01-22-2022, 03:48 AM
Imho, this also makes sense for security reasons: If you normally run your device off eMMC, an attacker with physical access could easily boot from sdcard and tamper with your installation.
If you experiment a lot and prefer to use the eMMC for performance reasons you can still put the bootloader to sd and the rest of the system to eMMC. Then, if you brick the OS stored in eMMC you can swap sdcards and fix or replace it. This approach will require some manual work, though.
Since the SPI has the highest priority, a better general solution would be to have a firmware (e.g. UEFI) in SPI and provide a boot menu from there, just like on x86. Afaik, some developers tried something in this direction, but we are not there yet. For a more general discussion about this, see also this post on Drew's blog:
https://drewdevault.com/2022/01/18/Pine6...ities.html
If you experiment a lot and prefer to use the eMMC for performance reasons you can still put the bootloader to sd and the rest of the system to eMMC. Then, if you brick the OS stored in eMMC you can swap sdcards and fix or replace it. This approach will require some manual work, though.
Since the SPI has the highest priority, a better general solution would be to have a firmware (e.g. UEFI) in SPI and provide a boot menu from there, just like on x86. Afaik, some developers tried something in this direction, but we are not there yet. For a more general discussion about this, see also this post on Drew's blog:
https://drewdevault.com/2022/01/18/Pine6...ities.html
