mac-rom/ProcessMgr/Switch.a
Elliot Nunn 4325cdcc78 Bring in CubeE sources
Resource forks are included only for .rsrc files. These are DeRezzed into their data fork. 'ckid' resources, from the Projector VCS, are not included.

The Tools directory, containing mostly junk, is also excluded.
2017-12-26 09:52:23 +08:00

449 lines
16 KiB
Plaintext

;
; File: Switch.a
;
; Contains: Assembler support routines required for process switching.
;
; Written by: Erich Ringewald
;
; Copyright: © 1986-1992 by Apple Computer, Inc., all rights reserved.
;
; Change History (most recent first):
;
; <8> 10/28/92 DTY It turns out that going through the trap dispatcher is really
; expensive, so go back to calling the BlockMove routine directly.
; However, set up D1 with the BlockMoveData trap word so that the
; cache doesnÕt get flushed. Add a conditional compile so that
; _BlockMove is used when building PsychicTV, so the emulator can
; still catch BlockMove.
; <7> 10/27/92 DTY Call BlockMoveData through the dispatcher instead of calling the
; BlockMove routine directly. This gets us two wins: 1) If we
; run under GaryÕs emulator, BlockMove is done natively. 2) On
; 68K machines, the cache wonÕt get flushed because we call
; BlockMoveData.
; <6> 3/22/91 DFH csd,#85216: DonÕt disable interrupts while neutralizing VBL
; tasks, because it leaves interrupts off too long. Instead, set
; the inVBL bit to keep the vertical retrace code from messing
; with the queue.
; <5> 1/14/91 DFH (JDR) Conditionalize out AUX support.
; <3> 12/14/90 DFH SwitchAllRegs now is careful to restore the SR before the SP.
; This is so things go smoothly when restoring the SR transitions
; us between supervisor and user modes.
; <2> 12/5/90 DFH Integrated AUX support.
; <0> x/xx/86 ELR New Today.
;
;--------------------------------------------------------------------
CASE OBJECT
LOAD 'ProcessMgrIncludes.D'
INCLUDE 'data.a'
SEG 'kernel_segment'
;-------------------------------------------------------------------------------
; void InitializeProcess. The first code that a process ever executes.
InitializeProcess PROC EXPORT
IMPORT BeginApplication:CODE
jsr BeginApplication ; initialize TB & OS
rts
ENDPROC ; InitializeProcess
;-------------------------------------------------------------------------------
; void FPInit(void)
; Clear out the initial FPU state for this process
FPInit PROC EXPORT
MC68881 ; using the damn FPU!
moveq.l #0,d0
move.l d0,-(sp) ; push null state frame
frestore (sp)+ ; and use it to reset FPU state
rts
ENDPROC ; FPInit
;-------------------------------------------------------------------------------
;
; SwitchAllRegs. This is the machine level context switch routine. It is preferred
; over SwitchCPURegs when a Floating Point Unit (FPU) is present. pOldSP points to the
; stack where the current application's machine context should be saved. pNewSP points
; the stack where the incoming application's machine context is stored.
; Call:
;
; void SwitchAllRegs(StackPtr pOldSP, StackPtr pNewSP);
;
SwitchAllRegs PROC EXPORT
IMPORT SwitchCPURegs:CODE
SaveRegs REG d0/d1 ; working registers
SaveRegsSize EQU 2*4
pOldSP EQU 4+SaveRegsSize ; first parameter
pNewSP EQU 8+SaveRegsSize ; second parameter
MC68881 ; using the damn FPU!
movem.l SaveRegs,-(sp) ; save working registers
move.l pOldSP(sp),d0 ; address of old save area
move.l pNewSP(sp),d1 ; address of new save area
; save the floating point registers of the outgoing process
fsave -(sp) ; save fpu context
tst.b (sp) ; need user regs?
beq.s FPRegsSaved ; nope
fmovem fp0-fp7,-(sp) ; save data regs
fmovem fpcr/fpsr/fpiar,-(sp) ; and control
st -(sp) ; push 'full' flag
FPRegsSaved
; switch the regular CPU regs (in new process after this call!)
