Read-only /boot?

[SuperMaximus]

How can I make sure my /boot is protected against power failure making eMMC of Tinkerboard corrupted?

Is it possible to mount read-only /boot while leaving the rest of FS writeable? I know about Overlay root FS, it's OK, but I need to protect only boot.

Please help to mount it properly.

Thanks!

[CryBaby]

Edit /etc/fstab line for boot partition and add ro option:

/dev/mmcblk0p1  /boot    vfat     defaults,noatime,noauto,x-systemd.automount,ro    0   0
 

[SuperMaximus]

@CryBaby 

Thanks! Is this action enough to prevent corruption of bootloader during unexpected power outage?

[CryBaby]

Yes, assuming /boot is a separate partition. I do this with my Raspberry Pis as I have very unreliable power. I also set them to check filesystems on boot by adding fsck.mode=force to the kernel command line. On OSMC that is in /boot/cmdline.txt, on armbian it might be in /boot/uBoot.env, on a grub machine in /etc/default/grub (then run update-grub).

[SuperMaximus]

@CryBaby Could you please advise how to make a separate partition on Armbian for "/boot"?

I was tinkering with attempts to make /boot read-only via u-boot CLI, but had no luck. I mean not only making a partition as such, but also telling Armbian that /boot is on another mmcblk.
I am using Tinkerboards EMMC.

Thanks!

[CryBaby]

If /boot is not already a separate partition I would think there is not much advantage in making it one. The main problem is machines that need a FAT formatted boot partition, as FAT is so fragile. I don't know if your Tinkerboard is one. If /boot is on an ext4 partition then fscking at boot is going to be adequate protection in most cases.

 

If you really want to mess with your partitions I think you will have to understand the boot process of your Tinkerboard in some detail. Does boot have to be the first partition? What filesystems are acceptable? What files need to be in it and what should they contain?