发信人: Reinhard.bbs@bbs.sjtu.edu.cn (摘星), 信区: cnhacker
标 题: 80386 保护模式简介 -5 by 软蛀 -- Alex 整理(转寄)
发信站: 饮水思源站 (Fri Apr 25 20:47:26 1997)
转信站: Lilac!ustcnews!ustcnews!sjtunews!sjtubbs
出 处: bbs.sjtu.edu.cn
┌┐┌┐∞
【 ８０３８６ 保护模式简介五 】 ┘└┘└┘
==========================================================================
前言：
底下是进入保护模式、进入 V86 的精简范例 ,执行前请确定 CPU 是处在真实模
式 ,程式码因为用到 386 指令 ,请用 TASM 3.1 来编译。
--------------------------------------------------------------------------
┌——————┐
│进入保护模式│
└——————┘
进入保护模式的程式范例 ,其目地是进入保护模式 ,并在保护模式下用绝对记忆
体读写的方式 ,直接将 'Protection Mode !' 字串写入 Video Ram (B800:0000) ,
本程式以最精简的方式撰写 ,没有任何错误处理 ,因此请确定电脑现在处在真实模式
下才可执行本程式。(禁挂 EMM 系保护模式软体)
程式流程如下：(底下所指记忆体位址皆为 32bit 绝对位址)
1. 设定 GDTtab 表所在的记忆体位址填入 GDTadds
2. 设定 Selector 0008 的记忆体起始位址就是现在 CS 的记忆体位址
设定 Selector 0010 的记忆体起始位址就是现在 CS 的记忆体位址
Selector 0018 的记忆体起始位址就是 000B8000 = (B800:0000)
3. 执行 LGDT FWORD PTR CS:GDTadds 告诉 CPU 一但进入保护模式 ,各
区段的记忆体起始位址、长度
4. 设定 CR0 的 Bit0 = '1' ,并透过 JMP 指令进入保护模式
※ 进入保护模式後 ,DS.ES.SS.CS.GS.FS 等等暂存器定址方式不再
是 Segment ,而变成 Selector
5. 秀字 将 0010:MSG_1 搬到 0018:0000
意即将 'Protection Mode !' 字串搬到 Video Ram 去
6. 设定 CR0 的 Bit0 = '0' ,并透过 JMP 指令回到真实模式
※ 回到真实模式後 ,DS.ES.SS.CS.GS.FS 等等暂存器定址方式不再
是 Selector ,而变成 Segment
5. 秀字 将 CS:MSG_2 搬到 B800:00A0
意即将 'Return Real Mode !' 字串搬到 Video Ram 去
6. 结束程式
----------------------------- P.ASM ------------------------------------
code segment
assume cs:code,ds:code
386p
start proc near
jmp next
gdtadds dw 001fh,0000h,0000h
gdttab db 000h,000h,00h,00h,00h,00h,00h,00h ;00 Null
db 0ffh,0ffh,00h,00h,00h,9bh,00h,00h ;08 PRG Seg
db 0ffh,0ffh,00h,00h,00h,93h,00h,00h ;10 PRG Seg
db 0ffh,0ffh,00h,80h,0bh,93h,00h,00h ;18 B8000
msg_1 db 'Protection Mode !'
msg_2 db 'Return Real Mode !'
next :
xor eax,eax ;
xor ebx,ebx ;
mov ax,cs ;设定 GDTadds
shl eax,04h ;
mov bx,offset gdttab ;
add eax,ebx ;
mov di,offset gdtadds+02h ;
mov cs:[di],eax ;
NOP
xor eax,eax ;
xor ebx,ebx ;
mov ax,cs ;
shl eax,04h ;
mov di,offset gdttab+08h ;设定 GDTtab 内的
mov si,offset gdttab+10h ;Selector 0008 及 0010
mov cs:[di+02h],ax ;两个段落的记忆体起始位址
mov cs:[si+02h],ax ;
shr eax,10h ;
mov cs:[di+04h],al ;
mov cs:[si+04h],al ;
mov cs:[di+07h],ah ;
mov cs:[si+07h],ah ;
NOP
cli
lgdt fword ptr cs:gdtadds ;载入 GDT 表格
mov eax,cr0 ;
or al,01h ;
mov cr0,eax ;
jmp protection_mode ;进入保护模式
protection_mode : ;
mov ax,0010h ;
mov ds,ax ;
mov si,offset msg_1 ;
mov ax,0018h ;将 0010:MSG_1 搬到 0018:0000
mov es,ax ;
mov di,0000h ;
mov ah,70h ;
mov cx,0011h ;
cld ;
L1 : ;
lodsb ;
stosw ;
loop L1 ;
NOP
mov eax,cr0 ;
and al,0feh ;
mov cr0,eax ;回到真实模式
jmp return_real_mode ;
return_real_mode : ;
sti
mov ax,cs ;
mov ds,ax ;
mov si,offset msg_2 ;
mov ax,0b800h ;
mov es,ax ;将 CS:MSG_2 搬到 B800:00A0
mov di,00a0h ;
mov ah,70h ;
mov cx,0012h ;
cld ;
L2 : ;
lodsb ;
stosw ;
loop L2 ;
mov ax,4cffh
int 21h
start endp
code ends
end start
--------------------------------------------------------------------------
因为保护模式下不能呼叫真实模式下的中断 ,所以笔者以直接填写显示卡记忆体
的方式秀字。这是一个简单、尚未使用中断向量表的范例。
注: 所谓一山不容二虎 ,如果已载入其它保护模式的程式 ,那本程式将会与它打架 ,
造成电脑当机。
┌————————┐
│进入虚拟 86 模式│ 为求精简 ,本程式毫无错误处理能力
└————————┘
