Messages in this thread | | | Date | Fri, 06 Oct 2023 10:37:41 +0200 | From | Michael Walle <> | Subject | Re: [PATCH v2 1/3] dt-bindings: mtd: fixed-partitions: Add binman compatible |
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Hi,
>> I'm still not sure why that compatible is needed. Also I'd need to >> change >> the label which might break user space apps looking for that specific >> name. >> >> Also, our board might have u-boot/spl or u-boot/spl/bl31/bl32, right >> now >> that's something which depends on an u-boot configuration variable, >> which >> then enables or disables binman nodes in the -u-boot.dtsi. So in linux >> we only have that "bootloader" partition, but there might be either >> u-boot+spl or u-boot+spl+bl31+bl32. >> >> Honestly, I'm really not sure this should go into a device tree. > > I think we might be getting a bit ahead of ourselves here. I thought > that the decision was that the label should indicate the contents. > If you have multiple things in a partition then it would become a > 'section' in Binman's terminology. Either the label programmatically > describes what is inside or it doesn't. We can't have it both ways. > What do you suggest?
As Rob pointed out earlier, it's just a user-facing string. I'm a bit reluctant to use it programatically. Taking my example again, the string "bootloader" is sufficient for a user. He doesn't care if it's u-boot with spl or u-boot with tfa, or even coreboot. It just says, "in this partition is the bootloader". If you have an "bootloader" image you can flash it there.
If it has a label "u-boot" and I want to switch to coreboot, will it have to change to "coreboot"? I really don't think this is practical, you are really putting software configuration into the device tree.
> At present it seems you have the image described in two places - one > is the binman node and the other is the partitions node. I would like > to unify these.
And I'm not sure that will work for all the corner cases :/
If you keep the binman section seperate from the flash partition definition you don't have any of these problems, although there is some redundancy: - you only have compatible = "binman", "fixed-partition", no further compatibles are required - you don't have any conflicts with the current partition descriptions - you could even use the labels, because binman is the (only?) user
But of course you need to find a place where to put your node.
> What does user space do with the partition labels?
I'm not sure. Also I'm not sure if it really matters, I just wanted to point out, that you'll force users to change it.
-michael
>> >> What if a board uses eMMC to store the firmware binaries? Will that >> >> then >> >> be a subnode to the eMMC device? >> > >> > I thought there was a way to link the partition nodes and the device >> > using a property, without having the partition info as a subnode of >> > the device. But I may have imagined it as I cannot find it now. So >> > yes, it will be a subnode of the eMMC device. >> >> Not sure if that will fly. > > I can't find it anyway. There is somelike like that in > simple-framebuffer with the 'display' property. > > Regards, > SImon
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