NewReset

; 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.
;
        SUBT    => NewReset

; DuffEntry is the address of "Nowhere"
;  - there should never be any page actually mapped to this address (L2PT entry always 0)
;  - a page that is not mapped in should always have this special address in its CAM entry,
;    ie. should only be one Nowhere
;
 [ HAL32
DuffEntry *     &FAFF8000
 |
DuffEntry *     &01F08000
 ]

Nowhere * DuffEntry  ; synonym


SoftReset       * 0                     ; Reset types
PowerOnReset    * 1
ControlReset    * 2

; CMOS RAM resetting stuff:
CMOSLimit       * &F0

; Keyboard flags
                ^ 1
 [ HAL
KbdScanActive   # 1
                # 2
KbdFlags        # 4
 |
CTRL_Down_Flag  # 1
SHIFT_Down_Flag # 1
KB_There_Flag   # 1

R_Down_Flag     # 1      ; note that these 4 form one word!!
T_Down_Flag     # 1
Del_Down_Flag   # 1
Copy_Down_Flag  # 1

KeyDataPtr      # 4

Port2Present    # 1      ; note that these 4 form one word!!
Port3Present    # 1
KeyState        # 1
KeyMSB          # 1
 ]

; On ARM600, InitIRQWs is in zero page - check it's big enough

        ASSERT  @ <= ?InitIRQWs


;       AddCamEntries
;
; in:   r0 -> appropriate part of CAM map
;       r1 = ap (+ CB bits in new world)
;       r2 = log address
;       r7 = amount of cam map to do
;       r8 = PageSize
;
; out:  r0, r3-r12 preserved
;       r1 corrupted
;       r2 updated by relevant amount

AddCamEntries ROUT
        Push    "r0, lr"
        MOV     lr, r1                  ; access privs (PPL)
        MOV     r1, r7
01
        STMIA   r0!, {r2, lr}           ; store logaddr, PPL
        ADD     r2, r2, r8              ; increment address by 1 page
        SUBS    r1, r1, #8              ; decrement count of how much to do
        BNE     %BT01
        Pull    "r0, pc"

; GetConfiguredSize - convert CMOS address into amount of memory
; in:   r0 = CMOS address
; out:  r0 corrupted
;       r2 = amount in bytes

; NB this routine doesn't do screen size mangling (yet!)

GetConfiguredSize Entry "r1"
        LDR     r1, =ZeroPage
        LDR     r1, [r1, #Page_Size]
        ADRL    lr, PageShifts-1
        LDRB    r1, [lr, r1, LSR #12]   ; r1 = log2 pagesize
        MOV     r2, #127                ; mask of value

        TEQ     r0, #FontCMOS           ; if fontsize
        MOVEQ   r1, #12                 ; then in units of 4K, not pagesize
        MOVEQ   r2, #255                ; and use full byte

        BL      Read                    ; read CMOS ram
        AND     r2, r0, r2              ; value anded with mask
        MOV     r2, r2, LSL r1          ; and shifted up accordingly
        EXIT

FudgeConfigureRMA
        Push   lr
        B      ConfigureRMA

ReadCMOSAndConfigure ROUT
; R0 = index into CMOS RAM of byte with size in
; R1 = place to save amount moved
; R2 = CAM entry number to start at: updated
; R3 = LogRam Address to move memory to
; r11  PPL
; Check for memory left, move as much as poss
        Push    lr
        BL      Read                    ; CMOS byte -> R0

        AND     R0, R0, #127            ; mask to same bitfield as status
ConfigureRMA
        LDR     R10, =ZeroPage
        LDR     R10, [R10, #Page_Size]
        MUL     R0, R10, R0             ; get size in bytes
        MOV     R5, #0                  ; amount moved
        CMP     R0, #0
        BEQ     NoMoreMemory

 [ GetPagesFromFreePool

; r0 = amount of memory to move
; r1 = address to store size in
; (r2 = page number to start at, ignored in our method)
; r3 = address of where to put memory
; r10 = page size
; r11 = ap + CB

        LDR     r4, =ZeroPage+FreePoolDANode
        MOV     r6, r11                         ; r6 = ap + CB
        LDR     r7, [r4, #DANode_Base]
        LDR     r8, [r4, #DANode_Size]
        ADD     r7, r7, r8                      ; r7 -> end of free pool +1
10
        CMP     r8, r10                         ; if no free memory left
        BCC     %FT20                           ; then tidy up
        SUB     r7, r7, r10                     ; move free pool pointer backwards
        Push    "r0, r1"
        MOV     r0, r7
        MOV     r1, r3
        BL      MovePageAtR0ToR1WithAccessR6
        Pull    "r0, r1"
        ADD     r3, r3, r10                     ; advance "to" pointer
        SUB     r8, r8, r10                     ; one less page of free memory
        ADD     r5, r5, r10                     ; one more page done
        SUBS    r0, r0, r10
        BNE     %BT10
20
        STR     r8, [r4, #DANode_Size]
 |
        LDR     R7, =ZeroPage
        LDR     R8, [R7, #RAMLIMIT]

; now set R6 = first entry not to use
;         R7 = end of gap   "   "  "
;         R8 = last entry we can use

        LDR     r6, [r7, #VideoSize]            ; find out how many pages in video area
;        MOV     r7, #0
        MOV     r6, r6, LSR #12                 ; = page number of start of skipped bit
        ASSERT  SoftCamMapSize = L2PTSize +4
        MOV     r7, #L2PTSize
        LDMIA   r7, {r7, lr}                    ; r7 = L2PTSize, lr = SoftCamMapSize
        ADD     r7, r7, lr                      ; add sizes together
        ADD     r7, r7, #StaticPagesSize + UndStackSize ; + number of bytes used for other static bits
        ADD     r7, r6, r7, LSR #12             ; r7 = page number after static bit
        MOV     r8, r8, LSR #12                 ; make r8 into highest page number+1

CAMZapLoop
        CMP     R2, R6                  ; if at gap, skip
        MOVEQ   R2, R7
        CMP     R2, R8                  ; if no more memory, give in
        BEQ     NoMoreMemory
        ADD     R5, R5, R10
        Push    "R0, R1, R6"
        BL      BangCamUpdate
        Pull    "R0, R1, R6"
        ADD     R2, R2, #1
        ADD     R3, R3, R10
        SUBS    R0, R0, R10
        BGT     CAMZapLoop
 ]
NoMoreMemory
        STR     R5, [R1]
        Pull    "PC"

; MassageScreenSize - called from ReadCMOSAndConfigure (above) and also from
; ReadSysInfo

MassageScreenSize ROUT
        Push    lr
        LDR     lr, =ZeroPage
        LDR     lr, [lr, #VRAMFlags]
        TST     lr, #2
        LDRNE   lr, =ZeroPage
        LDRNE   r0, [lr, #VideoSize]
        Pull    pc, NE

        CMP     r0, #0
        BNE     CmosScreenWillDo
      [ ZeroPage <> 0
        LDR     r0, =ZeroPage
      ]
        LDR     r0, [r0, #RAMLIMIT]
        CMP     r0, #512*1024
        MOVEQ   r0, #80*1024
        MOVNE   r0, #160*1024
CmosScreenWillDo
        CMP     r0, #20*1024            ; ensure mode 0 gettable
        ADDCC   r0, r0, r10             ; if not, then add another page
        BCC     CmosScreenWillDo
        CMP     r0, #ScreenMaxSize
        MOVHI   r0, #ScreenMaxSize
        Pull    pc

        LTORG

  [ HAL
    ! 0, "*** DUMMY CONT_Break, soft breaks/resets will not work yet with HAL"
CONT_Break
        AddressHAL
        MOV     a1, #1
        LDR     a2, =L1PT
        CallHAL HAL_Reset
  ]


  [ :LNOT: HAL

; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
; Data tables: VIDC := mode 0, all palette black

VIDCTAB

; Program Control Register first, to clear power-down bit
; Now depending upon the VIDCClockSource flag, re-program the clock source.
   [ VIDCClockSource = "VCO"
     [ VCOstartfix
        & &E0000404     ; CR: FIFO load 16 words, 1 bpp, ck/2, vclk (allow for doubled VCO freq)
     |
        & &E0000400     ; CR: FIFO load 16 words, 1 bpp, ck/1, vclk
     ]
   ]
   [ VIDCClockSource = "HCLK"
        & &E0000401     ; CR: FIFO load 16 words, 1 bpp, ck/1, hclk
   ]
   [ VIDCClockSource = "RCLK"
        & &E0000406     ; CR: FIFO load 16 words, 1 bpp, ck/2, rclk
   ]

; Don't bother programming all 256 palette entries, we'll be here all night
; Since we're setting up a 1 bit-per-pixel mode, just do colours 0 and 1

        & &10000000     ; Palette address register = 0
        & &00000000     ; Colour 0 = black
        & &00000000     ; Colour 1 = black
        & &40000000     ; Border colour = black
        & &50000000     ; Pointer colour 1 = black
        & &60000000     ; Pointer colour 2 = black
        & &70000000     ; Pointer colour 3 = black

; Get a stable display up so we get stable signals

        & &800003F8     ; HCR  = 76 + 88 + 96 + 640 + 96 + 28
        & &81000044     ; HSWR = 76
        & &82000098     ; HBSR = 76 + 88
        & &830000F2     ; HDSR = 76 + 88 + 96
        & &84000372     ; HDER = 76 + 88 + 96 + 640
        & &850003D8     ; HBER = 76 + 88 + 96 + 640 + 96
        & &860000F3     ; HCSR = HDSR

        & &90000137     ; VCR  = 3 + 19 + 16 + 256 + 16 + 2
        & &91000002     ; VSWR = 3
        & &92000015     ; VBSR = 3 + 19
        & &93000025     ; VDSR = 3 + 19 + 16
        & &94000125     ; VDER = 3 + 19 + 16 + 256
        & &95000135     ; VBER = 3 + 19 + 16 + 256 + 16
        & &96000025     ; VCSR = VDSR
        & &97000025     ; VCER = VDSR

        & &B1000001     ; SCR: sound disabled (+use 24MHz clock)

        & &C00F1003     ; EREG = comp sync, DACs on, ereg output ext lut
   [ VCOstartfix
        & &D0000302     ; FSYNREG, clk = (3+1)/(2+1) * 24MHz = 32MHz  (higher frequency as part of fix)
   |
        & &D0000305     ; FSYNREG, clk = (3+1)/(5+1) * 24MHz = 16MHz
   ]
        & &F0013000     ; DCR: bus D[31:0], Hdisc       ;RCM 29/9/94: changed from &F0012000 at PSwindells request
        & &FFFFFFFF     ; That's the lot


VIDCPhys        *       &03400000       ; used to address VIDC when MMU is off


; Entered here after RESET (or BREAK)

; This code must be capable of being executed at a non-ROM address and with the MMU off,
; and running in 32-bit mode up until the call to MemSize.

