lib386.txt

操作系统设计与实现源码

01713	        mov     ebx,12(ebx)
01714	        test    ebx,ebx
01715	        jnz     2f
01716	1:
01717	        mov     ebx,edx
01718	        test    ebx,ebx
01719	        jnz     2f
01720	.extern ECASE
01721	.extern .fat
01722	        mov     eax,ECASE
01723	        push    eax
01724	        jmp     .fat
01725	2:
01726	        jmp     ebx

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i386/em/em_csb4.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

01800	.sect .text; .sect .rom; .sect .data; .sect .bss
01801	.define .csb4
01802	
01803	.sect .text
01804	.csb4:
01805	                                !ebx, descriptor address
01806	                                !eax,  index
01807	        mov     edx,(ebx)
01808	        mov     ecx,4(ebx)
01809	1:
01810	        add     ebx,8
01811	        dec     ecx
01812	        jl      4f
01813	        cmp     eax,(ebx)
01814	        jne     1b
01815	        mov     ebx,4(ebx)
01816	2:
01817	        test    ebx,ebx
01818	        jnz     3f
01819	.extern ECASE
01820	.extern .fat
01821	        mov     eax,ECASE
01822	        push    eax
01823	        jmp     .fat
01824	3:
01825	        jmp     ebx
01826	4:
01827	        mov     ebx,edx
01828	        jmp     2b

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i386/em/em_cuf4.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

01900	.sect .text; .sect .rom; .sect .data; .sect .bss
01901	.define .cuf4
01902	
01903	        .sect .text
01904	.cuf4:
01905	        mov     bx,sp
01906	        fildl   8(bx)
01907	        cmp     8(bx),0
01908	        jge     1f
01909	        fisubl  (bigmin)
01910	        fisubl  (bigmin)
01911	1:
01912	        fstps   8(bx)
01913	        wait
01914	        ret

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i386/em/em_cuf8.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

02000	.sect .text; .sect .rom; .sect .data; .sect .bss
02001	.define .cuf8
02002	
02003	        .sect .text
02004	.cuf8:
02005	        mov     bx,sp
02006	        fildl   8(bx)
02007	        cmp     8(bx),0
02008	        jge     1f
02009	        fisubl  (bigmin)
02010	        fisubl  (bigmin)
02011	1:
02012	        fstpd   4(bx)
02013	        wait
02014	        ret

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i386/em/em_cuu.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

02100	.sect .text; .sect .rom; .sect .data; .sect .bss
02101	.define .ciu
02102	.define .cui
02103	.define .cuu
02104	
02105	.sect .text
02106	.ciu:
02107	.cui:
02108	.cuu:
02109	        pop     ebx              ! return address
02110	                                ! pop     ecx, dest. size
02111	                                ! pop     edx, source size
02112	                                ! eax is source
02113	        cmp     edx,ecx
02114	        jne     8f
02115	        jmp     ebx
02116	8:
02117	.extern EILLINS
02118	.extern .fat
02119	        mov     eax,EILLINS
02120	        push    eax
02121	        jmp     .fat

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i386/em/em_dup.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

02200	.sect .text; .sect .rom; .sect .data; .sect .bss
02201	.define .dup
02202	
02203	        ! #bytes in ecx
02204	        .sect .text
02205	.dup:
02206	        pop     ebx             ! return address
02207	        mov     eax,esi
02208	        mov     edx,edi
02209	        mov     esi,esp
02210	        sub     esp,ecx
02211	        mov     edi,esp
02212	        sar     ecx,2
02213	        rep movs
02214	        mov     esi,eax
02215	        mov     edi,edx
02216	        jmp     ebx

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i386/em/em_dvf4.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

02300	.sect .text; .sect .rom; .sect .data; .sect .bss
02301	.define .dvf4
02302	
02303	        .sect .text
02304	.dvf4:
02305	        mov     bx,sp
02306	        flds    8(bx)
02307	        fdivs   4(bx)
02308	        fstps   8(bx)
02309	        wait
02310	        ret

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i386/em/em_dvf8.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

02400	.sect .text; .sect .rom; .sect .data; .sect .bss
02401	.define .dvf8
02402	
02403	        .sect .text
02404	.dvf8:
02405	        mov     bx,sp
02406	        fldd    12(bx)
02407	        fdivd   4(bx)
02408	        fstpd   12(bx)
02409	        wait
02410	        ret

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i386/em/em_dvi.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

02500	.sect .text; .sect .rom; .sect .data; .sect .bss
02501	.define .dvi
02502	
02503	        ! #bytes in eax
02504	        .sect .text
02505	.dvi:
02506	        pop     ebx              ! return address
02507	        cmp     eax,4
02508	        jne     1f
02509	        pop     eax
02510	        cwd
02511	        pop     ecx
02512	        idiv    ecx
02513	        push    eax
02514	        jmp     ebx
02515	1:
02516	.extern EODDZ
02517	.extern .trp
02518	        mov     eax,EODDZ
02519	        push    ebx
02520	        jmp     .trp

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i386/em/em_dvu.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

02600	.sect .text; .sect .rom; .sect .data; .sect .bss
02601	.define .dvu
02602	
02603	        ! #bytes in eax
02604	        .sect .text
02605	.dvu:
02606	        pop     ebx              ! return address
02607	        cmp     eax,4
02608	        jne     1f
02609	        pop     eax
02610	        xor     edx,edx
02611	        pop     ecx
02612	        div     ecx
02613	        push    eax
02614	        jmp     ebx
02615	1:
02616	.extern EODDZ
02617	.extern .trp
02618	        mov     eax,EODDZ
02619	        push    ebx
02620	        jmp     .trp

