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Text File | 1984-07-09 | 13.7 KB | 626 lines

; ------------------------------------------------------------ ; .REL files are encoded as a bitstream according to certain ; rules which are spelled out in Microsoft's FORTRAN manual. ; As a consequence a normal disk dump program will not be very ; intelligible, even to people who have learned to recognize ; 8080 opcodes in hexadecimal form, or to spot ASCII constants ; in a program. The purpose of READREL.CMD is to generate a ; hexadecimal dump of a .REL file, interspersed with special ; directives as they are produced by M80.COM, F80.COM or other ; relocating assemblers using the same format. ; ; READREL - Copyright (C) 1983 ; Universidad Autonoma de Puebla ; November 24, 1983 ; ; [Harold V. McIntosh, 24 November 1983] ; ------------------------------------------------------------ BDOS equ 224 ;CP/M interrupt to BDOS TFCB equ 005CH TSIZ equ 0080H ;CP/M's record size DSIZ equ 0100H ;size of .OUT buffer (must be 100H) RSIZ equ 0400H ;size of relfile buffer LSIZ: equ 16 ;line length (maximum spaces per line) LF equ 0AH CR equ 0DH ; ------------- org 0100H ; ------------- BEGN: sto #0000,BCTR ;byte counter sto #DSIZ,DCTR ;output downcounter sto #DBUF,DPTR ;output pointer sto #0000,RCTR ;relfile counter sto #RBUF,RPTR ;relfile pointer stob #LSIZ,LCTR ;count 16 bytes/line stob #00,COLM ;FF=column 1 cmpb TFCB+1,#' ' jnz NNUL ld dx,#LOGO ;'UAP...' call MSSG ;type text at (dx) ld dx,#TUTO ;instructions for usage call MSSG ;type text at (dx) jmp GBYE ;normal exit NNUL: ld cl,#021H ;count ld dx,#TFCB ;source ld bx,#RFCB ;.REL FCB = destination call MIUC ;block move stob #'R',RFCB+9 stob #'E',RFCB+10 stob #'L',RFCB+11 stob #00H,RFCB+12 ld cl,#15 ;(0F) open file ld dx,#RFCB ;.REL FCB int BDOS cmpb al,#0FFH ld dx,#COSO ;'can''t open .REL file' jnz ORLF jmp TEMA ;type text at (dx), quit ORLF: stob #00,DOUT ;z=no disk output cmpb TFCB+17,#' ' ;output filename jz NOUT stob #0FFH,DOUT ;z=no disk output ld cl,#16 ld dx,#TFCB+16 ld bx,#TFCB ;CP/M's file control block (.OUT) call MIUC cmpb TFCB+9,#' ' ;output extension jnz YEXT stob #'O',TFCB+9 stob #'U',TFCB+10 stob #'T',TFCB+11 YEXT: ld cx,#0003 ld bx,#TFCB+9 ld dx,#RFCB+9 YEXX: xchg bx,dx ld al,[bx] xchg bx,dx cmp al,[bx] inc bx inc dx loopz YEXX jnz NEQL ld dx,#MEQL ;'extensions equal' jmp TEMA ;type text at (dx), quit NEQL: ld cl,#19 ;(13) delete file ld dx,#TFCB ;CP/M's file control block (.OUT) int BDOS ld cl,#22 ;(16) create file ld dx,#TFCB ;CP/M's file control block (.OUT) int BDOS ld cl,#15 ;(0F) open file ld dx,#TFCB ;CP/M's file control block (.OUT) int BDOS cmp al,#0FFH ld dx,#DDFU ;'no more directory' jnz NOUT jmp TEMA ;type text at (dx), quit NOUT: sto #0FF00H,ROBY ;rotating byte, bit counter call REFI ;process the .REL file cmpb DOUT,#00 ;z=no disk output jz FINI ; Fill the remainder of the output file with ^Z's, write ; the tag end to disk, and close the file. ld cx,DCTR ;output downcounter ld bx,DPTR ;output pointer ld al,#1AH ;^Z jcxz CLOP CLOO: sto al,[bx] loop CLOO CLOP: cmpb DBUF,#1AH ;^Z jz CLOS ld cl,#26 ;(1A) set DMA address ld dx,#DBUF int BDOS call BUDK ;record to disk cmpb DBUF+TSIZ,#1AH ;^Z jz CLOS ld cl,#26 ;(1A) set DMA address ld dx,#DBUF+TSIZ int BDOS call BUDK ;record to disk CLOS: ld cl,#16 ;(10) close file ld dx,#TFCB ;CP/M's file