Messages in this thread | | | From | finkler <> | Subject | Questions about the console keyboard driver / translation tables | Date | Sun, 11 Mar 2012 00:14:11 +0100 |
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Hi there,
I am trying to understand the logic of the Linux keyboard driver, I am not sure if this is the right place to ask, but I don't know where else I could.
Btw. I am talking about an unicode console here.
1.) The Linux kernel (currently) can take 256 translation tables (keymaps), I figured that if I have 8 Mod-Keys and I can press two at the same time, then this makes 256 possible modifications. E.g. the value of my keycode of the button 'a' is 0x0b61 (small letter a) in table 0 and 0x0b41 (capital letter A) in table 1, so is it true that table 1 is for shift pressed keycodes? If so, then why is shift (KG_SHIFT in linux/keyboard.h [1]) set to 0, and how do I compute the modifications, meaning how do I know what e.g. index 231 represents?
2.) As seen above, the value for 'a' is actually 0x0b61 instead of 0x0061, if b indicates a type (here KT_LOCK) why isn't it 0xfb61, because I thought that only values above 0xf000 represent typed values, and the values below are simply unicode values. The values above are read via the KDGKBENT ioctl [2], are these values read differently then written? E.g. would I only type 0xfb61 when using the KDSKBENT ioctl?
3.) If I wanted to assign "Return" to a keycode, what is the difference between using a simple 0x000d (13) and the KT_SPEC type with the function fn_enter (which is supposedly 0xf201)?
I hope anyone can help me out a little, thank you very much in advance, regards, Finkler
1: http://tomoyo.sourceforge.jp/cgi-bin...nux/keyboard.h 2: http://www.kernel.org/doc/man-pages/...e_ioctl.4.html
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