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update keyboard leds https://forum.osdev.org/viewtopic.php?f=1&t=10053 |
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Author: | bubach [ Wed Nov 24, 2004 5:58 am ] |
Post subject: | update keyboard leds |
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 |
Author: | distantvoices [ Wed Nov 24, 2004 6:37 am ] |
Post subject: | Re:update keyboard leds |
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 |
Author: | bubach [ Wed Nov 24, 2004 7:01 am ] |
Post subject: | Re:update keyboard leds |
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).. |
Author: | distantvoices [ Wed Nov 24, 2004 7:23 am ] |
Post subject: | Re:update keyboard leds |
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: 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. |
Author: | bubach [ Wed Nov 24, 2004 7:27 am ] |
Post subject: | Re:update keyboard leds |
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... |
Author: | bubach [ Fri Nov 26, 2004 4:42 am ] |
Post subject: | Re:update keyboard leds |
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: ;----------------------; ; 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: ;------------------------------; ; 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 |
Author: | bubach [ Fri Nov 26, 2004 2:44 pm ] |
Post subject: | Re:update keyboard leds |
[EDIT] For future forum viewers with the same problem, i now update this post with the correct and fully working code.. variable defined: Code: ;-------------------------------------------------------------------------; ; _________________ 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: ;-------------------------------------; ; 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: ;------------------------------; ; 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 |
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