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update keyboard leds
Posted: Wed Nov 24, 2004 5:58 am
by bubach
Hello, i recently added code in my keyboard irq to update teh leds when caps, num or scroll lock is pressed..
the problem is that bosch gives me a "keyboard buffer full"-error when i have this function enabled..
something i am missing?
thanks in advance..
/ Christoffer
Re:update keyboard leds
Posted: Wed Nov 24, 2004 6:37 am
by distantvoices
i wouldn't do this kind of operation in the isr. I'd do it in a sort of task - or a tasklet, which does the work after the isr has fetched the scancodes from kbd port 60 (iirc)
are you still reading scancodes from port 60?
If not, no wonder that bochs doesn't like it.
are you issueing the correct combo of command/data sequence? I don't know it by heart, but can lookup.
is your code caught in a condition which never/always becomes true?
just check it out. Without more info about *how* your kbd isr looks like (a rough sketch in human language or pseudocode suffices), we canna give that much help as we want to.
ha en bra dag
Re:update keyboard leds
Posted: Wed Nov 24, 2004 7:01 am
by bubach
Hmm. I?ll try to describe the process..
I read the scan code from port 0x60
I check if key is released or pressed. save status as bit in "special-byte"
If ctrl is pressed or not, saved as bit in the "special-byte"
if shift - ||-
if alt - || -
if ctrl+alt+del is pressed, add bit in special-byte..
if caps is pressed, save status in "status-byte"
if num - || -
if scroll - || -
at the end i add the scan code to a buffer, and updates the status and special bytes, after that i "call update_leds" and exits the isr as usual; ack to pic(?) with out 0x20 something..
the update_leds function is adapted from a swedish os, that have a keyboard isr that looks almost excatly like mine.
it sends some bytes (the status-byte and maybe something else) and call a simple "kbd_wait" function 2(?) times in between..
to bad i don?t have my source with me..
[edit] to cold in sweden right now for a "bra dag" (eng: good day)..
Re:update keyboard leds
Posted: Wed Nov 24, 2004 7:23 am
by distantvoices
Below are the crucial pieces of code from my own kbd led handling.
Basically you send a bitmask to the controller which tells, which led is on and which one is off.
How are you setting the corresponding bit in status byte say for caps lock?
Code: Select all
void kbd_ack(void){
while(!(inport(0x60)==0xfa));
}
void kbd_led_handling(uchar_t ledstatus){;
outport(0x60,0xed);
kbd_ack();
outport(0x60,ledstatus);
}
Here in vienna, sun shines but it is cooold as in devils arse.
But that shall not hinder us from enjoying a biiig snow feast.
Re:update keyboard leds
Posted: Wed Nov 24, 2004 7:27 am
by bubach
hmm. can?t remeber the right order right now, but its something like:
bit 1= 1 for num on, 0 for num off
bit 2= 1 for scroll on, 0 for scroll off
bit 3= 1 for caps on, 0 for caps off
bits 4-8 = 0
i think thats how it?s done.. but as i don?t have my sources right here...
Re:update keyboard leds
Posted: Fri Nov 26, 2004 4:42 am
by bubach
Okay, now i have my source.
Lets see.. Here?s how i check and set the bits in the "kbd_status" byte... (u can?t turn them of yet..)
Code: Select all
;----------------------;
; Keyboard IRQ ;
;----------------------;
keyboard_isr:
push eax
;-----------------------------------;
; get the scancode and statusbyte ;
;-----------------------------------;
xor eax, eax
in al, 0x60
mov ah, byte [kbd_special] ; for ctrl+alt+del etc..
;------------------------------;
; check if key was released ;
;------------------------------;
test al, 0x80
jz .key_down
or ah, 10000000b
;............... some code..............
;----------------------------------------------;
; a key was pressed, check for special keys ;
;----------------------------------------------;
.key_down:
and ah, 01111111b
;............... some code..............
.check_caps:
cmp al, 58
jnz .check_num
or byte [kbd_status], 00000100b
jmp .end
.check_num:
cmp al, 69
jnz .check_scroll
or byte [kbd_status], 00000010b
jmp .end
.check_scroll:
cmp al, 70
jnz .end
or byte [kbd_status], 00000001b
jmp .end
;.............. some more code...................
.end:
mov [kbd_raw_buffer], al
mov [kbd_special], ah
movzx eax, [kbd_status] ; to check if the statusbyte was correct..
call print_hex32
; call update_leds
mov al, 0x20
out 0x20, al
pop eax
ret
the (current) update_leds function
Code: Select all
;------------------------------;
; Update the keyboard LED?s ;
;------------------------------;
update_leds:
push ax
.l1:
in al, 0x64
and al, 0x02
jnz .l1
mov al, 0xED
out 0x60, al
.l2:
in al, 0x64
and al, 02
jnz .l2
mov al,[kbd_status]
out 0x60, al
pop ax
ret
Do you have any links to information about "advanced" keyboard programming? Becasue i would also like to know how to test the type of keyboard, know how to set diffrent "scan-modes(?) etc.
/ Christoffer
Re:update keyboard leds
Posted: Fri Nov 26, 2004 2:44 pm
by bubach
[EDIT] For future forum viewers with the same problem, i now update this post with the correct and fully working code..
variable defined:
Code: Select all
;-------------------------------------------------------------------------;
; _________________ LED status byte: ;
; |0|0|0|0|0|1|1|1| ;
; +---------------+ 1 = True 0 = False ;
; | | +---> scroll lock ;
; | +-----> num lock ;
; +-------> caps lock ;
;-------------------------------------------------------------------------;
kbd_status db 0 ; LED statusbyte
In the keyboard IRQ:
Code: Select all
;-------------------------------------;
; toggle caps, num and scroll lock ;
;-------------------------------------;
.check_caps:
cmp al, 58
jnz .check_num
xor byte [kbd_status], 4
call update_leds
jmp .end
.check_num:
cmp al, 69
jnz .check_scroll
xor byte [kbd_status], 2
call update_leds
jmp .end
.check_scroll:
cmp al, 70
jnz .end
xor byte [kbd_status], 1
call update_leds
jmp .end
And the functions required to change the LEDs:
Code: Select all
;------------------------------;
; Update the keyboard LED?s ;
;------------------------------;
update_leds:
push ax
call kbd_wait
mov al, 0xED
out 0x60, al
call kbd_wait
mov al, [kbd_status]
out 0x60, al
call kbd_wait
pop ax
ret
;------------------;
; keyboard wait ;
;------------------;
kbd_wait:
jmp $+2
in al,64h
test al,1
jz .ok
jmp $+2
in al,60h
jmp kbd_wait
.ok:
test al,2
jnz kbd_wait
ret
anyway, thanks for the help and major input..
/ Christoffer