Re: [bisect] Merge tag 'mmc-v4.6' of git://git.linaro.org/people/ulf.hansson/mmc (was [GIT PULL] MMC for v.4.6)

From: Peter Hurley
Date: Tue Apr 05 2016 - 20:25:16 EST


On 04/05/2016 01:59 AM, Ulf Hansson wrote:
> Although, what puzzles me around this particular issue, is how an SoC
> configuration can rely on this fragile behaviour.
> All you have to do to break the assumption of fixed mmcblk ids, is to
> boot with an SD card inserted and then without. Perhaps these SoCs
> just doesn't support this use case!?

Both configurations boot reliably; without the uSD inserted, the
boot and root partitions on the eMMC are booted instead.

Without a uSD inserted, the only mmc block device is the eMMC which is
/dev/mmcblk0, and the root partition is still /dev/mmcblk0p2.

Note though that this particular bootscript can load add'l bootscripts
from the boot partition; in this particular case, the eMMC root
partition is set as a fixed UUID in the bootscript from the
boot partition.

Regards,
Peter Hurley