CONT_Break
        MOV     r1, #1          ; parameter passed to InitMEMC, to indicate Break not Reset
        B       Continue

CONT    ROUT
        MOV     r1, #0          ; parameter passed to InitMEMC, to indicate Reset not Break
Continue

; First bang MEMC to ensure safety

        BL      InitMEMC        ; initialise MEMC CR, and turn off MMU if it's on

; VInit etc set on ze mode change: no DMA going yet so don't set owt.

        MOV     R1, #VIDCPhys   ; Must ALWAYS initialise VIDC on reset or else
        ADR     R2, VIDCTAB     ; we may get vsync interrupts that stiff us
10      LDR     R0, [R2], #4    ; permanently as VIDC is in an undefined state
        CMP     R0, #-1         ; so have mode 0 with all black palette
        STRNE   R0, [R1]
        BNE     %BT10

; Now bang IOC (disable all but keyboard interrupts)

        MOV     R1, #IOC
        MOV     R0, #&FF                ; all inputs
        STRB    R0, [R1, #IOCControl]   ; in case called by Tim

        MOV     R0, #0
        STRB    R0, [R1, #IOCIRQMSKA]   ; kein interrupts
        STRB    R0, [R1, #IOCFIQMSK]    ; disable FIQs
        STRB    R0, [R1, #IOMD_DMAMSK]  ; disable DMA interrupts, too
        STRB    R0, [R1, #IOMD_IRQMSKC] ; and the rest...
        STRB    R0, [R1, #IOMD_IRQMSKD]

  [ Keyboard_Type = "A1A500" :LOR: Keyboard_Type = "PC"
        MOV     R0, #KARTRxBit          ; used for Archi keyboard or IOMD PC keyboard
  ]
        STRB    R0, [R1, #IOCIRQMSKB]   ; allow communication with kbd, when I_bit gets cleared

; now bits to allow CMOS read/write : need timer

        LDR     R0, =20000-1    ; R0 = Timer delay (units of 0.5 microsecond)
                                ; 20000*0.5E-6 = 0.01 Seconds (100Hz ticker)
                                ; TMD 21-May-93: "-1" correction applied

        STRB    R0, [R1, #Timer0LL]     ; Set up the delay
        MOV     R0, R0, LSR #8
        STRB    R0, [R1, #Timer0LH]
        STRB    R0, [R1, #Timer0GO]     ; and start the ticks

        MOV     R0, #timer0_bit
        STRB    R0, [R1, #IOCIRQCLRA]   ; Clear pending t0 interrupt j.i.c.

  [ VCOstartfix
        ;2nd part of fix for VCO failing to start on A7000 (esp. 7500FE) - forcing PCOMP high for about 3 ms
        LDRB    R0, [R1,#IOMD_ID0]
        CMP     R0, #&E7
        LDREQB  R0, [R1,#IOMD_ID1]
        CMPEQ   R0, #&D4
        BEQ     vcofix_notMorris      ; risky to force PCOMP on Risc PC
        MOV     R0, #VIDCPhys
        LDR     R2, =&D0000342        ; VIDC20 FSYNREG, as in VIDCTAB but with force PCOMP high
        STR     R2, [R0]
        MOV     R0, #3072*2           ; time delay of about 3 ms (0.5 us units)
        STRB    R0, [R1, #Timer0LR]   ; copy counter into output latch
        LDRB    R2, [R1, #Timer0CL]   ; R2 := low output latch
vcofix_waitloop
        STRB    R0, [R1, #Timer0LR]   ; copy counter into output latch
        LDRB    R3, [R1, #Timer0CL]   ; R3 := low output latch
        TEQ     R3, R2                ; unchanged ?
        BEQ     vcofix_waitloop       ; then loop
        MOV     R2, R3                ; copy anyway
        SUBS    R0, R0, #1            ; decrement count
        BNE     vcofix_waitloop       ; loop if not finished
        MOV     R0, #VIDCPhys
        LDR     R2, =&D0000302        ; VIDC20 FSYNREG, as in VIDCTAB (PCOMP low again)
        STR     R2, [R0]
vcofix_notMorris
  ]

; now size memory

        BL      MemSize                 ; out: r0 = page size, r1 = memory size, r2 = MEMC CR value, r3-r14 corrupt

MemSized
        MOV     R8, R0                  ; R8 = page size in bytes
        MOV     R13, R1                 ; R13 is now the RAM size
        MOV     R9, R2                  ; need this to set soft copy right

   [ EmulatorSupport
        ARM_on_emulator R7
        MOVEQ   R7,#&80
        ORREQ   R7,R7,#&3E00            ; r7 := &3E80 = 16000 (standard Risc PC value)
        BLNE    TimeCPU                 ; r7 := CPU speed in kHz/MEMC1a flag
   |
        BL      TimeCPU                 ; r7 := CPU speed in kHz/MEMC1a flag
   ]

; the fixed areas give us : IRQ stack (in cursor), SVC stack (in sysheap base)
; and bottom block makes most sense done here

; now keyboard initialisation: initialise baud rate, send dummy, read dummy

        MOV     R0, #InitKbdWs
        MOV     R1, #0
        STRB    R1, [R0, #CTRL_Down_Flag] ; clear CTRL down flag, R down flag
        STRB    R1, [R0, #SHIFT_Down_Flag]
        STRB    R1, [R0, #KB_There_Flag]
        STR     R1, [R0, #R_Down_Flag]  ; all CMOS reset flags
        STR     R1, [R0, #KeyDataPtr]
        STR     R1, [R0, #Port2Present] ; all KbdRes vars

        B       SetUpKbd                ; No stack yet so branch and branch back.
SetUpKbdReturn


; set up reset interrupt handler (reads, discards keys, setting flags if CTRL or R)
; NB on ARM600 we need to go into 32-bit mode, so we can safely overwrite vectors

        MRS     r0, CPSR                ; switch into IRQ32, still IRQs disabled
        BIC     r0, r0, #&1F
        ORR     r1, r0, #IRQ32_mode
        MSR     CPSR_c, r1

        LDR     sp_irq, =IRQSTK         ; set up sp_irq

        ADRL    R2, MOSROMVecs          ; pick up from table
        LDR     R2, [R2, #&18]          ; this gets overwritten while active,
        MOV     R3, #0
        STR     R2, [R3, #&18]          ; but hopefully by the same value!

        ADDR    R2, IRQ_Test_CTRL_or_R_Pressed ; (could use ADRL, but ADDR macro is nicer)
        STR     R2, [R3, #InitIRQHandler] ; instruction is now a LDR PC,InitKbdHandler

        ORR     r0, r0, #SVC32_mode     ; switch into SVC32

 [ StrongARM
   ;for StrongARM, we need to do an IMB type thing for modifying code in vector area
        ARM_read_ID r1
        AND     r1,r1,#&F000
        CMP     r1,#&A000
        BNE     vectorpoke_notSA_1
        MOV     r1,#0                   ;we clean one cache entry, 0..1F, = vector area
  [ SAcleanflushbroken
        ARMA_clean_DCentry r1
        ARMA_flush_DCentry r1
  |
        ARMA_cleanflush_DCentry r1
  ]
        ARMA_drain_WB
        ARMA_flush_IC
vectorpoke_notSA_1
 ]

        BIC     r0, r0, #I32_bit        ; and enable IRQs
        MSR     CPSR_c, r0

 ; in SVC32 from now until we've finished poking around with vectors



 [ :LNOT: AlwaysClearRAM

; IF por OR FX200 bit set THEN clear memory
        MOV     R0, #IOC
        LDRB    R1, [R0, #IOCIRQSTAA]
        ANDS    R1, R1, #por_bit
        BNE     %FT20

        LDR     R0, =OsbyteVars + :INDEX: ESCBREAK
        LDRB    R1, [R0]
        CMP     R1, #2                  ; unlike popular rumour, bit 1 ain't
        CMPNE   R1, #3                  ; a flag
        BNE     %FT30
20
 ]
        BL      ClearPhysRAM
30
        MOV     r0, #0
        STR     r9, [r0, #MEMC_CR_SoftCopy] ; set soft copy.
        STR     r7, [r0, #MemorySpeed]  ; Remember CPU speed/MEMC1a flag
        STR     r8, [r0, #Page_Size]    ; r8 is still page size from way up there
        STR     r13, [r0, #RAMLIMIT]    ; save sussed memory size in LogRam

        LDR     sp, =SVCSTK             ; set up a stack

; do as much other initialisation as possible, to give keyboard stuff time
 [ StrongARM
        BL      Processor_Type          ; Determines the processor type & stores it in page 0.
 ]


  ]    ; :LNOT: HAL

Continue_after_HALInit

;StrongARM: OK, there is quite a bit of code poking below, to various addresses. We'll
;           defer IMB consideration till the poking's done, then do a full IMB (full
;           data cache clean). This avoids various little IMB's and removes chance of leaving
;           some unnoticed poked code in data cache. The deferral should be safe, because none
;           of the poked code will be used yet awhile (given that current IRQ hardware vector is
;           not actually changed below).

