Add recovery_subcode field to nvstorage and crossystem

This just adds a one-byte field in the nvstorage region for use in debugging
hard-to-catch errors. There's no official meaning or expectation for this
field. It's just a handy place to emit some information.


Just change the value and ensure that it persists across a (working) reboot.
It's only updated at specific points under very exacting error conditions,
so all we really want to test is that it works as a place to store some
extra info.

  crossystem recovery_subcode
  crossystem recovery_subcode=14
  crossystem recovery_subcode

The recovery_subcode byte is at index [6] of the VbNv.raw bytes that appear
when you press TAB, so you can find it there too:

  VbNv.raw: 60 20 00 00 00 00 0e 00 00 00 00 00 00 00 00 65

Decimal 14 == 0x0e

Change-Id: I1930b8f81a03ab838dbee99a8d72c35a444efdfd
Signed-off-by: Bill Richardson <>
Reviewed-by: Randall Spangler <>
5 files changed