Messages in this thread | | | From | Kay Sievers <> | Date | Thu, 2 Jun 2011 14:49:44 +0200 | Subject | Re: [PATCH] init: add root=PARTUUID=UUID+/-%d support |
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On Wed, Jun 1, 2011 at 21:49, Will Drewry <wad@chromium.org> wrote: > Not sure if this is practical and/or interesting to others, but it's a > minimal change -- > > Expands root=PARTUUID=UUID syntax to support selecting a root partition > by integer offset from a known, unique partition. This approach > provides similar properties to specifying a device and partition number, > but using the UUID as the unique path prior to evaluating the offset. > > For example, > root=PARTUUID=99DE9194-FC15-4223-9192-FC243948F88B+1 > selects the partition with UUID 99DE.. then select the next > partition. > > This change is motivated by a particular usecase in Chromium OS where > the bootloader can easily determine what partition it is on (by UUID) > but doesn't perform general partition table walking. > > That said, support for this approach provides a direct mechanism for the > user to modify the root partition to boot without specifically needing > to extract each PARTUUID or update the bootloader explicitly when the > root partition UUID is changed (if it is recreated to be larger, for > instance, restored, etc). Pinning to a /boot partition UUID with an > offset allows the arbitrary root partition reconfiguration/modifications > with slightly less ambiguity than just [dev][partition] and less > stringency than the specific root partition UUID.
Kind of a creative notation to add/substract something from a uuid. :)
If we are not sure we'll not need another magic thing in the future, we might want to go for a named parameter to add? Maybe instead of: root=PARTUUID=99DE9194-FC15-4223-9192-FC243948F88B+2 we could do: root=PARTUUID=99DE9194-FC15-4223-9192-FC243948F88B,PARTNROFF=2
Might be it's a but over the top, but the key is named PARTUUID, and a +- to it doesn't seem to explain what it does and can not really be expanded for even more creative uses. :)
Kay -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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