 [ ProcessorVectors
; Copy default processor vector table and default preveneers.
; Code relies on preveneers being immediately after processor vector table
; but could easily be changed into 2 copy loops.
        ASSERT  ProcVecPreVeneers = ProcVec_End
        ASSERT  DefaultPreVeneers = DefaultProcVecs+ProcVec_End-ProcVec_Start

        ADRL    R0, DefaultProcVecs
        LDR     R1, =ZeroPage+ProcVec_Start
        MOV     R2, #ProcVec_End-ProcVec_Start+ProcVecPreVeneersSize
39
        LDR     R3, [R0], #4
        STR     R3, [R1], #4
        SUBS    R2, R2, #4
        BNE     %BT39
 ]

; copy handler addresses
        ADRL    R1, MOSROMVecs+4        ; don't copy to 0: key stuff is using
                                        ; it as workspace!
        LDR     R0, =ZeroPage+4
        LDR     R3, =ZeroPage+EndMOSROMVecs-MOSROMVecs

40
        LDR     R2, [R1], #4            ; N.B. IRQ handler better be same as the one in there
        STR     R2, [R0], #4
        TEQ     R0, R3
        BNE     %BT40

        ChangedProcVecs r0

 [ :LNOT: No26bitCode
; Now we have set up the hardware vectors we can drop back to SVC26 mode

        MRS     r0, CPSR
        BIC     r0, r0, #&1F
        ORR     r0, r0, #SVC26_mode
        MSR     CPSR_c, r0
 ]

 [ CacheCMOSRAM
        DebugTX "InitCMOSCache entry"
        BL      InitCMOSCache           ; initialise cache of CMOS RAM
        DebugTX "InitCMOSCache done"
        TEQ     R0, #0                  ; returns zero on failure
      [ ZeroPage <> 0
        LDREQ   R0, =ZeroPage
      ]
        LDREQ   R1, [R0, #HAL_StartFlags]
        ORREQ   R1, R1, #OSStartFlag_NoCMOS
        STREQ   R1, [R0, #HAL_StartFlags]
 ]

; Now copy the initialised data
        LDR     R0, =ZeroPage+IRQ1V

; first save IOC soft copy so can restore it

        LDRB    R2, [R0, #IOCControlSoftCopy-IRQ1V]
        Push    "R2"
        LDRB    R2, [R0, #CannotReset-IRQ1V]
        Push    "R2"

        ADRL    r1, StartData
        LDR     R3, =ZeroPage+(EndData-StartData+IRQ1V)
DatCopy
        LDR     R2, [R1], #4
        STR     R2, [R0], #4
        TEQ     R0, R3
        BNE     DatCopy

        ADR     r2, CONT_Break
        LDR     r0, =ZeroPage
        STR     r2, [r0, #ResetIndirection]

        MOV     r3, #0                  ; initialise abort list
        STR     r3, [r0, #AbortIndirection]

; Now the SWI despatch + low part of SWI table
        ADRL    R3, DirtyBranch
        LDR     R0, =SWIDespatch
SVCTabCopy                              ; so copy the table
        LDR     R2, [R1], #4
        STR     R2, [R0], #4
        TEQ     R1, R3
        BNE     SVCTabCopy

; pad to 1K table here, rather than use ROM space
        ADRL    R2, NoSuchSWI
        LDR     R4, =1024+SvcTable      ; end of table
PadSVCTable
        CMP     R0, R4
        STRNE   R2, [R0], #4
        BNE     PadSVCTable

; now the dirty branch
        LDR     R1, [R1]
        STR     R1, [R0]

; conversion SWIs all go through same despatch point
        LDR     R0, =SvcTable
        ADRL    R1, despatchConvert
        STR     R1, [R0, #OS_ConvertStandardDateAndTime * 4]
        STR     R1, [R0, #OS_ConvertDateAndTime * 4]

        MOV     R2, #OS_ConvertHex1
conversionSWIfill
        STR     R1, [R0, R2, LSL #2]
        ADD     R2, R2, #1
        CMP     R2, #OS_ConvertVariform
        BLS     conversionSWIfill

; OK, that completes the poking around, some of which is code. Now let's
; do a full IMB type thing, to be safe
;
        LDR     r0, =ZeroPage
        ARMop   IMB_Full,,,r0
        DebugTX "IMB_Full done"

; Initialise CAO ptr to none.

        LDR     R0, =ZeroPage
        LDR     R1, =DuffEntry          ; nothing will be here!!
        STR     R1, [R0, #Curr_Active_Object]

KeyWait * 200000                 ; 1/5 sec wait (in microseconds)
 [ HAL
us      * 1
 |
us      * 2
 ]

 [ HAL
        AddressHAL
        MOV     r6, #25                 ; Check for keyboard 25 times (5 secs max).
        LDR     r4, =ZeroPage+InitIRQWs

kbdwait
        CallHAL HAL_KbdScan
        STR     r0, [r4, #KbdFlags]

        TST     r0, #KbdFlag_Done
        BNE     kbddone

      [ EmulatorSupport
        ARM_on_emulator r0
        MOVEQ   r0, #us
        LDRNE   r0, =KeyWait*us         ; Wait 1/5 second (give keys down a chance to come in).
      |
        LDR     r0, =KeyWait*us         ; Wait 1/5 second (give keys down a chance to come in).
      ]
        CallHAL HAL_CounterDelay
        SUBS    r6, r6, #1              ; else wait a maximum of 5 seconds.
        BNE     kbdwait
kbddone
        MSR     CPSR_c, #I32_bit+SVC32_mode
        CallHAL HAL_KbdScanFinish
        LDR     r1, =ZeroPage+InitIRQWs
        MOV     r0, #0
        STRB    r0, [r1, #KbdScanActive]
        MSR     CPSR_c, #SVC32_mode
        DebugTX "Keyboard scan complete"
 |
    [ KeyWait <> 0
; Check for keyboard there every 1/5 sec. but give up after 2 secs.
        MOV     r2, #IOC
        MOV     r6, #10                 ; Check for keyboard 10 times (2 secs max).
        MOV     r4, #InitKbdWs
kbdwait
        LDRB    r5, [r4, #KB_There_Flag]
      [ EmulatorSupport
        ARM_on_emulator r0
        MOVEQ   r0, #us
        LDRNE   r0, =KeyWait*us         ; Wait 1/5 second (give keys down a chance to come in).
      |
        LDR     r0, =KeyWait*us         ; Wait 1/5 second (give keys down a chance to come in).
      ]
        BL      DoMicroDelay
        TEQ     r5, #0                  ; If keyboard was there 1/5 second ago then
        BNE     kbdthere                ;   continue reset
        SUBS    r6, r6, #1              ; else wait a maximum of 2 seconds.
        BNE     kbdwait
kbdthere
    ]
 ]

 [ ValidateCMOS
; Do a POR if some super-critical values are shagged or if checksum is invalid.
        MOV     R3, #-1                 ; do all RAM if we do any
        BL      ValChecksum             ; Always check the checksum
        BNE     cmos_reset

 ]

 [ ValidateCMOS :LAND: STB

; ScreenSizeCMOS, RAMDiscCMOS, SysHeapCMOS, RMASizeCMOS and SpriteSizeCMOS
; should be 0. Happily they are at consecutive addresses so we can loop through
; them.
        MOV     R1, #ScreenSizeCMOS
reset_loop
        MOV     R0, R1
        BL      Read
        TEQ     R0, #0
        BNE     cmos_reset
        INC     R1
        TEQ     R1, #SpriteSizeCMOS
        BHI     reset_loop

; Year should be >=1995, <=2037 (when 32 bit signed Unix time breaks)
        MOV     R0, #YearCMOS+1
        BL      Read
        MOV     R1, R0
        MOV     R0, #YearCMOS+0
        BL      Read
        MOV     R2, #100
        MLA     R0, R2, R1, R0
        LDR     R1, =1995
        SUB     R0, R0, R1
        CMP     R0, #2037 - 1995
        BHI     cmos_reset

checkboot
; Bit 4 of DBTBCMOS should be 1 (Boot)
        MOV     R0, #DBTBCMOS
        BL      Read
        TST     R0, #(1:SHL:4)
        BEQ     cmos_reset
 ]


; IF power-on bit set AND R/T/Del/Copy pressed THEN reset CMOS RAM
; note that memory cleared if POR, so key info has had plenty of time!

 [ HAL
        LDR     R0, =ZeroPage+HAL_StartFlags
        LDR     R1, [R0]
        TST     R1, #OSStartFlag_NoCMOS ; If no CMOS, reset for sensible cache
        BNE     cmos_reset
        TST     R1, #OSStartFlag_POR
        BEQ     no_cmos_reset           ; not a power on reset
        DebugTX "POR detected"
      [ CheckProtectionLink
        TST     R1, #OSStartFlag_NoCMOSReset
        BNE     no_cmos_reset
      ]
        TST     R1, #OSStartFlag_CMOSReset
        BNE     cmos_reset
 |
        MOV     R0, #IOC
        LDRB    R1, [R0, #IOCIRQSTAA]
        ANDS    R1, R1, #por_bit
        BEQ     no_cmos_reset

      [ CheckProtectionLink
        LDR     r0, =IOMD_MonitorType

        ; on Issue A's the protection bit is only weakly pulled up,
        ; so force it high, then read it back
        LDRB    r1, [r0]
        ORR     r1, r1, #IOMD_ProtectionLinkBit
        STRB    r1, [r0]

        LDRB    r1, [r0]
        TST     r1, #IOMD_ProtectionLinkBit
        BEQ     no_cmos_reset           ; if zero then CMOS is protected
      ]

    [ STB :LAND: IOMD_C_FrontPanelButton <> 0
      [ FrontPanelButtClearsCMOS
        MOV     r0, #IOMD_Base          ; if front panel button pressed then CMOS reset
        LDRB    r0, [r0, #IOMD_CLINES]
        TST     r0, #IOMD_C_FrontPanelButton
        BEQ     cmos_reset
      ]
    ]

