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Re: compile redboot error for AT91EB40
>>>>> Gary Thomas writes:
>> Interestingly, the actual code is..
>>
>> #ifndef CYGARC_PHYSICAL_ADDRESS
>> # error
>> # define CYGARC_PHYSICAL_ADDRESS(x) (x)
>> #endif
>>
>> So it looks like whoever wrote the code thinks a sensible fall back is
>> to assume a straight 1-1 mapping. The HAL can override this if
>> required.
>>
>> May we should just remove the #error line and fix any HALs that are
>> reported not to work?
> I think the #error is serving it's purpose. IMO, there can be no
> reasonable fallback and making any assumptions like that is asking
> for trouble. I didn't write that particular line in that file, but
> I do agree with the idea [of forcing HAL writers to think about what's
> going on]
A reasonable fallback is possible. If MMU is off, its a 1-1 mapping. If
MMU is on, read the appropriate page table entry and construct the phys
address from that. Not fast, but accurate and reliable.
--Mark
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