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Re: The new "real" console doesn't display printk() messages like "early

To: "Ardelean, Andrei" <>
Subject: Re: The new "real" console doesn't display printk() messages like "early" console!
From: David Daney <>
Date: Mon, 22 Nov 2010 13:02:56 -0800
Cc: Sergei Shtylyov <>, Ricardo Mendoza <>,
In-reply-to: <>
Original-recipient: rfc822;
References: <><><> <> <> <> <>
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On 11/22/2010 12:51 PM, Ardelean, Andrei wrote:
Hi Sergei,

"     Are your UART registers identity mapped to virtual address space?"

My system has DDR memory 0x80000000..0x90000000 (kseg0) and UART is
mapped starting with bbf01000 (kseg1). Can you give me some details
about your question?

I didn't do anything special for the port other than
in gd-init.c

I think you need to reset your process here.

First you should probably get a prom_putchar() function working. Then enable CONFIG_EARLY_PRINTK. That will enable you to debug many things.

If need be, you can write a trivial prom_puts() to go with your prom_putchar().

If you have two serial ports available, all the better. Use one for printing debugging information and the other as the port you are trying to debug.

Asking people to stare at the thousands of lines of code that make up the serial I/O system and spot the error in your configuration will probably be less fruitful than tracing through it to find the problem.

David Daney

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