 ]

        LDR     R0, =ZeroPage+InitIRQWs
 [ HAL
        LDR     R7, [R0, #KbdFlags]
        TST     R7, #KbdFlag_R:OR:KbdFlag_T:OR:KbdFlag_Delete:OR:KbdFlag_Copy
 |
        LDR     R7, [R0, #R_Down_Flag]  ; Picks up R/T/Del/Copy flags all in one
        CMP     R7, #0
 ]
        LDRNE   R3, =ZeroPage
        MOVNE   R14, #1
        STRNEB  R14, [R3, #MentionCMOSReset]
        BEQ     no_cmos_reset           ; power on bit checked again there

      [ :LNOT: STB
        ADD     sp, sp, #4              ; junk CannotReset flag from stack
      ]

; CMOS reset detectified.
; **************************************************************************
; Note: if this CMOS reset code ever needs changing again, it's probably
; better to rewrite it. The Compact apparently has a table of default
; CMOS values; R-p.o. just writes the table, DEL-p.o. zeroes all, then
; writes the table. With skipping of the time CMOS, and post-prodding of
; the sync, that would probably be a better algorithm.
; **************************************************************************

 [ HAL
        TST     R7, #KbdFlag_Copy:OR:KbdFlag_Delete
 |
        ASSERT  (Del_Down_Flag - R_Down_Flag) = 2
        ASSERT  (Copy_Down_Flag - Del_Down_Flag) = 1
        MOVS    R3, R7, LSR #16         ; full reset or just system?
 ]

        MOVNE   R3, #-1                 ; Del or Copy does all RAM
        MOVEQ   R3, #UserCMOS           ; R or T just system
    [ ChecksumCMOS
        BL      ValChecksum             ; unless the CMOS ram's corrupt ..
        MOVNE   R3, #-1                 ; .. then blast it anyway.
cmos_reset
 [ STB
        ADD     sp, sp, #4              ; junk CannotReset flag from stack
 ]
        DebugTX "Reset CMOS"
        MOVNE   R0, #0                  ; even the econet station number
        MOVEQ   R0, #1
    |
        MOV     R0, #1                  ; leave the econet station number
    ]
        MOV     R1, #0                  ; zero it first
cmrlp   BL      Write                   ; CMOS(R0) := R1
        ADD     R0, R0, #1
        CMP     R0, R3
        MOVEQ   R0, #&80                ; skip user cmos
        CMP     r0, #YearCMOS
        ADDEQ   r0, r0, #2
        CMP     r3, #UserCMOS           ; system only?
        BNE     skipskipforTC
        CMP     r0, #NewADFSCMOS
        CMPNE   r0, #CountryCMOS        ; skip these if so
        ADDEQ   r0, r0, #1
skipskipforTC
        CMP     R0, #CMOSLimit
        BNE     cmrlp
    [ ChecksumCMOS
        BL      MakeChecksum            ; create a valid checksum
    ]
; now put nice values in where necessary
; first full reset defaults
        CMP     r3, #-1
        BNE     not_full_reset

 [ STB :LAND: IOMD_C_PALNTSCType <> 0
        MOV     r4, #IOMD_Base          ; configure territory, country and timezone based on PAL/NTSC bit
        LDRB    r4, [r4, #IOMD_CLINES]
        MOV     r0, #TerritoryCMOS
        TST     r4, #IOMD_C_PALNTSCType
        MOVEQ   r1, #0                  ; PAL = territory UK
        MOVNE   r1, #49                 ; NTSC = territory USA
        BL      Write
        MOV     r0, #CountryCMOS
        TST     r4, #IOMD_C_PALNTSCType
        MOVEQ   r1, #1                  ; PAL = country UK
        MOVNE   r1, #48                 ; NTSC = country USA
        BL      Write
        MOV     r0, #TimeZoneCMOS
        TST     r4, #IOMD_C_PALNTSCType
        MOVEQ   r1, #0                  ; PAL = 0 from UTC (GMT)
        MOVNE   r1, #&E0                ; NTSC = -8 hours from UTC (USA Pacific)
        BL      Write
   [ STB :LAND: :DEF: ObsoleteNC1CMOS
        MOV     r0, #MiscellaneousNCCMOS
        TST     r4, #IOMD_C_PALNTSCType
        MOVEQ   r1, #0                  ; PAL = A4 paper size
        MOVNE   r1, #1                  ; NTSC = US letter paper size
        BL      Write
   ]
 |
        MOV     r0, #CountryCMOS
        MOV     r1, #1                  ; country UK
        BL      Write
 ]

 [ :LNOT: STB
        MOV     r0, #NewADFSCMOS
        MOV     r1, #&41                ; floppies=1, ST506=0, IDE=1 (changed 01-Sep-93)
        BL      Write
 ]

not_full_reset

; IF R or Delete pressed THEN set sync 0 ELSE set sync Auto
        LDR     R0, =ZeroPage+InitIRQWs
 [ HAL
        LDR     R1, [R0, #KbdFlags]
        TST     R1, #KbdFlag_R:OR:KbdFlag_Delete
 |
        LDRB    R1, [R0, #R_Down_Flag]
        CMP     R1, #0
        LDREQB  R1, [R0, #Del_Down_Flag]
        CMPEQ   R1, #0
 ]
        MOV     R0, #VduCMOS
        MOVNE   R1, #MonitorTypeAuto :OR: Sync_Auto     ; if R or Del
        MOVEQ   R1, #MonitorTypeAuto :OR: Sync_Separate ; if T or Copy
        BL      Write

 [ HAL
     [ M_32
; M_32 used for IOMD based machines, select quadrature or PS2 as appropriate
        AddressHAL
        MOV     R0, #0
        MOV     R1, #&400
        CallHAL HAL_ControllerAddress
        CMP     R0, #0
        MOVEQ   R1, #PointerDevice_USB
        BEQ     program_mousetype
        LDRB    R1, [R0, #IOMD_ID1]
        LDRB    R0, [R0, #IOMD_ID0]
        ORR     R0, R0, R1, LSL #8
        LDR     R1, =IOMD_Original
        TEQ     R0, R1
        MOVEQ   R1, #PointerDevice_QuadMouse
        BEQ     program_mousetype
        LDR     R1, =IOMD_7500
        TEQ     R0, R1
        LDRNE   R1, =IOMD_7500FE
        TEQNE   R0, R1
        MOVEQ   R1, #PointerDevice_PS2Mouse
        MOVNE   R1, #PointerDevice_USB
program_mousetype
        MOV     R0, #MouseCMOS
        BL      Write
     |
        MOV     R0, #MouseCMOS
        MOV     R1, #PointerDevice_USB
        BL      Write
     ]

; set print and sound CMOS (16bit sound)
        MOV     R0, #TutuCMOS
        MOV     R1, #2_10100100  ; tbs chars valid, ctrlchars '|x'
        BL      Write

 |

 [ MorrisSupport
        MOV     R8, #IOMD_Base
        LDRB    r0, [r8, #IOMD_ID0]
        LDRB    r1, [r8, #IOMD_ID1]
        ORR     r0, r0, r1, LSL #8
        LDR     r1, =IOMD_Original
        TEQ     r0, r1
        BEQ     dont_program_mousetype
;
; Morris based machines use PS2 mice/tracker balls
;
        MOV     R0, #MouseCMOS
        MOV     R1, #PointerDevice_PS2Mouse     ;type 3
        BL      Write

  [ Select16BitSound
; set print and sound CMOS (16bit sound)
        B       Config16BitSound
  ]
dont_program_mousetype
 ] ; MorrisSupport

 [ Select16BitSound
        LDR     r0, =IOMD_MonitorType

; on Issue A's the protection bit is only weakly pulled up,
; so force it high, then read it back

        LDR     r1, [r0]
        ORR     r1, r1, #IOMD_SoundsystemLinkBit
        STR     r1, [r0]

        LDR     r1, [r0]
        TST     r1, #IOMD_SoundsystemLinkBit
        BEQ     Config16BitSound                ; if zero, must be Rimmer, so assume 16bit sound hardware present

; set print and sound CMOS (8bit sound)
        MOV     R0, #TutuCMOS
        MOV     R1, #2_0100  ; tbs chars valid, ctrlchars '|x'
        BL      Write
        B       ConfigSoundDone

Config16BitSound
; set print and sound CMOS (16bit sound)
        MOV     R0, #TutuCMOS
        MOV     R1, #2_10100100  ; tbs chars valid, ctrlchars '|x'
        BL      Write

ConfigSoundDone
 ]
 ] ; HAL

        ADR     R8, DefaultCMOSTable
50
        LDRB    R0, [R8], #1
        CMP     R0, #&FF
        BEQ     hard_reset              ; power on bit musta bin set
        LDRB    R1, [R8], #1
        BL      Write
        B       %BT50

