#10550 NORM 1.75-so: XO-1.75 os1 panic on missing rootfs if external SD card present

[Zarro Boogs per Child]

#10550: XO-1.75 os1 panic on missing rootfs if external SD card present
--------------------------------+-------------------------------------------
           Reporter:  Quozl     |       Owner:  buytenh      
               Type:  defect    |      Status:  new          
           Priority:  normal    |   Milestone:  1.75-software
          Component:  kernel    |     Version:  not specified
         Resolution:            |    Keywords:               
        Next_action:  diagnose  |    Verified:  0            
Deployment_affected:            |   Blockedby:               
           Blocking:            |  
--------------------------------+-------------------------------------------

Comment(by pgf):

 Replying to [comment:3 buytenh]:
 > If yes, then the real issue is that /dev/* nodes are not stable device
 identifiers, and booting with root=/dev/foo0 is inherently ambiguous if
 there are two of foo.  Possible solutions are specifying the root device
 by label/uuid, or maybe to reorder initialisation of the two SD interfaces
 (although that doesn't 100% guarantee stable device identifiers either).

 the names should be attached to the slot, not the device.  1.5 does this
 with udev:
 {{{
 # udev rules to assign persistent names to OLPC XO-1.5 SD cards and their
 # partitions, based on the MMC bus where they reside
 #
 # mmcblkXpY names cannot be used to reliably identify internal vs external
 # cards, because the "X" component is generated incrementally, regardless
 of
 # backing MMC bus number.

 SUBSYSTEM=="block", KERNEL=="mmcblk?", KERNELS=="mmc0",
 SYMLINK+="disk/mmc/mmc0"
 SUBSYSTEM=="block", KERNEL=="mmcblk?p?", KERNELS=="mmc0",
 SYMLINK+="disk/mmc/mmc0p%n"

 SUBSYSTEM=="block", KERNEL=="mmcblk?", KERNELS=="mmc1",
 SYMLINK+="disk/mmc/mmc1"
 SUBSYSTEM=="block", KERNEL=="mmcblk?p?", KERNELS=="mmc1",
 SYMLINK+="disk/mmc/mmc1p%n"

 SUBSYSTEM=="block", KERNEL=="mmcblk?", KERNELS=="mmc2",
 SYMLINK+="disk/mmc/mmc2"
 SUBSYSTEM=="block", KERNEL=="mmcblk?p?", KERNELS=="mmc2",
 SYMLINK+="disk/mmc/mmc2p%n"

 }}}

-- 
Ticket URL: <http://dev.laptop.org/ticket/10550#comment:4>
One Laptop Per Child <http://laptop.org/>
OLPC bug tracking system