------------------------ V86.ASM ---------------------------------------
code segment
assume cs:code,ds:code
386p
start proc near
jmp next
gdtadds dw 002fh,0000h,0000h
gdttab db 000h,000h,000h,000h,000h,000h,000h,000h ;00 Null
db 0ffh,0ffh,000h,000h,000h,09bh,000h,000h ;08 PRG Seg
db 0ffh,0ffh,000h,000h,000h,093h,08fh,000h ;10 Dos=Page
db 0ffh,0ffh,000h,000h,000h,089h,000h,000h ;18 TSSltr
db 0ffh,0ffh,000h,000h,000h,089h,000h,000h ;20 TSSjmp
db 0ffh,003h,000h,000h,000h,093h,000h,000h ;28 Stack (1K)
tssltr dd 00000000h
dd 000003ffh ;ESP
dw 0028h,0000h ;SS.0
dd 0,0,0,0,0
dw offset enter_v86,0000h ;EIP
dd 00000200h ;EFlag
dd 0,0,0,0
dd 000003ffh ;ESP
dd 0,0,0
dw 0010h,0000h ;ES.0
dw 0008h,0000h ;CS.0
dw 0028h,0000h ;SS.0
dw 0010h,0000h ;DS,0
dw 0010h,0000h ;FS.0
dw 0010h,0000h ;GS.0
dw 0000h,0000h ;LDT.0
dw 0000h,0068h ;0.IOMAP
dw 0ffffh
tssjmp dd 00000000h
dd 000003ffh ;ESP
dw 0028h,0000h ;SS.0
dd 0,0,0,0,0
dw offset enter_v86,0000h ;EIP
dd 00000000h ;EFlag
dd 0,0,0,0
dd 000003ffh ;ESP
dd 0,0,0
dw 0010h,0000h ;ES.0
dw 0008h,0000h ;CS.0
dw 0028h,0000h ;SS.0
dw 0010h,0000h ;DS,0
dw 0010h,0000h ;FS.0
dw 0010h,0000h ;GS.0
dw 0000h,0000h ;LDT.0
dw 0000h,0068h ;0.IOMAP
iomap db 1000h dup (0)
dw 0ffffh
buffer1 db 0400h dup (0) ;Stack
idtadds dw 07ffh,0000h,0000h
idttab dw offset new_00,0008h,0ee00h,0000h,offset
new_01,0008h,0ee00h,0000h
dw offset new_02,0008h,0ee00h,0000h,offset
new_03,0008h,0ee00h,0000h
dw offset new_04,0008h,0ee00h,0000h,offset
new_05,0008h,0ee00h,0000h
dw offset new_06,0008h,0ee00h,0000h,offset
new_07,0008h,0ee00h,0000h
dw offset new_08,0008h,0ee00h,0000h,offset
new_09,0008h,0ee00h,0000h
dw offset new_0a,0008h,0ee00h,0000h,offset
new_0b,0008h,0ee00h,0000h
dw offset new_0c,0008h,0ee00h,0000h,offset
new_0d,0008h,0ee00h,0000h
dw offset new_0e,0008h,0ee00h,0000h,offset
new_0f,0008h,0ee00h,0000h
dw offset new_10,0008h,0ee00h,0000h,offset
new_11,0008h,0ee00h,0000h
dw offset new_12,0008h,0ee00h,0000h,offset
new_13,0008h,0ee00h,0000h
dw offset new_14,0008h,0ee00h,0000h,offset
new_15,0008h,0ee00h,0000h
dw offset new_16,0008h,0ee00h,0000h,offset
new_17,0008h,0ee00h,0000h
dw offset new_18,0008h,0ee00h,0000h,offset
new_19,0008h,0ee00h,0000h
dw offset new_1a,0008h,0ee00h,0000h,offset
new_1b,0008h,0ee00h,0000h
dw offset new_1c,0008h,0ee00h,0000h,offset
new_1d,0008h,0ee00h,0000h
dw offset new_1e,0008h,0ee00h,0000h,offset
new_1f,0008h,0ee00h,0000h
dw offset new_20,0008h,0ee00h,0000h,offset
new_21,0008h,0ee00h,0000h
dw offset new_22,0008h,0ee00h,0000h,offset
new_23,0008h,0ee00h,0000h
dw offset new_24,0008h,0ee00h,0000h,offset
new_25,0008h,0ee00h,0000h
dw offset new_26,0008h,0ee00h,0000h,offset
new_27,0008h,0ee00h,0000h
dw offset new_28,0008h,0ee00h,0000h,offset
new_29,0008h,0ee00h,0000h
dw offset new_2a,0008h,0ee00h,0000h,offset
new_2b,0008h,0ee00h,0000h
dw offset new_2c,0008h,0ee00h,0000h,offset
new_2d,0008h,0ee00h,0000h
dw offset new_2e,0008h,0ee00h,0000h,offset
new_2f,0008h,0ee00h,0000h
dw offset new_30,0008h,0ee00h,0000h,offset
new_31,0008h,0ee00h,0000h
dw offset new_32,0008h,0ee00h,0000h,offset
new_33,0008h,0ee00h,0000h
dw offset new_34,0008h,0ee00h,0000h,offset
