I am trying to compile a newer Android kernel on my phone. The problem is it ends up in a boot loop without any means to access error messages. I can compile an older version of the kernel wich runs well on the phone, so I am able to add custom things to the kernel configuration if needed.
My goal is to boot up the phone with the old, working OS, then boot up the new kernel from the working OS and being able to get log messages during the new kernel's boot.
If this is impossible, is there a way (for example to save messages to the SD card) to access kernel (error) log messages later (after booting up an other working OS).