Messages in this thread | | | Date | Sun, 13 Jan 2008 19:50:34 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH] Default keyboard LEDs |
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Samuel Thibault wrote: > In many cases, one prefers to have e.g. the NumLock on by default. In > many cases, one doesn't want to have it by default, e.g. on laptops. > > Distributions actually have a very hard time trying to set this > correctly after the kernel boot, and that doesn't work for new consoles > that are created via the openvt(1) command anyway. This hence adds a > keyboard.default_leds boot parameter that permits to configure the > default keyboard LEDs. > > Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org> > > Actually, what would be perfect would be to use the configuration that > the BIOS sets at boot by default. That is device-dependent, however. >
It is, but it can be read out either by INT calls at initialization time, or by reading out the byte at physical address 0x417:
--------K-M00400017-------------------------- MEM 0040h:0017h - KEYBOARD - STATUS FLAGS 1 Size: BYTE SeeAlso: MEM 0040h:0018h,INT 16/AH=02h,MEM 0040h:0096h
Bitfields for keyboard status flags 1: Bit(s) Description (Table M0010) 7 INSert active 6 Caps Lock active 5 Num Lock active 4 Scroll Lock active 3 either Alt pressed 2 either Ctrl pressed 1 Left Shift pressed 0 Right Shift pressed SeeAlso: #M0011,#00587
The same information is available through INT 16h, AH=02h.
-hpa
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