new_35,0008h,0ee00h,0000h
dw offset new_36,0008h,0ee00h,0000h,offset
new_37,0008h,0ee00h,0000h
dw offset new_38,0008h,0ee00h,0000h,offset
new_39,0008h,0ee00h,0000h
dw offset new_3a,0008h,0ee00h,0000h,offset
new_3b,0008h,0ee00h,0000h
dw offset new_3c,0008h,0ee00h,0000h,offset
new_3d,0008h,0ee00h,0000h
dw offset new_3e,0008h,0ee00h,0000h,offset
new_3f,0008h,0ee00h,0000h
dw offset new_40,0008h,0ee00h,0000h,offset
new_41,0008h,0ee00h,0000h
dw offset new_42,0008h,0ee00h,0000h,offset
new_43,0008h,0ee00h,0000h
dw offset new_44,0008h,0ee00h,0000h,offset
new_45,0008h,0ee00h,0000h
dw offset new_46,0008h,0ee00h,0000h,offset
new_47,0008h,0ee00h,0000h
dw offset new_48,0008h,0ee00h,0000h,offset
new_49,0008h,0ee00h,0000h
dw offset new_4a,0008h,0ee00h,0000h,offset
new_4b,0008h,0ee00h,0000h
dw offset new_4c,0008h,0ee00h,0000h,offset
new_4d,0008h,0ee00h,0000h
dw offset new_4e,0008h,0ee00h,0000h,offset
new_4f,0008h,0ee00h,0000h
dw offset new_50,0008h,0ee00h,0000h,offset
new_51,0008h,0ee00h,0000h
dw offset new_52,0008h,0ee00h,0000h,offset
new_53,0008h,0ee00h,0000h
dw offset new_54,0008h,0ee00h,0000h,offset
new_55,0008h,0ee00h,0000h
dw offset new_56,0008h,0ee00h,0000h,offset
new_57,0008h,0ee00h,0000h
dw offset new_58,0008h,0ee00h,0000h,offset
new_59,0008h,0ee00h,0000h
dw offset new_5a,0008h,0ee00h,0000h,offset
new_5b,0008h,0ee00h,0000h
dw offset new_5c,0008h,0ee00h,0000h,offset
new_5d,0008h,0ee00h,0000h
dw offset new_5e,0008h,0ee00h,0000h,offset
new_5f,0008h,0ee00h,0000h
dw offset new_60,0008h,0ee00h,0000h,offset
new_61,0008h,0ee00h,0000h
dw offset new_62,0008h,0ee00h,0000h,offset
new_63,0008h,0ee00h,0000h
dw offset new_64,0008h,0ee00h,0000h,offset
new_65,0008h,0ee00h,0000h
dw offset new_66,0008h,0ee00h,0000h,offset
new_67,0008h,0ee00h,0000h
dw offset new_68,0008h,0ee00h,0000h,offset
new_69,0008h,0ee00h,0000h
dw offset new_6a,0008h,0ee00h,0000h,offset
new_6b,0008h,0ee00h,0000h
dw offset new_6c,0008h,0ee00h,0000h,offset
new_6d,0008h,0ee00h,0000h
dw offset new_6e,0008h,0ee00h,0000h,offset
new_6f,0008h,0ee00h,0000h
dw offset new_70,0008h,0ee00h,0000h,offset
new_71,0008h,0ee00h,0000h
dw offset new_72,0008h,0ee00h,0000h,offset
new_73,0008h,0ee00h,0000h
dw offset new_74,0008h,0ee00h,0000h,offset
new_75,0008h,0ee00h,0000h
dw offset new_76,0008h,0ee00h,0000h,offset
new_77,0008h,0ee00h,0000h
dw offset new_78,0008h,0ee00h,0000h,offset
new_79,0008h,0ee00h,0000h
dw offset new_7a,0008h,0ee00h,0000h,offset
new_7b,0008h,0ee00h,0000h
dw offset new_7c,0008h,0ee00h,0000h,offset
new_7d,0008h,0ee00h,0000h
dw offset new_7e,0008h,0ee00h,0000h,offset
new_7f,0008h,0ee00h,0000h
dw offset new_80,0008h,0ee00h,0000h,offset
new_81,0008h,0ee00h,0000h
dw offset new_82,0008h,0ee00h,0000h,offset
new_83,0008h,0ee00h,0000h
dw offset new_84,0008h,0ee00h,0000h,offset
new_85,0008h,0ee00h,0000h
dw offset new_86,0008h,0ee00h,0000h,offset
new_87,0008h,0ee00h,0000h
dw offset new_88,0008h,0ee00h,0000h,offset
new_89,0008h,0ee00h,0000h
dw offset new_8a,0008h,0ee00h,0000h,offset
new_8b,0008h,0ee00h,0000h
dw offset new_8c,0008h,0ee00h,0000h,offset
new_8d,0008h,0ee00h,0000h
