I have decided to go for a little Intel-N5095-powered Mini PC, sweet 8.5x8.5cm and close to the size of a Raspberry. The device is having two Ethernet ports, which makes it ideal for OpenWRT.
I have created the USB Stick with ext4-combined-efi, that worked so far. But currently, the system boots from USB Stick, as soon as I detach the, stick, the system won't boot. I need to permamently install OpenWRT on /dev/sda. I have tried this by the command "DD if=...img of=/dev/sda". This did not work out.
Any hint for me?
The command to copy the image to the internal drive has to use the image for efi, otherwise the system will not boot.
dd if=openwrt-22.03.3-x86-64-generic-ext4-combined-efi.img of=/dev/sda
Thanks for your support. A little impression from this tiny device: It's powered up by 12V / 2.5A PoE Splitter with DC jack. Dual-NIC by Realtek with 1Gbps, M2.2240 SSD with 256GB, which can even be extended. Unfortunately the RAM size is fix and cannot be upgraded.
By USB the VDSL modem is powered up as well, which "only" consumes 0.5A.