control block (.OUT) int BDOS cmp al,#0FFH ld dx,#NCLO ;'can''t close file' jnz FINI jmp EDSK ;delete .OUT file, type messages FINI: call CRLF ;CR,LF GBYE: ld dl,#00 ld cl,#00 int BDOS ; Type CR, LF. CRLF: ld al,#CR call CONA ;console from A ld al,#LF call CONA ;console from A stob #LSIZ,LCTR ;count 16 bytes/line stob #0FFH,COLM ;FF=column 1 ld cl,#11 ;(0B) console status int BDOS or al,al jz CRLR ld cl,#1 ;(01) read console int BDOS ld dx,#IRRP ;'analysis interrupted' call MSSG cmpb DOUT,#00 ;z=no disk output jz GBYE jmp EDSQ ;delete .OUT file, type messages CRLR: ret ; word: type dx as four nibbles. ; byte: type A as two nibbles. WORD: mov al,dh call BYTE ;type A as two nibbles mov al,dl BYTE: call TADR ;type address if column 1 BEIT: push ax rcr al rcr al rcr al rcr al call NIBL ;type A as hex pop ax NIBL: and al,#0FH add al,#90H daa adc al,#40H daa CONA: push bx push dx push ax ld cl,#2 ;(02) write console mov dl,al int BDOS pop ax cmpb DOUT,#00 ;z=no disk output jz CONB call DDDA CONB: pop dx pop bx ret ; Type several spaces. DUBL: call SNGL ;type one space SNGL: decb LCTR ;count 16 bytes/line jnz NOCR call CRLF NOCR: ld al,#' ' jmp CONA ; Type relative address if at start of a new line. TADR: push bx incb COLM ;FF=column 1 jnz TRET push ax ld al,#'(' call CONA ld bx,BCTR mov al,bh call BEIT mov al,bl call BEIT ld al,#')' call CONA call SNGL pop ax TRET: pop bx ret ; Type message at (dx). MSSG: xchg bx,dx MSSH: ld al,[bx] cmp al,#'$' jz MSSR call CONA inc bx jmp MSSH MSSR: ret ; Type message, erase .OUT file, quit. EDSK: call MSSG EDSQ: ld cl,#19 ;(13) delete file ld dx,#TFCB ;CP.M's file control block (.OUT) int BDOS ;don't leave a partial file ld dx,#ERAD ;'output file erased' TEMA: call MSSG jmp GBYE ; Block move. MIUC: xchg bx,dx ld al,[bx] xchg bx,dx sto al,[bx] inc bx inc dx dec cl jnz MIUC ;block move ret ; Place disk output in buffer, store the buffer in the ; disk as it is filled and reinitialize it. DDDA: cmp DCTR,#0000 jnz DDDB call BUDI ;output downcounter DDDB: dec DCTR ld bx,DPTR ;output pointer sto al,[bx] inc DPTR ;output downcounter ret ; Send DBUF to disk. BUDI: push ax call BUDJ sto #DBUF,DPTR ;output pointer sto #DSIZ,DCTR pop ax ret BUDJ: ld cl,#26 ;(1A) set DMA address ld dx,#DBUF ;output buffer int BDOS call BUDK ;record to disk ld cl,#26 ;(1A) set DMA address ld dx,#DBUF+TSIZ ;CP/M's record size int BDOS BUDK: ld cl,#21 ;(15) write one record ld dx,#TFCB ;CP/M's file control block (.OUT) int BDOS cmp al,#00H ld dx,#DIWR ;'disk write error' jnz EDSK ;delete .OUT file, type messages ret ; Get next bit. GEBI: incb ROBY+1 jnz GEBJ call NXHX stob al,ROBY stob #0F8H,ROBY+1 ;-8 GEBJ: rclb ROBY ret ; Read sixteen bits from the .REL file, leave them in dx. GEWO: call GEBY push ax call GEBY pop dx mov dh,al ret ; Read a full byte from the .REL file, leave it in al. GEBY: ld cl,#08 BITS: ld ch,#00 MORE: call GEBI ;get next bit rcl ch dec cl jnz MORE mov al,ch ret ; Get next relfile element. NXHX: push cx push bx cmp RCTR,#0000 ;relfile counter jnz NXHV ;byte available sto #RBUF,RPTR NXHY: cmp RPTR,#(RBUF+RSIZ) jnc NXHU ;reset relfile, read 1st element ld cl,#26 ;(1A) set DMA address ld dx,RPTR ;relfile buffer int BDOS ld cl,#20 ;(14) read one record ld dx,#RFCB ;.REL FCB int BDOS cmp al,#000H jnz NXHZ add RPTR,#TSIZ add RCTR,#TSIZ jmp NXHY NXHZ: cmp al,#001H ld dx,#DIRD ;'disk