move.l d1,-(sp) ; pass new area for SwitchCPURegs
move.l d0,-(sp) ; pass old area for SwitchCPURegs
jsr SwitchCPURegs ; go context switch
addq #8,sp ; skip these parameters
; restore floating point registers of incoming process
tst.b (sp) ; check for null or not-null
beq.s FPUserRegsOK ; no user areas
addq.l #2,sp ; throw away not-null flag
fmovem (sp)+,fpcr/fpsr/fpiar ; restore part of user FP regs
fmovem (sp)+,fp0-fp7 ; restore remainder
FPUserRegsOK
frestore (sp)+ ; restore normal FP regs
movem.l (sp)+,SaveRegs ; restore working registers
rts
ENDPROC ; SwitchAllRegs
;__________________________________________________________________________________
;
; SwitchCPURegs. This is the machine level context switch routine. It is preferred
; over SwitchAllRegs when a Floating Point Unit (FPU) is *not* present. pOldSP points
; to the stack where the current application's machine context should be saved. pNewSP
; points the stack where the incoming application's machine context is stored.
; Call:
;
; void SwitchCPURegs(StackPtr pOldSP, StackPtr pNewSP);
;
pOldSP EQU 4 ; first parameter
pNewSP EQU 8 ; second parameter
RegsToSwitch REG d2-d7/a2-a6 ; regs that we need to switch
SizeOfRegSwitch EQU (11*4) + 2 ; bytes in RegsToSwitch and sr
SwitchCPURegs PROC EXPORT
; save old state on the old stack (PC is already there, from JSR to this routine)
move.l pOldSP(sp),a0 ; get ptr to PEntry->p_sp from stack
move sr,-(sp) ; save old sr
movem.l RegsToSwitch,-(sp) ; save old regs
cmpa #0,a0 ; have place to save resulting sp?
beq.s noSave ; jump if not
move.l sp,(a0) ; save old sp into PEntry
noSave
; set new stack pointer, then the rest of the registers (PC restored via RTS)
move.l SizeOfRegSwitch+pNewSP(sp),a0 ; get new guy's sp
movem.l (a0)+,RegsToSwitch ; set up his saved regs
move.w (a0)+,sr ; restore his sr
movea.l a0,sp ; restore stack ptr after sr
rts ; and return (to new process)
ENDPROC ; SwitchCPURegs
;__________________________________________________________________________________
; disable. Turn off interrupts except for the NMI. Return the interrupt level that
; we wiped. spl is our buddy.
disable PROC EXPORT
moveq #0,d0
move sr,d0 ; get current priority
lsr #8,d0 ; shift into low bytes
andi #7,d0 ; mask trace/supervisor
ori #$0700,sr ; force to level 7
rts
ENDPROC ; disable
;__________________________________________________________________________________
; spl. Set the CPU interrupt level to the given value. Companion of disable.
spl PROC EXPORT
move sr,d0 ; get current setting
move 6(sp),d1 ; get desired level
lsl #8,d1 ; up into top byte
andi #$F8FF,d0 ; down to level 0
or d1,d0 ; set our level bits
move d0,sr ; this is our new sr
rts
ENDPROC ; spl
;__________________________________________________________________________________
; AtomicVBLSave. Neutralizes VBLs whose routine address is located between lowAddr and
; highAddr. Saves restoration information in specified handle. Does this with
; interrupts off so that we're not fouled up by VBLs that alter the VBL queue.
; Call:
;
; void AtomicVBLSave(Handle saveArea, unsigned long lowAddr, unsigned long highAddr);
;
AtomicVBLSave PROC EXPORT
IMPORT disable, spl, dummyvbl:CODE
IF (&TYPE('HAS_AUX_PROCESSMGR') <> 'UNDEFINED') THEN
IMPORT AUXIsPresent:DATA
ENDIF
SaveRegs REG a2-a3 ; registers we need to save and restore
SaveRegSize EQU 2*4 ; size of registers we save on stack
saveArea EQU 4+SaveRegSize ; first parameter
lowAddr EQU 8+SaveRegSize ; second parameter
highAddr EQU 12+SaveRegSize ; third parameter
movem.l SaveRegs,-(sp) ; save regs we use
bset.b #inVBL, qFlags+VBLQueue ; we own the queue now
movea.l lowAddr(sp),a2 ; get low end of range
movea.l highAddr(sp),a3 ; get high end of range
movea.l qHead+VBLQueue,a1 ; get address of first VBL
move.l sp,d2 ; remember stack pointer
; first -- loop to neutralize VBLs, saving their state on the stack (temporarily)
infoLoop
move.l a1,d0 ; all done?
beq.s saveInfo ; jump if so
move.l vblAddr(a1),d0 ; get routine address
_StripAddress ; strip it!
cmp.l d0,a2 ; is it above the base?
bhi.s nextVBL ; jump if not
cmp.l d0,a3 ; is it below the bound?
