Armada XP Internal registers

Matthew Minter matthew_minter at xyratex.com
Tue Oct 22 11:56:17 EDT 2013


Hi guys,

I am preparing all the requested info and will send it to the list
soon, unfortunately I am away from the office right now so cant sent
it immediately (I don't have my serial logs on this computer) but will
send all the data as soon as I can.

Best regards,
Matthew

On 22 October 2013 14:29, Thomas Petazzoni
<thomas.petazzoni at free-electrons.com> wrote:
> Jason, Matthew,
>
> On Mon, 21 Oct 2013 14:42:19 -0400, Jason Cooper wrote:
>
>> > Hm.. so if you upgraded the bootloader and the internal register address
>> > is now 0xf100000 then it makes sense to fix your DT accordingly.
>>
>> Agreed.
>>
>> > Are you enabling CONFIG_DEBUG_LL? In that case, please note there's a
>> > new option that will let you move to the 'new' internal regs address.
>>
>> The option is CONFIG_DEBUG_MVEBU_UART.  Since you swapped out the
>> bootloader, you need to tell it so.  (Early printk assumes the
>> bootloader setup the uart and just writes to it blindly.  If it's at a
>> different address than expected, it'll crash.)
>
> I do confirm what Ezequiel and Jason said. The earlier U-Boot versions
> from Marvell remapped the registers at 0xd0000000, while the more
> recent versions remap the registers at 0xf1000000.
>
> In recent kernel versions (I guess since 3.10 or 3.11), we've made sure
> that changing the DT Mbus informations was enough to switch the entire
> kernel to use the correct internal register base address. With the
> exception of DEBUG_LL, which can't really on the DT, so that's why we
> have two separate Kconfig options, one for 0xd0000000 and another one
> for 0xf1000000.
>
> That being said, I don't think the issue Matthew is seeing is related
> to improper DEBUG_LL configuration. He wouldn't be getting "Unhandled
> fault: external abort on non-linefetch (0x808) at 0xf0144010". He would
> simply be getting *nothing* if the DEBUG_LL configuration was wrong.
>
> Matthew, can you tell me which U-Boot version exactly you're using, and
> give me the diff of the changes you've made to your Device Tree, so I
> can see if I can reproduce the problem? For what it's worth, register
> 0x44010 is part of the PCIe registers, but I don't see right now what
> could be the reason for the problem you're seeing.
>
> Best regards,
>
> Thomas
> --
> Thomas Petazzoni, CTO, Free Electrons
> Embedded Linux, Kernel and Android engineering
> http://free-electrons.com

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