On 2016-03-14, Ian Campbell wrote: > On Sun, 2016-02-07 at 19:50 -0800, Vagrant Cascadian wrote: >> On 2016-02-06, Heinrich Schuchardt wrote: >> > Booting with u-boot-imx requires imx6q-wandboard-revb1.dtb. >> > linux-image-4.3.0-1-armmp installs imx6q-wandboard.dtb >> > leaving me with a system that will not boot. >> > >> > With imx6q-wandboard-revb1.dtb the system boots. ... >> When the revc was added, backwards compatibility was broken by renaming >> the revb .dtb file instead of keeping it and introducing the revc in a >> new .dtb... kind of hard to fix correctly now... >> Adding support for flash-kernel to copy multiple, or even optionally all >> .dtb files could at least work around the issue. > flash-kernel's DTB entry can reference a script to run which prints the > DTB filename to use, so if you can distinguish the variants by poking > at /sys etc (e.g the current sole user is kirkwood-qnap which looks at > properties of the PCI host bridge etc) then that might be an option? I still think it would be better to copy multiple .dtb files, to make sure all variants are available. This also makes it possible to use the same SD card image on multiple wandboards. > Were any of these boards supported in Jessie? In Jessie, they both work using the same .dtb provided by linux 3.16.x, although installing 4.x from jessie-backports on a wandboard rev B might cause issues. > If so then making upgrade work smoothly would be nice, but if not then > this might just be a case of Testing/Unstable users having > occasionally to manually fix things, but once this is done and the > correct DTB is in use flash-kernel should form then on DTRT and > Stretch will just work for fresh installs. Upgrading u-boot is the tricky part, as we don't currently automatically upgrade u-boot(and it's a bit tricky to do so). Depending on which u-boot version is installed, u-boot will set fdtfile to a value that may not be correct depending on which combination of linux + flash-kernel + board variant is being booted. I think this can partially be worked around by updating the wandboard bootscript to have fallbacks to /boot/dtb-$ver (like the u-boot-generic bootscript). Then the user can set the appropriate .dtb in /etc/flash-kernel/db. Though I still think it makes sense to support multiple .dtb files for a platform, and optionally install all .dtbs. I'd take another stab at coding one or both of those. live well, vagrant
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