dw offset new_8e,0008h,0ee00h,0000h,offset
new_8f,0008h,0ee00h,0000h
dw offset new_90,0008h,0ee00h,0000h,offset
new_91,0008h,0ee00h,0000h
dw offset new_92,0008h,0ee00h,0000h,offset
new_93,0008h,0ee00h,0000h
dw offset new_94,0008h,0ee00h,0000h,offset
new_95,0008h,0ee00h,0000h
dw offset new_96,0008h,0ee00h,0000h,offset
new_97,0008h,0ee00h,0000h
dw offset new_98,0008h,0ee00h,0000h,offset
new_99,0008h,0ee00h,0000h
dw offset new_9a,0008h,0ee00h,0000h,offset
new_9b,0008h,0ee00h,0000h
dw offset new_9c,0008h,0ee00h,0000h,offset
new_9d,0008h,0ee00h,0000h
dw offset new_9e,0008h,0ee00h,0000h,offset
new_9f,0008h,0ee00h,0000h
dw offset new_a0,0008h,0ee00h,0000h,offset
new_a1,0008h,0ee00h,0000h
dw offset new_a2,0008h,0ee00h,0000h,offset
new_a3,0008h,0ee00h,0000h
dw offset new_a4,0008h,0ee00h,0000h,offset
new_a5,0008h,0ee00h,0000h
dw offset new_a6,0008h,0ee00h,0000h,offset
new_a7,0008h,0ee00h,0000h
dw offset new_a8,0008h,0ee00h,0000h,offset
new_a9,0008h,0ee00h,0000h
dw offset new_aa,0008h,0ee00h,0000h,offset
new_ab,0008h,0ee00h,0000h
dw offset new_ac,0008h,0ee00h,0000h,offset
new_ad,0008h,0ee00h,0000h
dw offset new_ae,0008h,0ee00h,0000h,offset
new_af,0008h,0ee00h,0000h
dw offset new_b0,0008h,0ee00h,0000h,offset
new_b1,0008h,0ee00h,0000h
dw offset new_b2,0008h,0ee00h,0000h,offset
new_b3,0008h,0ee00h,0000h
dw offset new_b4,0008h,0ee00h,0000h,offset
new_b5,0008h,0ee00h,0000h
dw offset new_b6,0008h,0ee00h,0000h,offset
new_b7,0008h,0ee00h,0000h
dw offset new_b8,0008h,0ee00h,0000h,offset
new_b9,0008h,0ee00h,0000h
dw offset new_ba,0008h,0ee00h,0000h,offset
new_bb,0008h,0ee00h,0000h
dw offset new_bc,0008h,0ee00h,0000h,offset
new_bd,0008h,0ee00h,0000h
dw offset new_be,0008h,0ee00h,0000h,offset
new_bf,0008h,0ee00h,0000h
dw offset new_c0,0008h,0ee00h,0000h,offset
new_c1,0008h,0ee00h,0000h
dw offset new_c2,0008h,0ee00h,0000h,offset
new_c3,0008h,0ee00h,0000h
dw offset new_c4,0008h,0ee00h,0000h,offset
new_c5,0008h,0ee00h,0000h
dw offset new_c6,0008h,0ee00h,0000h,offset
new_c7,0008h,0ee00h,0000h
dw offset new_c8,0008h,0ee00h,0000h,offset
new_c9,0008h,0ee00h,0000h
dw offset new_ca,0008h,0ee00h,0000h,offset
new_cb,0008h,0ee00h,0000h
dw offset new_cc,0008h,0ee00h,0000h,offset
new_cd,0008h,0ee00h,0000h
dw offset new_ce,0008h,0ee00h,0000h,offset
new_cf,0008h,0ee00h,0000h
dw offset new_d0,0008h,0ee00h,0000h,offset
new_d1,0008h,0ee00h,0000h
dw offset new_d2,0008h,0ee00h,0000h,offset
new_d3,0008h,0ee00h,0000h
dw offset new_d4,0008h,0ee00h,0000h,offset
new_d5,0008h,0ee00h,0000h
dw offset new_d6,0008h,0ee00h,0000h,offset
new_d7,0008h,0ee00h,0000h
dw offset new_d8,0008h,0ee00h,0000h,offset
new_d9,0008h,0ee00h,0000h
dw offset new_da,0008h,0ee00h,0000h,offset
new_db,0008h,0ee00h,0000h
dw offset new_dc,0008h,0ee00h,0000h,offset
new_dd,0008h,0ee00h,0000h
dw offset new_de,0008h,0ee00h,0000h,offset
new_df,0008h,0ee00h,0000h
dw offset new_e0,0008h,0ee00h,0000h,offset
new_e1,0008h,0ee00h,0000h
dw offset new_e2,0008h,0ee00h,0000h,offset
new_e3,0008h,0ee00h,0000h
dw offset new_e4,0008h,0ee00h,0000h,offset
new_e5,0008h,0ee00h,0000h
dw offset new_e6,0008h,0ee00h,0000h,offset
