git: boot - Fix BIOS lockup due to H2 probe on small medias

[Matthew Dillon]

commit be19e6e57abb07bfc57e9f749804dfe83da6a8d4
Author: Matthew Dillon <dillon at apollo.backplane.com>
Date:   Tue Jun 24 15:10:31 2014 -0700

    boot - Fix BIOS lockup due to H2 probe on small medias
    
    * Some BIOSes (found w/Intel atom D525 w/Foxconn mobo, AMIBIOS) will
      implode when asked to read a disk address beyond the EOM.  The HAMMER2
      probe tries to read a volume header at the 0, 2G, 4G, and 6G marks.
      This appears to blow up the BIOS when booting from USB media.
    
    * To work around the problem, for now we do not proceed to test all four
      volume header offsets if the first one (at offset 0) does not have a
      HAMMER2 signature.
    
    * Thanks to tm512 (Kyle Davis) for spending ~4+ hours helping us find
      the problem.
    
    Reported-by: tm512 (Kyle Davis)

Summary of changes:
 lib/libstand/hammer2.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff/be19e6e57abb07bfc57e9f749804dfe83da6a8d4


-- 
DragonFly BSD source repository