Ubuntu Debugging

Boot Ubuntu without the graphical interface
It could be useful to boot our standard OMAP releases Ubuntu without the graphical environment, for example when you have an experimental kernel which limited graphics support, or when you just need to ssh on your system for native compiling (in which case the graphics would waste RAM and CPU).

To do this, you just need to add a parameter to the kernel bootargs. In the U-boot command line, just type:

setenv bootargs ${bootargs} text boot

Of course, you could add saveenv to make this change permanent.

What's nice about this technique is that it doesn't require any change in the root filesystem.

Debug the userspace init sequence
To trace the sequence of processes and events during the init sequence, you can run  in debug mode by adding   to the kernel command line. In the U-boot shell, for example:

setenv bootargs ${bootargs} init=/sbin/init --debug

This shows debug information in the system console.