"There is also a possibility not to use an SD at all, but it require you to write in a write once memory,
which is non reversible : you will never more boot that RPi from a SD card, and should the process
fails your RPi will be DEAD ! "
this is wrong.^^^^^^^
no worry's about setting the bit for booting without sd card.
It's not like you are DISABLING sd card booting by doing this
The Pi boot ROM code looks for an SD card first. Only if a bootable SD card isn't found will it look for a bootable MassStorageDevice.
i have it set on mine and still booting openplotter from sd card and Raspbian from usb.
patiently waiting for an img.
which is non reversible : you will never more boot that RPi from a SD card, and should the process
fails your RPi will be DEAD ! "
this is wrong.^^^^^^^
no worry's about setting the bit for booting without sd card.
It's not like you are DISABLING sd card booting by doing this
The Pi boot ROM code looks for an SD card first. Only if a bootable SD card isn't found will it look for a bootable MassStorageDevice.
i have it set on mine and still booting openplotter from sd card and Raspbian from usb.
patiently waiting for an img.