在自定义内核中打开/关闭PS / 2键盘的Caps Lock LED

Question

I'm developing a kernel with Assembly and C and in the boot up process, I want the kernel to turn the Caps lock key on then off. I have found the reference for the LED on the key here . How could I call that function with C or assembly (nasm style)?

Answer 1

SetKeyBoardLeds:
   push  eax
   mov   al,0xed                 
   out   60h,al                 
KeyBoardWait:
   in    al,64h
   test  al,10b                 
   jne   KeyBoardWait              
   mov   al,byte [keyBoardStatus]
   and   al,111b
   out   60h,al                 
   pop   eax
   ret

eg:

   mov   [keyBoardStatus],0xb0    ; Initialise keyboard LED state
   call  SetKeyBoardLeds      
;--------------------------------- This will toggle CapsLock LED
   xor   [keyBoardStatus],4
   call  SetKeyBoardLeds
;---------------------------------
   and   [keyBoardStatus],0xfb
   call  SetKeyBoardLeds

where keyBoardStatus is a byte (It will hold the current keyboard LED state).

Answer 2

You can read my code for reference: irq_ex2.c: An interrupt handler example. This code binds itself to IRQ 1, which is the IRQ of the keyboard controlled under Intel architectures. Then, when it receives a keyboard interrupt, it reads the information about status led and keycode into the work queue. Pressing:

• ESC ---> Caps Lock Led OFF

• F1,F2 ---> Caps Lock ON