        LTORG

 [ ValidateCMOS :LAND: STB
DefaultCMOSTable ; list of non-zero options wanted :
; byte pairs of offset, value
; terminated by offset &FF
        =       KeyDelCMOS,             32
        =       KeyRepCMOS,             8
        =       MODETVCMOS,             &10                                     ; TV 0,1
        =       StartCMOS,              (1:SHL:7):OR:(2:SHL:3)                  ; NONUM, NOCAPS
        =       DBTBCMOS,               (1:SHL:4)                               ; Boot
        =       YearCMOS,               02
        =       YearCMOS+1,             20
  [ IOMD_C_MonitorType = 0 :LAND: IOMD_C_PALNTSCType = 0
; TV if we don't have a MonitorType auto-detect bit
        =       VduCMOS,                Sync_Separate :OR: MonitorType0
  |
; auto-detect if we have a MonitorType auto-detect bit
        =       VduCMOS,                Sync_Auto :OR: MonitorTypeAuto
  ]
        =       MouseStepCMOS,          2
        =       SystemSpeedCMOS,        (1:SHL:2):OR:(1:SHL:4):OR:(0:SHL:5)
                                      ; Delete-etc reset
                                      ;              WimpMode auto
                                      ;                           Cache on
 | ;ValidateCMOS
DefaultCMOSTable ; list of non-zero options wanted :
; byte pairs of offset, value
; terminated by offset &FF
        =       KeyDelCMOS,     32
   [ M_CortexA8 :LOR: M_CortexA9
        =       FileLangCMOS,   fsnumber_SCSIFS ; SCSIFS for OMAP3, etc.
   |
    [ M_ARM11ZF
        =       FileLangCMOS,   fsnumber_SDFS   ; SDFS for Pi, etc.
    |
        =       FileLangCMOS,   fsnumber_adfs   ; ADFS
    ]
   ]
        =       FontCMOS,       64      ; KJB 13-Dec-02: Changed to 256K from 64K
        =       PigCMOS,        10
        =       KeyRepCMOS,     8
        =       RMASizeCMOS,    0
        =       SpriteSizeCMOS, 0
        =       SysHeapCMOS,    8
        =       MODETVCMOS,     &10     ; TV 0,1
        =       NetFSIDCMOS,    254
        =       NetPSIDCMOS,    235
        =       PSITCMOS,      (3:SHL:2) :OR: (1:SHL:5)
                              ; Baud 3
                              ;                print 1

        =       DBTBCMOS,      (1:SHL:4) :OR: (4:SHL:5)
                              ; Boot (changed from NoBoot 01-Sept-93)
                              ;                Data 4

        =       StartCMOS,     (4:SHL:0) :OR: (2:SHL:3) :OR: (1:SHL:6) :OR: (0:SHL:7)
                              ; ^              ^              ^              ^
                              ; ADFS DR.4      NOCAPS         NODIR (moot)   NUM

     [ NewClockChip                     ; only on A1's!
        =       NewADFSCMOS+1,  &FF     ; step 3 for each drive
     ]

        =       NewADFSCMOS+2,  1       ; ADFSBuffers 1
        =       SoundCMOS,      &F0     ; speaker on, volume 7, channel 1

        =       LanguageCMOS,   ConfiguredLang
        =       YearCMOS,       04
        =       YearCMOS+1,     20
 [ :LNOT: Select16BitSound
        =       TutuCMOS,       2_0100  ; tbs chars valid, ctrlchars '|x'
 ]
        =       NetFilerCMOS,  (0:SHL:0) :OR: (1:SHL:1) :OR: (0:SHL:2)
                              ; FS list order by name
                              ;                Use $.Arthurlib
                              ;                               Large icons

     ;  =       Mode2CMOS,      WimpModeAutoBit :OR: CMOSResetBit ;AKA SystemSpeedCMOS - removed by RManby and SCormie 8/3/95
        =       DesktopCMOS,    2_01000000      ; verbose ON
        =       WimpFlagsCMOS,  2_01101111      ; instant effects, drags off screen
        =       ProtectionCMOS, 2_01110110      ; allow only peek and user RPC
        =       MouseStepCMOS,  2
        =       FileSwitchCMOS,(1:SHL:0) :OR: (1:SHL:1) :OR: (0:SHL:2) :OR: (0:SHL:3) :OR: (0:SHL:6)
                              ; truncate names
                              ;                Use DragASprite (changed 01-Sept-93)
                              ;                               Interactive file copying
                              ;                                              Wimp dither colours off
                              ;                                                             last shutdown ordinary

        =       DesktopFeaturesCMOS,(1:SHL:0) :OR: (8:SHL:1) :OR: (0:SHL:7)
                              ;      3D look
                              ;                     Homerton.Medium
                              ;                                    tiled window background

        [ STB
        =       SystemSpeedCMOS,(1:SHL:0):OR:(0:SHL:1):OR:(1:SHL:2):OR:(0:SHL:3):OR:(1:SHL:4):OR:(0:SHL:5):OR:(1:SHL:6):OR:(0:SHL:7)
                              ;  AUN ROMBoot Enabled
                              ;               AUN auto-station numbering off
                              ;                            Delete-etc reset
                              ;                                         power saving off
                              ;                                                      WimpMode auto
                              ;                                                                  Cache on
                              ;                                                                               Broadcast loader disabled
                              ;                                                                                            broadcast loader colours off
        |
        =       SystemSpeedCMOS,(0:SHL:0):OR:(0:SHL:1):OR:(1:SHL:2):OR:(0:SHL:3):OR:(1:SHL:4):OR:(0:SHL:5):OR:(1:SHL:6):OR:(0:SHL:7)
                              ;  AUN BootNet Disabled
                              ;               AUN auto-station numbering off
                              ;                            Delete-etc reset
                              ;                                         power saving off
                              ;                                                      WimpMode auto
                              ;                                                                  Cache on
                              ;                                                                               Broadcast loader disabled
                              ;                                                                                            broadcast loader colours off
        ]

        [ :LNOT: STB
        =       FontMaxCMOS,    64      ; 4096k
        =       FontMax2CMOS,   36:EOR:12 ; 36 point
        =       FontMax3CMOS,   36:EOR:24 ; 36 point
        =       FontMax4CMOS,   16      ; 16 point
        |
        ;       yes, omitting FontMaxCMOS is deliberate!
        =       FontMax2CMOS,   &2C     ; 32 point
        =       FontMax3CMOS,   &38     ; 32 point
        ]
        =       AlarmAndTimeCMOS,2_00010000 ; !Alarm autosave on
        =       FSLockCMOS+5,   &EA     ; Checksum for no password
   [ M_CortexA8 :LOR: M_CortexA9 :LOR: M_ARM11ZF
        =       CDROMFSCMOS,    &C0                     ; drives = 0, buffer size = 256K
        =       NetworkFlags,   LanManFStransport       ; LMTransport is NetBIOS over IP
        =       WimpDragMoveLimitCMOS, (1:SHL:2)        ; WimpIconiseButton
        =       SparrowMarker,  FreewayNoAutoAddress    ; Stop Freeway assigning addresses to interfaces
   |
        =       CDROMFSCMOS,    &C1     ; drives = 1, buffer size = 256K
   ]
  ]
        =       &FF
        ALIGN


no_cmos_reset                           ; R1 has por_bit set if power on
        Push    "r1"
        MOV     r0, #SystemSpeedCMOS
        BL      Read
        BIC     r1, r0, #CMOSResetBit   ; clear bit indicating CMOS reset
        MOV     r0, #SystemSpeedCMOS
        BL      Write
        Pull    "r1"

        Pull    r0                      ; always pull CannotReset flag
 [ SoftResets
        TST     r1, #por_bit
        BNE     hard_reset              ; it was a power-on, so it's a hard reset
        CMP     r0, #0
 [ DebugForcedReset
        MOVNE   r2, #Reset_CannotResetFlag
 ]
        BNE     hard_reset_forced

; IF control pressed OR memory implausible (Check SysHpd, CAM map sensible) THEN hard reset

        LDR     R0, =SysHeapStart
        LDR     R8, [R0, #:INDEX: hpdmagic]
        LDR     R2, =magic_heap_descriptor
        CMP     R8, R2                  ; check sysheap initialised
 [ DebugForcedReset
        MOVNE   r2, #Reset_SysHeapCorrupt
 ]
        BNE     hard_reset_forced

; also check CAM map sensible

        LDR     R5, =ZeroPage
        LDR     R4, [R5, #Page_Size]    ; R4 = page size
        ADRL    R3, PageShifts-1
        LDRB    R4, [R3, R4, LSR #12]   ; R4 = log2(pagesize)
        LDR     R3, [R5, #RAMLIMIT]     ; R3 = total RAM size
        MOV     R2, R3, LSR R4          ; number of pages=total memory / pagesize
        CMP     R2, #256                ; but if fewer than 128 (eg 64 on A305) (NB if <256 then <=128)
        MOVCC   R2, #128                ; then use 128 (all MEMC1's pages need initialising,
                                        ; even if half of them are not in use)
        SUB     R2, R2, #1
        LDR     R3, =CamEntriesForVicky

        LDR     R4, [R5, #MaxCamEntry]  ; get highest CAM entry
        LDR     R5, [R5, #CamEntriesPointer] ; and pointer to CAM soft copy

        CMP     R5, R3                  ; if not the same
 [ DebugForcedReset
        MOVNE   r2, #Reset_WrongCamMapAddress
        BNE     hard_reset_forced
 ]
        CMPEQ   R4, R2                  ; or number of pages not the same
 [ DebugForcedReset
        MOVNE   r2, #Reset_WrongNumberOfPages
 ]
        BNE     hard_reset_forced       ; then do a hard reset

; now check all cam contains sensible values

        LDR     R4, =ZeroPage
        LDR     R4, [R4, #Page_Size]
        SUB     R4, R4, #1
        ORR     R4, R4, #&F0000000      ; can have addresses above 64M
CamCheck
        LDR     R3, [R5, R2, LSL #2]
        BIC     r3, r3, #&F0000000      ; remove PPL
        TST     R3, R4
 [ DebugForcedReset
        MOVNE   r2, #Reset_CamMapCorrupt
 ]
        BNE     hard_reset_forced       ; wally entry: not pagesize multiple, or >= 32M
        SUBS    R2, R2, #1
        BPL     CamCheck

; leave CTRL test till last, so the keyboard's had as much time to
; wiggle the wet string as we can give it
        LDR     R0, =ZeroPage+InitKbdWs
        LDRB    R1, [R0, #CTRL_Down_Flag]
        CMP     R1, #0
        BNE     hard_reset

soft_reset
; clear out 4K of scratchspace, to use as a reverse CAM soft copy;
; set bytes to indicate page mapped to that address. Can then recalculate
; end of memory.