IF (&TYPE('HAS_AUX_PROCESSMGR') <> 'UNDEFINED') THEN
bhi.s saveVBL ; jump if so, switch this VBL
; VBLs owned by AUX coffs can also be above PhysMemTop
tst.w AUXIsPresent ; running under AUX?
beq.s nextVBL ; if not, check is not valid
cmp.l PhysMemTop,d0 ; is VBL address above PhysMemTop?
bcs.s nextVBL ; if not, VBL needn't be switched
ELSE
bls.s nextVBL ; if not, VBL needn't be switched
ENDIF
; save info in format of a VBLDesc
saveVBL
move.w vblCount(a1),-(sp) ; save count
move.l vblAddr(a1),-(sp) ; save (unstripped) routine address
move.l a1,-(sp) ; save VBL address
; neutralize this VBL
move #$7FFF,vblCount(a1) ; VERY large count
lea dummyvbl,a0 ; address of dummy VBL
move.l a0,vblAddr(a1) ; route VBL there
nextVBL
movea.l vblink(a1),a1 ; move to next VBL
bra.s infoLoop ; and repeat
; second - copy VBL state info into the handle
saveInfo
bclr.b #inVBL, qFlags+VBLQueue ; free the queue for use
movea.l d2,a1 ; get original stack pointer
movea.l saveArea(a1),a0 ; get the handle
move.l d2,d0 ; original stack pointer
sub.l sp,d0 ; size we'll need
move.l d0,d1 ; save it for block move
_SetHandleSize ; adjust the size
bne.s leaveNow ; jump if it didn't work
move.l d1,d0 ; (count) size we'll need
beq.s leaveNow ; jump if we found nothing
movea.l saveArea(a1),a1 ; get the handle
movea.l (a1),a1 ; (destination) get pointer heap block
movea.l sp,a0 ; (source) get pointer to stacked info
_BlockMoveData ; copy the data
; cleanup up and leave
leaveNow
move.l d2,sp ; restore stack pointer
movem.l (sp)+,SaveRegs ; restore regs we used
rts
ENDPROC ; AtomicVBLSave
; dummyvbl. The routine address we stuff in a VBL descriptor that belongs to
; a switched out process. Just resets the counter. This keeps the VBL around.
dummyvbl PROC EXPORT
move #$7FFF,vblCount(a0) ; reset the swapped out vbl.
rts
ENDPROC ; dummyvbl
;__________________________________________________________________________________
; save_lmemtab. Copy the switchable lomem into a safe area.
save_lmemtab PROC EXPORT
IMPORT (switchTabPtr, blockTrapAddr):DATA
SaveRegs REG a2-a4/d1-d2
SaveRegSize EQU 5*4
movem.l SaveRegs,-(sp) ; save work registers
move.l SaveRegSize+4(sp),a4 ; get pointer to PCB storage
move.l switchTabPtr,a2 ; set up ptr to switch tab
move.l blockTrapAddr,a3
; major loop - save all the ranges of lomem we care about
SaveAllLoop
moveq.l #0,d0 ; because _BlockMove takes a longword
move.w (a2)+,d0 ; get length word
beq.s AllSaved ; 0 terminates table
move.l (a2)+,a0 ; get address longword
IF (&TYPE('SWITCH_MEMBLOCKS') <> 'UNDEFINED') THEN
; support for saving contents of handles or pointers -- not needed!!
