#!/usr/bin/perl -w
use strict;

my %ints = (
	0x20 => 'int20',
	0x09 => 'keyboard_irq',
	0x08 => 'timer_irq',
	0x01 => 'int20'
);


my @idt;
my @funcs;

my $nextint=0;
my $unhandmsg = "*** Unhandled Exception: 0xXX ***";
my $XXlcn = index($unhandmsg,"XX");

foreach my $int (sort { $a <=> $b } keys %ints){
	my $n = sprintf("%02X",$int);
#	print STDERR "$n\n";
	my $func = $ints{$int};
	for(my $i=$nextint;$i<$int;$i++){
		my $n = sprintf("%02X",$i);
		push @funcs,"unhand${n}:\n\tmov word[unhandmsg + $XXlcn],'$n'\n\tjmp dounhand\n";
		push @idt,"\tdw unhand${n}\n\tdw 0x0008\n\tdb 0\n\tdb 0x8E\n\tdw 0\n";
	}
	push @funcs,"
EXTERN $func
int${n}_wrapper:
	pusha
	call $func
	popa
	iret
";
	push @idt,"\tdw int${n}_wrapper\n\tdw 0x0008\n\tdb 0\n\tdb 0x8E\n\tdw 0\n";
	$nextint = $int + 1;
}

print <<EOF;
SECTION .text
BITS 32
GLOBAL setupidt
EXTERN print

setupidt:
	lidt [idtr]
	ret

idt:
EOF

foreach(@idt){
	print "$_\n";
}

print <<EOF;
idt_end:

idtr:
	dw idt_end - idt - 1
	dd idt

EOF

foreach(@funcs){
	print "$_\n";
}

print <<EOF;
dounhand:
	mov eax,unhandmsg
	push eax
	call print
	jmp \$

SECTION .text
unhandmsg:
	db "$unhandmsg",10,0
EOF