Hi John, Am 07.08.2016 um 08:42 schrieb John Crispin: > > > On 06/08/2016 18:25, Josua Mayer wrote: >> Hi everyone, >> >> During my work on supporting a block-device as overlay partition, >> without using extroot I came across this phenomenon: >> >> When booting my mvebu-based board with an initramfs, mount_root was not >> executed. This seems unusual to me, I certainly expected the init >> process to be exactly the same. >> So I traced the cause to line 15 in the 80_mount_root preinit script. >> It says: [ "$INITRAMFS" = "1" ] || boot_hook_add preinit_main do_mount_root >> >> Very clearly, this behaviour is intentional. Would anyone be willing to >> shed some light on why this is? >> Can it be removed? And if not: What is stopping us? > > its by design. initramfs will reside in ram. in your usecase, you would > want to run the initramfs and then mount an external media as root. at > this point the initramfs's rootfs will continue to reside in ram and > waste it. Thanks for clarifying this. I am on your side there, it makes little sense to waste ram with an initramfs. Only I was doing my tests with an initramfs because thats the only image type already properly implemented for the Clearfog.
Perhaps we can add a console message stating that mount_root was skipped on purpose? This would make it much easier for future developers should they ever run into the same situation. > > why do you not want to use extroot ? it is desinged for the exact > purpose of what you are trying to do. Well, this is why: a) I did not yet understand how to set up extroot when creating images, aka in the target/linux/mvebu/.../Makefile b) Isn't extroot meant for the user to control? What would happen if extroot was already set up in teh read-only rootfs? Chain-extroot? c) I would really love a solution thats obvious when inspecting the system. So to me that means: 3 partitions, and all the magic visible in bootargs (e.g. root=/dev/mmcblk0p2 rootfstype=squashfs overlay=/dev/mmcblk0p3) Now I already got this working, and intend to submit a new version of that patch once I can show off how it is meant to be used. br Josua Mayer > > John > >> >> John I added you in CC because it is your commit that added the >> initramfs-check: >> https://git.lede-project.org/?p=source.git;a=blobdiff;f=package/base-files/files/lib/preinit/80_mount_root;h=9a99ee91097129205e7cee966ce4bf2ecd0d7c72;hp=ad24fb8ace70707e434c9980d948399834ce160f;hb=f43b7934d2850c2f545736253a0f8cbe4915fdff;hpb=1360067c4a75cd1804710e6f25871f695d3271b2 >> >> br >> Josua Mayer >> >> _______________________________________________ >> Lede-dev mailing list >> [email protected] >> http://lists.infradead.org/mailman/listinfo/lede-dev >> > > _______________________________________________ > Lede-dev mailing list > [email protected] > http://lists.infradead.org/mailman/listinfo/lede-dev > _______________________________________________ Lede-dev mailing list [email protected] http://lists.infradead.org/mailman/listinfo/lede-dev
