1 1
cIddeab

BananaPi M2+, how to Overlayfs ?

Recommended Posts

(edited)

Hi all,

I've been struggling with the issue in the topic for a few days now. Actually the ideal solution would be a read-only root file system (with a writable overlayfs on top), so that I can just turn the power off, without risking any SD-card/filesystem corruption. There seems to be an easy solution for that according to this page:

https://docs.armbian.com/User-Guide_Advanced-Features/

section "How to freeze your filesystem?". But the package "overlayroot" that is mentioned there does not seem to be available for Debian (Armbian Stretch).

A quick attempt to adopt the overlayfs-startup scripts to Debian failed, because Debian is using systemd and the script that I found was obviously for sysv-init.

Anyway, next best solution that I searched for was using the on-board power button to shut down the system. I found two posts that seemed like a solution: using acpid and adding a udev-rule to detect the onboard power button as acpi-power-button. But neither of the two worked on my BananaPi M2+ board.

https://frank-mankel.de/kategorien/10-bananapi/62-bananapibananapro-powerbutton

https://stackoverflow.com/questions/53757996/banana-pi-m2-execute-script-when-power-button-was-pressed-via-udev-does-not-wo

I've not been able to see any events in acpid (acpi_listen or in the acpi-log files) when pressing the power button. And in the meantime, I doubt, that it can work on the BananaPi M2+, as the power button is connected to one of the GPIO-Pins here.

 

What I did manage to do so far, after inspecting the circuit diagrams of the board and thus finding out which GPIO-pin the power button is connected to, is to write a little python program that estabilshes an interrupt when that GPIO shows a fallig edge (i. e. when the power button is pressed) and then shuts down the system. This python script I have installed as a systemd service. So currently, I managed to shut down the BananaPi by pressing the power button.

(For anyone who is interested: I uploaded the source code to GitLab here:

https://gitlab.com/cIdde/bananapim2pluspowerbuttonshutdownservice

)

Anyway, I am still interested in the readonly-root / overlayfs / overlayroot solution for Debian stretch, as this is safer in the long run. Does anyone have any pointers for me there? Has anyone tried that already or is there a solution for the u-boot / systemd combination that would be easy to adopt?

Edited by Tido
I changed the title as you look for Overlay, not shutdown

Share this post


Link to post
Share on other sites

@yam1: thanks for the link. After reading it, I still think, that overlayfs is the best way to go. Well, as there doesn't seem to be a ready-to-use solution, it looks like I'll have to do some porting of the "overlayroot"-package solution to systemd ... 

Will surely take a while, but when I have something, I'll report it here - for anyone else, who might be looking for such a solution.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
1 1