ARMADA 370 - Kernel panic during boot

[Gregory CLEMENT]

On 29/09/2014 17:23, post at twien.net wrote:
> Thanks, that made it!
> 
> Actually to change the Physical base address of the debug UART was 
> actually a shot in the dark, because I got nothing out, and I just 
> decided to give it a try.
> To me this is somewhat confusing: I thought the physical address of 
> those register were 0xd0000000 (according to the hardware specification) 
> and that the U-boot remapped those to the virtual address 0xf1000000. 
> Well, since it worked on another board with 0xd0000000 (ref. mail from 
> Gregory), 

Actually I modified your config by using CONFIG_DEBUG_MVEBU_UART instead of
CONFIG_DEBUG_MVEBU_UART_ALTERNATE. Indeed my bootloader is an old one which
didn't modify the physical address of the internal register. I didn't mentioned
it because for me to have the traces you showed, this addressed must have been
properly set. I was wrong, the kernel was more tolerant then I thought!

> I assume this is not so simple, and that this may vary 
> depending on how U-boot remaps the registers, or? I'm using the U-boot 
> provided by Marvell.

Yes the change of this physical address was usually done by U-Boot. This
"feature" is very specific to Marvell. The earlier versions of U-Boot use
0xd0000000, and later they switched to 0xf1000000 because it allows to
have a bigger space address for the RAM.

> 
> I have to debug further though, because it stopped with the message 
> bootconsole [...] disabled. I guess the problem is that the switch chip

this message means that you switched to the "real" serial driver, and if you
don't see anything after it is that this driver was misconfigured. Either you
use the wrong value for console= or you have another mistake in your dts.

Gregory

> (88E6532) is not detected (in the U-boot OK though, as egiga0), and this 
> is my only way out.... (SGMII->PHY)




> 
> So thanks for the help. I'll keep on with the debugging.
> Tormod
> 
> 
> 
> On 2014-09-29 15:57, Thomas Petazzoni wrote:
>> Hello,
>>
>> On Mon, 29 Sep 2014 13:25:03 +0200, post at twien.net wrote:
>>
>>> 	soc {
>>> 		ranges = <MBUS_ID(0xf0, 0x01) 0 0xd0000000 0x100000
>>
>> Are you really sure about the 0xd0000000 value here? Your earlyprintk
>> works using CONFIG_DEBUG_MVEBU_UART_ALTERNATE=y according to
>> your .config, which indicates that your internal registers are mapped 
>> at
>> 0xf1000000 and not at 0xd0000000 as your Device Tree indicates.
>>
>> Can you change this line to:
>>
>> 	ranges = <MBUS_ID(0xf0, 0x01) 0 0xf1000000 0x100000
>>
>> And try again?
>>
>> Thanks,
>>
>> Thomas


-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com