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it is a custom board with a mpc8xx.

Then the answer to your question is simple: you made some errors in your port of U-Boot to your hardware. I know, this is just an anwer to your question, not a solution to your problem.

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I think that most of the config is board independant. (

Prog of the BRG,

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Prog of the CPM ... )

You are wrong. A LOT of the configuration parameters are hardware specific.

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U-Boot finds 9600 for the baudrate in the env. So I wonder where board specific items can make it hang.

Basicly anything. Bad clock configuration for example.

You right. It seems that with new values for clock registers it works much better... So it doesn't hang anymore and I reach the getc(). I still don't have anything on my terminal console but the solution can't be far !

Chris