Hi Robert, On Tue, Jun 30, 2020 at 04:20:17PM +0200, Robert Karszniewicz wrote: > The problem is that we want to be able to have the rootfs and kernel on > separate partitions. Why do you want to have that? It's kind of traditional to have the kernel separated from the rootfs in some extra "kernel" partition, but are there good reasons for it? There's an overhead in that the bootloader has to read from a filesystem instead of only a raw partition. Is that the reason? Here at Pengutronix we are happy that we only have one partition image that has everything needed to boot, including a description how to boot it and including the kernel. No extra items that the bootloader has to take care of, just put one thing somewhere and be done with it. > We've looked into the Boot Loader Specification, but > from what we saw, it makes A-B systems difficult (according to the spec, > there can only be one "$BOOT" filesystem on a device). barebox is more relaxed here. What we do here is to put two full root filesystems into two different partitions on a SD/MMC. Each of the partitions has one or more /loader/entries/*.conf file(s) and kernels. You can then boot with "boot mmc0.0" into the first rootfs or with "boot mmc0.1" into the second. This may not be really conform to the specification, but works in barebox and is a supported usecase. We do this for A/B Boot scenarios in many projects. Regards, Sascha -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