new_e7,0008h,0ee00h,0000h
dw offset new_e8,0008h,0ee00h,0000h,offset
new_e9,0008h,0ee00h,0000h
dw offset new_ea,0008h,0ee00h,0000h,offset
new_eb,0008h,0ee00h,0000h
dw offset new_ec,0008h,0ee00h,0000h,offset
new_ed,0008h,0ee00h,0000h
dw offset new_ee,0008h,0ee00h,0000h,offset
new_ef,0008h,0ee00h,0000h
dw offset new_f0,0008h,0ee00h,0000h,offset
new_f1,0008h,0ee00h,0000h
dw offset new_f2,0008h,0ee00h,0000h,offset
new_f3,0008h,0ee00h,0000h
dw offset new_f4,0008h,0ee00h,0000h,offset
new_f5,0008h,0ee00h,0000h
dw offset new_f6,0008h,0ee00h,0000h,offset
new_f7,0008h,0ee00h,0000h
dw offset new_f8,0008h,0ee00h,0000h,offset
new_f9,0008h,0ee00h,0000h
dw offset new_fa,0008h,0ee00h,0000h,offset
new_fb,0008h,0ee00h,0000h
dw offset new_fc,0008h,0ee00h,0000h,offset
new_fd,0008h,0ee00h,0000h
dw offset new_fe,0008h,0ee00h,0000h,offset
new_ff,0008h,0ee00h,0000h
new_00 :
push 0000h
jmp int_emu
new_01 :
push 0001h
jmp int_emu
new_02 :
push 0002h
jmp int_emu
new_03 :
push 0003h
jmp int_emu
new_04 :
push 0004h
jmp int_emu
new_05 :
push 0005h
jmp int_emu
new_06 :
push 0006h
jmp int_emu
new_07 :
push 0007h
jmp int_emu
new_08 :
push 0008h
jmp int_emu
new_09 :
push 0009h
jmp int_emu
new_0a :
push 000ah
jmp int_emu
new_0b :
push 000bh
jmp int_emu
new_0c :
push 000ch
jmp int_emu
new_0d :
push 000dh
jmp int_emu
new_0e :
push 000eh
jmp int_emu
new_0f :
push 000fh
jmp int_emu
new_10 :
push 0010h
jmp int_emu
new_11 :
push 0011h
jmp int_emu
new_12 :
push 0012h
jmp int_emu
new_13 :
push 0013h
jmp int_emu
new_14 :
push 0014h
jmp int_emu
new_15 :
cmp ah,87h
jnz L3
push bp
mov bp,sp
add bp,02h
push eax
push ebx
push ecx
push edx
push edi
push esi
mov ebx,ss:[bp+14h]
shl ebx,04h
and esi,0000ffffh
add ebx,esi
mov ax,0010h
mov ds,ax
mov es,ax
mov esi,ds:[ebx+12h]
mov edi,ds:[ebx+1ah]
and esi,00ffffffh
and edi,00ffffffh
or cx,cx
jz L2
L1 :
mov ax,ds:[esi]
mov es:[edi],ax
add esi,02h
add edi,02h
loop L1
L2 :
pop esi
pop edi
pop edx
pop ecx
pop ebx
pop eax
pop bp
iretd
L3 :
push 0015h
jmp int_emu
new_16 :
push 0016h
jmp int_emu
new_17 :
push 0017h
jmp int_emu
new_18 :
push 0018h
jmp int_emu
new_19 :
push 0019h
jmp int_emu
new_1a :
push 001ah
jmp int_emu
new_1b :
push 001bh
jmp int_emu
new_1c :
push 001ch
jmp int_emu
new_1d :
push 001dh
jmp int_emu
new_1e :
push 001eh
jmp int_emu
new_1f :
push 001fh
jmp int_emu
new_20 :
push 0020h
jmp int_emu
new_21 :
push 0021h
jmp int_emu
new_22 :
push 0022h
jmp int_emu
new_23 :
push 0023h
jmp int_emu
new_24 :
push 0024h
jmp int_emu
new_25 :
push 0025h
jmp int_emu
new_26 :
push 0026h
jmp int_emu
new_27 :
push 0027h
jmp int_emu
new_28 :
push 0028h
jmp int_emu
new_29 :
push 0029h
jmp int_emu
new_2a :
push 002ah
jmp int_emu
new_2b :
push 002bh
jmp int_emu
new_2c :
push 002ch
jmp int_emu
new_2d :
push 002dh
jmp int_emu
new_2e :
push 002eh
jmp int_emu
new_2f :
push 002fh
jmp int_emu
new_30 :
push 0030h
jmp int_emu
new_31 :
push 0031h
jmp int_emu
new_32 :
push 0032h
jmp int_emu
new_33 :
push 0033h
jmp int_emu
new_34 :
push 0034h
jmp int_emu
new_35 :
push 0035h
jmp int_emu
new_36 :
push 0036h
jmp int_emu
new_37 :
push 0037h
jmp int_emu
new_38 :
