Re : where to set the BEV to normal of status in kernel source?

Re : where to set the BEV to normal of status in kernel source?

[Florian DELIZY]

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Subject : where to set the BEV to normal of status in kernel source?
> i don't find it in load_mmu(), who can point out for me?
> thanks!

Well, if you are speaking about the BEV flag from the Status (SR) register 
(CP0_STATUS aka $12 of the 1st coprocessor)
then it controls the interruption/exception handler place, I don't see the 
relation with mmu ... 

> is that must be set in bootloader?

OK, I see, it should be set to 0 by the boot loader so that the TLB 
exceptions (related to the MMU) goes in RAM. So 
the kernel does not change it actually and hope the boot loader did.

-- Florian Delizy






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Re: Re : where to set the BEV to normal of status in kernel source?

[Kevin D. Kissell]

The BEV bit of Status is cleared by the macro setup_c0_status_pri which
is invoked in kernel_entry.  See arch/mips/kernel/head.S.  It's of course
possible that a bootloader will already have cleared it, but it should not
be necessary.  grep is your friend.  ;o)

		Regards,

		Kevin K.

Florian DELIZY wrote:
> Subject : where to set the BEV to normal of status in kernel source?
> 
>>i don't find it in load_mmu(), who can point out for me?
>>thanks!
> 
> 
> Well, if you are speaking about the BEV flag from the Status (SR) register 
> (CP0_STATUS aka $12 of the 1st coprocessor)
> then it controls the interruption/exception handler place, I don't see the 
> relation with mmu ... 
> 
> 
>>is that must be set in bootloader?
> 
> 
> OK, I see, it should be set to 0 by the boot loader so that the TLB 
> exceptions (related to the MMU) goes in RAM. So 
> the kernel does not change it actually and hope the boot loader did.
> 
> -- Florian Delizy
> 
> 
> 
> 
> 
>