How can I debug the RPi's kernel without a monitor?

3 posts
by alexgolec » Thu Jun 28, 2012 2:22 pm
I'm building a kernel from scratch, and for various reasons I need to be able to debug with a monitor attached. Specifically, my problem is that I've clearly screwed up the configuration, because the kernel boot is hanging so early that init doesn't even start. Does the RPi have any sort of support for outputting debug info over USB, ethernet, or serial port?
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by dom » Thu Jun 28, 2012 2:50 pm
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
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by summers » Thu Jun 28, 2012 3:04 pm
Something else to add.

When booting the kernel pass the argument


Where /dev/whatever is the device file of the serial line you are watching ...

Kernel takes a short time to get far enough though to be able to direct messages to the console though - so you may not get a message ...
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