title LOCATE (EXE2BIN)
;Loader for EXE files under 86-DOS
;The following switch allows use with the "old linker", which put a version
;number where the new linker puts the number of bytes used in the last page.
;If enabled, this will cause a test for 0004 at this location (the old linker
;version number), and if equal, change it to 200H so all of the last page
;will be used.
;VER. 1.5
; 05/21/82 Added rev number
;
;VER. 1.6
; 07/01/82 A little less choosy about size matches
;
;VER. 2.0 Rev. 1 M.A.Ulloa
; 10/08/82 Modified to use new 2.0 system calls for file i/o
;
; Rev. 2 M.A.Ulloa
; 10/27/82 Added the DOS version check
FALSE EQU 0
TRUE EQU NOT FALSE
OLDLINK EQU 0 ;1 to enable, 0 to disable
.xlist
INCLUDE DOSSYM.ASM
.list
subttl Main Code Area
page
code segment byte
code ends
DATA SEGMENT PUBLIC BYTE
EXTRN bad_vers_err:BYTE,NOTFND:BYTE,NOROOM:BYTE,DIRFULL:BYTE
EXTRN CANTFIX:BYTE,RDBAD:BYTE,FULL:BYTE,PROMPT:BYTE,CRLF:BYTE
make db "MAUlloa/Microsoft/V20"
rev db "2"
file1_ext db ".EXE",00h
file2_ext db ".BIN",00h
per1 db 0
per2 db 0
file1 db 64 dup(?)
handle1 dw 1 dup(?)
file2 db 64 dup(?)
handle2 dw 1 dup(?)
INBUF DB 5,0
DB 5 DUP(?)
;The following locations must be defined for storing the header:
RUNVAR LABEL BYTE ;Start of RUN variables
RELPT DW ?
LASTP LABEL WORD
RELSEG DW ?
SIZ LABEL WORD ;Share these locations
PAGES DW ?
RELCNT DW ?
HEADSIZ DW ?
DW ?
LOADLOW DW ?
INITSS DW ?
INITSP DW ?
DW ?
INITIP DW ?
INITCS DW ?
RELTAB DW ?
RUNVARSIZ EQU $-RUNVAR
DATA ENDS
STACK SEGMENT WORD STACK
DB 80H DUP (?)
STACK ENDS
ZLOAD SEGMENT
ZLOAD ENDS
LOAD EQU ZLOAD
CODE SEGMENT BYTE
ASSUME CS:CODE
LOCATE PROC FAR
JMP SHORT LOCSTRT
HEADER DB "Vers 2.00"
LOCSTRT:
MOV SI,81H
PUSH DS
XOR AX,AX
PUSH AX ;Push return address to DS:0
;Code to print header
; PUSH DS
; MOV DX,DATA
; MOV DS,DX
; MOV DX,OFFSET HEADER
; MOV AH,STD_CON_STRING_OUTPUT
; INT 21H
; POP DS
;----- Check Version Number --------------------------------------------;
mov ah,Get_Version
int 21h
cmp al,2
jge vers_ok ; version >= 2, enter locate
push ds
mov dx,data
mov ds,dx
mov dx,offset bad_vers_err
MOV AH,STD_CON_STRING_OUTPUT
INT 21H
pop ds
ret ;long return to DOS
;-----------------------------------------------------------------------;
vers_ok:
MOV BX,WORD PTR DS:2 ;Get size of memory
MOV DX,DATA
MOV ES,DX
assume es:data
;-----------------------------------------------------------------------;
;----- Get the first file name
call kill_bl
jnc sj01
mov ds,dx
jmp bad_file
sj01:
mov di,offset file1
sj0:
lodsb ;get character of file name
cmp al,' '
je sj2
cmp al,0dh
je sj2
cmp al,'.' ;an extension separator found?
jne sj1
mov es:[per1],-1
sj1:
stosb
jmp short sj0
sj2:
dec si
mov byte ptr es:[di],00h ;nul terminate the filename
call kill_bl
jc no_second
;----- Get the second file name
mov di,offset file2
sj3:
lodsb ;get character of file name
cmp al,' '
je sj5
cmp al,0dh
je sj5
cmp al,'.' ;an extension separator found?
