lib86.txt

操作系统设计与实现源码

03007	        mov     di,sp
03008	        add     di,cx
03009	        sar     cx,#1
03010	1:
03011	        pop     ax
03012	        or      ax,(di)
03013	        stos
03014	        loop    1b
03015	        mov     di,dx
03016	        jmp     (bx)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i86/em/isar.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

03100	.define .isar
03101	.text
03102	
03103	.isar:
03104	        pop     cx
03105	        pop     ax
03106	        cmp     ax,#2
03107	.extern .unknown
03108	        jne     .unknown
03109	        pop     bx      ! descriptor address
03110	        pop     ax      ! index
03111	        push    cx
03112	.extern .sar2
03113	        jmp    .sar2

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i86/em/lar2.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

03200	.define .lar2
03201	.text
03202	
03203	.lar2:
03204	                                ! bx, descriptor address
03205	                                ! ax, index
03206	        pop     cx
03207	        pop     dx              ! base address
03208	        push    cx
03209	        push    si
03210	        mov     si,dx
03211	        sub     ax,(bx)
03212	        mov     cx,4(bx)
03213	        imul    cx
03214	        add     si,ax
03215	        sar     cx,#1
03216	        jnb     1f
03217	        xorb    ah,ah
03218	        lodsb
03219	        pop     si
03220	        pop     bx
03221	        push    ax
03222	        jmp     (bx)
03223	1:
03224	        pop     dx              ! saved si
03225	        mov     ax,4(bx)
03226	        pop     bx              ! return address
03227	        sub     sp,ax
03228	        mov     ax,di           ! save di
03229	        mov     di,sp
03230	        rep
03231	        mov
03232	        mov     di,ax
03233	        mov     si,dx
03234	        jmp     (bx)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i86/em/lfr6.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

03300	.define .lfr6
03301	.text
03302	.extern .retarea
03303	
03304	.lfr6:
03305	        pop     bx
03306	        push    .retarea+4
03307	        push    .retarea+2
03308	        push    .retarea
03309	        jmp     (bx)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i86/em/lfr8.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

03400	.define .lfr8
03401	.text
03402	.extern .retarea
03403	
03404	.lfr8:
03405	        pop     bx
03406	        push    .retarea+6
03407	        push    .retarea+4
03408	        push    .retarea+2
03409	        push    .retarea
03410	        jmp     (bx)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i86/em/loi.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

03500	.define .loi
03501	.define .los
03502	.text
03503	
03504	        ! #bytes in cx
03505	        ! address in bx
03506	        ! save si/di. they might be register variables
03507	.los:
03508	        mov     dx,si
03509	        mov     si,bx
03510	        pop     bx
03511	        mov     ax,cx
03512	        sar     cx,#1
03513	        jnb     1f
03514	        xorb    ah,ah
03515	        lodsb
03516	        mov     si,dx
03517	        push    ax
03518	        jmp     (bx)
03519	1:
03520	        sub     sp,ax
03521	        jmp     1f
03522	
03523	.loi:
03524	        ! only called with size > 4
03525	        mov     dx,si
03526	        mov     si,bx
03527	        pop     bx
03528	        sub     sp,cx
03529	        sar     cx,#1
03530	1:
03531	        mov     ax,di
03532	        mov     di,sp
03533	        rep
03534	        mov
03535	        mov     si,dx
03536	        mov     di,ax
03537	        jmp     (bx)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i86/em/mli4.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

03600	.define .mli4
03601	.text
03602	
03603	yl=2
03604	yh=4
03605	        ! x * y
03606	        ! xl in ax
03607	        ! xh in dx
03608	
03609	.mli4:
03610	        mov     bx,sp
03611	        push    dx
03612	        mov     cx,ax
03613	        mul     yh(bx)           ! xl*yh
03614	        pop     dx
03615	        push    ax
03616	        mov     ax,dx
03617	        mul     yl(bx)          ! xh * yl
03618	        pop     dx
03619	        add     dx,ax           ! xh*yl+xl*yh
03620	        mov     ax,cx
03621	        mov     cx,dx
03622	        mul     yl(bx)           ! xl*yl
03623	        add     dx,cx
03624	        ret     4

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i86/em/mon.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

03700	.define .mon
03701	.text
03702	
03703	.mon:
03704	.extern .stop
03705	        call    .stop

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i86/em/nop.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

03800	.define .nop
03801	.text
03802	.nop:
03803	        ret

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i86/em/rck.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

03900	.define .rck
03901	.text
03902	
03903	        ! descriptor address in bx
03904	        ! value in ax, must be left there
03905	.rck:
03906	        cmp     ax,(bx)
03907	        jl      2f
03908	        cmp     ax,2(bx)
03909	        jg      2f
03910	        ret
03911	2:
03912	        push    ax
03913	ERANGE = 1
03914	.extern .error
03915	        mov     ax,#ERANGE
03916	        call    .error
03917	        pop     ax
03918	        ret

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i86/em/ret6.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

04000	.define .ret6
04001	.text
04002	.extern .retarea
04003	
04004	.ret6:
04005	        pop     bx
04006	        pop     .retarea
04007	        pop     .retarea+2
04008	        pop     .retarea+4
04009	        jmp     (bx)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i86/em/ret8.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

04100	.define .ret8
04101	.text
04102	.extern .retarea
04103	
04104	.ret8:
04105	        pop     bx
04106	        pop     .retarea
04107	        pop     .retarea+2
04108	        pop     .retarea+4
04109	        pop     .retarea+6
04110	        jmp     (bx)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i86/em/retarea.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

