[U-Boot-Users] 1.1.4 and 2.6 kernel - missing startup messages - solved!

[Michael Schwingen]

Michael Schwingen wrote:
>> Did same kernel crash later on with u-boot and not redboot ? As in I
>> am curious to know that did change in boot loader cause some other
>> issue apart from crash also ?
>>   
>>     
> No. Once I corrected the startup issues (which turned out to be a typo 
> in the commandline arguments), the kernel started up fine (I did not 
> test further than mounting the root fs).
>
> cu
> Michael
>   
Just for the record:
my problems have disappeared now. It turns out the problem was caused by 
the LL_DEBUG code in Linux, which expects the UART to be enabled and 
initialized. Now, when u-boot and kernel disagree about which UART is to 
be used for console output, the kernel messages simply disappear.

This was complicated by the fact that the kernel LL_DEBUG code for 
IXP4xx always uses UART1, while my board only has UART2 connected, and I 
configured the IXDP425 board for a similar setup.

I modified my u-boot to always initialize both UARTS - that way, you can 
at least see the messages on boards that have both UARTS connected. As 
long as noone writes to the unused UART, this should not cause any harm.

The reason why I got no "normal" console output was a typo in the 
"mem=..." commandline parameter, which lead to errors early in memory 
management initialization in the kernel.

cu
Michael