; This code doesn't currently work on ARM600 versions -
; 4K of workspace isn't enough to do this with a 4K page size
; We'd probably want to do it differently anyway, using the L2PT
; But since we're removing soft resets it's not worth the effort

        ASSERT  MEMM_Type <> "ARM600"

        MOV     R5, #ScratchSpace
        MOV     R1, #4*1024
        MOV     R2, #0
clrscratch
        SUBS    R1, R1, #4
        STRPL   R2, [R5, R1]
        BPL     clrscratch

        LDR     r7, =ZeroPage
        LDR     R2, [R7, #Page_Size]
        ADRL    R8, PageShifts-1
        LDRB    R8, [R8, R2, LSR #12]

        LDR     r2, [r7, #RAMLIMIT]
        MOV     r2, r2, LSR r8          ; last valid page
        SUB     r2, r2, #1

        LDR     R7, [R7, #CamEntriesPointer]
        LDR     R12, =DuffEntry

restoreCAMloop
        LDR    R3, [R7, R2, LSL #2]
        MOV    r11, r3, LSR #28
        BIC    r3, r3, #&F0000000

        MOV    R0, R3, LSR R8              ; logram page number
        LDRB   R4, [R5, R0]
        CMP    r4, #0                      ; check for doubly mapped pages
        BEQ    rclon

        ORR    r3, r12, #&30000000         ; force to invalid place if so.
        STR    r3, [R7, R2, LSL #2]
        MOV    r3, r12
        MOV    r11, #3                     ; protected
        MOV    R0, R3, LSR R8
        LDRB   R4, [R5, R0]
rclon
        CMP    r3, #16*1024*1024           ; in application space?
        MOVLT  r11, #0                     ; noprot if so
        STRLT  r3, [R7, R2, LSL #2]
        ADD    R4, R4, #1
        STRB   R4, [R5, R0]                ; sema for interesting pages
        BL     BangCam
        SUBS   R2, R2, #1
        BPL    restoreCAMloop

; now do post-scan to see if we need to do more CAM bashing to get pages back.
; any entries that aren't validateable should be remapped.

        LDR     R1, =ZeroPage
        MOV     R12, #ScratchSpace
        LDR     R2, [R1, #Page_Size]
        MOV     R7, #0
findapplend
        LDRB    R3, [R12], #1
        CMP     R3, #0
        ADDNE   R7, R7, R2
        BNE     findapplend
        STR     R7, [R1, #AplWorkSize]  ; verified value
        LDR     R3, [R1, #RAMLIMIT]     ; calc last valid page:
        MOV     R3, R3, LSR R8          ; RAMLIMIT >> R8
        LDR     R4, [R1, #CamEntriesPointer] ; no PPL
testforremap
        SUBS    R3, R3, #1
        BMI     finishedremap
        LDR     R0, [R4, R3, LSL #2]
        BIC     r0, r0, #&F0000000      ; remove PPL
        ADD     R1, R0, R2
        SWI     XOS_ValidateAddress
        BCC     testforremap

        Push    "R2-R4"
        MOV     R0, R0, LSR R8          ; curr logram page number
        LDRB    R4, [R5, R0]
        SUB     R4, R4, #1
        STRB    R4, [R5, R0]            ; dec sema
        MOV     R2, R3                  ; entry no
        MOV     R3, R7                  ; addr to set to
        BL      BangCamUpdate
        Pull    "R2-R4"
holefilled
        ADD     R7, R7, R2
        LDRB    R0, [R12], #1           ; reinspect our reverse map
        CMP     R0, #0
        BNE     holefilled
      [ ZeroPage <> 0
        LDR     R0, =ZeroPage
      ]
        STR     R7, [R0, #AplWorkSize]
        B       testforremap

finishedremap
        MOV     R12, #NVECTORS-1
        LDR     R11, =ZeroPage+VecPtrTab
freenextvec
        LDR     R2, [R11, R12, LSL #2]
loseveclink
        LDR     R3, [R2, #TailPtr]
        BL      FreeSysHeapNode
        MOVVC   R2, R3
        BVC     loseveclink
        CMP     R3, #0                  ; were we at the end of the chain?
 [ DebugForcedReset
        MOVNE   r2, #Reset_VectorChainCorrupt
 ]
        BNE     hard_reset_forced
        SUBS    R12, R12, #1
        BPL     freenextvec
; so that's the code for restore default vectors, basically
        BL      InitVectors
        LDR     R0, =ZeroPage
        LDR     R1, [R0, #AplWorkSize]
        STR     R1, [R0, #MemLimit]

        LDR     R3, =TickNodeChain
        LDR     R2, [R3]

loseticknodes
        CMP     R2, #0
        BEQ     ticknodesallgone

        LDR     R3, [R2]
        BL      FreeSysHeapNode
 [ DebugForcedReset
        MOVVS   r2, #Reset_TickNodesCorrupt
 ]
        BVS     hard_reset_forced
        MOV     R2, R3
        B       loseticknodes

ticknodesallgone
; and now it's time to free the IRQ structures

        MOV     R12, #(NoInterrupt-1)*12+8      ; last device link offset
        LDR     R11, =DefaultIRQ1V-DefaultIRQ1Vcode+Devices
freenextdev
        LDR     R2, [R11, R12]
losedevlink
        CMP     R2, #0
        BEQ     stepdevice

        LDR     R3, [R2, #8]
        BL      FreeSysHeapNode
 [ DebugForcedReset
        MOVVS   r2, #Reset_DeviceVectorCorrupt
 ]
        BVS     hard_reset_forced
        MOV     R2, R3
        B       losedevlink
stepdevice
        SUBS    R12, R12, #12
        BPL     freenextdev

; now the PIRQ structures and CallBack_Vector
        LDR     R11, =ZeroPage+PIRQ_Chain
        MOV     r4, #PodDesp_Link
losepirqchain
        LDR     R2, [R11]
        CMP     r2, #0                  ; for CallBack_Vector
        BEQ     doobry
losepirqlink
        LDR     R3, [R2, r4]
        BL      FreeSysHeapNode
        MOVVC   R2, R3
        BVC     losepirqlink
        CMP     R3, #0                  ; were we at the end of the chain?
 [ DebugForcedReset
        MOVNE   r2, #Reset_PoduleOrCallBackCorrupt
 ]
        BNE     hard_reset_forced
        LDR     R2, =ZeroPage+PIRQ_Chain
        CMP     R11, R2
        LDR     R2, =ZeroPage+PFIQasIRQ_Chain
        MOVEQ   R11, R2
        CMPNE   r11, r2
        LDREQ   r11, =ZeroPage+CallBack_Vector
    [ PodDesp_Link <> 0
        MOVEQ   r4, #0
    ]
        BEQ     losepirqchain


doobry  Pull    "R1"                    ; IOCControl restoration
        LDR     R0, =ZeroPage
        STRB    R1, [R0, #IOCControlSoftCopy]
        ASSERT  :LNOT: HAL
        MOV     R0, #IOC                ; and bash the hardware
        STRB    R1, [R0, #IOCControl]

        MOV     R0, #SoftReset
        B       ResetPart1Done

 |

; if soft resets are disabled, drop thru into hard reset code

 ] ; end of code to do with soft resets

hard_reset
 [ DebugForcedReset
        MOV     r2, #0                  ; indicate normal hard reset
 ]
hard_reset_forced
        LDR     r8, =ZeroPage
 [ DebugForcedReset
        STR     r2, [r8]                ; store to logical address zero
 ]

        Pull    "R2"                    ; discard old IOC state

; fill in relevant CamMap entries, so can soft start.

        LDR     R8, [R8, #Page_Size]
        ADRL    R1, PageShifts-1
        LDRB    R1, [R1, R8, LSR #12]

        LDR     r2, =ZeroPage
        LDR     r0, [r2, #VideoSize]    ; offset from start of physical pages to static part
        MOV     r0, r0, LSR r1          ; r0 := cam entry number
        MOV     r0, r0, LSL #3          ; r0 := offset into CAM map for start of static part

        MOV     R7, #32*1024*8
        MOV     R7, R7, LSR R1          ; r7 := cam entry offset for 32K

        LDR     R12, [R2, #RAMLIMIT]    ; R12 = total RAM size

 [ :LNOT:HAL
                                        ; new code which allows for MEMC2's small pages
        MOV     R1, R12, LSR R1         ; R1 = number of pages
        CMP     R1, #256                ; but if fewer than 128 (eg 64 on A305) (NB if <256 then <=128)
        MOVCC   R1, #128                ; then use 128 (all MEMC1's pages need initialising,
                                        ; even if half of them are not in use)

        SUB     R3, R1, #1
        STR     R3, [R2, #MaxCamEntry]

        LDR     R1, =CamEntriesForVicky
        STR     R1, [R2, #CamEntriesPointer]


; On ARM600 we must zap all the soft CAM map before adding any entries,
; since the old contents are used in BangCamUpdate

        Push    "r0"
        ADD     r2, r1, r3, LSL #3      ; r2 -> last entry to do
        LDR     r0, =DuffEntry
        MOV     lr, #AP_Duff            ; PPL = no access
WallopDuffOnes
        STMDA   r2!, {r0, lr}           ; store address, PPL
        CMP     r2, r1
        BCS     WallopDuffOnes
        Pull    "r0"
        ADD     R0, R0, R1

        LDR     R2, =CursorChunkAddress
        LDR     r1, =AP_CursorChunk
        BL      AddCamEntries

        CMP     R12, #512*1024
        SUBEQ   R0, R0, R7              ; previous entries
        ADDNE   R0, R0, R7              ; next entries
        MOV     R2, #0
        MOV     r1, #AP_PageZero
        BL      AddCamEntries

        CMP     R12, #512*1024
        SUBEQ   R0, R0, R7              ; previous entries
        ADDNE   R0, R0, R7              ; next entries
        LDR     R2, =SysHeapChunkAddress
        MOV     r1, #AP_SysHeap :OR: PageFlags_Unavailable
        BL      AddCamEntries

