汇编全局描述符表实验.doc

全局描述符表试验.MODELTINY.386.STACK100.DATAGDTDB1000H DUP(0);存放读取的全局描述符表bPAEDB0;操作系统是Winxp SP2或更新COUNTDW0COUNT1DW0bufferDB80 DUP(0)sCodeDB4,CodesDataDB4,DatasTSS32DB6,TSS32 s32DB2,32s16DB2,16sDPLDB4,DPL:.CODESTART:MOVAH,00HMOVAL,03HINT10H;清屏LEAEDI,GDTMOVAH,0FEHMOVAL,00HINT21H;读GDT SGDTEDILEAEBX,GDTMOVCX,EBXINCCX;CX: 全局描述符表长度MOVCOUNT,CXMOVEBX,EBX+2;EBX: 全局描述符表在系统中的地址(逻辑地址)LEAEDI,GDT;EDI: 存放读取的全局描述符表首地址MOVAH,0FEHMOVAL,01HINT21H;读取数据MOVCX,COUNTSHRCX,3LEAESI,GDTSTART1:MOVEAX,ESIOREAX,ESI+4JNZSTART3ADDESI,8START2:INCCOUNT1LOOPSTART1START17:CALLIfExitJZSTART17JMPEXITSTART3:LEAEDI,BUFFERMOVAX,COUNT1CALLDisplayWordMOVAL,:STOSBMOVAL, STOSBPUSHECXMOVECX,8START4:LODSBCALLDisplayByteMOVAL, STOSBLOOPSTART4MOVAL,:STOSBMOVAL, STOSBPUSHESIMOVDL,ESI-3MOVDH,ESI-2TESTDL,10HJZSTART7LEASI,sCode;代码段TESTDL,08HJNZSTART5LEASI,sData;数据段或堆栈段START5:CALLCopyStrLEASI,s32TESTDH,40HJNZSTART6LEASI,s16JMPSTART6START7:LEASI,sTSS32;系统段START6:CALLCopyStrMOVAL, STOSBPOPESIMOVAL,ESI-1;显示段基地址CALLDisplayByteMOVAL,ESI-4CALLDisplayByteMOVAL,ESI-5CALLDisplayByteMOVAL,ESI-6CALLDisplayByteMOVAL, STOSBTESTDH,80H;显示结束地址JZSTART8MOVAL,DHANDAL,0FHCALLToASCIISTOSBMOVAX,ESI-8CALLDisplayWordMOVAL,FSTOSBSTOSBSTOSBJMPSTART9START8:MOVAL,0STOSBSTOSBSTOSBMOVAL,DHANDAL,0FHCALLToASCIISTOSBMOVAX,ESI-8CALLDisplayWordSTART9:MOVAL, STOSBPUSHESILEASI,sDPL;显示DPLCALLCopyStrPOPESIMOVAL,60HANDAL,DLRORAL,5ORAL,0STOSBMOVAL, STOSBTESTDL,80HJZSTART10MOVAL,PSTOSBMOVAL, STOSBJMPSTART11START10:MOVAL,NSTOSBMOVAL,PSTOSBSTART11:MOVAL, STOSBTESTDL,10HJZSTART16TESTDL,08HJZSTART14;代码段TESTDL,04HJZSTART12MOVAL,CSTOSBSTART12:TESTDL,02HJZSTART13MOVAL,RSTOSBJMPSTART13;数据段或堆栈段START14:TESTDL,04HJZSTART15MOVAL,ESTOSBSTART15:MOVAL,RSTOSBTESTDL,02HJZSTART13MOVAL,WSTOSBJMPSTART13START16:;系统段MOVAL, STOSBMOVAL,0FHANDAL,DLCALLToASCIISTOSBSTART13:MOVAL,0DHSTOSBMOVAL,0AHSTOSBMOVAL,$STOSBLEADX,bufferMOVAH,09HINT21HPOPECXJMPSTART2ToASCIIPROCNEARORAL,30HCMPAL,3AHJBToASCII1ADDAL,07HToASCII1:RETToASCIIENDPDisplayBytePROCNEARPUSHAXANDAL,0F0HRORAL,4CALLToASCIISTOSBPOPAXANDAL,0FHCALLToASCIISTOSBRETDisplayByteENDPDisplayWordPROCNEARXCHGAL,AHCALLDisplayByteXCHGAL,AHCALLDisplayByteRETDisplayWordENDPCopyStrPROCNEARLODSBXORAH,AHMOVCX,AXREPMOVSBRE