; Copyright 1996 Acorn Computers Ltd
;
; Licensed under the Apache License, Version 2.0 (the "License");
; you may not use this file except in compliance with the License.
; You may obtain a copy of the License at
;
; http://www.apache.org/licenses/LICENSE-2.0
;
; Unless required by applicable law or agreed to in writing, software
; distributed under the License is distributed on an "AS IS" BASIS,
; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
; See the License for the specific language governing permissions and
; limitations under the License.
;
TTL => NewIRQs
; *****************************************************************************
;
; Main IRQ routine:
; Push workregs,lr
; IRQsema -> TOS
; stack -> IRQsema
; call IRQ1V
; IRQs off
; TOS ->IRQsema
; process callback, pulling workregs,pc at some point
;
; *****************************************************************************
Initial_IRQ_Code ROUT
SUB lr, lr, #4
Push "r0-r3, r11, r12, lr"
; ** For Pete's sake remember to change the heap manager if you change the above
; ** register list!!!!!!! And the [sp_irq, #4*6] below
[ IRQSTK - 7*4 :AND: 15 <> 0
! 0,"IRQ STM/LDM making extra S cycle into N"
]
[ CPU_Type = "ARM600"
BIC pc, pc, #&FC000000 ; get back out of shadow ROM
NOP ; (this instruction skipped)
mrs AL, r0, SPSR_all ; r0 = saved PSR
AND r1, r0, #I32_bit + F32_bit ; r1 = caller I&F flags, in ARM6 place
ORR lr, lr, r1, LSL #IF32_26Shift ; put IF in place
AND r1, r0, #&F0000003 ; r1 = caller NZCV and mode bits
ORR lr, lr, r1 ; lr = 26 bit style return addr + PSR
STR lr, [sp_irq, #4*6] ; store back into stack
BIC r0, r0, #&1F ; clear out foreground mode bits
ORR r0, r0, #I32_bit + IRQ26_mode ; force IRQ_26 mode and I_bit set
msr AL, CPSR_all, r0
]
MOV r12, #0
LDR r0, [r12, #IRQsema]
Push r0
STR sp_irq, [r12, #IRQsema]
MOV lr, pc
LDR pc, [r12, #IRQ1V]
; IRQ1V called with r0-r3,r11,r12 trashable. r12=0
; Stu has a theory that 1N cycle can be saved by the default IRQ1V pointing
; at a location containing a branch to our code; we then do something like
; LDR R0, [R12, #IRQ1V]
; CMP R0, #OurIRQ1V
; BNE somebodysonIRQ1V
; .... fall into default IRQ1V code
MOV r11, #0
Pull r0
STR r0, [r11, #IRQsema]
LDRB r11, [r11, #CallBack_Flag]
CMP r11, #0
Pull "r0-r3, r11, r12, pc", EQ, ^
TST r11, #CBack_Postpone
LDREQ lr, [sp_irq, #4*6]
TSTEQ lr, #SVC_mode :OR: I_bit
Pull "r0-r3, r11, r12, pc", NE, ^
; Do a CallBack: asked for, not postponed, and we're returning into user mode.
Pull "r0-r3, r11, r12"
TEQP pc, #SVC_mode
MOVNV r0, r0
Push "r10-r12"
TEQP pc, #IRQ_mode
MOVNV r0, r0
Pull "r12" ; lr really
TEQP pc, #SVC_mode
MOVNV r0, r0
MOV lr, r12
MOV r10, #0
LDRB r11, [r10, #CallBack_Flag]
B Do_CallBack
LTORG
; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
; Default IRQ1V: despatch on interrupting device
; Now copied to RAM, together with vector entries and device tables
DefaultIRQ1Vcode ROUT
[ IO_Type = "IOMD"
MOV r3, #IOC ; base for IOC and IOMD
LDRB r0, [r3, #IOMD_DMAREQ]
TEQ r0, #0
ADRNE r1, IrqDMADevnos
LDREQB r0, [r3, #IOCIRQREQB] ; if not DMA then assume IRQB until we know otherwise
ADREQ r1, IrqReqBDevnos
[ MorrisSupport
;>>>RCM Says should we use separate Morris specific code, cos Morris doesn't support
;>>>RCM all IOMD_DMAREQ bits and non Morris machines don't have IOMD_IRQRQD.
;>>>RCM Look at use of NoInterrupt.