jne sj4
mov es:[per2],-1
sj4:
stosb
jmp short sj3
sj5:
mov byte ptr es:[di],00h ;nul terminate
jmp short check_ext
;----- Copy file1 to file2
no_second:
mov ds,dx
assume ds:data
mov si,offset file1
mov di,offset file2
sj6:
lodsb
cmp al,'.'
je sj7
cmp al,00h
je sj7
stosb
jmp short sj6
sj7:
mov byte ptr [di],00h
;----- Check that files have an extension, otherwise set default
check_ext:
mov ds,dx
assume ds:data
cmp [per1],-1
je file1_ok
mov si,offset file1
sj8:
lodsb
cmp al,00h
jne sj8
mov di,si
mov si,offset file1_ext
call put_ext
file1_ok:
cmp [per2],-1
je file2_ok
mov si,offset file2
sj9:
lodsb
cmp al,00h
jne sj9
mov di,si
mov si,offset file2_ext
call put_ext
jmp short file2_ok
;----- Fill in the default extent
put_ext proc near
dec di
mov cx,5 ;move extent: period,extent,null
rep movsb
ret
put_ext endp
;----- Find the first non-blank
kill_bl proc near
cld
sj10:
lodsb
cmp al,' '
je sj10
dec si
cmp al,0dh
clc
jne sj11
stc
sj11:
ret
kill_bl endp
file2_ok:
;-----------------------------------------------------------------------;
mov dx,offset file1
mov ah,open
mov al,0 ;ror reading only
INT 21H ;Open input file
jc bad_file
mov [handle1],ax
jmp exeload
bad_file:
MOV DX,OFFSET NOTFND
xERROR:
MOV AH,STD_CON_STRING_OUTPUT
INT 21H
RET ;FAR return to MS-DOS
TOOBIG:
MOV DX,OFFSET NOROOM
JMP xERROR
BADEXE:
MOV DX,OFFSET CANTFIX
ERRORJ: JMP xERROR
EXELOAD:
MOV DX,OFFSET RUNVAR ;Read header in here
MOV CX,RUNVARSIZ ;Amount of header info we need
push bx
mov bx,[handle1]
MOV AH,read
INT 21H ;Read in header
pop bx
CMP [RELPT],5A4DH ;Check signature word
JNZ BADEXE
MOV AX,[HEADSIZ] ;size of header in paragraphs
ADD AX,31 ;Round up first
CMP AX,1000H ;Must not be >=64K
JAE TOOBIG
AND AX,NOT 31
MOV CL,4
SHL AX,CL ;Header size in bytes
push dx
push cx
push ax
push bx
mov dx,ax
xor cx,cx
mov al,0
mov bx,[handle1]
mov ah,lseek
int 21h
pop bx
pop ax
pop cx
pop dx
XCHG AL,AH
SHR AX,1 ;Convert to pages
MOV DX,[PAGES] ;Total size of file in 512-byte pages
SUB DX,AX ;Size of program in pages
CMP DX,80H ;Fit in 64K?
JAE TOOBIG
XCHG DH,DL
SHL DX,1 ;Convert pages to bytes
MOV AX,[LASTP] ;Get count of bytes in last page
OR AX,AX ;If zero, use all of last page
JZ WHOLEP
IF OLDLINK
CMP AX,4 ;Produced by old linker?
JZ WHOLEP ;If so, use all of last page too
ENDIF
SUB DX,200H ;Subtract last page
ADD DX,AX ;Add in byte count for last page
WHOLEP:
MOV [SIZ],DX
ADD DX,15
SHR DX,CL ;Convert bytes to paragraphs
MOV BP,LOAD
ADD DX,BP ;Size + start = minimum memory (paragr.)
CMP DX,BX ;Enough memory?
