X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=ld45_start_nothing;a=blobdiff_plain;f=src%2Fintr.asm;h=fdd06ef6cba075ef77a58dba09983fe2392a44e5;hp=1bbf3197e6e470a5714485fa55c50665cc0d483c;hb=74628dd7656a232ac4a701079fd81a742600985e;hpb=6bbbb04131204b22367677209d7de8c3f906d0e2

diff --git a/src/intr.asm b/src/intr.asm
index 1bbf319..fdd06ef 100644
--- a/src/intr.asm
+++ b/src/intr.asm
@@ -1,21 +1,132 @@
 ; vi:filetype=nasm ts=8 sts=8 sw=8:
 	section .text
 
+%define INTR_ASM_
 %include "intr.inc"
 
+GATE_INTR equ 0600h
+GATE_TRAP equ 0700h
+GATE_DEFAULT equ 0800h
+GATE_PRESENT equ 8000h
+
 	global init_intr
 init_intr:
 	call init_pic
+	; install trap handlers
+	set_trap 0, trap_entry_div
+	set_trap 1, trap_entry_debug
+	set_trap 2, trap_entry_nmi
+	set_trap 3, trap_entry_bp
+	set_trap 4, trap_entry_overflow
+	set_trap 5, trap_entry_bound
+	set_trap 6, trap_entry_ill
+	set_trap 7, trap_entry_nodev
+	set_trap 8, trap_entry_dfault
+	set_trap 9, trap_entry_copseg
+	set_trap 10, trap_entry_tss
+	set_trap 11, trap_entry_segpres
+	set_trap 12, trap_entry_stack
+	set_trap 13, trap_entry_prot
+	set_trap 14, trap_entry_page
+	set_trap 15, trap_entry_reserved
+	set_trap 16, trap_entry_fpu
+	set_trap 17, trap_entry_align
+	set_trap 18, trap_entry_mce
+	set_trap 19, trap_entry_sse
+
+	; install dummy interrupt handlers for all IRQ vectors
+%assign i 0
+%rep 8
+	set_irq_vector i, dummy_intr_pic1
+	set_irq_vector i+8, dummy_intr_pic2
+%assign i i+1
+%endrep
 	ret
 
+%macro trap_err 2
+	global trap_entry_%2
+trap_entry_%2:
+	push dword %1
+	jmp trap_entry_common
+%endmacro
+
+%macro trap_noerr 2
+	global trap_entry_%2
+trap_entry_%2:
+	push dword 0
+	push dword %1
+	jmp trap_entry_common
+%endmacro
+
+trap_entry_common:
+	pusha
+	; do exception handling
+	popa
+	add esp, 8	; remove error code and exception number from stack
+	iret
+	
+	trap_noerr 0, div
+	trap_noerr 1, debug
+	trap_noerr 2, nmi
+	trap_noerr 3, bp
+	trap_noerr 4, overflow
+	trap_noerr 5, bound
+	trap_noerr 6, ill
+	trap_noerr 7, nodev
+	trap_err 8, dfault
+	trap_noerr 9, copseg
+	trap_err 10, tss
+	trap_err 11, segpres
+	trap_err 12, stack
+	trap_err 13, prot
+	trap_err 14, page
+	trap_noerr 15, reserved
+	trap_noerr 16, fpu
+	trap_err 17, align
+	trap_noerr 18, mce
+	trap_noerr 19, sse
+
+
 	global set_intr
 set_intr:
+	push ebp
+	mov ebp, esp
+	push ebx
+
+	mov ebx, [ebp + 8]
+	mov ax, GATE_TRAP
+	cmp ebx, 32	; determine if it's an IRQ or an exception (trap)
+	jb .notirq
+	mov ax, GATE_INTR
+.notirq:
+	lea ebx, [ebx * 8 + idt] ; ebx <- pointer to gate descriptor
+	; type|dpl goes to the 3rd word of the descriptor (dpl is 0)
+	or ax, (GATE_DEFAULT | GATE_PRESENT)
+	mov [ebx + 4], ax
+	; address low 16bits go to the first word of the descriptor
+	mov eax, [ebp + 12]
+	mov [ebx], ax
+	; address high 16bits go to the last word of the descriptor
+	shr eax, 16
+	mov [ebx + 6], ax
+	; selector (kcode:1) goes to the second word of the descriptor
+	mov word [ebx + 2], 08h
+
+	pop ebx
+	pop ebp
 	ret
 
-PIC1_CMD equ 20h
-PIC1_DATA equ 21h
-PIC2_CMD equ 0a0h
-PIC2_DATA equ 0a1h
+dummy_intr_pic1:
+	pusha
+	end_of_irq 0
+	popa
+	iret
+
+dummy_intr_pic2:
+	pusha
+	end_of_irq 8
+	popa
+	iret
 
 ; PIC initialization command word 1 bits
 ICW1_ICW4_NEEDED	equ 01h
@@ -29,8 +140,6 @@ ICW4_AUTO_EOI		equ 02h
 ICW4_BUF_SLAVE		equ 08h
 ICW4_BUF_MASTER		equ 0ch
 ICW4_SPECIAL		equ 10h
-; PIC operation command word 2 bits
-OCW2_EOI		equ 20h
 
 init_pic:
 	; send ICW1 saying we'll follow with ICW4 later on