TEQEQ r0, #0
LDREQB r0, [r3, #IOMD_IRQRQD]
ADREQ r1, IrqReqDDevnos
]
TEQEQ r0, #0
LDREQB r0, [r3, #IOCIRQREQA] ; not DMA and not IRQB so assume IRQA
ADREQ r1, IrqReqADevnos
LDRB r0, [r1, r0] ; pick up offset in device despatcher
ADD r1, pc, r0, LSL #2 ; so table contains DevNo * 3
LDMIA r1, {r12, pc}
|
MOV r3, #IOC
LDRB r0, [r3, #IOCIRQREQB]
CMP r0, #0
LDREQB r0, [r3, #IOCIRQREQA]
ADREQ r1, IrqReqADevnos
ADRNE r1, IrqReqBDevnos
LDRB r0, [r1, r0] ; pick up offset in device despatcher
ADD r1, pc, r0, LSL #2 ; so table contains DevNo * 3
LDMIA r1, {r12, pc}
]
; ******* IRQ device handlers entered with r0-r3,r11,r12,r14 trashable *******
; r3 -> IOC
; r12 = what they asked for
; r14 = return address to MOS IRQ exit sequence
[ IO_Type = "IOMD"
[ MorrisSupport
NoInterrupt * 27 ; Morris has IOMD's extra interrupts plus 5 of its own
|
NoInterrupt * 22 ; IOMD has 6 more interrupts for DMA
]
|
NoInterrupt * 16 ; internal devno; when ReqA = 0!
]
Devices
; Register A devices
; pbusy handler
& 0 ; R12 value
& IRQ ; call address
& 0 ; link
; ringing handler
& 0
& IRQ
& 0
; printer acknowledge
[ DriversInKernel
& OsbyteVars
& PrinterIRQ
& 0
|
& 0
& IRQ
& 0
]
; vsync handler
& OsbyteVars
& VsyncIRQ
& 0
; power on reset: this can't happen, but call IRQ2V if it does.
& 0
& IRQ
& 0
; timer0
& OsbyteVars
& TickOne
& 0
; timer1
& 0
& IRQ
& 0
; FIQ downgrade
& 0
& IRQ
& 0
; register B devices
; PFIQ downgrade
& PFIQasIRQ_Chain - (PodDesp_Link-PodDesp_R12Val)
& PFIQasIRQ_Despatch
& 0
; sound
& 0
& IRQ
& 0
; serial
[ DriversInKernel
& OsbyteVars
& RS423IRQ
& 0
|
& 0
& IRQ
& 0
]
; winnie IRQ
& 0
& IRQ
& 0
; Disc changed
& 0
& IRQ
& 0
; podule IRQ
& PIRQ_Chain - (PodDesp_Link-PodDesp_R12Val)
& PIRQ_Despatch
& 0
; serial TX (Keyboard serial transmit register empty)
& IOC
[ Keyboard_Type = "A1A500"
& IrqTx
|
& IRQ
]
& 0
; serial RX (Keyboard serial receive register full)
& IOC
[ Keyboard_Type = "A1A500"
& IrqRx
|
& IRQ
]
& 0
[ IO_Type = "IOMD"
; IOMD DMA devices
; DMA channel 0
& 0
& IRQ
& 0
; DMA channel 1
& 0
& IRQ
& 0
; DMA channel 2
& 0
& IRQ
& 0
; DMA channel 3
& 0
& IRQ
& 0
; Sound DMA channel 0
& 0
& IRQ
& 0
; Sound DMA channel 1
& 0
& IRQ
& 0
]
[ MorrisSupport
; register D devices
; Mouse port Rx full
& IOC
& IRQ
& 0
; Mouse port Tx empty
& IOC
& IRQ
& 0
; AtoD (Joystick)
& 0
& IRQ
& 0
; Nevent1
& 0
& IRQ
& 0
; Nevent2
& 0
& IRQ
& 0
]
; Neither A or B is interrupting, which is impossible: just call IRQ2V anyway
& 0
& IRQ
& 0