push 0038h
jmp int_emu
new_39 :
push 0039h
jmp int_emu
new_3a :
push 003ah
jmp int_emu
new_3b :
push 003bh
jmp int_emu
new_3c :
push 003ch
jmp int_emu
new_3d :
push 003dh
jmp int_emu
new_3e :
push 003eh
jmp int_emu
new_3f :
push 003fh
jmp int_emu
new_40 :
push 0040h
jmp int_emu
new_41 :
push 0041h
jmp int_emu
new_42 :
push 0042h
jmp int_emu
new_43 :
push 0043h
jmp int_emu
new_44 :
push 0044h
jmp int_emu
new_45 :
push 0045h
jmp int_emu
new_46 :
push 0046h
jmp int_emu
new_47 :
push 0047h
jmp int_emu
new_48 :
push 0048h
jmp int_emu
new_49 :
push 0049h
jmp int_emu
new_4a :
push 004ah
jmp int_emu
new_4b :
push 004bh
jmp int_emu
new_4c :
push 004ch
jmp int_emu
new_4d :
push 004dh
jmp int_emu
new_4e :
push 004eh
jmp int_emu
new_4f :
push 004fh
jmp int_emu
new_50 :
push 0050h
jmp int_emu
new_51 :
push 0051h
jmp int_emu
new_52 :
push 0052h
jmp int_emu
new_53 :
push 0053h
jmp int_emu
new_54 :
push 0054h
jmp int_emu
new_55 :
push 0055h
jmp int_emu
new_56 :
push 0056h
jmp int_emu
new_57 :
push 0057h
jmp int_emu
new_58 :
push 0058h
jmp int_emu
new_59 :
push 0059h
jmp int_emu
new_5a :
push 005ah
jmp int_emu
new_5b :
push 005bh
jmp int_emu
new_5c :
push 005ch
jmp int_emu
new_5d :
push 005dh
jmp int_emu
new_5e :
push 005eh
jmp int_emu
new_5f :
push 005fh
jmp int_emu
new_60 :
push 0060h
jmp int_emu
new_61 :
push 0061h
jmp int_emu
new_62 :
push 0062h
jmp int_emu
new_63 :
push 0063h
jmp int_emu
new_64 :
push 0064h
jmp int_emu
new_65 :
push 0065h
jmp int_emu
new_66 :
push 0066h
jmp int_emu
new_67 :
push 0067h
jmp int_emu
new_68 :
push 0068h
jmp int_emu
new_69 :
push 0069h
jmp int_emu
new_6a :
push 006ah
jmp int_emu
new_6b :
push 006bh
jmp int_emu
new_6c :
push 006ch
jmp int_emu
new_6d :
push 006dh
jmp int_emu
new_6e :
push 006eh
jmp int_emu
new_6f :
push 006fh
jmp int_emu
new_70 :
push 0070h
jmp int_emu
new_71 :
push 0071h
jmp int_emu
new_72 :
push 0072h
jmp int_emu
new_73 :
push 0073h
jmp int_emu
new_74 :
push 0074h
jmp int_emu
new_75 :
push 0075h
jmp int_emu
new_76 :
push 0076h
jmp int_emu
new_77 :
push 0077h
jmp int_emu
new_78 :
push 0078h
jmp int_emu
new_79 :
push 0079h
jmp int_emu
new_7a :
push 007ah
jmp int_emu
new_7b :
push 007bh
jmp int_emu
new_7c :
push 007ch
jmp int_emu
new_7d :
push 007dh
jmp int_emu
new_7e :
push 007eh
jmp int_emu
new_7f :
push 007fh
jmp int_emu
new_80 :
push 0080h
jmp int_emu
new_81 :
push 0081h
jmp int_emu
new_82 :
push 0082h
jmp int_emu
new_83 :
push 0083h
jmp int_emu
new_84 :
push 0084h
jmp int_emu
new_85 :
push 0085h
jmp int_emu
new_86 :
push 0086h
jmp int_emu
new_87 :
push 0087h
jmp int_emu
new_88 :
push 0088h
jmp int_emu
new_89 :
push 0089h
jmp int_emu
new_8a :
push 008ah
jmp int_emu
new_8b :
push 008bh
jmp int_emu
new_8c :
push 008ch
jmp int_emu
new_8d :
push 008dh
jmp int_emu
new_8e :
push 008eh
jmp int_emu
new_8f :
push 008fh
jmp int_emu
new_90 :
push 0090h
jmp int_emu
new_91 :
push 0091h
jmp int_emu
new_92 :
push 0092h
jmp int_emu
new_93 :
push 0093h
jmp int_emu
new_94 :
push 0094h
jmp int_emu
new_95 :
push 0095h
jmp int_emu
new_96 :
push 0096h
jmp int_emu
new_97 :
push 0097h
jmp int_emu
new_98 :
push 0098h
