Re: [問題] object code的定義

看板Programming作者FredLu.時間13年前 (2012/03/20 02:01)推噓0(0推 0噓 1→)

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==> newpuli.bbs@ptt.cc (= =) 提到: > 對於object code的定義, > 我似乎搞混了, > 所以我想要請板上的各位們請教一下... > 我目前對objcet code的認知是: > 程式的source code會先被編譯成object code, > object code裡面包含的內容就是機器指令, > 然後這個程式如果要被執行, > 他的object code會先被載入到記憶體裡, > 然後就直接跑這個object code了. > 不知我的認知是否有誤呢? > 如果有誤的話,可否麻煩請指正一下, > 看看我的說法要如何修改才是正確的呢? > 如果我的想法是正確的話, > 那我是不是可以說 "object code就等於是機器碼"呢? > 謝謝~ 參考一下早期 X86 16位元的 Compiler 出的 obj 檔案結構 (173) ID {0xA0},offset [0xF39] ,Size = 1028(0x404) -- Segment Data - Segment 1 ,org 0x0 (174) ID {0x9C},offset [0x1340] ,Size = 785(0x311) -- Relocation List - Ex: external segment & offset data - (group 3) [0x3FA] is load by OS - Ex: external offset data - (seg 11) [0x3F7] is load by OS - Ex: external offset data - (seg 12) [0x3F3] is load by OS - Ex: external offset data - (seg 12) [0x3EC] is load by OS - Ex: external offset data - (group 2) [0x3E6] is load by OS int matherr(struct exception *a) { oper_rlt=-2; return 1; } 0C67:0F39 0100 ADD [BX+SI],AX 0C67:0F3B 00558B ADD [DI-75],DL 0C67:0F3E EC IN AL,DX 0C67:0F3F 1E PUSH DS 0C67:0F40 B80000 MOV AX,0000 0C67:0F43 8ED8 MOV DS,AX 0C67:0F45 C706D6D3FEFF MOV WORD PTR [D3D6],FFFE 0C67:0F4B B80100 MOV AX,0001 0C67:0F4E EB00 JMP 0F50 0C67:0F50 1F POP DS 0C67:0F51 5D POP BP 0C67:0F52 CB RETF int oper_result(void) { return(oper_rlt); } 0C67:0F53 55 PUSH BP 0C67:0F54 8BEC MOV BP,SP 0C67:0F56 1E PUSH DS 0C67:0F57 B80000 MOV AX,0000 0C67:0F5A 8ED8 MOV DS,AX 0C67:0F5C A1D6D3 MOV AX,[D3D6] 0C67:0F5F EB00 JMP 0F61 0C67:0F61 1F POP DS 0C67:0F62 5D POP BP 0C67:0F63 CB RETF double A_to_N(char *string) { int i,k=35; double num=0; for(i=0;i<k && string[i]!=0;i++); if(i==k || i==0) oper_rlt=-2; else { oper_rlt=0; num=atof(string); if(num>1.78e308) oper_rlt=-2; } return(num); } 0C67:0F64 55 PUSH BP 0C67:0F65 8BEC MOV BP,SP 0C67:0F67 83EC0A SUB SP,+0A 0C67:0F6A 56 PUSH SI 0C67:0F6B 57 PUSH DI 0C67:0F6C 1E PUSH DS 0C67:0F6D B80000 MOV AX,0000 0C67:0F70 8ED8 MOV DS,AX 0C67:0F72 BF2300 MOV DI,0023 0C67:0F75 9B WAIT 0C67:0F76 D9EE FLDZ 0C67:0F78 9B WAIT 0C67:0F79 DD5EF8 FSTP QWORD PTR [BP-08] 0C67:0F7C 33F6 XOR SI,SI 0C67:0F7E 90 NOP 0C67:0F7F 9B WAIT 0C67:0F80 EB01 JMP 0F83 0C67:0F82 46 INC SI 0C67:0F83 3BF7 CMP SI,DI 0C67:0F85 7D09 JGE 0F90 0C67:0F87 C45E06 LES BX,[BP+06] 0C67:0F8A 26 ES: 0C67:0F8B 803800 CMP BYTE PTR [BX+SI],00 0C67:0F8E 75F2 JNZ 0F82 0C67:0F90 3BF7 CMP SI,DI 0C67:0F92 7404 JZ 0F98 0C67:0F94 0BF6 OR SI,SI 0C67:0F96 7508 JNZ 0FA0 0C67:0F98 C706D6D3FEFF MOV WORD PTR [D3D6],FFFE 0C67:0F9E EB33 JMP 0FD3 0C67:0FA0 C706D6D30000 MOV WORD PTR [D3D6],0000 0C67:0FA6 FF7608 PUSH [BP+08] 0C67:0FA9 FF7606 PUSH [BP+06] 0C67:0FAC 9A00000000 CALL 0000:0000 0C67:0FB1 83C404 ADD SP,+04 0C67:0FB4 9B WAIT 0C67:0FB5 DD5EF8 FSTP QWORD PTR [BP-08] 0C67:0FB8 9B WAIT 0C67:0FB9 DD46F8 FLD QWORD PTR [BP-08] 0C67:0FBC 9B WAIT 0C67:0FBD DC1EE4D3 FCOMP QWORD PTR [D3E4] 0C67:0FC1 9B WAIT 0C67:0FC2 DD7EF6 FSTSW [BP-0A] 0C67:0FC5 90 NOP 0C67:0FC6 9B WAIT 0C67:0FC7 8B46F6 MOV AX,[BP-0A] 0C67:0FCA 9E SAHF 0C67:0FCB 7606 JBE 0FD3 0C67:0FCD C706D6D3FEFF MOV WORD PTR [D3D6],FFFE 0C67:0FD3 9B WAIT 0C67:0FD4 DD46F8 FLD QWORD PTR [BP-08] 0C67:0FD7 EB00 JMP 0FD9 0C67:0FD9 1F POP DS 