; Following tables encode the priority of the devices within each register
GBLA DTabC
DTabC SETA 1
; generic IRQA bits
IrqReqAPrio0 * por_bit
IrqReqADev0 * PowerOn_DevNo
IrqReqAPrio2 * pbusy_bit
IrqReqADev2 * PrinterBusy_DevNo
IrqReqAPrio4 * timer1_bit
IrqReqADev4 * Timer1_DevNo
IrqReqAPrio5 * vsync_bit
IrqReqADev5 * VSync_DevNo
IrqReqAPrio6 * timer0_bit
IrqReqADev6 * Timer0_DevNo
IrqReqAPrio7 * force_bit
IrqReqADev7 * FIQDowngrade_DevNo
; Machine specific IRQB bits
[ IO_Type = "IOC-A1" :LOR: IO_Type = "IOC-A500"
IrqReqAPrio1 * ring_bit
IrqReqADev1 * Ringing_DevNo
IrqReqAPrio3 * pack_bit
IrqReqADev3 * PrinterAck_DevNo
]
[ IO_Type = "IOEB"
IrqReqAPrio1 * IOEB_battery_low_bit
IrqReqADev1 * Ringing_DevNo
IrqReqAPrio3 * IOEB_floppy_index_bit
IrqReqADev3 * PrinterAck_DevNo
]
[ IO_Type = "IOMD"
IrqReqAPrio1 * 1:SHL:1 ; not used
IrqReqADev1 * Ringing_DevNo
IrqReqAPrio3 * IOMD_floppy_index_bit
IrqReqADev3 * PrinterAck_DevNo
]
IrqReqADevnos
= NoInterrupt*3
WHILE DTabC <256
[ (DTabC:AND:IrqReqAPrio7)<>0
= IrqReqADev7*3
|
[ (DTabC:AND:IrqReqAPrio6)<>0
= IrqReqADev6*3
|
[ (DTabC:AND:IrqReqAPrio5)<>0
= IrqReqADev5*3
|
[ (DTabC:AND:IrqReqAPrio4)<>0
= IrqReqADev4*3
|
[ (DTabC:AND:IrqReqAPrio3)<>0
= IrqReqADev3*3
|
[ (DTabC:AND:IrqReqAPrio2)<>0
= IrqReqADev2*3
|
[ (DTabC:AND:IrqReqAPrio1)<>0
= IrqReqADev1*3
|
[ (DTabC:AND:IrqReqAPrio0)<>0
= IrqReqADev0*3
]
]
]
]
]
]
]
]
DTabC SETA DTabC+1
WEND
; generic IRQB bits
IrqReqBPrio2 * podule_FIQ_as_IRQ_bit
IrqReqBDev2 * PFIQasIRQ_DevNo
IrqReqBPrio3 * serial_Tx_bit
IrqReqBDev3 * SerialTx_DevNo
IrqReqBPrio4 * serial_Rx_bit
IrqReqBDev4 * SerialRx_DevNo
IrqReqBPrio5 * podule_IRQ_bit
IrqReqBDev5 * Podule_DevNo
IrqReqBPrio7 * serial_bit
IrqReqBDev7 * Serial_DevNo
; Machine specific IRQB bits
[ IO_Type = "IOC-A500"
IrqReqBPrio0 * 0
IrqReqBDev0 * NoInterrupt
IrqReqBPrio1 * sound_IRQ_bit
IrqReqBDev1 * Sound_DevNo
IrqReqBPrio6 * winnie_IRQ_bit :OR: winnie_DRQ_bit
IrqReqBDev6 * WinnieIRQ_DevNo
]
[ IO_Type = "IOC-A1"
IrqReqBPrio0 * winnie_DRQ_bit
IrqReqBDev0 * DiscChanged_DevNo
IrqReqBPrio1 * sound_IRQ_bit
IrqReqBDev1 * Sound_DevNo
IrqReqBPrio6 * winnie_IRQ_bit
IrqReqBDev6 * WinnieIRQ_DevNo
]
[ IO_Type = "IOEB"
IrqReqBPrio0 * IOEB_ide_IRQ_bit
IrqReqBDev0 * DiscChanged_DevNo
IrqReqBPrio1 * IOEB_sound_IRQ_bit
IrqReqBDev1 * Sound_DevNo
IrqReqBPrio6 * IOEB_floppy_IRQ_bit
IrqReqBDev6 * WinnieIRQ_DevNo
]
[ IO_Type = "IOMD"
IrqReqBPrio0 * IOMD_floppy_IRQ_bit
IrqReqBDev0 * DiscChanged_DevNo
IrqReqBPrio1 * IOMD_HardDisc_IRQ_bit
