From being powerer-on the Pi has, AIUI, to find bootloader code on an SD card. But there is nothing to stop that bootloader code fetching further executable code from across a network.
Have any of you guys already tried booting the Pi from an image which is stored on a server? What Pi bootloader did you use? Is there one that you would recommend? I don't need or want any flexibility or complexity such as command line operation or menus or the ability to boot from multiple sources. A bootloader that does the minimum to carry out a network boot (with adequate diagnostics if things went wrong) would be good.
I have seen forum posts which suggest loading a minimal Linux and a ramdisk just to run a network boot but that should not be necessary. All that should be required is:
- GPU loads bootloader file from SD card and starts CPU running it
- Bootloader does DHCP and TFTP to get and vet a file from the network.
After that the bootloader can just start executing the file that it has loaded. That file will do the rest.
Anyone already tried this?