Hi,
I looked and can’t find info on this. Supposedly newer 4Bs have no problem to boot from USB but I didn’t see where or if there is a place in dietpi-config to set the boot order. Ideally I’d like it to try booting from USB if any USB devices are present and if not, fall back to the micro SD card.
Can anybody shed some light on this please? Thank you.
Hi,
this has not really something to do with DietPi. Boot process is fully related to Raspberry Pi device / Raspberry OS. https://www.raspberrypi.org/documentation/hardware/raspberrypi/bootmodes/msd.md
Best to my knowledge, RPi will prefer SD card always, if present.
Hi, thank you.
Well, I saw that page but it seems to be referring to rasbpi tools which I thought would have dietpi equivalents. I didn’t find a similar management interface in dietpi-config and the raspi-config mentioned on that page does not seem to be present in dietpi.
bootloader on RPi4 can be managed using rpi-eeprom-config
https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm2711_bootloader_config.md
If you really need, you could install raspi-config yourself. But you would need to be carful using it as there might be a chance breaking some DietPi configs. Especially on network level if you would use it for network configuration.
Thanks a lot. I have some goodies coming, I’ll try this over the weekend.
I know this is a stale thread, but for anyone else who comes along looking for this, I worked through this last week.
At first I tried to figure out how to get a dietpi iso that I could flash to an sd card and install the OS to my NVMe SSD (using a hat that connects using a USB3 jumper). I couldn’t find any documentation on this nor an installer iso, so was stumped for a bit.
Once I had it capable of booting from USB/SSD I was stumped on how to get dietpi installed, as I couldn’t find an external enclosure for the SSD or other way to plug it into another computer to flash it. About a day later it finally struck me - flash dietpi twice…
So after I had it set up to allow me to boot from USB/SSD (confirmed by seeing that option every time it boots), I flashed an SD with dietpi and booted to that. I went through the install/config stuff fairly quickly - this was only a temporary OS install so I didn’t really think too hard about software or security or that stuff. The only thing I installed then was an imager.
From the raspberry Pi running off the SD card I then flashed dietpi to the SSD. After flashing, I removed the SD card and powered it up - it booted up fine (and quite a bit faster) and took me through the installation process again (this time I paid attention to the software and config options).
It’s been running fine off the SSD ever since. Hopefully this can help others that run into this.
Note - I did this on an rpi 4B. I’m not sure which older models may or may not be able to boot from USB as well. I did purchase it when it was first released (for actual MSRP - I miss those days), so it did not have the ability to boot from USB originally - I’m not sure if the first step above would be necessary for newer 4Bs that may have this ability OOB. Either way, flashing to the USB/SSD from within the pi running off of the sd card should work.
Welcome to our community @evynly
I guess some part of your guide are not needed.
Usually it should be fine to flash DietPi on a SD card, boot and perform first time setup. During this procedure, DietPi will install latest version of eeprom. This will ensure mass storage boot to work on a RPi4. Once initial setup complete, you are able to configure boot order if needed and to flash DietPi on your NVMe SSD.
Basically you could skip whole stuff around Raspberry Pi Imager 
Official RPI docs for USB mass storage boot Raspberry Pi Documentation - Raspberry Pi Hardware
Thanks for the guide!