#11690 NORM 12.1.0: OFW should size root partition to fill the disk

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#11690: OFW should size root partition to fill the disk
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           Reporter:  pgf          |       Owner:  Quozl        
               Type:  enhancement  |      Status:  assigned     
           Priority:  normal       |   Milestone:  12.1.0       
          Component:  kernel       |     Version:  not specified
         Resolution:               |    Keywords:               
        Next_action:  design       |    Verified:  0            
Deployment_affected:               |   Blockedby:               
           Blocking:  10040        |  
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Comment(by Quozl):

 In adding additional checks to the code, I could not explain the number of
 sectors chosen by sfdisk for the root filesystem partition.  Being unable
 to explain it means I can't build a reliable check for it.

 For .zd4, the disk image size is set in examples/olpc-os-11.3.1-xo1.75.ini
 as 3865470566 (0xe6666666) bytes.  This is 7549747 sectors, plus 102
 bytes.

 sfdisk is run in olpc-os-builder:modules/sd_card_image/image.50.makefs.sh
 with -S 32 -H 32, which implies a cylinder size of 1024 sectors.

 After fs-update of but before growing the partition, parted reports:
 {{{
 # parted -m /dev/mmcblk0 "unit S print"
 BYT;
 /dev/mmcblk0:7733248s:sd/mmc:512:512:msdos:MMC SEM04G;
 1:8192s:139263s:131072s:ext2::boot;
 2:139264s:7549119s:7409856s:ext4::;
 }}}

 These values are starting sector on disk, ending sector on disk, and size
 in sectors.

 The ending sector is calculated; the partition table entry only contains
 starting sector number and size.

 sfdisk has left a gap of 627 sectors after the partition and before the
 end of the image.

-- 
Ticket URL: <http://dev.laptop.org/ticket/11690#comment:3>
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