        ADD     R0, R0, R7              ; next entries (ignore 512K machines)
        MOV     r7, #0
        LDR     r7, [r7, #L2PTSize]
        MOV     r7, r7, LSR #12-3       ; number of pages * 8
        LDR     R2, =L2PT
        LDR     r1, =AP_L2PT :OR: PageFlags_Unavailable
        BL      AddCamEntries

        ADD     r2, r0, #((L1PT-L2PT):SHR:(12-3))   ; point at PPL for 1st L1 page
        ADD     r2, r2, #4
        LDR     r1, =AP_L1PT
        STR     r1, [r2], #8            ; store 4 CAM entries for 4 x 4K = 16K of L1
        STR     r1, [r2], #8            ; mark them as unavailable for removal
        STR     r1, [r2], #8
        STR     r1, [r2], #8

        ADD     R0, R0, R7              ; add on enough pages for L2PT

        MOV     r7, #0
        LDR     r7, [r7, #SoftCamMapSize] ; number of bytes in soft cam map
        ADD     r7, r7, #UndStackSize
        MOV     r7, r7, LSR #12-3       ; number of bytes of cam map for this
        LDR     R2, =UndStackSoftCamChunk
        MOV     r1, #AP_UndStackSoftCam
        BL      AddCamEntries
 ]
        DebugTX "InitDynamicAreas"

; let's boogie with the CMOS for a bit
; read info and move as much memory as we can

        BL      InitDynamicAreas

; RMA
        Push    "r0-r12"
        MOV     r1, #ChangeDyn_RMA      ; Area number
        MOV     r2, #4096               ; Initial size
        MOV     r3, #RMAAddress         ; Base address
        MOV     r4, #AP_RMA             ; Area flags
        MOV     r5, #RMAMaxSize         ; Maximum size
        ADRL    r6, DynAreaHandler_RMA  ; Pointer to handler
        MOV     r7, r3                  ; Workspace ptr points at area itself
        ADRL    r8, AreaName_RMA        ; Title string - node will have to be reallocated
                                        ; after module init, to internationalise it
        BL      DynArea_Create          ; ignore any error, we're stuffed if we get one!
        Pull    "r0-r12"

; Screen
        Push    "r0-r12"
        MOV     r0, #ScreenSizeCMOS
        BL      Read

        LDR     r5, =ZeroPage
        LDR     r10, [r5, #Page_Size]   ; needed by MassageScreenSize
        MUL     r0, r10, r0             ; convert to bytes
        LDR     r5, [r5, #VideoSize]    ; maximum size
        BL      MassageScreenSize

        MOV     r1, #ChangeDyn_Screen   ; area number
        MOV     r2, r0                  ; initial size
        MOV     r3, #-1                 ; Base address dynamic
        LDR     r4, =AP_Screen          ; area flags
        ADRL    r6, DynAreaHandler_Screen ; handler
        VDWS    r7                      ; workspace pointer
        MOV     r8, #0
        STR     r8, [r7, #CursorFlags]  ; put zero in CursorFlags as an indication that VDU not yet inited
        STR     r2, [r7, #TotalScreenSize]
        ADRL    r8, AreaName_Screen     ; area name
        BL      DynArea_Create
        STR     r3, [r7, #ScreenEndAddr]
        Pull    "r0-r12"

  [ LongCommandLines :LAND: (:LNOT: HAL)
        ;sort out the Kernel buffers dynamic area
        Push    "r0-r12"
        MOV     r1, #ChangeDyn_Kbuffs   ; Area number
        MOV     r2, #KbuffsSize         ; Initial (and in fact permanent) size
        LDR     r3, =KbuffsBaseAddress  ; Base address
        MOV     r4, #AP_Kbuffs          ; Area flags
        MOV     r5, #KbuffsMaxSize      ; Maximum size
        MOV     r6, #0                  ; no handler
        MOV     r7, #0
        ADRL    r8, AreaName_Kbuffs     ; Title string - node will have to be reallocated
                                        ; after module init, to internationalise it
        BL      DynArea_Create          ; ignore any error, we're stuffed if we get one!
        Pull    "r0-r12"
  ]

; SpriteArea
        Push    "r0-r12"
        MOV     r0, #0                  ; initialise SpriteSize to zero
      [ ZeroPage = 0
        STR     r0, [r0, #SpriteSize]   ; (fixes bug MED-00811)
      |
        LDR     r1, =ZeroPage
        STR     r0, [r1, #SpriteSize]   ; (fixes bug MED-00811)
      ]

        MOV     r0, #SpriteSizeCMOS     ; find out how much spritesize configured
        BL      GetConfiguredSize       ; in: r0 = CMOS address, out: r2 = size

        MOV     r1, #ChangeDyn_SpriteArea ; Area number
        MOV     r3, #-1                 ; Base address dynamic
        MOV     r4, #AP_Sprites         ; Area flags
        MOV     r5, #16*1024*1024       ; Maximum size (changed from -1, address space preservation)
        ADRL    r6, DynAreaHandler_Sprites ; Pointer to handler
        MOV     r7, #-1                 ; Use base address as workspace ptr
        ADRL    r8, AreaName_SpriteArea ; Title string - node will have to be reallocated
                                        ; after module init, to internationalise it
        BL      DynArea_Create          ; ignore any error, we're stuffed if we get one!
        Pull    "r0-r12"

; RAMDisc
        Push    "r0-r12"
        MOV     r0, #RAMDiscCMOS        ; find out how much RAM disc configured
        BL      GetConfiguredSize       ; in: r0 = CMOS address, out: r2 = size

        MOV     r1, #ChangeDyn_RamFS    ; Area number
        MOV     r3, #-1                 ; Base address dynamic
        ARM_read_ID r4
        AND     r4, r4, #&F000
        CMP     r4, #&A000
        MOVEQ   r4, #AP_RAMDisc_SA      ; Area flags, if StrongARM  (introduced for Ursula)
        MOVNE   r4, #AP_RAMDisc         ; Area flags
      [ {FALSE}
        MOV     r5, #16*1024*1024       ; Limit maximum size to 16MB while fiddling with FileCore
      |
        MOV     r5, #128*1024*1024      ; A trade off between nice big disc and complete waste of address space
      ]
        ADRL    r6, DynAreaHandler_RAMDisc ; Pointer to handler
        MOV     r7, #-1                 ; Use base address as workspace ptr
        ADRL    r8, AreaName_RAMDisc    ; Title string - node will have to be reallocated
                                        ; after module init, to internationalise it
        BL      DynArea_Create          ; ignore any error, we're stuffed if we get one!
        Pull    "r0-r12"

; FontArea
        Push    "r0-r12"
        MOV     r0, #FontCMOS           ; find out how much font cache configured
        BL      GetConfiguredSize       ; in: r0 = CMOS address, out: r2 = size

        MOV     r1, #ChangeDyn_FontArea ; Area number
        MOV     r3, #-1                 ; Base address dynamic
        MOV     r4, #AP_FontArea        ; Area flags
        MOV     r5, #32*1024*1024       ; Maximum size changed from -1 for Ursula (limit address
                                        ; space usage on large memory machines)
        ADRL    r6, DynAreaHandler_FontArea ; Pointer to handler
        MOV     r7, #-1                 ; Use base address as workspace ptr
        ADRL    r8, AreaName_FontArea   ; Title string - node will have to be reallocated
                                        ; after module init, to internationalise it
        BL      DynArea_Create          ; ignore any error, we're stuffed if we get one!
        Pull    "r0-r12"

; get here with R2 = highest CAM entry used (in old model)

; [ HAL32
;        MOV     R0, #0
;        LDR     R0, [R0, #RAMLIMIT]
;        SUB     R0, R0, #32*1024
;        MOV     R0, R0, LSR #12
; |
        LDR     R0, =(AplWorkMaxSize-32*1024):SHR:12    ; maximum number of pages in aplspace
; ]
        MOV     R3, #32*1024            ; aplwork start
        LDR     R1, =ZeroPage+AplWorkSize ; aplwork size
        MOV     r11, #AP_AppSpace
        BL      FudgeConfigureRMA       ; put as much as possible in aplspace

        LDR     R0, =ZeroPage
        LDR     R1, [R0, #AplWorkSize]
        ADD     R1, R1, #32*1024
        STR     R1, [R0, #AplWorkSize]
        STR     R1, [R0, #MemLimit]

        DebugTX "InitVectors"
        BL      InitVectors               ; ready for OsByte to read mode

        LDR     R1, =ZeroPage+ModuleSWI_HashTab
        MOV     R2, #ModuleSHT_Entries
      [ ZeroPage <> 0
        MOV     R0, #0
      ]
clearmswis
        SUBS    R2, R2, #1
        STR     R0, [R1, R2, LSL #2]
        BGT     clearmswis

      [ ZeroPage <> 0
        LDR     R2, =ZeroPage
      ]

     [  International
        MOV     R1, #-1                                 ; We don't have a message file yet !
        STRB    R1, [R2, #ErrorSemaphore]               ; Don't translate errors.
        STR     R0, [R2, #KernelMessagesBlock]          ; No message file open.
      [ CacheCommonErrors
        STR     R0, [R2, #CachedErrorBlocks]            ; No cached errors
      ]
     ]

  [ HAL
        LDR     R0, =ZeroPage+HAL_StartFlags
        LDR     R1, [R0]
        TST     R1, #OSStartFlag_POR
  |
        MOV     R0, #IOC
        LDRB    R1, [R0, #IOCIRQSTAA]
        ANDS    R1, R1, #por_bit
        STRNEB  R1, [R0, #IOCIRQCLRA]   ; clear POR if set
  ]


        ; Make the choice between PowerOn and Hard reset based purely on
        ; the state of the POR bit and NOT on whether memory was cleared.
 [ {FALSE}
        LDREQ   R0, =ZeroPage+OsbyteVars + :INDEX: LastBREAK
        LDREQB  R0, [R0]
        TSTEQ   R0, #&80                ; tbs set if memory cleared
 ]
        MOVNE   R0, #PowerOnReset
        MOVEQ   R0, #ControlReset


