#10818 NORM Not Tri: interrupting fs-update can lead to bootable system

[Zarro Boogs per Child]

#10818: interrupting fs-update can lead to bootable system
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 Reporter:  dsd           |                 Owner:  dsd          
     Type:  defect        |                Status:  new          
 Priority:  normal        |             Milestone:  Not Triaged  
Component:  build-system  |               Version:  not specified
 Keywords:                |           Next_action:  package      
 Verified:  0             |   Deployment_affected:               
Blockedby:                |              Blocking:               
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 Quanta reported that if power is lost during a fs-update run, the system
 will still boot into Linux afterwards.

 This is because the "important" stuff gets written at the start of the
 disk, and if the end of the disk is not written then you won't see
 problems until later - but the problems would probably be nasty and
 confusing.

 This can be fixed by tweaking the zhashfs program to create .zd files that
 write the first block last. As the entire disk is erased at the start of
 the fs-update process, it means that you will end up with an all-zero
 sector 0 if you interrupt fs-update, and the system will not boot.

 However, these .zd files confuse OFW, which then reports that only 0 of X
 blocks were written. (the data is written correctly though)

 After fixing OFW, we should also modify the .zsp file creation to patch
 that final routine to avoid the confusing warning. That way, secure mode
 reflash users won't see a confusing error message.

 Unsecure users will see a confusing error until they upgrade their
 firmware, but we can simply communicate this to the community, and ship
 the fixed firmware from the very first build image that uses this "new
 format" (so it would be a one-off).

 Quanta will not see any confusing error because they will flash the new
 firmware which avoids displaying the confusing error message.

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Ticket URL: <http://dev.laptop.org/ticket/10818>
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