I created a doc that describes all of the pain that is involved with debugging a Recovery image failure:

https://docs.google.com/document/d/1DTN-s0TwD-G1kjD66HQFnvQvuc1fT1Yvr3ScUCGB940/edit

Even a two page document doesn't include debugging signing and verification debugging.

The short version is:
 * Get serial console working in a test image, discovery ttyS# port
 * Hack mod_image_for_recovery.sh to enable serial for this port
 * Hack initramfs/recovery/init to send output to console
 * Rebuild, flash, and boot Recovery on hardware

Related, testing in a VM is broken: https://bugs.chromium.org/p/chromium/issues/detail?id=714774


 

I created a doc that describes all of the pain that is involved with debugging a Recovery image failure:

https://docs.google.com/document/d/1DTN-s0TwD-G1kjD66HQFnvQvuc1fT1Yvr3ScUCGB940/edit

Even a two page document doesn't include debugging signing and verification debugging.

The short version is:
 * Get serial console working in a test image, discovery ttyS# port
 * Hack mod_image_for_recovery.sh to enable serial for this port
 * Hack initramfs/recovery/init to send output to console
 * Rebuild, flash, and boot Recovery on hardware

Related, testing in a VM is broken: https://bugs.chromium.org/p/chromium/issues/detail?id=714774

Action items:

 1. Make passing serial console flags and USE flags to mod_image_for_recovery.sh possible.
 2. Investigate sending init console output to console by default (or optionally).