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Problem with timer/counter3
Posted: Sun Jul 21, 2013 7:18 am
by hrm
Hi guys...
I wrote a beep function for my simple 64-bits OS and works well. but as I call it , "Double Fault Exception" occur.
this is my beep function code:
Code: Select all
; AX : Frequency
; BX : Lentgh
Beep:
push rbx
push rax
mov al,0xff
out 0x21,al ; Disable IRQ0
mov al,PIT_M_SW|PIT_RWF|PIT_T2
out 0x43,al
pop rax
mov bx,ax
mov eax,PIT_BF/2
mov edx,eax
and edx,0xFFFF0000
shr edx,16
div bx
push ax
out 0x42,al
mov al,ah
out 0x42,al
xor rax,rax
in al,0x61
or al,3
out 0x61,al
pop ax
pop rbx
mul bx
xor ebx,ebx
and eax,0xFFFF
mov ebx,eax
and edx,0xFFFF
shl edx,16
or ebx,edx
_b0:
in al,0x61
and al,1<<5
jz _b0
dec ebx
jnz _b0
in al,0x61
and al,0xFE
out 0x61,al
xor al,al
out 0x21,al ; Enable IRQ0
ret
Where is my problem?
thanks in advance.
Problem with timer/counter3
Posted: Sun Jul 21, 2013 7:27 am
by hrm
Re: Problem with timer/counter3
Posted: Sun Jul 21, 2013 7:31 am
by xenos
hrm wrote:Where is my problem?
Insufficient debugging skills.
At which instruction does the double fault occur? What is causing the double fault? Which exception is raised before the double fault? What does the Bochs log tell you about these things?
Re: Problem with timer/counter3
Posted: Mon Jul 22, 2013 6:40 am
by hrm
Thank you for your attention.
I don't know what is causing it...
This is Bochs log , but I can't understand anything
Code: Select all
00179620622d[CPU0 ] long mode activated
00179620623d[CPU0 ] page walk for address 0x0000000000002b5f
00179620623d[CPU0 ] page walk for address 0x00000000000027a4
00179620623d[CPU0 ] page walk for address 0x000000000002fff8
00179620644d[CPU0 ] page walk for address 0x00000000000b8000
00179627559d[CPU0 ] inhibit interrupts mask = 1
00189515185d[CPU0 ] interrupt(): vector = 08, TYPE = 0, EXT = 1 // #DF Occured
00189515185d[CPU0 ] page walk for address 0x0000000000045080
00189515185d[CPU0 ] interrupt(long mode): INTERRUPT TO SAME PRIVILEGE
00189515185d[CPU0 ] page walk for address 0x000000000000102b // Print Message
00189515190d[CPU0 ] page walk for address 0x0000000000002d77
00189515200d[CPU0 ] page walk for address 0x0000000000002d16
00189515893d[CPU0 ] page walk for address 0x0000000000002e26
00189515893d[CPU0 ] page walk for address 0x0000000000002d16
00189515905d[CPU0 ] page walk for address 0x0000000000002e26
00189515905d[CPU0 ] page walk for address 0x0000000000002d16
00189515917d[CPU0 ] page walk for address 0x0000000000002d77
00189515917d[CPU0 ] page walk for address 0x0000000000002d16
00189515962d[CPU0 ] LONG MODE IRET
Re: Problem with timer/counter3
Posted: Mon Jul 22, 2013 6:42 am
by Combuster
EXT = 1
You forgot to read the
FAQ
Re: Problem with timer/counter3
Posted: Mon Jul 22, 2013 6:53 am
by Casm
Code: Select all
xor al,al
out 0x21,al ; Enable IRQ0
Have you got handlers for all the interrupts you are enabling there?
Re: Problem with timer/counter3
Posted: Mon Jul 22, 2013 7:43 am
by xenos
And did you properly remap the PIC?
Re: Problem with timer/counter3
Posted: Mon Jul 22, 2013 8:14 am
by hrm
Code: Select all
And did you properly remap the PIC?
Thanks a lot , I did it. but my problem was too more simple!
Code: Select all
Code:
xor al,al
out 0x21,al ; Enable IRQ0
Have you got handlers for all the interrupts you are enabling there?
Yeah! I had removed some of the ISR's yesterday. but I had forgotten it! My problem solved. Really thank you...
