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#define IO_PIC 0x20
#define IRQ_OFFSET 32
#define IO_PIT 0x40
#define TIMER_FREQ 1193182
#define TIMER_DIV(x) ((TIMER_FREQ+(x)/2)/(x))
#define TEST_COUNT 0x0200
.code16gcc
.text
.globl _start
.type _start, @function
_start:
/*
* fill up noop handlers
*/
xorw %ax, %ax
xorw %di, %di
movw %ax, %es
movw $256, %cx
fill_noop_idt:
movw $noop_handler, %es:(%di)
movw %cs, %es:2(%di)
add $4, %di
loop fill_noop_idt
set_idt:
movw $timer_isr, %es:(IRQ_OFFSET*4)
movw %cs, %es:(IRQ_OFFSET*4+2)
set_pic:
# ICW1
mov $0x11, %al
mov $(IO_PIC), %dx
out %al,%dx
# ICW2
mov $(IRQ_OFFSET), %al
mov $(IO_PIC+1), %dx
out %al, %dx
# ICW3
mov $0x00, %al
mov $(IO_PIC+1), %dx
out %al, %dx
# ICW4
mov $0x3, %al
mov $(IO_PIC+1), %dx
out %al, %dx
set_pit:
# set 8254 mode
mov $(IO_PIT+3), %dx
mov $0x34, %al
outb %al, %dx
# set 8254 freq 1KHz
mov $(IO_PIT), %dx
movb $(TIMER_DIV(1000) % 256), %al
outb %al, %dx
movb $(TIMER_DIV(1000) / 256), %al
outb %al, %dx
enable_irq0:
mov $0xfe, %al
mov $(IO_PIC+1), %dx
out %al, %dx
sti
loop:
1:
jmp 1b
test_ok:
mov $0x3f8,%dx
cs lea msg2, %si
mov $(msg2_end-msg2), %cx
cs rep/outsb
/* Reboot by using the i8042 reboot line */
mov $0xfe, %al
outb %al, $0x64
timer_isr:
cli
pushaw
pushfw
mov $0x3f8,%dx
mov $0x2e, %al # .
out %al,%dx
decw count
jz test_ok
popfw
popaw
iretw
noop_handler:
iretw
count:
.word TEST_COUNT
msg2:
.asciz "\nTest OK\n"
msg2_end:
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