read error' jz NXHU jmp TEMA ;type text at (dx), quit NXHU: sto #RBUF,RPTR NXHV: dec RCTR ld bx,RPTR inc RPTR ld al,[bx] pop bx pop cx ret ; ------------------- ; Read the .REL file. ; ------------------- ; The first bit read determines whether a single byte ; follows (bit = 0), to be used without alteration, or ; whether the following information may be relocatable ; (bit = 1). REFI: call GEBI ;get next bit jc RELA ;not absolute byte call GEBY ;full byte from .REL call BYTE ;type A as two nibbles call SNGL ;type one space inc BCTR ;byte counter jmp REFI ;.REL read loop ; When the leadin bit is 1, two more bits are read to ; distinguish four alternatives: 00 for further analysis, ; 01 for program segment, 10 for data segment, or 11 for ; common segment. In the latter three cases, a two-byte ; address will be read, which a loader would assign to its ; proper memory segment. RELA: ld cl,#2 call BITS ;get C bits from .REL or al,al jz SPEC ;'special LINK element' call TADR ;type address if column 1 call GTYQ ;fetch segment descriptor call MSSG ;type text at (dx) call GEWO ;sixteen bits from .REL call WORD ;type dx as four nibbles call CRLF ;CR, LF ld bx,BCTR ;byte counter inc bx inc bx sto bx,BCTR ;byte counter jmp REFI ;.REL read loop ; There are sixteen 'special LINK elements' ranging from ; entry point definitions to the EOF indicator. They fall ; into three or four general groups, depending on whether ; they are associated with an eight-byte ASCII label, a ; relocatable address, both, or neither. Since they represent ; parenthetic information, they are set off on a line by ; themselves. SPEC: cmpb LCTR,#LSIZ ;max spaces/line jz SPED call CRLF ;CR,LF SPED: stob #0,COLM ;FF=column 1 ld cl,#4 call BITS ;get C bits from .REL ld ah,#0 add ax,ax ;case number indexes two tables mov bx,ax ld di,#META ;case table for messages ld dx,[bx+di] ld di,#JUTA ;case table for action addresses push [bx+di] jmp MSSG ;type text at (dx) ; Message table, to correspond to the 'special' relocation ; elements, of which there are sixteen. These are the ; descriptive messages inserted into the output stream. META: dw ME0 ;'entry symbol' dw ME1 ;'COMMON block' dw ME2 ;'program name' dw ME3 ;'request library search' dw ME4 ; reserved dw ME5 ;'COMMON size' dw ME6 ;'chain external' dw ME7 ;'define entry' dw ME8 ; reserved dw ME9 ;'external add offset' dw MEA ;'size of DATA area' dw MEB ;'loading location counter' dw MEC ;'chain address' dw MED ;'define program size' dw MEE ;'end of program' dw MEF ;'end of file' ; There may be a label or a further address associated ; with each 'special LINK item.' These subroutines take ; the appropriate action in each case. JUTA: dw TEXT ;ASCII label dw TEXT ;ASCII label dw TEXT ;ASCII label dw TEXT ;ASCII label dw TEXT ;ASCII label dw STYP ;storage type dw STYP ;storage type dw STYP ;storage type dw STYP ;storage type dw PHUE ;storage type w/ address dw PHUE ;storage type w/ address dw PHUE ;storage type w/ address dw PHUE ;storage type w/ address dw PHUE ;storage type w/ address dw PHOO ;program end - flush byte dw EOFI ;EOF ; The 'special LINK item' includes an 8-byte label ; or similar ASCII string. 