; NOTE: What if handle is purged??
bclr #15,d0 ; clear top bit
beq.s SaveRange ; branch if wasn't already set
move.l (a0),a0 ; deref once for ptr
bclr #14,d0 ; clear next bit
beq.s SavePtrBlock ; branch if wasn't already set
move.l (a0),a0 ; deref again for handle
tst.w d0 ; is count known?
bne.s SaveRange ; if so, go do it
_GetHandleSize ; set d0 to switch entire handle
bra.s SaveRange ; and go do transfer
SavePtrBlock
tst.w d0 ; is count known?
bne.s SaveRange ; if so, go do it
_GetPtrSize ; set d0 to switch entire ptr
SaveRange
ENDIF
; have source, count, and destination -- decide whether to call BlockMove or to do it by hand
cmp.w #FastBMSize,d0 ; enough for _BlockMove to be efficient?
bge.s UseBlockMove ; if so, branch
; minor loop -- move the bytes ourselves, since it'll be faster than BlockMove
subq.w #1,d0 ; alias it to zero-based
SaveOneLoop
move.b (a0)+,(a4)+ ; move the byte
dbra d0,SaveOneLoop ; and loop
bra.s SaveAllLoop ; now get next entry
; call _BlockMove, since it's faster for larger chunks
;
; <8> Going through the trap dispatcher is more expensive than I thought. Go back
; to calling the BlockMove routine directly. However, set up D1 so that the caches
; still donÕt get flushed. We still want to call the trap for PsychicTV however, so
; that the emulator can do itÕs native BlockMove.
UseBlockMove
move.l a4,a1 ; a1 = destination
add.l d0,a4 ; update our storage address
if not(PsychicTV) then
move.w #$A22E,d1 ; <8>
jsr (a3)
else
_BlockMove ; <8>
endif
bra.s SaveAllLoop ; now get next entry
; cleanup and leave
AllSaved
movem.l (sp)+,SaveRegs ; restore work registers
rts
ENDPROC ; save_lmemtab
;__________________________________________________________________________________
; restore_lmemtab. Copy the saved switchable lomem back into lomem.
restore_lmemtab PROC EXPORT
IMPORT (switchTabPtr, blockTrapAddr):DATA
SaveRegs REG a2-a4/d1-d2
SaveRegSize EQU 5*4
movem.l SaveRegs,-(sp) ; save work registers
move.l SaveRegSize+4(sp),a4 ; get pointer to PCB storage
move.l switchTabPtr,a2 ; set up dest register
move.l blockTrapAddr,a3
; major loop - restore all the ranges of lomem we care about
RestoreAllLoop
moveq.l #0,d0 ; because _BlockMove takes a longword
move.w (a2)+,d0 ; get length word
beq.s AllRestored ; 0 terminates table
move.l (a2)+,a1 ; get address longword
IF (&TYPE('SWITCH_MEMBLOCKS') <> 'UNDEFINED') THEN
; support for saving contents of handles or pointers -- not needed!!
; NOTE: What if handle is purged??
bclr #15,d0 ; clear top bit
beq.s RestoreRange ; branch if wasn't already set
move.l (a1),a1 ; deref once for ptr
bclr #14,d0 ; clear next bit
beq.s RestorePtrBlock ; branch if wasn't already set
move.l (a1),a1 ; deref again for hdl
tst.w d0 ; is it 0?
bne.s RestoreRange ; if not done
_GetHandleSize
bra.s RestoreRange ; and go do transfer
RestorePtrBlock
tst.w d0 ; is it 0?
bne.s RestoreRange ; if not done
_GetPtrSize
RestoreRange
ENDIF
; have source, count, and destination -- decide whether to call BlockMove or to do it by hand
cmp.w #FastBMSize,d0 ; is it big enough to use _BlockMove?
bge.s UseBlockMove ; if so, branch
; minor loop -- move the bytes ourselves, since it'll be faster than BlockMove
subq.w #1,d0 ; alias it to zero-based
RestoreOneLoop
move.b (a4)+,(a1)+ ; move the byte
dbra d0,RestoreOneLoop ; and loop
bra.s RestoreAllLoop ; now get next entry
; call _BlockMove, since it's faster for larger chunks
;
; <8> Going through the trap dispatcher is more expensive than I thought. Go back
; to calling the BlockMove routine directly. However, set up D1 so that the caches
; still donÕt get flushed. We still want to call the trap for PsychicTV however, so
; that the emulator can do itÕs native BlockMove.
;
UseBlockMove
move.l a4,a0 ; setup source pointer for blockmove
add d0,a4 ; and increment pointer by count
if not(PsychicTV) then
move.w #$A22E,d1 ; <8>
jsr (a3)
else
_BlockMove ; <8>
endif
bra.s RestoreAllLoop ; now get next entry
; cleanup and leave
AllRestored
movem.l (sp)+,SaveRegs ; restore work registers
rts
ENDPROC ; restore_lmemtab
END