04200	.define .retarea
04201	
04202	.bss
04203	.retarea:
04204	        .zerow 8/2

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i86/em/return.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

04300	.define .sdret, .dsret, .sret, .dret, .cret 
04301	.text
04302	
04303	.dsret:
04304	        pop     di
04305	.sret:
04306	        pop     si
04307	.cret:
04308	        mov     sp,bp
04309	        pop     bp
04310	        ret
04311	
04312	.sdret:
04313	        pop     si
04314	.dret:
04315	        pop     di
04316	        jmp     .cret

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i86/em/rmi4.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

04400	.define .rmi4
04401	.text
04402	
04403	yl=6
04404	yh=8
04405	xl=10
04406	xh=12
04407	
04408	.rmi4:
04409	        push    si
04410	        push    di
04411	        mov     si,sp           ! copy of sp
04412	        mov     bx,yl(si)
04413	        mov     ax,yh(si)
04414	        cwd
04415	        cmp     dx,ax
04416	        jne     7f
04417	        and     dx,dx
04418	        jge     1f
04419	        neg     bx
04420	        je      7f
04421	1:
04422	        xor     dx,dx
04423	        mov     cx,xl(si)
04424	        mov     ax,xh(si)
04425	        and     ax,ax
04426	        jge     2f
04427	        neg     ax
04428	        neg     cx
04429	        sbb     ax,dx
04430	2:
04431	        div     bx
04432	        xchg    ax,cx
04433	        div     bx              ! dx= result(low), 0=result(high)
04434	        xor     bx,bx
04435	9:
04436	        cmp     xh(si),#0
04437	        jge     1f
04438	        neg     bx
04439	        neg     dx
04440	        sbb     bx,#0
04441	1:
04442	                        ! bx is high order result
04443	                        ! dx is low order result
04444	        mov     ax,dx
04445	        mov     dx,bx   ! result in ax/dx
04446	        pop     di
04447	        pop     si
04448	        ret     8
04449	
04450	7:
04451	        mov     di,ax
04452	        xor     bx,bx
04453	        and     di,di
04454	        jge     1f
04455	        neg     di
04456	        neg     yl(si)
04457	        sbb     di,bx
04458	1:
04459	        mov     ax,xl(si)
04460	        mov     dx,xh(si)
04461	        and     dx,dx
04462	        jge     1f
04463	        neg     dx
04464	        neg     ax
04465	        sbb     dx,bx
04466	1:
04467	        mov     cx,#16
04468	1:
04469	        shl     ax,#1
04470	        rcl     dx,#1
04471	        rcl     bx,#1
04472	        cmp     di,bx
04473	        ja      3f
04474	        jb      2f
04475	        cmp     yl(si),dx
04476	        jbe     2f
04477	3:
04478	        loop    1b
04479	                ! dx=result(low), bx=result(high)
04480	        jmp     9b
04481	2:
04482	        sub     dx,yl(si)
04483	        sbb     bx,di
04484	        inc     ax
04485	        loop    1b
04486	1:
04487	                ! dx=result(low), bx=result(high)
04488	        jmp     9b

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i86/em/rmu4.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

04500	.define .rmu4
04501	.text
04502	
04503	yl=6
04504	yh=8
04505	xl=10
04506	xh=12
04507	
04508	.rmu4:
04509	        push    si
04510	        push    di
04511	        mov     si,sp           ! copy of sp
04512	        mov     bx,yl(si)
04513	        mov     ax,yh(si)
04514	        or      ax,ax
04515	        jne     7f
04516	1:
04517	        xor     dx,dx
04518	        mov     cx,xl(si)
04519	        mov     ax,xh(si)
04520	2:
04521	        div     bx
04522	        xchg    ax,cx
04523	        div     bx
04524	        xor     bx,bx
04525	9:
04526	                        ! bx is high order result
04527	                        ! dx is low order result
04528	        mov     ax,dx
04529	        mov     dx,bx
04530	        pop     di
04531	        pop     si
04532	        ret     8       ! result in ax/dx
04533	
04534	7:
04535	        mov     di,ax
04536	        xor     bx,bx
04537	        mov     ax,xl(si)
04538	        mov     dx,xh(si)
04539	        mov     cx,#16
04540	1:
04541	        shl     ax,#1
04542	        rcl     dx,#1
04543	        rcl     bx,#1
04544	        cmp     di,bx
04545	        ja      3f
04546	        jb      2f
04547	        cmp     yl(si),dx
04548	        jbe     2f
04549	3:
04550	        loop    1b
04551	                ! dx=result(low), bx=result(high)
04552	        jmp     9b
04553	2:
04554	        sub     dx,yl(si)
04555	        sbb     bx,di
04556	        inc     ax
04557	        loop    1b
04558	1:
04559	                ! dx=result(low), bx=result(high)
04560	        jmp     9b

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i86/em/sar2.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

04600	.define .sar2
04601	.text
04602	
04603	.sar2:
04604	                                ! bx, descriptor address
04605	                                ! ax, index
04606	        pop     cx
04607	        pop     dx              ! base address
04608	        push    cx
04609	        xchg    di,dx           ! di = base address, dx is saved di
04610	        sub     ax,(bx)
04611	        mov     cx,4(bx)
04612	        push    dx
04613	        imul    cx
04614	        pop     dx
04615	        add     di,ax
04616	        sar     cx,#1
04617	        jnb     1f