; ; UnixDir.asm (c) 1988 Software Dimensions. ; ______ ; / /\ All Rights Reserved ; /_____/ |\ Written by Murray Bennett and Mark Cyster ; |\ |\ /| Software Dimensions ; | \/__|_\/ | 6th Floor, 239 Adelaide Tce ; |__| | | Perth WA 6000 ; \ | 4 | / Australia ; \|_____|/ ; BBS:(In Australia !??) ; ;---------------------------------------------------------------------------- ; This material is Copyright (C) 1988 and 1989 Software Dimensions. ; It may be distributed freely as long as the following restrictions are met: ; ; 1. All files present in the distribution package must be redistributed ; with the package. If you distribute on diskette, all files must be ; on a single diskette. ; Files in this distribution are listed in FILES.LIST ; ; 2. The distributor agrees to cease distributing the programs and data ; involved if requested to do so by authors or any member of The ; Software Distillery. ; ; DISCLAIMER ; ; Neither Software Dimensions nor any of its members will be liable for ; any damage arising from the failure of this program to perform as described, ; or any destruction of other programs or data residing on a system ; attempting to run the program. While we know of no damaging errors, the ; user of this program uses it at his or her own risk. ; ; DONATIONS ; ; Welcome (but we realise it's a long way to Australia). ; ;---------------------------------------------------------------------------- ; ; Date 27-2-89 ; ; This is the loader part of UnixDirs ; ; This stub simply loads L:UnixDirs-Handler into ; memory and modifies the appropriate DOS calls ; so we get called ; ; Note: It makes assumptions about the format of the loaded segment ; ; ; This program SetFunction's the following DOS library vectors : ; ; CreateDir ; DeleteFile ; LoadSeg ; Lock ; Open ; Rename ; SetComment ; SetProtection ; ; Note: The DOS library jump table is not in the statndard EXEC library ; format. ; moveq FunctionNum,d0 $70 'FunctionNum'(8 Bit) total = 2 Bytes ; bra.l DOSFunction $6000 'DosFunction'(16 Bit) total = 4 Bytes ; ;---------------------------------------------------------------------------- NOLIST INCLUDE "UnixDirs.i" LIST xref _LVOAlert xref _LVOCloseLibrary xref _LVOForbid xref _LVOLoadSeg xref _LVOOpenLibrary xref _LVOOutput xref _LVOPermit xref _LVOSetFunction xref _LVOUnLoadSeg xref _LVOWrite ; replaced functions xref _LVOCreateDir xref _LVODeleteFile xref _LVOLoadSeg xref _LVOLock xref _LVOOpen xref _LVORename xref _LVOSetComment xref _LVOSetProtection MoveqNumD0 equ $70 ; ; Places the old DOS function number in UnixTable (the passed parameters) ; or jumps to ErrorBadDOSFormat if library not in DOS format ; GET_OLD_NUM MACRO move.l #_LVO\1,d0 bsr GetDOSNum bne ErrorBadDOSFormat move.l d0,\1Num(TableBase) ENDM ; ; Replaces the old DOS jump vector with a jump to the new routine ; REPL_OLD_FUNC MACRO ; Replaces DOS function \1 move.l #_LVO\1,d1 ; DBPrint <'Replacing dos function \1'> lea.l \1JumpInst+UnixTable_Sizeof(TableBase),a0 bsr ReplaceDOSFunction ENDM ; ****** ; start ; ****** ArpBase equr a5 TableBase equr a3 ; Points to top of Passed Parameters ; ; RESIDENT 2000 STARTUP ; ; open arp library lea.l ArpLibrary,a1 move.l #ArpVersion,d0 move.l AbsExecBase,a6 LINKEXEC OpenLibrary tst.l d0 beq NoArpExit move.l d0,ArpBase ; arp library open - everything OK ; ; load 'handler' lea.l handler,a0 move.l a0,d1 move.l DosBase(ArpBase),a6 LINKDOS LoadSeg BTOC d0 beq LoadHandlerError add.l #SegmentStart_Sizeof,d0 ; Handler loaded successfully move.l d0,TableBase move.l ArpBase,SaveArpBase(TableBase) ; Save ArpBase ; ; Forbid - as we don't want anyone changing the DOS jump table ; or using it while we change it move.l AbsExecBase,a6 LINKEXEC Forbid ; ; All DOS functions jump to the same function so first we ; get a pointer to this function and keep it ; ; The DOS table doesn't have the standard format jump table ; but it's own peculiar format : ; moveq FunctionNum,d0 $70 'FunctionNum'(8 Bit) total = 2 Bytes ; bra.l DOSFunction $6000 'DosFunction'(16 Bit) total = 4 Bytes ; ; ; Get and Pass (to 'handler') pointer to the 'DOSFunction' move.l DosBase(ArpBase),a0 add.l #_LVOLoadSeg,a0 ; Any dos function will do move.w 4(a0),d0 ; Get 'DOSFunction' lea.l 4(a0,d0.w),a0 ; jmp val - jumps from end of jump instruction (before val) move.l a0,DOSFunction(TableBase) ; ; Save DOS function call numbers in UnixTable ; Don't modify yet - first check all are in DOS format ; if not exit -> allows for easier cleanup move.l DosBase(ArpBase),a0 GET_OLD_NUM CreateDir GET_OLD_NUM DeleteFile GET_OLD_NUM LoadSeg GET_OLD_NUM Lock GET_OLD_NUM Open GET_OLD_NUM Rename GET_OLD_NUM SetComment GET_OLD_NUM SetProtection REPL_OLD_FUNC CreateDir REPL_OLD_FUNC DeleteFile REPL_OLD_FUNC LoadSeg REPL_OLD_FUNC Lock REPL_OLD_FUNC Open REPL_OLD_FUNC Rename REPL_OLD_FUNC SetComment REPL_OLD_FUNC SetProtection ; ; Permit CleanUp1 move.l AbsExecBase,a6 LINKEXEC Permit ; Display a message to say that everything went OK lea.l InstalledOKMessage,a1 move.l ArpBase,a6 LINKARP Puts ; ; Exit with return code 0 move.l #0,d0 ; ; end - with arp ; exit move.l ArpBase,a6 move.l #0,d1 move.l #0,d2 LINKARP ArpExit rts ; ; Dos Library already modified ErrorBadDOSFormat lea.l BadLibraryFormat,a1 move.l ArpBase,a6 LINKARP Puts bsr UnloadSegment move.l #5,d0 bra exit ; ; Unload the loaded handler because of an error ; condition. ; CPTR to handler is TableBase - SegmentStart_Sizeof ; UnloadSegment move.l TableBase,d1 sub.l #SegmentStart_Sizeof,d1 CTOB d1 move.l DosBase(ArpBase),a6 LINKDOS UnLoadSeg rts ; ; unable to load 'handler' ; LoadHandlerError lea.l LoadError,a1 move.l ArpBase,a6 LINKARP Puts move.l #10,d0 bra exit ; ; end - without arp ; NoArpExit ;exec base is still in a6 lea.l DOSLibrary,a1 moveq #0,d0 ;version unimportant LINKEXEC OpenLibrary tst.l d0 beq BadExit move.l d0,a6 ;DOSBase LINKDOS Output move.l d0,d1 lea.l NoArp,a0 move.l a0,d2 move.l #(NoArpEnd-NoArp),d3 LINKDOS Write move.l a6,a1 ;Closing dos.library move.l AbsExecBase,a6 LINKEXEC CloseLibrary DosExit move.l #20,d0 rts ; ; couldn't even find DOS ; BadExit ALERT (AG_OpenLib|AO_DOSLib) bra DosExit ; ****** ; OldNum = GetDOSNum(_LVOffset,DosBase) ; d0 d0 a0 ; ; Where OldNum is the value passed in d0 to the 'DosFunction' ; when you call the specific DOS routine at the ; '_LVOffset' you pass ; - if the jump table is in non DOS format we fail ; and return with the Z-flag set ; (which it will be if we are already implemented) ; ****** GetDOSNum move.b (a0,d0),d1 move.b 1(a0,d0),d0 ext.w d0 ext.l d0 cmp.b #MoveqNumD0,d1 rts ; ****** ; OldBranchInstruction = ReplaceDOSFunction(_LVOffset,NewFunction) ; d0 d1 a0 ; ; ****** ReplaceDOSFunction move.l DosBase(ArpBase),a1 ; library = DosBase move.l a0,d0 ; New function move.l d1,a0 ; offset move.l AbsExecBase,a6 ; Exec call LINKEXEC SetFunction rts ; ; DSEG DOSLibrary DOSNAME NoArp dc.b 'Can',$27,'t open ' ArpLibrary ArpName dc.b 10,13 NoArpEnd LoadError dc.b 'Unable to load ' handler dc.b 'L:UnixDirs-Handler',0 OutOfMem dc.b 'Out of memory',0 BadLibraryFormat dc.b 'The DOS library jump table has already been modified',0 InstalledOKMessage dc.b 'UnixDirs Installed',0 end