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i386/em/em_error.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

02700	.sect .text; .sect .rom; .sect .data; .sect .bss
02701	.define .error
02702	.define .Xtrp
02703	
02704	        ! eax is trap number
02705	        ! all registers must be saved
02706	        ! because return is possible
02707	        ! May only be called with error no's <16
02708	.sect .text
02709	.error:
02710	        mov  ecx,eax
02711	        mov  ebx,1
02712	        sal  ebx,cl
02713	.extern .ignmask
02714	.extern .trp
02715	        test ebx,(.ignmask)
02716	        jne  2f
02717	        call    .trp
02718	2:
02719	        ret
02720	
02721	.Xtrp:
02722	        pusha
02723	        cmp     eax,16
02724	        jge     1f
02725	        call    .error
02726	        popa
02727	        ret
02728	1:
02729	        call    .trp
02730	        popa
02731	        ret

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i386/em/em_exg.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

02800	.sect .text; .sect .rom; .sect .data; .sect .bss
02801	.define .exg
02802	
02803	        ! #bytes in ecx
02804	.sect .text
02805	.exg:
02806	        push    edi
02807	        mov     edi,esp
02808	        add     edi,8
02809	        mov     ebx,edi
02810	        add     ebx,ecx
02811	        sar     ecx,2
02812	1:
02813	        mov     eax,(ebx)
02814	        xchg    eax,(edi)
02815	        mov     (ebx),eax
02816	        add     edi,4
02817	        add     ebx,4
02818	        loop    1b
02819	2:
02820	        pop     edi
02821	        ret

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i386/em/em_fat.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

02900	.sect .text; .sect .rom; .sect .data; .sect .bss
02901	.sect .text
02902	.define .fat
02903	
02904	.fat:
02905	.extern .trp
02906	.extern .stop
02907	        call    .trp
02908	        call    .stop
02909	        ! no return

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i386/em/em_fef4.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

03000	.sect .text; .sect .rom; .sect .data; .sect .bss
03001	.define .fef4
03002	
03003	        .sect .text
03004	.fef4:
03005	                                ! this could be simpler, if only the
03006	                                ! fxtract instruction was emulated properly
03007	        mov     bx,sp
03008	        mov     ax,8(bx)
03009	        and     ax,0x7f800000
03010	        je      1f              ! zero exponent
03011	        shr     ax,23
03012	        sub     ax,126
03013	        mov     cx,ax           ! exponent in cx
03014	        mov     ax,8(bx)
03015	        and     ax,0x807fffff
03016	        or      ax,0x3f000000   ! load -1 exponent
03017	        mov     bx,4(bx)
03018	        mov     4(bx),ax
03019	        mov     (bx),cx
03020	        ret
03021	1:                              ! we get here on zero exp
03022	        mov     ax,8(bx)
03023	        and     ax,0x007fffff
03024	        jne     1f              ! zero result
03025	        mov     bx,4(bx)
03026	        mov     (bx),ax
03027	        mov     4(bx),ax
03028	        ret
03029	1:                              ! otherwise unnormalized number
03030	        mov     cx,8(bx)
03031	        and     cx,0x807fffff
03032	        mov     dx,cx
03033	        and     cx,0x80000000
03034	        mov     ax,-125
03035	2:
03036	        test    dx,0x800000
03037	        jne     1f
03038	        dec     ax
03039	        shl     dx,1
03040	        or      dx,cx
03041	        jmp     2b
03042	1:
03043	        mov     bx,4(bx)
03044	        mov     (bx),ax
03045	        and     dx,0x807fffff
03046	        or      dx,0x3f000000   ! load -1 exponent
03047	        mov     4(bx),dx
03048	        ret

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			src/lib/i386/em/em_fef8.s	 	 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

03100	.sect .text; .sect .rom; .sect .data; .sect .bss
03101	.define .fef8
03102	
03103	        .sect .text
03104	.fef8:
03105	                                ! this could be simpler, if only the
03106	                                ! fxtract instruction was emulated properly
03107	        mov     bx,sp
03108	        mov     ax,12(bx)
03109	        and     ax,0x7ff00000
03110	        je      1f              ! zero exponent
03111	        shr     ax,20
03112	        sub     ax,1022
03113	        mov     cx,ax           ! exponent in cx
03114	        mov     ax,12(bx)
03115	        and     ax,0x800fffff
03116	        or      ax,0x3fe00000   ! load -1 exponent
03117	        mov     dx,8(bx)
03118	        mov     bx,4(bx)
03119	        mov     4(bx),dx
03120	        mov     8(bx),ax
03121	        mov     (bx),cx
03122	        ret
03123	1:                              ! we get here on zero exp
03124	        mov     ax,12(bx)
03125	        and     ax,0xfffff
03126	        or      ax,8(bx)
03127	        jne     1f              ! zero result
03128	        mov     bx,4(bx)
03129	        mov     (bx),ax
03130	        mov     4(bx),ax
03131	        mov     8(bx),ax
03132	        ret
03133	1:                              ! otherwise unnormalized number
03134	        mov     cx,12(bx)
03135	        and     cx,0x800fffff
03136	        mov     dx,cx
03137	        and     cx,0x80000000
03138	        mov     ax,-1021
03139	2:
03140	        test    dx,0x100000
03141	        jne     1f
03142	        dec     ax
03143	        shl     8(bx),1
03144	        rcl     dx,1
03145	        or      dx,cx
03146	        jmp     2b
03147	1:
03148	        and     dx,0x800fffff
03149	        or      dx,0x3fe00000   ! load -1 exponent
03150	        mov     cx,8(bx)
03151	        mov     bx,4(bx)
03152	        mov     (bx),ax