On Sat, Sep 28, 2024 at 03:02:47PM +0200, Krzysztof Kozlowski wrote: > On 28/09/2024 14:47, Daniel Golle wrote: > > Add the 'volume-is-critical' boolean property which marks a UBI volume > > as critical for the device to boot. If set it prevents the user from > > all kinds of write access to the volume as well as from renaming it or > > detaching the UBI device it is located on. > > > > Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx> > > --- > > .../devicetree/bindings/mtd/partitions/ubi-volume.yaml | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/mtd/partitions/ubi-volume.yaml b/Documentation/devicetree/bindings/mtd/partitions/ubi-volume.yaml > > index 19736b26056b..2bd751bb7f9e 100644 > > --- a/Documentation/devicetree/bindings/mtd/partitions/ubi-volume.yaml > > +++ b/Documentation/devicetree/bindings/mtd/partitions/ubi-volume.yaml > > @@ -29,6 +29,15 @@ properties: > > description: > > This container may reference an NVMEM layout parser. > > > > + volume-is-critical: > > + description: This parameter, if present, indicates that the UBI volume > > + contains early-boot firmware images or data which should not be clobbered. > > + If set, it prevents the user from renaming the volume, writing to it or > > + making any changes affecting it, as well as detaching the UBI device it is > > + located on, so direct access to the underlying MTD device is prevented as > > + well. > > + type: boolean > > UBI volumes are mapping to partitions 1-to-1, right? So rather I would > propose to use partition.yaml - we already have read-only there with > very similar description. No, that's not the case. An MTD partition can be used as UBI device. A UBI device (and hence MTD partition) can host *several* UBI volumes. Marking the MTD partition as 'read-only' won't work, as UBI needs read-write access to perform bad block relocation, scrubbing, ... Also, typically not all UBI volumes on a UBI device are read-only/critical but only a subset of them. But you are right that the description is inspired by the description of the 'read-only' property in partition.yaml ;) I initially thought to also name the property 'read-only', just like for MTD partitions. However, as the desired effect goes beyond preventing write access to the volume itself, I thought it'd be better to use a new name.
