[coreboot] MIPS Yamon replacement?
c-d.hailfinger.devel.2006 at gmx.net
Thu Mar 27 19:02:45 CET 2008
On 27.03.2008 15:32, Robin Randhawa wrote:
> Hi again.
> On Thu, 2008-03-27 at 15:18 +0100, Carl-Daniel Hailfinger wrote:
>>> Traditionally, the MIPS reset vector has been in what is known as the
>>> KSEG1 window which is an uncached view of the lower 512MB of physical
>>> memory and is accessible from physical address 0x1FC00000 onwards. I'll
>>> be happy to provide any hints if you need them.
>> Good. Now I just need to know how the ROM is mapped into that window.
> I see. Sorry, I should've been more specific. Since the reset vector is
> physical address 0x1FC00000 (which happens to be KSEG1 Addr 0xBFC00000 -
> but that's getting too involved too soon), system designers ensure that
> the Boot ROM begins at this address.
> In the case of the Malta Evaluation board which MIPS advertises as the
> evaluation board of choice, there is 4MB of NOR Flash which is mapped at
> this location onwards.
So the flash appears from 0x1FC00000-0x1FFFFFFF and the reset vector is
located in the lowest address of the flash? That's what we call a bottom
boot block. Bottom boot blocks need my special LAR patch. I'll make sure
it will get merged (it was unmerged because we were not sure whether
coreboot would ever support architectures with a bottom boot block).
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