I've been trying to follow Extroot configuration on my MikroTik RB750Gr3 without much success. I've got the SD card configured and can copy files to/from it just fine. The problem seems to be, when loading modules during pre-boot, something is failing causing extroot to not work.
[ 7.779043] mount_root: loading kmods from internal overlay
[ 8.193430] kmodloader: failed to open /tmp/overlay/upper/lib/modules/5.4.143/xhci-hcd.ko
[ 8.202007] kmodloader: failed to open /tmp/overlay/upper/lib/modules/5.4.143/xhci-mtk.ko
[ 8.210530] kmodloader: failed to open /tmp/overlay/upper/lib/modules/5.4.143/xhci-pci.ko
[ 8.219095] kmodloader: failed to open /tmp/overlay/upper/lib/modules/5.4.143/xhci-plat-hcd.ko
[ 8.264626] mount_root: failed to launch kmodloader from internal overlay
[ 8.443393] block: attempting to load /tmp/jffs_cfg/upper/etc/config/fstab
[ 8.512286] block: extroot: device not present, retrying in 15 seconds
Then, later, when modules.d loaded - things are great! But unfortunately, it fell back to the JFFS2 filesystem before that.
[ 23.656900] block: extroot: cannot find device mmcblk0p1
[ 23.663547] mount_root: switching to jffs2 overlay
[ 25.758223] kmodloader: done loading kernel modules from /etc/modules.d/*
[ 26.159171] mmc0: new high speed SDHC card at address 09b1
[ 26.169444] mmcblk0: mmc0:09b1 SD16G 14.9 GiB
[ 26.184155] mmcblk0: p1
I have the following symlinks:
lrwxrwxrwx 1 root root 16 Oct 10 15:06 mmc -> ../modules.d/mmc
lrwxrwxrwx 1 root root 25 Oct 10 16:20 sdhci-mt7620 -> ../modules.d/sdhci-mt7620
Contents:
root@hex-router:/etc/modules-boot.d# ls mm* | xargs cat
mmc_block
mmc_core
sdhci
mtk_sd
root@hex-router:/etc/modules-boot.d# ls sd* | xargs cat
mtk_sd
A similar problem that required a custom image: Usb-storage fail to load in preinit. Is that required here as well to get these into the /rom partition somehow?