***************************************************************** * * * FILE * * $VER: TrapStubs.asm 1.0 (11.04.95) * * * * DESCRIPTION * * A simple Stubs interface to call C functions from * * inside the Bus Error Trap ("segv") * * * * NOTES * * The most part of this Module was taken from * * "Enforcer/Enforcer.doc" by M.Sinz (only 68030 part is * * used and some of its parts have been commented out) * * See There for further notes. * * * * HISTORY * * 11-04-95 b_noll Created * * * ***************************************************************** * INCLUDE "EXEC/EXECBASE.I" * Needed for "ThisTask" * * xdef TrapData * xdef TrapVector * xdef TrapVector040 * * xdef _TrapData * xdef @TrapData * xdef _TrapVector * xdef @TrapVector * xdef _TrapVector040 * xdef @TrapVector040 * * xref _TrapCode * __asm __interrupt void TrapCode(void); * section text,code * ok let's go ... ; ; The following code is inserted into the bus error vector. ; Make sure you follow the VBR to find the vector. ; Store the old vector in the address OldVector ; Make sure you already have the single-step trap vector ; installed before you install this. Note that any extra ; code you add in the comment area *MUST NOT* cause a bus ; fault of any kind, including reading of location 4. ; ; This is the 68020 and 68030 version... ; ***************************************************************** * * * Variables are in CODE Area - Be Aware!!!!!!!! * * Resulting Executable MUST NOT be made Residentable * * * ***************************************************************** * TrapData: * @TrapData: * C Names for the data area _TrapData: * ***************************************************************** *EnforcerHit: ds.l 1 ; Some private flag *MyTask: ds.l 1 ; Task under test MyExecBase: ds.l 1 ; The local copy OldVector: ds.l 1 ; One long word ***************************************************************** * OwnVector: ds.l 1 * Our own C Routine ... InputTask: ds.l 1 * Don't change its Priority! RecentTask: ds.l 1 * This is the Task recently Hitting Active: ds.l 1 * Is Handler still active? CallingSSP: ds.l 1 * Where did we start from? * ds.l 32 * Some more Room for C variables usage * TrapVector: * _TrapVector: * C Names for the code area @TrapVector: * * NewVector: cmp.l #4,$10(sp) ; 68020 and 68030 beq.s TraceSkip ; If AbsExecBase, OK ; ; Now, if you wish to only trap a specific task, ; do the check at this point. For example, a ; simple single-task debugger would do something ; like this: move.l a0,-(sp) ; Save this... move.l MyExecBase(pc),a0 ; Get ExecBase... move.l ThisTask(a0),a0 ; Get ThisTask *cmp.l MyTask(pc),a0 ; Are they the same? *move.l (sp)+,a0 ; Restore A0 (no flags) *bne.s TraceSkip ; If not my task, skip ; ***************************************************************** * * * Stubs to call 'C' TraceCode * * (It's just I hate Assembler) * * * ***************************************************************** * cmp.l InputTask(PC),A0 *** We mustn't touch beq.s TaskSkip * "input.device" cmp.l RecentTask(PC),A0 * and we needn't touch beq.s TaskSkip * tasks, that are already move.l A0,RecentTask * marked Hitting move.l (SP)+,A0 * (we expect that at least bra.s CallC * after the next Switch TaskSkip: move.l (SP)+,A0 * this task is suspended bra.s TraceSkip * so we check only one task) * CallC: * move.l A7,CallingSSP *** Save Calling StackPtr * movem.l A0-A1/D0-D1,-(SP) *** Save Scratch Registers move.l Active(PC),D0 * before calling C Function beq.s InActive * * IFD USE_OwnVector * move.l OwnVector(PC),A0 *** Call C Function via cmp.l #0,A0 * TrapData.OwnVector beq.s NoVector * jsr (A0) * ELSE * bsr.w _TrapCode *** Call C Function directly ENDC * * InActive: * NoVector: movem.l (SP)+,A0-A1/D0-D1 *** Restore Regs * ****************************************************************** *bset.b #7,(sp) ; Set trace bit... ; If you have any other data to set, do it now... ; Set as setting the EnforcerHit bit in your data... *addq.l #1,EnforcerHit ; Count the hit... TraceSkip: move.l OldVector(pc),-(sp) ; Ready to return rts ; ; This is the 68040 version... ; ***************************************************************** * TrapVector040: * _TrapVector040: * C Names for the code area @TrapVector040: * * NewVector040: cmp.l #4,$14(sp) ; 68040 beq.s TraceSkip040 ; If AbsExecBase, OK ; ; Now, if you wish to only trap a specific task, ; do the check at this point. For example, a ; simple single-task debugger would do something ; like this: move.l a0,-(sp) ; Save this... move.l MyExecBase(pc),a0 ; Get ExecBase... move.l ThisTask(a0),a0 ; Get ThisTask *cmp.l MyTask(pc),a0 ; Are they the same? *move.l (sp)+,a0 ; Restore A0 (no flags) *bne.s TraceSkip ; If not my task, skip ; ***************************************************************** * * * This part has never been tested!!!!!!!!! * * * ***************************************************************** * cmp.l InputTask(PC),A0 *** We mustn't touch beq.s TaskSkip40 * "input.device" cmp.l RecentTask(PC),A0 * and we needn't touch beq.s TaskSkip40 * tasks, that are already move.l A0,RecentTask * marked Hitting move.l (SP)+,A0 * (we expect that at least bra.s CallC40 * after the next Switch TaskSkip40: move.l (SP)+,A0 * this task is suspended bra.s TraceSkip040 * so we check only one task) * CallC40: * move.l A7,CallingSSP *** Save Calling StackPtr * movem.l A0-A1/D0-D1,-(SP) *** Save Scratch Registers move.l Active(PC),D0 * before calling C Function beq.s InActive40 * * IFD USE_OwnVector * move.l OwnVector(PC),A0 *** Call C Function via cmp.l #0,A0 * TrapData.OwnVector beq.s NoVector40 * jsr (A0) * ELSE * bsr.w _TrapCode *** Call C Function directly ENDC * * InActive40: * NoVector40: movem.l (SP)+,A0-A1/D0-D1 *** Restore Regs * ****************************************************************** *bset.b #7,(sp) ; Set trace bit... ; If you have any other data to set, do it now... ; Set as setting the EnforcerHit bit in your data... *addq.l #1,EnforcerHit : Count the hit... ; TraceSkip040: move.l OldVector(pc),-(sp) ; Ready to return rts ***************************************************************** * * That's all folks ... 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