README: Extend with some more information

README.md

@@ -4,6 +4,9 @@ based on the [CodeAurora Little Kernel fork](https://source.codeaurora.org/quic/
 It provides an Android Fastboot interface on devices where the stock bootloader
 does not provide Fastboot (e.g. Samsung).
 
+On MSM8916 it is also used for some quirks for mainline devices, e.g. to set
+a proper WiFi/BT MAC address in the device tree.
+
 lk2nd does not replace the stock bootloader. It is packaged into an Android
 boot image and then loaded by the stock bootloader as a "secondary" bootloader.
 The real Android boot image is placed into the boot partition with 1 MB offset,
@@ -26,13 +29,22 @@ and then loaded by lk2nd.
 ## Usage
 lk2nd provides the standard Android fastboot protocol for flashing/booting Android boot images.
 
+Press `Volume Down` while booting to enter Fastboot mode.
+Press `Volume Up` while booting to boot into Recovery mode.
+
+**Note:** If your stock bootloader uses the same key combinations, you need to wait a bit before
+pressing the volume keys. Usually, waiting until the screen turns on and/or the device vibrates
+should be enough to make the stock bootloader ignore the keys.
+
 `fastboot flash lk2nd lk2nd.img` can be used to update lk2nd directory from its
 fastboot interface.
 
 **Note:** `fastboot flash boot boot.img` will flash the actual boot image with 1 MB offset
 into the boot partition. This is done to avoid replacing lk2nd (since it is also booted from
 the boot partition).
 
+Other fastboot commands work normally.
+
 ## Building
 ```
 $ make TOOLCHAIN-PREFIX=arm-none-eabi- msm8916_secondary
@@ -59,6 +71,3 @@ Replace `TOOLCHAIN_PREFIX` with the path to your tool chain.
 
 ## Contact
 Ping `minecrell`/`Mis012` on [`#postmarketos-mainline`](https://wiki.postmarketos.org/wiki/Matrix_and_IRC).
-
-## License
-GPL-2.0-only