Posts: 56
Joined: Tue May 02, 2017 12:47 pm

building new sd card Q, preconfigured for my use

Fri Jan 31, 2020 5:00 pm

Hi All;

I've installed the full 10.1 image to a fresh 64G card, and have replaced the networking with stuff from a running card so I should have networking up and running at boot up. (insert laff track here). Stuff replaced includes /etc/fstab because the running card has a couple ssd's plugged into sata to usb3 adapters. But the fstab is using PARTUUID's to identify the partitions.

The idea is to make it boot, bring it uptodate, then install my custom kernel from the attached ssd's.
So my question is, are those going to be scrambled when booting almost the same card, major diff is that until its booted, the replacement card will have your kernel running instead of my custom preempt-rt kernel.

2nd related question: If booted and running normally, can I:
cd to the built kernels top level on the ssd
sudo cp arch/arm/boot/dts/*.dtb /boot/
sudo cp arch/arm/boot/dts/overlays/*.dtb* /boot/overlays/
sudo cp arch/arm/boot/dts/overlays/README /boot/overlays/
sudo cp arch/arm/boot/zImage /boot/kernel7l

and reboot.

If that reboots, which it should but the system wasn't live the last time I did that, and its working well right now.

Since I can't use sshfs as root, part of my security model here, I'd have to do a 2 stage transfer to this machine as me so I can become root and operate on the card in a reader here. Which is how I built this card several months ago. Can I use the live shortcut described above? I've seen a rock64 running armbian do it.

The eventual target is to move the high traffic /tmp, /var and the linuxcnc data dirs to one of the ssd's to relieve the write pressure from the u-sd card for longer mostly read-only life. And then make backup copies. Amanda is backing it up every night anyway.

Many thanks.

Posts: 56
Joined: Tue May 02, 2017 12:47 pm

Re: building new sd card Q, preconfigured for my use

Sat Feb 01, 2020 4:00 am


Since the above post I've built 2 more kernels, and found then all now missing the arch/arm/boot/dts/overlays directory.

Can I assume that the zImage being built now compensates for this, by looking for the "overlays" in the dts directory?

If not, where do I put the stuff formerly put in /boot/dts/overlays?

Thanks alll.

Cheers, gene1934

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