IrqReqBDev1 * Sound_DevNo
IrqReqBPrio6 * IOMD_Network_IRQ_bit
IrqReqBDev6 * WinnieIRQ_DevNo
]
DTabC SETA 1
IrqReqBDevnos
= NoInterrupt*3
WHILE DTabC <256
[ (DTabC:AND:IrqReqBPrio7)<>0
= IrqReqBDev7*3
|
[ (DTabC:AND:IrqReqBPrio6)<>0
= IrqReqBDev6*3
|
[ (DTabC:AND:IrqReqBPrio5)<>0
= IrqReqBDev5*3
|
[ (DTabC:AND:IrqReqBPrio4)<>0
= IrqReqBDev4*3
|
[ (DTabC:AND:IrqReqBPrio3)<>0
= IrqReqBDev3*3
|
[ (DTabC:AND:IrqReqBPrio2)<>0
= IrqReqBDev2*3
|
[ (DTabC:AND:IrqReqBPrio1)<>0
= IrqReqBDev1*3
|
[ (DTabC:AND:IrqReqBPrio0)<>0
= IrqReqBDev0*3
]
]
]
]
]
]
]
]
DTabC SETA DTabC+1
WEND
[ IO_Type = "IOMD"
; Prioritised IOMD DMA device numbers
IrqDMAPrio0 * 1:SHL:5
IrqDMADev0 * IOMD_DMASound1_DevNo
IrqDMAPrio1 * 1:SHL:4
IrqDMADev1 * IOMD_DMASound0_DevNo
IrqDMAPrio2 * 1:SHL:3
IrqDMADev2 * IOMD_DMAChannel3_DevNo
IrqDMAPrio3 * 1:SHL:2
IrqDMADev3 * IOMD_DMAChannel2_DevNo
IrqDMAPrio4 * 1:SHL:1
IrqDMADev4 * IOMD_DMAChannel1_DevNo
IrqDMAPrio5 * 1:SHL:0
IrqDMADev5 * IOMD_DMAChannel0_DevNo
DTabC SETA 1
IrqDMADevnos
= NoInterrupt*3
; Top 2 bits are always 0 so table need only be 64 bytes
WHILE DTabC <64
[ (DTabC:AND:IrqDMAPrio5)<>0
= IrqDMADev5*3
|
[ (DTabC:AND:IrqDMAPrio4)<>0
= IrqDMADev4*3
|
[ (DTabC:AND:IrqDMAPrio3)<>0
= IrqDMADev3*3
|
[ (DTabC:AND:IrqDMAPrio2)<>0
= IrqDMADev2*3
|
[ (DTabC:AND:IrqDMAPrio1)<>0
= IrqDMADev1*3
|
[ (DTabC:AND:IrqDMAPrio0)<>0
= IrqDMADev0*3
]
]
]
]
]
]
DTabC SETA DTabC+1
WEND
]
[ MorrisSupport
; Prioritised IRQD device numbers
IrqReqDPrio0 * 1:SHL:4
IrqReqDDev0 * IOMD_Event2_DevNo
IrqReqDPrio1 * 1:SHL:3
IrqReqDDev1 * IOMD_Event1_DevNo
IrqReqDPrio2 * 1:SHL:2
IrqReqDDev2 * IOMD_AtoD_DevNo
IrqReqDPrio3 * 1:SHL:1
IrqReqDDev3 * IOMD_MouseTxEmpty_DevNo
IrqReqDPrio4 * 1:SHL:0
IrqReqDDev4 * IOMD_MouseRxFull_DevNo
DTabC SETA 1
IrqReqDDevnos
= NoInterrupt*3
; Top 3 bits are always 0 so table need only be 32 bytes
WHILE DTabC <32
[ (DTabC:AND:IrqReqDPrio4)<>0
= IrqReqDDev4*3
|
[ (DTabC:AND:IrqReqDPrio3)<>0
= IrqReqDDev3*3
|
[ (DTabC:AND:IrqReqDPrio2)<>0
= IrqReqDDev2*3
|
[ (DTabC:AND:IrqReqDPrio1)<>0
= IrqReqDDev1*3
|
[ (DTabC:AND:IrqReqDPrio0)<>0
= IrqReqDDev0*3
]
]
]
]
]
DTabC SETA DTabC+1
WEND
]
DefaultIRQ1Vcode_end
ASSERT DefaultIRQ1Vcode_end - DefaultIRQ1Vcode <= DefIRQ1Vspace
; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
; Specialist despatchers for podules
^ 0
PodDesp_Address # 4 ; address of IRQ status byte
PodDesp_Mask # 4 ; for use on above
PodDesp_R12Val # 4
PodDesp_CallAddr # 4 ; address to call if ?Address AND Mask <> 0