8 bytes is maximum, there ; must be at least 1, 8 is taken for 0. TEXT: ld cl,#3 call BITS ;get C bits from .REL or al,al ;take 0 to mean 8 jnz X2X ld al,#8 X2X: push ax call GEBY ;full byte from .REL call CONA pop ax dec al jnz X2X call CRLF ;CR,LF jmp REFI ;.REL read loop ; The 'special LINK item' requires identification via ; the following two bits, as to whether it is absolute ; (00), code (01), data (10), or common (11). STYP: call GTYP ;ascertain storage type call MSSG ;type text at (dx) call TWRD ;read & type word from .REL call DUBL ;type one space jmp TEXT ;ASCII label ; Read two bits to ascertain storage type, then load ; address of appropriate descriptor for console typing. GTYP: ld cl,#2 call BITS ;get C bits from .REL GTYQ: ld dx,#MABS ;'ABS:' or al,al jz GTYR ld dx,#MPRG ;'PREL' dec al jz GTYR ld dx,#MDAT ;'DREL' dec al jz GTYR ld dx,#MCOM ;'CREL' GTYR: ret ; This class of 'special LINK items' require a two-bit ; storage classigication followed by a two-byte address. PHUE: call GTYP ;ascertain storage type call MSSG ;type text at (dx) call TWRD ;read & type word from .REL call CRLF ;CR,LF jmp REFI ;.REL read loop ; At the program end, the bit stream should be squared ; off at a byte boundary. A start address may be present. PHOO: call GTYP ;ascertain storage type call MSSG ;type text at (dx) call TWRD ;read & type word from .REL call CRLF ;CR,LF sto #0FF00H,ROBY ;rotating byte, bit counter jmp REFI ;.REL read loop ; End of File. EOFI: ret ; Read a word from .REL and type it. TWRD: call GEWO ;sixteen bits from .REL jmp WORD ;type dx as four nibbles ; ------------------------------------------------------- LOGO: db CR,LF db ' READREL/ICUAP',CR,LF db 'Universidad Autonoma de Puebla',CR,LF db ' November 24, 1983',CR,LF,'$' TUTO: db CR,LF db 'READREL.CMD will decompose the bitstream which',CR,LF db 'constitutes a .REL file into hexadecimal bytes',CR,LF db 'and addresses interspersed with commentaries',CR,LF db 'derived from the ''special LINK elements'' and',CR,LF db 'other clarifying information. The command:',CR,LF,CR,LF db ' READREL [D:]FILE[.REL] [[D:]LIST[.OUT]]',CR,LF,CR,LF db 'will analyze the requested file. If no extension',CR,LF db 'is given, .REL will be used. The analysis will',CR,LF db 'always appear at the console. When a second file is',CR,LF db 'given (with default extension .OUT), it will gather',CR,LF db 'in the output listing. Pressing any key will stop',CR,LF db 'the program.',CR,LF db '$' ME0: db 'entry symbol $' ME1: db 'COMMON block $' ME2: db 'program name $' ME3: db 'req lib srch $' ME4: db 'reserved $' ME5: db 'COM size $' ME6: db 'chain ext $' ME7: db 'def entry $' ME8: db 'reserved $' ME9: db 'extnl + offset $' MEA: db 'size DATA area $' MEB: db 'ldng locn cntr $' MEC: db 'chain address $' MED: db 'def prgrm size $' MEE: db 'end of program $' MEF: db 'EOF$' MABS: db 'ABS: $' MPRG: db 'PREL $' MDAT: db 'DREL $' MCOM: db 'CREL $' DIRD: db 'Disk read error.$' DIWR: db 'Disk write error.$' COSO: db 'Can''t open .REL file.$' DDFU: db 'Disk or Directory full.$' NCLO: db 'Cannot close file.$' MEQL: db 'Duplicate extensions.$' IRRP: db '-- Analysis interrupted --',CR,LF,'$' ERAD: db '- Output file suppressed -$' RFCB: ds 21H ;.REL FCB RBUF: ds RSIZ ;relfile buffer (400H) RPTR: ds 2 ;relfile pointer RCTR: ds 2 ;relfile counter ROBY: ds 2 ;rotating byte, bit counter DOUT: ds 1 ;z=no disk output DCTR: ds 2 ;output downcounter DPTR: ds 2 ;output pointer LCTR: ds 1 ;count 16 bytes/line COLM: ds 1 ;FF=column 1 BCTR: ds 2 ;byte counter DBUF: ds DSIZ ;.OUT buffer end