[U-Boot-Users] [PATCH 6/6] cfi_flash: Use map_physmem() and unmap_physmem()

Andrew Dyer
2007-12-11T22:55:09Z

On Dec 11, 2007 4:10 PM, Wolfgang Denk <wd@denx.de> wrote:
> In message <1197386900-14570-7-git-send-email-hskinnemoen@atmel.com> you wrote:
> > Use map_physmem() and unmap_physmem() to convert from physical to
> > virtual addresses. This gives the arch a chance to provide an uncached
>
> Virtual addresses? We don't have virtual memory in U-Boot...

Virtual addesses don't imply demand paged virtual memory.

For example on MIPS all software addresses are virtual and go through
a translation to a physical address (granted for some regions of
memory it's just forcing some address bits). Some procs (Au1xxx) go
as far as to require using the TLB to access all of the 36-bit
physical space in the 32-bit virtual space. For u-boot we can usually
get away with a static mapping, but the mapping is still there.

--
Hardware, n.:
The parts of a computer system that can be kicked.