PodDesp_Link # 4 ; next node
PodDesp_NodeSize # 0
[ True
; In r12 = PFIQasIRQ_Chain - (PodDesp_Link-PodDesp_R12Val)
; or PIRQ_Chain - (PodDesp_Link-PodDesp_R12Val) from despatcher
PFIQasIRQ_Despatch ROUT
PIRQ_Despatch ; All the same thing now
|
PFIQasIRQ_Despatch ROUT
LDR r12, =PFIQasIRQ_Chain - (PodDesp_Link-PodDesp_R12Val)
B %FT01
PIRQ_Despatch ; NOROUT
LDR r12, =PIRQ_Chain - (PodDesp_Link-PodDesp_R12Val)
]
01 LDR r12, [r12, #PodDesp_Link-PodDesp_R12Val]
LDMIA r12!, {r1, r2} ; address and mask
[ Fix11
; TMD 09-Jun-89: Don't corrupt r0 - it's needed by the default IRQ2 routine
LDRB r1, [r1]
ANDS r1, r1, r2
|
LDRB r0, [r1]
ANDS r0, r0, r2
]
BEQ %BT01
LDMIA r12, {r12, pc}
Default_PIRQHandler_Node
Default_PFIQasIRQHandler_Node
& .+4 ; address we know has non-zero value!
& -1 ; mask
& 0 ; handler r12
& IRQ ; handler code
& 0 ; null link for naff release checking
; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
; Claim of device vectors
; r0 = Device number
; r1 = call address
; r2 = r12 value
; r0 = PFIQ|PIRQ devno -> r3 = interrupt location
; r4 = interrupt mask
DeviceVector_Claim ROUT
Push "r0-r3, lr"
01 SWI XOS_ReleaseDeviceVector ; Release until bored
BVC %BT01
LDR r0, [sp]
CMP r0, #NoInterrupt
BGE DV_Fail_NaffDevNo
CMP r0, #Podule_DevNo
CMPNE r0, #PFIQasIRQ_DevNo
BEQ PoduleChainClaim
MOV r3, #12
BL ClaimSysHeapNode
BVS DV_Exit
LDR r0, [sp]
ADD r0, r0, r0, LSL #1 ; *3
LDR r1, =DefaultIRQ1V-DefaultIRQ1Vcode+Devices
ADD r1, r1, r0, LSL #2
TEQP pc, #SVC_mode+I_bit ; IRQs off for update
LDMIA r1, {r0, r3, r10}
STMIA r2, {r0, r3, r10} ; copy current head into node
LDR r10, [sp, #4*2] ; r12 value
LDR r11, [sp, #4*1] ; call address
MOV r12, r2
STMIA r1, {r10-r12} ; copy given info into head
DV_Exit STRVS r0, [sp] ; Common exit for both claim + release
Pull "r0-r3, lr"
B SLVK_TestV
DV_Fail_NaffDevNo
ADR r0, ErrorBlock_NaffDevNo
[ International
BL TranslateError
|
SETV
]
B DV_Exit
MakeErrorBlock NaffDevNo
PoduleChainClaim
MOV r3, #PodDesp_NodeSize
BL ClaimSysHeapNode
BVS DV_Exit
MOV r10, r2
LDMFD sp, {r0-r3}
STR r1, [r10, #PodDesp_CallAddr]
STR r2, [r10, #PodDesp_R12Val]
STR r3, [r10, #PodDesp_Address]
STR r4, [r10, #PodDesp_Mask]
CMP r0, #Podule_DevNo
LDREQ r0, =PIRQ_Chain
LDRNE r0, =PFIQasIRQ_Chain
TEQP pc, #SVC_mode+I_bit ; IRQs off for update
LDR r1, [r0]
STR r1, [r10, #PodDesp_Link]
STR r10, [r0]
B DV_Exit
; .............................................................................