jmp int_emu
new_99 :
push 0099h
jmp int_emu
new_9a :
push 009ah
jmp int_emu
new_9b :
push 009bh
jmp int_emu
new_9c :
push 009ch
jmp int_emu
new_9d :
push 009dh
jmp int_emu
new_9e :
push 009eh
jmp int_emu
new_9f :
push 009fh
jmp int_emu
new_a0 :
push 00a0h
jmp int_emu
new_a1 :
push 00a1h
jmp int_emu
new_a2 :
push 00a2h
jmp int_emu
new_a3 :
push 00a3h
jmp int_emu
new_a4 :
push 00a4h
jmp int_emu
new_a5 :
push 00a5h
jmp int_emu
new_a6 :
push 00a6h
jmp int_emu
new_a7 :
push 00a7h
jmp int_emu
new_a8 :
push 00a8h
jmp int_emu
new_a9 :
push 00a9h
jmp int_emu
new_aa :
push 00aah
jmp int_emu
new_ab :
push 00abh
jmp int_emu
new_ac :
push 00ach
jmp int_emu
new_ad :
push 00adh
jmp int_emu
new_ae :
push 00aeh
jmp int_emu
new_af :
push 00afh
jmp int_emu
new_b0 :
push 00b0h
jmp int_emu
new_b1 :
push 00b1h
jmp int_emu
new_b2 :
push 00b2h
jmp int_emu
new_b3 :
push 00b3h
jmp int_emu
new_b4 :
push 00b4h
jmp int_emu
new_b5 :
push 00b5h
jmp int_emu
new_b6 :
push 00b6h
jmp int_emu
new_b7 :
push 00b7h
jmp int_emu
new_b8 :
push 00b8h
jmp int_emu
new_b9 :
push 00b9h
jmp int_emu
new_ba :
push 00bah
jmp int_emu
new_bb :
push 00bbh
jmp int_emu
new_bc :
push 00bch
jmp int_emu
new_bd :
push 00bdh
jmp int_emu
new_be :
push 00beh
jmp int_emu
new_bf :
push 00bfh
jmp int_emu
new_c0 :
push 00c0h
jmp int_emu
new_c1 :
push 00c1h
jmp int_emu
new_c2 :
push 00c2h
jmp int_emu
new_c3 :
push 00c3h
jmp int_emu
new_c4 :
push 00c4h
jmp int_emu
new_c5 :
push 00c5h
jmp int_emu
new_c6 :
push 00c6h
jmp int_emu
new_c7 :
push 00c7h
jmp int_emu
new_c8 :
push 00c8h
jmp int_emu
new_c9 :
push 00c9h
jmp int_emu
new_ca :
push 00cah
jmp int_emu
new_cb :
push 00cbh
jmp int_emu
new_cc :
push 00cch
jmp int_emu
new_cd :
push 00cdh
jmp int_emu
new_ce :
push 00ceh
jmp int_emu
new_cf :
push 00cfh
jmp int_emu
new_d0 :
push 00d0h
jmp int_emu
new_d1 :
push 00d1h
jmp int_emu
new_d2 :
push 00d2h
jmp int_emu
new_d3 :
push 00d3h
jmp int_emu
new_d4 :
push 00d4h
jmp int_emu
new_d5 :
push 00d5h
jmp int_emu
new_d6 :
push 00d6h
jmp int_emu
new_d7 :
push 00d7h
jmp int_emu
new_d8 :
push 00d8h
jmp int_emu
new_d9 :
push 00d9h
jmp int_emu
new_da :
push 00dah
jmp int_emu
new_db :
push 00dbh
jmp int_emu
new_dc :
push 00dch
jmp int_emu
new_dd :
push 00ddh
jmp int_emu
new_de :
push 00deh
jmp int_emu
new_df :
push 00dfh
jmp int_emu
new_e0 :
push 00e0h
jmp int_emu
new_e1 :
push 00e1h
jmp int_emu
new_e2 :
push 00e2h
jmp int_emu
new_e3 :
push 00e3h
jmp int_emu
new_e4 :
push 00e4h
jmp int_emu
new_e5 :
push 00e5h
jmp int_emu
new_e6 :
push 00e6h
jmp int_emu
new_e7 :
push 00e7h
jmp int_emu
new_e8 :
push 00e8h
jmp int_emu
new_e9 :
push 00e9h
jmp int_emu
new_ea :
push 00eah
jmp int_emu
new_eb :
push 00ebh
jmp int_emu
new_ec :
push 00ech
jmp int_emu
new_ed :
push 00edh
jmp int_emu
new_ee :
push 00eeh
jmp int_emu
new_ef :
push 00efh
jmp int_emu
new_f0 :
push 00f0h
jmp int_emu
new_f1 :
push 00f1h
jmp int_emu
new_f2 :
push 00f2h
jmp int_emu
new_f3 :
push 00f3h
jmp int_emu
new_f4 :
push 00f4h
jmp int_emu
new_f5 :
push 00f5h
jmp int_emu
new_f6 :
push 00f6h
jmp int_emu
new_f7 :
push 00f7h
jmp int_emu
new_f8 :
push 00f8h
