;-------------------------------------------------------------------- ; Multipart support for trackmos ; ; In my former demo system I used a6 as a base pointer to the demo ; framework and a4 as a pointer to my demo part variables. That ; seemed a bit wasteful and so the new system uses one pointer for ; both framework AND part variables for the current part. This, ; however, means that the framework base needs to be relocated ; depending on the part because, of course, the size of the ; local variables may vary. ; ; You must start your local variable space with ; ; STRUCTURE PartData,fw_SIZEOF ; ; and end it with ; ; LABEL pd_SIZEOF ; ;-------------------------------------------------------------------- ; Allocate the part variables ; ; The first thing each demo part needs to do is to call InitPart. ; I repeat: Start your code with: ; IFD FW_DEMO_PART ; move.l #pd_SIZEOF,d0 ; CALLFW InitPart ; ENDC ; ; Otherwise, no part variables are available via a6 and no other ; framework calls can be made (the jumping table is not available). ; ; After this call, a6 will be pointing to the new framework base ; with all your variable space cleared. ; ; Make sure that you don't free the memory allocated here until ; the end of your part! The demo framework will call ; RestoreFrameworkBase automatically at exit of your part. ; ; Flushes the caches (if available), too. ; ; In : d0 = pd_SIZEOF (part data structure size including fw_SIZEOF) ; Out: a6 = new base pointer ; Trashes: everything except a5/a6 ; fw_InitPart: PUTMSG 10,<"%d: InitPart(%ld)">,fw_FrameCounter-2(a6),d0 PUSHM d0 bsr fw_RestoreFrameworkBase POPM DISABLE_INTS move.l fw_PartFwBase(a6),a0 move.l d0,fw_PartDataSize(a6) add.l #-FWLVOPOS,d0 bsr fw_AllocFast lea -FWLVOPOS(a0),a1 PUTMSG 40,<"LVOs from %p to %p">,a1,a0 move.l a6,a0 move.l a6,a3 move.l a1,a6 move.w #(fw_SIZEOF/4)-1,d7 PUTMSG 40,<"Copying %d LW from %p to %p">,d7,a0,a1 .copynew move.l (a0)+,(a1)+ dbra d7,.copynew move.l a6,fw_PartFwBase(a6) move.l fw_PartDataSize(a6),d7 sub.l #fw_SIZEOF-3,d7 lsr.l #2,d7 beq.s .skipclr subq.w #1,d7 moveq.l #0,d0 .clrnew move.l d0,(a1)+ dbra d7,.clrnew .skipclr move.l a6,a0 lea fw_lvo_offsets(pc),a1 .lvoloop move.w (a1)+,d0 beq.s .lvodone lea -2(a1,d0.w),a2 move.l a2,-(a0) move.w #%0100111011111001,-(a0) ; $4ef9 jmp x.L bra.s .lvoloop .lvodone IF FW_MULTITASKING_SUPPORT ; The task list header is now broken after copying! We need to fix it. lea fw_Tasks(a6),a1 bsr fw_RelocateList bsr fw_FixA6BaseInTaskStacks ENDC lea fw_BasePtr(pc),a0 move.l a6,(a0) bsr fw_FlushCaches ENABLE_INTS PUTMSG 20,<"%d: InitPart done %p">,fw_FrameCounter-2(a6),a6 rts ;-------------------------------------------------------------------- ; Restore global framework base ; ; Removes the custom framework variable space and makes the global ; one active again. ; ; Out: a6 = new base pointer ; Trashes: everything except a5/a6 ; fw_RestoreFrameworkBase: PUTMSG 10,<"%d: RestoreFrameworkBase(%p)">,fw_FrameCounter-2(a6),a6 DISABLE_INTS move.l fw_PartFwBase(a6),a0 move.l fw_PrimaryFwBase(a6),a1 PUTMSG 40,<"Part %p, Primary %p">,a0,a1 cmp.l a1,a0 beq.s .noold move.l a0,a3 PUTMSG 40,<"Restore from %p to %p">,a0,a1 move.l a1,a6 move.w #(fw_SIZEOF/4)-1,d7 .copyold move.l (a0)+,(a1)+ dbra d7,.copyold IF FW_MULTITASKING_SUPPORT bsr fw_FixA6BaseInTaskStacks ENDC move.l a6,fw_PartFwBase(a6) clr.l fw_PartDataSize(a6) IF FW_MULTITASKING_SUPPORT ; The task list header is now broken after copying! We need to fix it. lea fw_Tasks(a6),a1 bsr.s fw_RelocateList ENDC lea fw_BasePtr(pc),a0 move.l a6,(a0) .noold ENABLE_INTS rts ;-------------------------------------------------------------------- ; Helper function to relocate a doubly-linked list ; ; When relocating the framework base structure, we need to fix the ; contents of lists, otherwise BadThings(TM) will happen. ; This function goes through the relocated list and fixes the linkage. ; ; In: a1 = ListHead ; Trashes: a0/a1 ; IF FW_MULTITASKING_SUPPORT fw_RelocateList: move.l LH_HEAD(a1),a0 subq.l #4,a0 cmp.l LH_TAILPRED(a1),a0 bne.s .nonewlist PUTMSG 10,<"Fixup empty list %p">,a1 move.l a1,LH_TAILPRED(a1) ; fix empty list addq.l #4,a1 move.l a1,-(a1) bra.s .listfixed .nonewlist PUTMSG 10,<"Fixup existing list %p">,a1 move.l a1,4+LN_PRED(a0) ; fixup LN_PRED of first node (points to LH_HEAD) move.l LH_TAILPRED(a1),a0 ; get last node addq.l #4,a1 ; now points to LH_TAIL move.l a1,LN_SUCC(a0) ; fixup LN_SUCC of last node (pointing to LH_TAIL) .listfixed rts ENDC ;-------------------------------------------------------------------- ; Running tasks will have the old framework base stored in their ; register context. We need to fix these occurrences. Note that ; this is not completely fool-proof, but should work for 99% of the ; cases (there shouldn't be framework-relative things). ; ; In: a3 = old base ; a6 = new base fw_FixA6BaseInTaskStacks: lea fw_Tasks(a3),a1 .loop TSTNODE a1,a1 beq.s .done move.l ft_USP(a1),a0 lea ft_StackEnd(a1),a2 .findloop cmp.l a0,a2 beq.s .loop cmp.l (a0),a3 bne.s .notmatched PUTMSG 10,<"Replacing base at %p">,a0 move.l a6,(a0) .notmatched addq.l #2,a0 bra.s .findloop .done rts fw_lvo_offsets: FWGENLVOTABLE SET 1 include "framework_lvos.i" dc.w 0 FWGENLVOTABLE SET 0