[Bug 1306841] Re: Wandboard i.MX6 Quad Board has different boot device

[Stéphane Graber]

Fixes uploaded to the trusty and vivid queues.

** Description changed:

- The Wandboard i.MX6 Quad Board has two sdcard slots. The boot device is
- set to "/dev/mmcblk1p1", but this device only exists if both sdcard
- slots are used. I use just one sdcard and my boot device is called
- "/dev/mmcblk0p1".
+ == Rationale ==
+ The wandboards have two microsd slots, one directly tied to the SoC and one on the main board. The wandboard only boots from the one tied to the SoC.
+ 
+ Unfortunately, the device numbering is wrong, in that when only the SoC
+ slot is populated, it'll appear as mmcblk0, but when both slots are, the
+ SoC slot becomes mmcblk1.
+ 
+ So far flash-kernel has only supported the configuration with both slots
+ populated, but it's reasonably common for people to only use the SoC
+ slot and then use the SATA port to attach more storage.
+ 
+ The fix is to use the constant path name from udev which always points
+ to the right slot.
+ 
+ == Testcase ==
+  - Run flash-kernel before update => fails to find sdcard
+  - Run flash-kernel after update => finds sdcard and install kernel
+  - Reboot to check that things boot as expected
+ 
+ == Regression potential ==
+ Should a system somehow miss the /dev/disk/by-path symlink, flash-kernel may fail to install the new kernel. Note that testing on 5 different boards showed that this symlink is constant, regardless of storage configuration, so this shouldn't be an actual problem.
+ 
+ == Original bug report ==
+ The Wandboard i.MX6 Quad Board has two sdcard slots. The boot device is set to "/dev/mmcblk1p1", but this device only exists if both sdcard slots are used. I use just one sdcard and my boot device is called "/dev/mmcblk0p1".
  
  flash-kernel need to dynamically detect the correct sdcard slot or use a
  unique device name.
  
  I have following device symlink on my system:
  /dev/disk/by-id/mmc-SD16G_0xd62aac9a-part1
  /dev/disk/by-path/platform-2198000.usdhc-part1
  /dev/block/179:1
- 
- ProblemType: Bug
- DistroRelease: Ubuntu 14.04
- Package: flash-kernel 3.0~rc.4ubuntu48+fix1
- ProcVersionSignature: Ubuntu 3.13.0-20.42-generic 3.13.7
- Uname: Linux 3.13.0-20-generic armv7l
- ApportVersion: 2.14.1-0ubuntu1
- Architecture: armhf
- Date: Sat Apr 12 01:55:45 2014
- SourcePackage: flash-kernel
- UpgradeStatus: No upgrade log present (probably fresh install)

** Changed in: flash-kernel (Ubuntu Trusty)
       Status: New => In Progress

** Changed in: flash-kernel (Ubuntu Vivid)
       Status: New => In Progress

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to flash-kernel in Ubuntu.
https://bugs.launchpad.net/bugs/1306841

Title:
  Wandboard i.MX6 Quad Board has different boot device

Status in flash-kernel package in Ubuntu:
  Fix Released
Status in flash-kernel source package in Trusty:
  In Progress
Status in flash-kernel source package in Vivid:
  In Progress

Bug description:
  == Rationale ==
  The wandboards have two microsd slots, one directly tied to the SoC and one on the main board. The wandboard only boots from the one tied to the SoC.

  Unfortunately, the device numbering is wrong, in that when only the
  SoC slot is populated, it'll appear as mmcblk0, but when both slots
  are, the SoC slot becomes mmcblk1.

  So far flash-kernel has only supported the configuration with both
  slots populated, but it's reasonably common for people to only use the
  SoC slot and then use the SATA port to attach more storage.

  The fix is to use the constant path name from udev which always points
  to the right slot.

  == Testcase ==
   - Run flash-kernel before update => fails to find sdcard
   - Run flash-kernel after update => finds sdcard and install kernel
   - Reboot to check that things boot as expected

  == Regression potential ==
  Should a system somehow miss the /dev/disk/by-path symlink, flash-kernel may fail to install the new kernel. Note that testing on 5 different boards showed that this symlink is constant, regardless of storage configuration, so this shouldn't be an actual problem.

  == Original bug report ==
  The Wandboard i.MX6 Quad Board has two sdcard slots. The boot device is set to "/dev/mmcblk1p1", but this device only exists if both sdcard slots are used. I use just one sdcard and my boot device is called "/dev/mmcblk0p1".

  flash-kernel need to dynamically detect the correct sdcard slot or use
  a unique device name.

  I have following device symlink on my system:
  /dev/disk/by-id/mmc-SD16G_0xd62aac9a-part1
  /dev/disk/by-path/platform-2198000.usdhc-part1
  /dev/block/179:1

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/flash-kernel/+bug/1306841/+subscriptions