappings between physical and virtual
> addresses. This allows us to bypass the cache when accessing the flash
> without having to do any physical-to-virtual address mapping in the CFI
> driver.
> 
> The virtual memory mappings are defined at compile time through a sorted
> array of virtual memory range objects. When a TLB miss exception
> happens, the exception handler does a binary search through the array
> until it finds a matching entry and loads it into the TLB. The u-boot
> image itself is covered by a fixed TLB entry which is never replaced.
> 
> This makes the 'saveenv' command work again on ATNGW100 and other boards
> using the CFI driver, hopefully without breaking any rules.
> 
> Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen at atmel.com>
Tested-by: Andreas Bießmann <biessmann at corscience.de>