0C67:0FDA 5F POP DI 0C67:0FDB 5E POP SI 0C67:0FDC C9 DB C9 0C67:0FDD CB RETF 這是以下的程式分析結果 10 input "Input .obj file name: ",a$ 20 gosub 800 30 yes_obj=0 40 open "i",#1,a$ 50 page_num=3 60 data1=asc(input$(1,#1)) 70 file_location=file_location+1 80 if buff_index<100 then buff[buff_index]=data1 90 if buff_index<100 then buff_index=buff_index+1 100 block_sum=block_sum+data1 110 if file_location=1 and data1=0x80 then gosub 900 120 if yes_obj=1 and file_location=block_next then gosub 1000 130 if yes_obj=1 and file_location=block_next-1 then gosub 2000 140 if file_location=1 and yes_obj=0 then print "Bad .obj file!" : goto 160 150 if not eof(1) then goto 60 160 close #1 500 end 800 rem got file name 810 dot_flag=0 820 for i=1 to len(a$) 830 if mid$(a$,i,1)="." then dot_flag=1 840 next 850 if dot_flag=0 then a$=a$+".obj" 860 seg_info_num=0 870 seg_info[0]=0 880 return 900 rem check if obj file 910 print "Got Obj file:",a$ 920 yes_obj=1 930 block_next=1 940 return 1000 rem get block_length 1010 block_id=data1 1020 data1=asc(input$(1,#1)) 1030 data2=asc(input$(1,#1)) 1040 file_location=file_location+2 1050 block_size=data2*256+data1 1060 block_next=block_next+3+block_size 1070 block_count=block_count+1 1080 block_sum=block_id+data1+data2 1090 print "(";block_count;") ID {0x";hex$(block_id);"},offset [0x";hex$(file_location);"]";" ,Size =",block_size;"(0x";hex$(block_size);")"; 1100 buff_index=1 1120 return 2000 rem got block_type block_sum=block_sum and 0xff if block_id=0x80 then print " -- Module Name" if block_id=0x8a then print " -- End of Module" if block_id=0x8c then print " -- External Symbols" if block_id=0x90 then print " -- Public Symbols" if block_id=0x94 then print " -- Line Number Info" if block_id=0x96 then print " -- Segment/Group Symbols" if block_id=0x98 then print " -- Info for Specific seg" if block_id=0x9a then print " -- Info for Specific group" if block_id=0x9c then print " -- Relocation List" if block_id=0xa0 then print " -- Segment Data" if block_id=0xa2 then print " -- Duplicated Seg Data" if block_size<=2 then 2300 if block_id=0x80 then gosub 3000 if block_id=0x88 then gosub 4100 if block_id=0x8a then gosub 3900 if block_id=0x8c then gosub 3600 if block_id=0x90 then gosub 3500 if block_id=0x94 then gosub 4000 if block_id=0x96 then gosub 3400 if block_id=0x98 then gosub 3700 if block_id=0x9a then gosub 3800 if block_id=0x9c then gosub 3200 if block_id=0xa0 then gosub 3100 if block_id=0xa2 then gosub 3300 2300 if block_sum<>0 then print " CRC error." else print page_num=page_num+1 rem if page_num>23 then print "Hit a key to continue ,or Q to quit" : a$=input$(1) : page_num=0 : if cap$(a$)="Q" then 160 return 3000 rem print module name a$="" for i=1 to buff[1] a$=a$+chr$(buff[i+1]) next m_name$=a$ print " - Module Name:",a$; page_num=page_num+1 return 3100 rem print segment info a=buff[1] b=buff[2]+buff[3]*0x100 print " - Segment",a,",org 0x";hex$(b); page_num=page_num+1 return 3200 rem print reloation ex 3210 j=0 3220 rel_addr=0 rel_cont=0 a=buff[j+1] and 3 b=buff[j+2]+a*0x100 c=buff[j+1] and 0xc0 if c<>0xc0 then print " - bad relocation list -"; : return d=buff[j+1] and 8 e=buff[j+1] and 4 a$="" if d=8 then a$="segment" if e=4 and d=0 then a$="offset" if e=4 and d=8 then a$="segment & offset" d=buff[j+1] and 2 e=buff[j+3] and 0x10 if d=2 then b$="external" else b$="" if e=0x10 then c$="group" else c$="seg" f=buff[j+3] and 0x40 g=buff[j+3] and 4 if f=0 then rel_cont=buff[j+6]+buff[j+7]*0x100 else rel_cont=buff[j+5]+buff[j+6]*0x100 if f=0 and g=0 then rel_cont_seg=buff[j+5] else rel_cont_seg=buff[j+4] print " - Ex:",b$,a$,"data"; if g=0 then print " - store : (seg",rel_cont_seg;") 0x";hex$(rel_cont),"to (seg",buff[j+4];") [0x";hex$(b);"]"; if g=4 and f=0 then print " - (";c$,buff[j+4];") [0x";hex$(b);"] is external symbol",buff[j+5]; if g=4 and f=0x40 then print " - (";c$,buff[j+4];") [0x";hex$(b);"] is load by OS"; if g=0 then h=6 else h=4 if f=0 then h=h+1 j=j+h page_num=page_num+1 if j+1<block_size and j+1<20 then print : goto 3220 return 3300 rem print duplication ex a=buff[1] b=buff[2]+buff[3]*0x100 c=buff[4]+buff[5]*0x100+buff[6]*0x10000+buff[7]*0x1000000 d=buff[8] print " - Ex: Seg",a,"[0x";hex$(b);"] ,",c,"dup(",e$; for i=1 to d print "0x";hex$(buff[8+i]);" "; next print ")"; page_num=page_num+1 return 3400 rem print segment symbol 3410 print " - Segment Symbol:",; 3420 if buff[1]=0 then j=2 else j=1 3430 a=buff[j] for i=1 to a c$=chr$(buff[i+j]) print c$; next page_num=page_num+1 if j+a+1<block_size then print "."; : j=j+a+1 : goto 3430 return 3500 rem print public symbol 3510 segment=buff[2] 3520 j=3 3530 a=buff[j] b=buff[j+a+1]+buff[j+a+2]*0x100+buff[j+a+3]*0x10000 print " - Public Symbol: Seg",segment,"[0x";hex$(b);"]",; for i=1 to a c$=chr$(buff[i+j]) print c$; next page_num=page_num+1 if j+a+4<block_size and j+a+4<80 then print : j=j+a+4 : goto 3530 return 3600 rem print external symbol 3610 j=1 ext_sym_no=0 ext_sym_group=ext_sym_group+1 3620 a=buff[j] ext_sym_no=ext_sym_no+1 print " - External Symbol (";ext_sym_group;")",ext_sym_no;":"; ext_seg_no=ext_seg_no+1 for i=1 to a c$=chr$(buff[i+j]) print c$; next page_num=page_num+1 if j+a+2<block_size and j+a+2<80 then print : j=j+a+2 : goto 3620 return 3700 rem print segment specifics a=buff[1] b=a and 0x60 if b=0 then c$="specific segment alignment" if b=0x20 then c$="BYTE boundary" if b=0x40 then c$="WORD boundary" if b=0x60 then c$="PARAGRAPH boundary" d=buff[2]+buff[3]*0x100 e=buff[4] seg_info_num=seg_info_num+1 seg_info[seg_info_num]=e f=a and 8 if f=8 then d$="public" else d$="" g=a and 4 if g=4 then e$="stack" else e$="" print " - Segment ",e/2,",total size",d,"(0x";hex$(d);") is",d$,e$,c$; page_num=page_num+1 return 3800 rem print group specifics a=buff[1] b=buff[3] print " - Symbol number:",a,",Segment number",b; page_num=page_num+1 return 3900 rem print end message print " - End Messages:",; for i=1 to block_size-1 a$="00"+hex$(buff[i]) b$=right$(a$,2) print b$,; next page_num=page_num+1 return 4000 rem print line info 4010 a=buff[2] 4020 j=3 4030 b=buff[j]+buff[j+1]*0x100 c=buff[j+2]+buff[j+3]*0x100 print " - Ex: (seg",a;") [0x";hex$(c);"] - Line",b,"in",m_name$; j=j+4 page_num=page_num+1 if j<block_size and j<20 then print : goto 4030 return 4100 rem print end message k=block_size if k>15 then k=15 print print " - Messages:",; for i=1 to k-1 a=buff[i] a=a and 0xff a$="00"+hex$(a) b$=right$(a$,2) print b$,; next page_num=page_num+1 return -- ☆ [Origin:椰林風情] [From: host-58-115-151-138.dynamic] [Login: **] [Post: **]