After some more research it appears like this:
On startup, the bootloader has control over the notification led and after the OS has been loaded, it takes control over the notification led.
It seems like you can tell which bootloader is installed by checking how many and which colors the LED shows while booting. The Pinephone's default bootloader shows only one colour: red.
Tow-Boot shows red first, but then switches to a second color, depending on the location it boots from: yellow for eMMC, cyan if booting from microSD-card (holding Volume down) or blue if enabling the mass storage mode (holding Volume up).
I found this issue on GitHub.
I was hoping for a command to check the bootloader in the terminal, but it seems, this is the best for now...
I'll not mark this as answered yet in the case I am mistaken and somebody wants to correct me or has a terminal solution.
On startup, the bootloader has control over the notification led and after the OS has been loaded, it takes control over the notification led.
It seems like you can tell which bootloader is installed by checking how many and which colors the LED shows while booting. The Pinephone's default bootloader shows only one colour: red.
Tow-Boot shows red first, but then switches to a second color, depending on the location it boots from: yellow for eMMC, cyan if booting from microSD-card (holding Volume down) or blue if enabling the mass storage mode (holding Volume up).
I found this issue on GitHub.
I was hoping for a command to check the bootloader in the terminal, but it seems, this is the best for now...
I'll not mark this as answered yet in the case I am mistaken and somebody wants to correct me or has a terminal solution.