trp.s

minux的源代码,一个非常小的操作系统

.define .trpdivz
.define .trpilin
.define .trpcase
.define .trprang
.define .trpset
.define .trpnofp
.define .trpheap
.define .trp

.bss
.M: .zerow 24/2

.text
.extern .trpdivz
.extern .trpilin
.extern .trpcase
.extern .trprang
.extern .trpset
.extern .trpnofp
.extern .trpheap
.extern .trp

.trpdivz:
mov ax,#6
mov dx,#.Mdivz
jmp .Trp
.trpilin:
mov ax,#18
mov dx,#.Milin
jmp .Trp
.trpcase:
mov ax,#20
mov dx,#.Mcase
jmp .Trp
.trprang:
mov ax,#1
mov dx,#.Mrang
jmp .Trp
.trpset:
mov ax,#2
mov dx,#.Mset
jmp .Trp
.trpnofp:
mov ax,#18
mov dx,#.Mnofp
jmp .Trp
.trpheap:
mov ax,#17
mov dx,#.Mheap
jmp .Trp

.Trp:
xor     bx,bx
.extern .trppc
xchg    bx,.trppc
test    bx,bx
jz      2f
push    ax
call    (bx)
pop     ax
ret
2:
mov bx,#22
push bx
push dx
mov ax,#2
push ax
call .Write
call __exit

.trp:
mov dx,ax
cmp dx,#21
jae 1f
sal dx,#1
mov bx,#.Mtable
add bx,dx
mov bx,(bx)
test bx,bx
jz 1f
mov dx,bx
jmp 2f
1:
mov bx,#.Mtrp+14
mov cx,#6
mov dx,ax
1:
and dx,#7
add dx,'0'
movb (bx),dl
dec bx
sar dx,#1
sar dx,#1
sar dx,#1
loop 1b
mov dx,#.Mtrp
2:
jmp .Trp

.Write:
push bp
mov bp,sp
mov .M+2,#4
mov bx,4(bp)
mov .M+4,bx
mov bx,8(bp)
mov .M+6,bx
mov bx,6(bp)
mov .M+10,bx
mov ax,#.M
push ax
mov ax,#1
push ax

mov ax,#1
mov bx,#.M
mov cx,#3
int 32
mov sp,bp
pop bp
ret


.data
.Mtable:
	.data2 0,	.Mrang,	.Mset,	0,	0,	0,	.Mdivz,	0
	.data2 0,	0,	0,	0,	0,	0,	0,	0
	.data2 0,	.Mheap,	.Milin,	.Milin,	.Mcase

.Mdivz: .asciz "Error: Division by 0 \n"
.Milin: .asciz "Illegal EM instruct'n\n"
.Mcase: .asciz "Err in EM case instr \n"
.Mrang: .asciz "Variable out of range\n"
.Mset:  .asciz "Err in EM set instr  \n"
.Mnofp: .asciz "Floating pt not impl.\n"
.Mheap: .asciz "Heap overflow        \n"

.Mtrp:	.asciz "EM trap 0000000 octal\n"