; Release of device vectors
; r0 = Device number
; r1 = call address
; r2 = r12 value
; r0 = PFIQ|PIRQ devno -> r3 = interrupt location (LDRB always used)
; r4 = interrupt mask
DeviceVector_Release ROUT
Push "r0-r3, lr" ; Ensure same regset as above
CMP r0, #NoInterrupt
BGE DV_Fail_NaffDevNo
TEQP pc, #SVC_mode + I_bit ; IRQs off while holding context
CMP r0, #Podule_DevNo
CMPNE r0, #PFIQasIRQ_DevNo
BEQ PoduleChainRelease
ADD r0, r0, r0, LSL #1 ; *3
LDR r12, =DefaultIRQ1V-DefaultIRQ1Vcode+Devices
ADD r12, r12, r0, LSL #2 ; address of node
MOV r11, #-1 ; "fudge" predecessor node
01 LDMIA r12, {r3, r10}
CMP r3, r2
CMPEQ r10, r1
BEQ %FT02 ; found it
MOV r11, r12
LDR r12, [r12, #8] ; get the link
CMP r12, #0
BNE %BT01
11 ADR r0, ErrorBlock_BadDevVecRel
[ International
BL TranslateError
|
SETV
]
B DV_Exit
MakeErrorBlock BadDevVecRel
02 CMP r11, #-1
BEQ %FT03
MOV r2, r12
LDR r12, [r2, #8]
STR r12, [r11, #8] ; node delinked
B %FT04
03 LDR r2, [r12, #8] ; freeable = nextnode
LDMIA r2, {r0, r1, r3} ; copy next node into head posn
STMIA r12, {r0, r1, r3}
04
BL FreeSysHeapNode ; free block
B DV_Exit
PoduleChainRelease
CMP r0, #Podule_DevNo
LDREQ r0, =PIRQ_Chain-PodDesp_Link
LDRNE r0, =PFIQasIRQ_Chain-PodDesp_Link
10 LDR r12, [r0, #PodDesp_Link]
CMP r12, #0
BEQ %BT11
LDR r11, [r12, #PodDesp_Address]
CMP r11, r3
LDREQ r11, [r12, #PodDesp_Mask]
CMPEQ r11, r4
LDREQ r11, [r12, #PodDesp_CallAddr]
CMPEQ r11, r1
LDREQ r11, [r12, #PodDesp_R12Val]
CMPEQ r11, r2
MOVNE r0, r12
BNE %BT10
LDR r11, [r12, #PodDesp_Link]
STR r11, [r0, #PodDesp_Link]
MOV r2, r12
B %BT04
; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
; Default device owner for IRQ not recognised by system: pass to IRQ2V
IRQ ROUT
Push "r10, lr"
[ False
ASSERT VIDC_Type <> "VIDC20"
MOV r14, #11
MUL r14, r0, r14
MOV r14, r14, LSR #5
ADR r10, irq_vtable
LDR r14, [r10, r14, LSL #2]
MOV r10, #VIDC
STR r14, [r10]
]
MOV r10, #IrqV
BL CallVector
Pull "r10, pc" ; return: someone will always claim it.
[ False
irq_vtable
DCD &40000000 + &444
DCD &40000000 + &008
DCD &40000000 + &080
DCD &40000000 + &088
DCD &40000000 + &800
DCD &40000000 + &808
DCD &40000000 + &880
DCD &40000000 + &FA8
DCD &40000000 + &8AF
DCD &40000000 + &00F
DCD &40000000 + &0F0
DCD &40000000 + &0FF
DCD &40000000 + &F00
DCD &40000000 + &F0F
DCD &40000000 + &FF0
DCD &40000000 + &FFF
]
; *****************************************************************************
; Default IRQ2V:
; r0 must still have devno*3 in it
; r12 is 0 (from vector)
; Clear mask, clear IRQ as appropriate/possible
; NB. a cheap way of dividing by ~3 is *11,/32: accurate for 0..31 result ...
