[U-Boot-Users] MIPS question

Shinya Kuribayashi skuribay at ruby.dti.ne.jp
Thu Oct 11 17:30:36 CEST 2007


Vlad Lungu wrote:
> Shinya Kuribayashi wrote:
>> Vlad Lungu wrote:
>>  
>>> in include/asm-mips/addrspace.h line 52, there is a
>>>
>>> #define UNCACHED_SDRAM(a) PHYSADDR(a)
>>>
>>> The question is: shouldn't we use KSEG1ADDR() instead of PHYSADDR()?
>>>     
>>
>> I think we should. At least my target boards need that change.
>>
>> http://www.nabble.com/MIPS-cache-management-%28and-build%29-questions.-tf4434068.html#a12651921 
>>
>>   
> And what board would that be? Or it's not in the tree?

It's NEC mips custom board, and is not (will not be) in upstream.
These are VRcore-based or MIPScore-based, not Au1XXX-based.

>> note: Wrt dcache_disable() part, please take into account
>>       Stefan's comment.
>>
>> Anyway I seriously wonder whether other mips ports work as it is.
>>
>>   
> <comment mode="AOL"> me too </comment>
> 
> The RAM might be mapped at 0 too on some boards, that's why it works 
> with PHYSADDR(). Or people are

Hmm.. our board has system RAM physically mapped at zero, but never
works with PHYSADDR(). If TLB uninitialized, we encounter tlb address
error on 0x0 access. Am I miss something?

> simply bootelf-ing Linux, that's why the bug was not catched before (I 
> think the only use of that macro is in lib_mips/mips_linux.c i.e. 

Agreed.

> bootm). Note that the Au1x00 boards ( and another one, can't remember 
> the name) do 0x20000000|a or something like that, which when you go from 
> KSEG0 (0x8???????)
> produces 0xa???????, an address in KSEG1.

True, I think UNCACHED_SDRAM() works only with au1xxx for now.

> Wolfgang, should I submit a patch on this for 1.3.0?

Feel free to add my signed-off-by:

Singed-off-by: Shinya Kuribayashi <shinya.kuribayashi at necel.com>

thanks,

    Shinya





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