Why is bootloader not turning off write permission?

Posted Apr 12, 2019 9:44 UTC (Fri) by metux2 (guest, #131412)
In reply to: Why is bootloader not turning off write permission? by bokr
Parent article: Bricking systems using rm

> If systemd needs to change some variables,

I really wonder why the init system should ever want to modify bootloader variables.

--mtx

Why is bootloader not turning off write permission?

Posted Apr 12, 2019 9:52 UTC (Fri) by zdzichu (subscriber, #17118) [Link]

There are probably multitude of reasons. One I could think of is when the system is in boot-crash loop (unable to finish boot process), init may want to inform the firmware “hey, next time boot this recovery environment, not generic system”.
Or “reboot to firmware setup”. Pressing Del/F2 to enter firmware setup generally doesn't work on modern hardware, this need to be mediated by operating system.
Or even selecting which kernel to boot, this could be stored in firmware variables also.