JA TOOBIG
MOV DX,OFFSET CANTFIX
MOV AX,[INITSS]
OR AX,[INITSP]
OR AX,[INITCS]
ERRORNZ:
jz xj
JMP ERRORJ ;Must not have SS, SP, or CS to init.
xj: MOV AX,[INITIP]
OR AX,AX ;If IP=0, do binary fix
JZ BINFIX
CMP AX,100H ;COM file must be set up for CS:100
JNZ ERRORNZ
push dx
push cx
push ax
push bx
mov dx,100h ;chop off first 100h
xor cx,cx
mov al,1 ;seek from current position
mov bx,[handle1]
mov ah,lseek
int 21h
pop bx
pop ax
pop cx
pop dx
SUB [SIZ],AX ;And count decreased size
CMP [RELCNT],0 ;Must have no fixups
JNZ ERRORNZ
BINFIX:
XOR BX,BX ;Initialize fixup segment
;See if segment fixups needed
CMP [RELCNT],0
JZ LOADEXE
GETSEG:
MOV DX,OFFSET PROMPT
MOV AH,STD_CON_STRING_OUTPUT
INT 21H
MOV AH,STD_CON_STRING_INPUT
MOV DX,OFFSET INBUF
INT 21H ;Get user response
MOV DX,OFFSET CRLF
MOV AH,STD_CON_STRING_OUTPUT
INT 21H
MOV SI,OFFSET INBUF+2
MOV BYTE PTR [SI-1],0 ;Any digits?
JZ GETSEG
DIGLP:
LODSB
SUB AL,"0"
JC DIGERR
CMP AL,10
JB HAVDIG
AND AL,5FH ;Convert to upper case
SUB AL,7
CMP AL,10
JB DIGERR
CMP AL,10H
JAE DIGERR
HAVDIG:
SHL BX,1
SHL BX,1
SHL BX,1
SHL BX,1
OR BL,AL
JMP DIGLP
DIGERR:
CMP BYTE PTR [SI-1],0DH ;Is last char. a CR?
JNZ GETSEG
LOADEXE:
XCHG BX,BP ;BX has LOAD, BP has fixup
MOV CX,[SIZ]
MOV AH,read
push di
mov di,[handle1]
PUSH DS
MOV DS,BX
XOR DX,DX
push bx
mov bx,di
INT 21H ;Read in up to 64K
pop bx
POP DS
pop di
Jnc HAVEXE ;Did we get it all?
MOV DX,OFFSET RDBAD
jmp xERROR ;Non fatal, print warning
HAVEXE:
CMP [RELCNT],0 ;Any fixups to do?
JZ STORE
MOV AX,[RELTAB] ;Get position of table
push dx
push cx
push ax
push bx
mov dx,ax
xor cx,cx
mov al,0
mov bx,[handle1]
mov ah,lseek
int 21h
pop bx
pop ax
pop cx
pop dx
MOV DX,OFFSET RELPT ;4-byte buffer for relocation address
RELOC:
MOV DX,OFFSET RELPT ;4-byte buffer for relocation address
MOV CX,4
MOV AH,read
push bx
mov bx,[handle1]
INT 21H ;Read in one relocation pointer
pop bx
Jnc RDCMP
JMP BADEXE
RDCMP:
MOV DI,[RELPT] ;Get offset of relocation pointer
MOV AX,[RELSEG] ;Get segment
ADD AX,BX ;Bias segment with actual load segment
MOV ES,AX
ADD ES:[DI],BP ;Relocate
DEC [RELCNT] ;Count off
JNZ RELOC
STORE:
MOV AH,CREAT
MOV DX,OFFSET file2
xor cx,cx
INT 21H
Jc MKERR
mov [handle2],ax
MOV CX,[SIZ]
MOV AH,write
push di
mov di,[handle2]
PUSH DS
MOV DS,BX
XOR DX,DX ;Address 0 in segment
push bx
mov bx,di
INT 21H
pop bx
POP DS
pop di
Jc WRTERR ;Must be zero if more to come
MOV AH,CLOSE
push bx
mov bx,[handle2]
INT 21H
pop bx
RET
WRTERR:
MOV DX,OFFSET FULL
JMP xERROR
MKERR:
MOV DX,OFFSET DIRFULL
JMP xERROR
LOCATE ENDP
CODE ENDS
END LOCATE
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