jmp int_emu
new_f9 :
push 00f9h
jmp int_emu
new_fa :
push 00fah
jmp int_emu
new_fb :
push 00fbh
jmp int_emu
new_fc :
push 00fch
jmp int_emu
new_fd :
push 00fdh
jmp int_emu
new_fe :
push 00feh
jmp int_emu
new_ff :
push 00ffh
jmp int_emu
int_emu :
push bp
mov bp,sp
add bp,04h
push eax
push ebx
mov ax,0010h ;
mov ds,ax ;
mov ax,ss:[bp+0ch] ;
sub ax,06h ;
mov ss:[bp+0ch],ax ;
xor eax,eax ;
xor ebx,ebx ;
mov ax,ss:[bp+10h] ;V86 下 IRET 要返回的位址
shl eax,04h ;
mov bx,ss:[bp+0ch] ;
add ebx,eax ;
mov ax,ss:[bp+00h] ;
mov ds:[ebx],ax ;
mov ax,ss:[bp+04h] ;
mov ds:[ebx+02h],ax ;
mov ax,ss:[bp+08h] ;
mov ds:[ebx+04h],ax ;
nop
xor ebx,ebx ;
mov bx,ss:[bp-02h] ;
shl ebx,02h ;
mov ax,ds:[ebx] ;IRETD後跳到何处执行
mov ss:[bp+00h],ax ;(查 0000:0000 的中断表)
mov ax,ds:[ebx+02h] ;
mov ss:[bp+04h],ax ;
mov eax,ss:[bp+08h]
or eax,00032000h
and eax,0fffffeffh
mov ss:[bp+08h],eax
pop ebx
pop eax
pop bp
add sp,02h
iretd
set_base :
mov cs:[di+02h],ax
shr eax,0010h
mov cs:[di+04h],al
mov cs:[di+07h],ah
ret
next :
xor eax,eax
xor ebx,ebx
mov ax,cs
shl eax,04h
mov bx,offset gdttab
add eax,ebx
mov di,offset gdtadds+02h
mov cs:[di],eax ;设定 gdtadds
NOP
xor eax,eax
xor ebx,ebx
mov ax,cs
shl eax,04h
mov di,offset gdttab+08h
call set_base ;设定 PRG Seg 的 Base
NOP
xor eax,eax
xor ebx,ebx
mov ax,cs
shl eax,04h
mov bx,offset tssltr
add eax,ebx
mov di,offset gdttab+18h
call set_base
NOP ;设定 TSSltr 的 Base
xor eax,eax
xor ebx,ebx
mov ax,cs
shl eax,04h
mov bx,offset tssjmp
add eax,ebx
mov di,offset gdttab+20h
call set_base
NOP ;设定 TSSjmp 的 Base
xor eax,eax
xor ebx,ebx
mov ax,cs
shl eax,04h
mov bx,offset buffer1
add eax,ebx
mov di,offset gdttab+28h
call set_base
NOP ;设定 Stack 的 Base
xor eax,eax
xor ebx,ebx
mov ax,cs
shl eax,04h
mov bx,offset idttab
add eax,ebx
mov di,offset idtadds+02h
mov cs:[di],eax ;设定 idtadds
NOP
cli
lgdt fword ptr cs:gdtadds
lidt fword ptr cs:idtadds
mov eax,cr0
or al,01h
mov cr0,eax
mov bx,0018h
ltr bx
db 0eah,00h,00h,20h,00h ;根据TSS表可知跳到enter_v86
enter_v86 :
mov ax,0028h
mov es,ax
xor eax,eax
mov ax,code
push eax ;GS
push eax ;FS
push eax ;DS
push eax ;ES
push eax ;SS
mov ax,0f000h
push eax ;ESP
mov eax,00023000h ;设定VM=1 等级=3
push eax ;Eflag
xor eax,eax
mov ax,code
push eax ;CS
mov ax,offset return_dos
push eax ;EIP
clts ;将 387 切换成 32 位元模式
iretd ;回到 V86 (共弹出24h BYTE)
;-------------------------------------------------------------------------
; 下面的程式便是回到 V86 继续执行的程式
;-------------------------------------------------------------------------
return_dos :
sti
mov ax,cs
mov ds,ax
mov dx,offset next
add dx,0200h
int 27h
start endp
code ends
end start
;-------------------------------------------------------------------------
如何侦测现在是在真实模式下或保护模式呢 ,重点就在於 CR0 暂存器的 Bit0
是否为 '1' ,若为 '1' 则表示现在在保护模式 ,反之则为真实模式 ,不过如果要
执行 MOV EAX,CR0 这个指令必需要在特权等级才能执行 ,所以您要侦测这个位元的
话 ,可以使用 SMSW AX ,来读取 CR0 的低位元部份。
┌———————————————————————————————————┐
│ Soft Bugger 软体蛀虫 90:90/2 软体新技术的实行者 │
│ BBS:02-5955461 24HR ID:Werong Ho -- 软蛀 -- │
└———————————————————————————————————┘
--
沉默的人
Reinhard Young
※ 来源:·饮水思源站 bbs.sjtu.edu.cn·[FROM: 202.96.212.29]
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