RFI doesn't branch off?

RFI doesn't branch off?

[Amit Shah]

Hi all,

I have a strange issue with a custom board running a 750GX on a
Marvell 64360 bridge. I transferred control to the uImage via u-boot
(which I had to modify for my board-specific UART and SDRAM inits,
also disabling PCI).

Using the UART that's initialized by u-boot, I put some putchar()s in
head.S to figure out where the kernel was freezing. It seems 'rfi' in
mmu_off doesn't jump off to '__after_mmu_off' as expected. I also put
some pattern into SDRAM before an after mmu_off. I just see the
pattern (via a PCI interface) put before mmu_off.

The contents of SRR0 correctly point to __after_mmu_off just before
the 'rfi'. However, the 'rfi' documentation says the value of SRR0 is
concatenated with '0x0b00'. I don't think this should be done.
Anyways, since this code is supposed to work, I'm not sure why it
isn't working.

Can any u-boot initializations be causing this? I guess not, I've not
touched any CPU-specific settings in u-boot.

Can anyone give me some pointers?

Thanks,
Amit.
--
Amit Shah
http://amitshah.nav.to/

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Re: RFI doesn't branch off?

[Amit Shah]

Amit Shah wrote:

>
> Hi all,
>
> I have a strange issue with a custom board running a 750GX on a
> Marvell 64360 bridge. I transferred control to the uImage via u-boot
> (which I had to modify for my board-specific UART and SDRAM inits,
> also disabling PCI).
>
> Using the UART that's initialized by u-boot, I put some putchar()s in
> head.S to figure out where the kernel was freezing. It seems 'rfi' in
> mmu_off doesn't jump off to '__after_mmu_off' as expected. I also put
> some pattern into SDRAM before an after mmu_off. I just see the
> pattern (via a PCI interface) put before mmu_off.
>
> The contents of SRR0 correctly point to __after_mmu_off just before
> the 'rfi'. However, the 'rfi' documentation says the value of SRR0 is
> concatenated with '0x0b00'. I don't think this should be done.
> Anyways, since this code is supposed to work, I'm not sure why it
> isn't working.

If I keep the DR enabled in MSR, the RFI goes back properly... disabling DR
causes some randomness.

>
> Can any u-boot initializations be causing this? I guess not, I've not
> touched any CPU-specific settings in u-boot.
>
> Can anyone give me some pointers?

--
Amit Shah
http://amitshah.nav.to/


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

RFI doesn't branch off?

[Saari, James]

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I am chasing a very similar problem. Did you ever find resolution to
your problem? Can you share what you did to get past this?

 

Thanks.

 

--

 

Amit Shah shahamit at gmail.com
<mailto:linuxppc-embedded%40ozlabs.org?Subject=RFI%20doesn%27t%20branch%
20off%3F&In-Reply-To=> 
Wed Aug 25 20:20:33 EST 2004 

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  _____  

Amit Shah wrote:
 
> 
> Hi all,
> 
> I have a strange issue with a custom board running a 750GX on a
> Marvell 64360 bridge. I transferred control to the uImage via u-boot
> (which I had to modify for my board-specific UART and SDRAM inits,
> also disabling PCI).
> 
> Using the UART that's initialized by u-boot, I put some putchar()s in
> head.S to figure out where the kernel was freezing. It seems 'rfi' in
> mmu_off doesn't jump off to '__after_mmu_off' as expected. I also put
> some pattern into SDRAM before an after mmu_off. I just see the
> pattern (via a PCI interface) put before mmu_off.
> 
> The contents of SRR0 correctly point to __after_mmu_off just before
> the 'rfi'. However, the 'rfi' documentation says the value of SRR0 is
> concatenated with '0x0b00'. I don't think this should be done.
> Anyways, since this code is supposed to work, I'm not sure why it
> isn't working.
 
If I keep the DR enabled in MSR, the RFI goes back properly... disabling
DR
causes some randomness.
 
> 
> Can any u-boot initializations be causing this? I guess not, I've not
> touched any CPU-specific settings in u-boot.
> 
> Can anyone give me some pointers?
 
--
Amit Shah
http://amitshah.nav.to/
 
 

 


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