NOIRQ ROUT
[ False
ASSERT VIDC_Type <> "VIDC20"
MOV r14, #11
MUL r14, r0, r14
MOV r14, r14, LSR #5
ADR r10, irq_vtable
LDR r14, [r10, r14, LSL #2]
MOV r10, #VIDC
STR r14, [r10]
]
01 SUBS r0, r0, #3
ADDGE r12, r12, #1
BGT %BT01 ; r12 := r0 DIV 3
[ MorrisSupport
; RCM 31-Jan-95 fix MED-04355, need to cope with interrupts from new Morris register
CMP R12, #IOMD_MouseRxFull_DevNo
SUBHS R12, R12, #IOMD_MouseRxFull_DevNo ;reduce to bit number 0..7
MOVHS R0, #IOMD_IRQMSKD ; in IRQ D interrupt register
BHS %FT03
]
; ** TMD 14-Feb-94 - insert code here to fix MED-02859
; ** Old code did not cope with the DMA case here
[ IO_Type = "IOMD"
CMP r12, #16 ; check if a DMA device
BCC %FT02 ; it's not, so skip
SUB r12, r12, #16 ; convert to a bit number in mask
MOV r1, #1
MOV r1, r1, LSL r12 ; convert to bit mask
LDR r0, =IOC+IOMD_DMAMSK ; point at mask register
LDRB r12, [r0] ; load mask
BIC r12, r12, r1 ; knock out bit
STRB r12, [r0] ; store back
Pull pc,,^ ; and exit, claiming vector
02
]
; ** end of insertion
CMP r12, #8
MOVGE r0, #IOCIRQMSKB
SUBGE r12, r12, #8
MOVLT r0, #IOCIRQMSKA
[ MorrisSupport
03
]
ADD r0, r0, #IOC
MOV r1, #1
MOV r1, r1, LSL r12 ; bit to clear
[ :LNOT: NewClockChip ; fudge winnieDRQ on A500
CMP r1, #winnie_IRQ_bit
CMPEQ r0, #IOCIRQMSKB
ORREQ r1, r1, #winnie_DRQ_bit ; turn both off.
]
MOV lr, pc
TEQP pc, #IRQ_mode+I_bit+F_bit
LDRB r12, [r0] ; FIQs off for updating IOCIRQMSKA
BIC r12, r12, r1
STRB r12, [r0] ; relevant IRQ disabled
TEQP lr, #0 ; absolute minimum FIQ disable period
STRB r1, [r0, #IOCIRQCLRA-IOCIRQMSKA] ; Clear IRQ
Pull pc,,^ ; claim vector
; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
; The following bits have been appropriated from source.pmf.oseven to make
; sure Tim's old code doesn't overwrite us when he gets back!
; SWI OS_GenerateEvent: call event vector if enabled
GenEvent ROUT
Push lr
TEQP pc, #SVC_mode+I_bit ; Disable IRQs. MUST call these ones
BL OSEVEN ; in SVC mode as people expect it
Pull lr
B SLVK
; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
; Subroutine call version
; In r0 = event type
; r1,r2 parameters
; Out C=0 => event was enabled, or was >= 32 anyway
; C=1 => event was disabled, so vector not called
OSEVEN ROUT
Push lr
CMP r0, #31 ; Events >= 32 are ALWAYS raised. SKS
; flags are HI if so, ie. NE
LDRLSB r14, [r0, #OsbyteVars + :INDEX: EventSemaphores]
; get semaphore for this event 0..31
CMPLS r14, #0 ; non-zero => enabled
Pull pc, EQ ; if disabled, exit with C=1
Push "r0-r3, r10-r12" ; r3 excessive ???
MOV r10, #EventV ; call event vector
BL CallVector
CLC ; indicate event enabled
Pull "r0-r3, r10-r12, pc"
; ...................... default owner of EventV ..............................
; Call Event handler
; In r12 = EvtHan_ws
DefEvent ROUT
MOV lr, pc ; link with all the bits
LDMIA r12, {r12, pc} ; call EventHandler, returns to ...
TEQ r12, #1
Pull pc,NE,^
LDRB r14, [r12, #CallBack_Flag-1] ; IRQs are still disabled
ORR r14, r14, #CBack_OldStyle
STRB r14, [r12, #CallBack_Flag-1]
Pull pc,,^ ; claim EventV
; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
; Process timer zero IRQ device (100Hz clock)
; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
TickOne ROUT
Push r14
MOV R0, #timer0_bit
STRB R0, [R3, #IOCIRQCLRA] ; clear timer 0 interrupt
LDRB R0, CentiCounter ; Counter for VDU CTRL timing
SUBS R0, R0, #1
STRCSB R0, CentiCounter ; decrement if not zero
LDR R0, IntervalTimer +0
ADDS R0, R0, #1 ; Increment the low 4 bytes
STR R0, IntervalTimer +0
LDREQB R0, IntervalTimer +4
ADDEQ R0, R0, #1 ; and carry into 5th byte if necessary
STREQB R0, IntervalTimer +4
Push "R4,R12" ; R0-R3 already pushed
TEQEQ R0, #&100 ; has interval timer crossed zero ?
