[coreboot-gerrit] Patch merged into coreboot/master: vboot/vbnv_flash: Binary search to find last used entry

the following patch was just integrated into master:
commit aa1d314ac2febafc5243266b420ff57b280621c5
Author: Randall Spangler 
Date:   Fri Aug 26 16:01:16 2016 -0700

vboot/vbnv_flash: Binary search to find last used entry

This improves the previous linear search to O(log n).  No change in
    storage format.

BUG=chromium:640656
    BRANCH=none
    TEST=Manual
    	(test empty)
    	flashrom -i RW_NVRAM -e
    	Reboot; device should boot normally.

(start using records)
    	crossystem kern_nv=0xaab0
    	crossystem recovery_request=1 && reboot
    	Device should go into recovery mode with reason 1
    	Reboot again; it should boot normally.
    	crossystem kern_nv (should still contain 0xaab0)
    	Repeat steps several times with request=2, 3, etc.

flashrom -i RW_NVRAM -r nvdata
    	Modify nvdata to copy the first record across all valid
    	records
    	flashrom -i RW_NVRAM -w nvdata
    	Reboot; device should boot normally.

Change-Id: Ieb97563ab92bd1d18a4f6a9e1d20157efe311fb4
    Signed-off-by: Martin Roth 
    Original-Commit-Id: db9bb2d3927ad57270d7acfd42cf0652102993b1
    Original-Change-Id: I1eb5fd9fa6b2ae56833f024bcd3c250147bcc7a1
    Original-Signed-off-by: Randall Spangler 
    Original-Reviewed-on: https://chromium-review.googlesource.com/376928
    Original-Reviewed-by: Julius Werner 
    Reviewed-on: https://review.coreboot.org/16577
    Tested-by: build bot (Jenkins)
    Reviewed-by: Vadim Bendebury 
    Reviewed-by: Patrick Georgi

See https://review.coreboot.org/16577 for details.

-gerrit