Entry | |
---|---|
R0 | 16 (reason code) |
R1 | Keyboard number |
Keyboard drivers should make this call when the last keyboard they manage is removed from the system. This allows any other drivers which might want to use a different keyboard number to issue a call to KeyV 0 in order to switch the OS to the correct keyboard layout. For example, the builtin keyboard of the Pandora uses keyboard number 4, but if a USB keyboard is attached then the USB drivers will set the keyboard number to 2. Once the last USB keyboard is removed the USB drivers will issue this service call to allow PandoraKey? to set the keyboard type back to 4, allowing InternationalKeyboard to switch back to the keyboard mapping required for the builtin keyboard to function correctly.
When a keyboard driver receives this service all and wishes to make itself the active driver, it should issue a call to KeyV 0 and then claim the KeyV 16 call.