MOVEQ R0, #Event_IntervalTimer ; Event ITCZ
BLEQ OSEVEN
BL CentiSecondTick ; Notify keyboard of a centisecond
Pull "R4,R12"
[ :LNOT: NewClockChip
LDRB R1, SecondsDirty
TEQ R1, #0 ; if seconds dirty
BNE %FT10 ; we haven't synced yet
]
LDR R0, RealTime +0 ; Increment 5-byte real time
ADDS R0, R0, #1
STR R0, RealTime +0
LDRCSB R0, RealTime +4
ADDCS R0, R0, #1 ; Won't wrap until 2248 and then it
STRCSB R0, RealTime +4 ; all falls over anyway
[ :LNOT: NewClockChip
LDRB R0, CentiTime
ADD R0, R0, #1
TEQ R0, #100
MOVEQ R0, #0
STRB R0, CentiTime
LDRB R0, SecondsTime
ADDEQ R0, R0, #1 ; increment only if wrap from centisecs
TEQEQ R0, #60
MOVEQ R0, #0
STRB R0, SecondsTime
B NoTickThisTime ; don't do dirty code
10
LDRB R0, MinTick
MOV R1, #IOC
LDRB R3, [R1, #IOCControl] ; IOC control register
AND R3, R3, #rtc_minutes_bit
TEQ R3, R0 ; Look for transition
BEQ NoTickThisTime
TEQ R3, #rtc_minutes_bit ; from zero to one = minute!!!
STRB R3, MinTick ; One to zero = 30 seconds
MOV R0, #0
STRB R0, SecondsDirty ; Mark the seconds as OK now !
STRB R0, CentiTime ; When the minutes tick, ZERO the centiseconds!
MOVEQ R0, #30
STRB R0, SecondsTime ; And set the seconds to 0 or 30 !
LDR R0, =ticksperminute ; get offset for 1 minute (60 secs)
MOVEQ R0, R0, LSR #1 ; halve it if 30 second tick
LDR R1, RealTime +0
ADDS R1, R1, R0
STR R1, RealTime +0
LDRCSB R1, RealTime +4
ADDCS R1, R1, #1
STRCSB R1, RealTime +4
NoTickThisTime
]
LDRB R0, TimerState ; get switch state
TEQ R0, #5 ; toggles between 5 and 10
LDREQ R1, TimerAlpha +0 ; either load from one
LDREQB R2, TimerAlpha +4
LDRNE R1, TimerBeta +0 ; or the other
LDRNEB R2, TimerBeta +4
ADREQ R3, TimerBeta +0 ; and point to t'other
ADRNE R3, TimerAlpha +0
ADDS R1, R1, #1 ; increment
ADC R2, R2, #0 ; with carry
STR R1, [R3] ; and store back
STRB R2, [R3, #4]
EOR R0, R0, #&0F ; 5 <-> 10
STRB R0, TimerState
Push R10
[ TickIrqReenter
MOV R10, #TickerV ; call 100Hz vector
BL CallVector ; IRQ's still disabled
BL ProcessTickEventChain ; Re-enables IRQs
|
BL ProcessTickEventChain
MOV R10, #TickerV ; call 100Hz vector
BL CallVector
]
Pull "R10,PC"
; ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
; Process VSync IRQ device
; ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
VsyncIRQ ROUT
Push r14
MOV R0, #vsync_bit
STRB R0, [R3, #IOCIRQCLRA] ; Clear the vsync interrupt
LDRB R0, CFStime ; decrement 'CFS' timer !
SUB R0, R0, #1
STRB R0, CFStime
VDWS WsPtr ; Do our stuff before issuing VSYNC event
BL VsyncCall
BYTEWS WsPtr
MOV R0, #Event_VSync ; VSYNC event number
BL OSEVEN
LDRB R1, FlashCount
SUBS R1, R1, #1
Pull PC, CC ; was zero, so frozen
STRNEB R1, FlashCount ; else if now non-zero, store it back
Pull PC, NE ; not time to flash yet
LDRB R1, FlashState ; Get the state and
EORS R1, R1, #1 ; flip to the other one (setting flags)
STRB R1, FlashState
LDREQB R2, SpacPeriod ; get appropriate new period
LDRNEB R2, MarkPeriod
STRB R2, FlashCount ; and put into counter
VDWS WsPtr
Push R4
BEQ dothesecondflash
dothefirstflash
BL DoFirstFlash
Pull "R4, PC"
dothesecondflash
BL DoSecondFlash
Pull "R4, PC"
; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
END