Rather than just being able to run Endless from an sd card, might it be possible to install Endless on a fast ssd with a small boot disk sd so as to benefit from the faster usb3 channel?
The RPi4 documentation indicates that USB boot from the firmware isn’t supported yet:
but when they implement this, hopefully soon, it may even be possible to do this without having to tweak anything.
Before they do that, there is the possibility of having the firmware find the bootloader on SD, but then switch to USB for the rest of the boot process. I can’t recall if u-boot has USB support on RPi4…
Thanks Daniel. Aware of the current RPi firmware constraint. The RPi community has been waiting for some time for this to be addressed. In the meantime I have read a post by James Chambers and others on having the firmware find the boot loader on SD and then continuing via the usb. I have just ordered a sandisk extreme 250 portable ssd and am going to try this solution running a Rachel Pi server. Do you think it would be difficult in the Endless RPi implementation to get a SD/USB combination boot process up and running?
Assuming that u-boot doesn’t have USB support, I think you would be able to do this on our current RPi4 release:
- Flash Endless to USB SSD and SD card
- Rename the ostree partition on the SD card to something else
- Boot with both SD & USB connected
It will load the bootloader, kernel and initramfs from SD, but then when looking for the root filesystem, it would find it on USB (through the ‘ostree’ partition label).
Thanks Daniel. I can quickly try this out using a usb stick. To rename the ostree partition on the SD card what commands would I need to use (fdisk commands as in Linux)?
e2label will do it
If you’re running Endless or similar you can also do it within GNOME’s Disks graphical app.
Thanks Daniel. This has worked fine. I notice two immediate things in using Endless on the RPi4B4:
(a) thermometer appears in top righthand corner when running Youtube as a graphics/video test. Added manual fan to RPi and this seems to have addressed this.
(b) can’t seem to get sound to work. Will look at other entries to see if this has already been addressed.
Thanks for the feedback!
We do anticipate a more efficient graphics and video pipeline in future, which might help bring the temperature down on youtube. But even then I think that it’ll still be beneficial to run with a fan in order to keep the CPU running at maximum speed - likely true on any RPi4 software setup.
HDMI audio output should be working OK, but the analog audio jack is not yet supported by the mainline Linux kernel.