ResetPart1Done                          ; R0 is reset type
        WritePSRc SVC_mode + I_bit, r1  ; interrupts off since kbd bash done
        LDR     R1, =ZeroPage+OsbyteVars + :INDEX: LastBREAK
        STRB    R0, [R1]

        LDR     R1, =ZeroPage+InitIRQWs
 [ HAL
        LDR     R0, [R1, #KbdFlags]
        AND     R1, R0, #KbdFlag_Shift
        AND     R0, R0, #KbdFlag_Present
 |
        LDRB    R0, [R1, #KB_There_Flag]
        LDRB    R1, [R1, #SHIFT_Down_Flag]
 ]
        Push    "R0, R1"                ; save until after MOSInit

        DebugTX "InitIRQ1"
        BL      InitialiseIRQ1Vtable

        LDR     R3, =ZeroPage
        ADRL    R1, Default_PIRQHandler_Node
        STR     R1, [R3, #PIRQ_Chain]
        STR     R1, [R3, #PFIQasIRQ_Chain]
 ASSERT Default_PFIQasIRQHandler_Node = Default_PIRQHandler_Node

        MOV     R0, #0                  ; put in IRQ handler, word at 0
        STRB    r0, [r3, #FIQclaim_interlock]
        STRB    r0, [r3, #CallBack_Flag]
        STR     r0, [r3, #CallBack_Vector]

; Create the Branch Through 0 Trampoline in the system heap
        MOV     R3, #Branch0_Trampoline_Size
        BL      ClaimSysHeapNode
        ADRVCL  R0, Branch0_Trampoline
        ASSERT  Branch0_Trampoline_Init = 20
        LDMVCIA R0, {R1,R3,R4,R5,R14}
        STMVCIA R2, {R1,R3,R4,R5,R14}
        LDRVC   R0, =ZeroPage
        STRVC   R2, [R0, #ProcVec_Branch0]

 [ :LNOT: No26bitCode

; we're poking locations 0 and &18 here, so we'd best go back to SVC32

        MRS     r2, CPSR
        BIC     r3, r2, #&1F
        ORR     r3, r3, #SVC32_mode
        MSR     CPSR_c, r3
 ]

 [ DebugForcedReset
        LDR     R1, [R0]
        TEQ     R1, #0                                  ; if normal hard reset
        LDREQ   R1, BranchThroughZeroInstruction2       ; then get branchthruzero code
 |
        LDR     R1, BranchThroughZeroInstruction2
 ]
        STR     R1, [R0]                                ; put branch through 0 code at 0

        LDR     R1, RealIRQHandler
        STR     R1, [R0, #&18]

        LDR     R2, =ZeroPage+InitIRQWs                 ; clear temp ws
        MOV     R3, #0
        MOV     R4, #0
        STMIA   R2!, {R3,R4}
        STMIA   R2!, {R3,R4}
        DebugTX "IMB_Full"

   ;we need to do an IMB type thing for modifying code in vector area,
   ;and for copying irq handler code
   ;
        ARMop   IMB_Full,,,r0
        ChangedProcVecs r0
        LDR     r0,=ZeroPage


 [ :LNOT:No26bitCode

; now back to SVC26

        MSR     CPSR_c, r2
 ]

        MOV     R1, #&100
        STR     R1, [R0, #RCLimit]
        MOV     R1, #0
        STR     R1, [R0, #ReturnCode]
        STR     R1, [R0, #TickNodeChain]

; clear the keyboard workspace (tidy!)
        ADD     R0, R0, #&1C
        MOV     R2, #InitWsEnd - &1C
        BL      memset

;now put in error handler and escape handler
        BL      DEFHAN
        BL      DEFHN2
        MOV     R0, #ExceptionDumpArea
        LDR     R1, =ZeroPage+DUMPER
        SWI     XOS_ChangeEnvironment

        VDWS    WsPtr                   ; main MOS initialisation
        DebugTX "VduInit"
        BL      VduInit
        DebugTX "ExecuteInit"
        BL      ExecuteInit
        DebugTX "KeyInit"
        BL      KeyInit
        DebugTX "MouseInit"
        BL      MouseInit
        DebugTX "OscliInit"
        BL      OscliInit               ; before initialising modules

        DebugTX "Enabling IRQs"
        WritePSRc SVC_mode, R14         ; enable IRQs
        DebugTX "IRQs on"

 [ DebugTerminal
        MOV     R0, #RdchV
        ADRL    R1, DebugTerminal_Rdch
        LDR     R2, =ZeroPage
        LDR     R2, [R2, #HAL_Workspace]
        SWI     XOS_Claim
        MOV     R0, #WrchV
        ADRL    R1, DebugTerminal_Wrch
        SWI     XOS_Claim
        DebugTX "Debug terminal on"
 ]

        [ DoInitialiseMode :LOR: :LNOT: Embedded_UI
        BL      InitialiseMode          ; select correct screen mode, in case any
                                        ; module prints anything in initialisation
        ]

        MOV     R0, #&FD                ; read last reset type
        MOV     R1, #0
        MOV     R2, #&FF
        SWI     XOS_Byte
        CMP     R1, #SoftReset          ; soft reset?
        BEQ     SkipHardResetPart2

; HardResetPart2
 [ HAL
        DebugTX "HAL_InitDevices"
        AddressHAL
        MOV     R0, #0
      [ ZeroPage = 0
        STR     R0, [R0, #DeviceCount]
        STR     R0, [R0, #DeviceTable]
      |
        LDR     R1, =ZeroPage
        STR     R0, [R1, #DeviceCount]
        STR     R0, [R1, #DeviceTable]
      ]
        CallHAL HAL_InitDevices         ; get HAL to register any devices it has
        BL      LookForHALRTC ; Check if an RTC was just added. This is currently the only place where HAL RTCs are checked for; if we wanted to check anywhere else (e.g. after ROM module initialisation) then we'd have to listen for Service_Hardware so we can cope with device removal
 |
        BL      L1L2PTenhancements      ; little tricks on cacheability etc for performance
 ]
        DebugTX "InitVariables"
        BL      InitVariables
        DebugTX "AMBControl_Init"
        BL      AMBControl_Init         ; initialise AMBControl section
        DebugTX "ModuleInit"
        BL      ModuleInit              ; initialise modules
                                        ; scan podules, copy modules.

        MOV     R0, #0                  ; shrink sysheap as far as will go.
        SUB     R1, R0, #4*1024*1024
        SWI     XOS_ChangeDynamicArea
        MOV     R0, #ReadCMOS
        MOV     R1, #SysHeapCMOS
        SWI     XOS_Byte
        AND     R2, R2, #2_111111       ; mask to same size as status
        LDR     R0, =ZeroPage
        LDR     R0, [R0, #Page_Size]
        MULTIPLY R3, R0, R2             ; size spare wanted
        BL      ClaimSysHeapNode
        MOV     R0, #HeapReason_Free
        SWI     XOS_Heap

        MOV     R0, #ReadCMOS
        MOV     R1, #FileLangCMOS
        SWI     XOS_Byte
        MOV     R1, R2
        MOV     R0, #FSControl_SelectFS ; set configured filing system
        SWI     XOS_FSControl

        ; OS_ReadSysInfo 9,2 now relies on the Territory module, which may
        ; enable IRQs. But the PRMs say OS_ReadSysInfo shouldn't alter the IRQ
        ; state. So call it once here just to initialise the string which it
        ; uses the Territory module to generate.
        ; This won't account for any modules using it during ModuleInit, but
        ; that should be pretty rare (or at least rare from within IRQ-sensitive
        ; code)
        MOV     R0, #9
        MOV     R1, #2
        SWI     XOS_ReadSysInfo

  [ UseNewFX0Error
        ; Also, *FX 0
        BL      InitNewFX0Error
  ]

  [ DebugROMInit
        SWI     XOS_WriteS
        =       "Service_PostInit",0
        SWI     XOS_NewLine
  ]
        MOV     r1, #Service_PostInit   ; issue post-initialisation service
        BL      Issue_Service

; New code added here by TMD 01-Apr-92
; Changed to use OS_LeaveOS 16-Oct-02

  [ DebugROMInit
        SWI     XOS_WriteS
        =       "callbacks",0
        SWI     XOS_NewLine
  ]
        SWI     XOS_LeaveOS
        SWI     XOS_EnterOS             ; switch back to SVC mode (IRQs, FIQs enabled)
  [ :LNOT: HAL :LAND: RO371Timings
        BL      finalmemoryspeed
  ]
; end of added code

     [ International                    ; Open the kernel messages file.
        LDR     r0, =ZeroPage+KernelMessagesBlock+4
        ADR     r1, MessageFileName
        MOV     r2, #0                  ; Use file directly.
        SWI     XMessageTrans_OpenFile
        MOVVC   r0, #-1
      [ ZeroPage = 0
        STRVC   r0, [r0, #KernelMessagesBlock+1]  ; Message file is now open.
      |
        LDR     lr, =ZeroPage
        STRVC   r0, [lr, #KernelMessagesBlock]  ; Message file is now open.
      ]
     ]

SkipHardResetPart2                      ; code executed on all types of reset
      [ International
        LDR     r0, =ZeroPage
        LDR     r1, [r0, #KernelMessagesBlock] ; if we've managed to open message file
        TEQ     r1, #0
        ASSERT  (ZeroPage :AND: 255) = 0
        STRNEB  r0, [r0, #ErrorSemaphore] ; then allow errors to be translated
      ]

      [ DoInitialiseMode :LOR: :LNOT: Embedded_UI
        BL      InitialiseMode
      ]
    [ :LNOT: Embedded_UI
        LDR     R0, =ZeroPage
        LDRB    R14, [R0, #MentionCMOSReset]
        TEQ     R14, #0
        BEQ     %FT12
      [ International
        SWI     XOS_WriteI+10
        BVS     %FT09
        BL      WriteS_Translated
        =       "CmosRst:CMOS RAM reset, press ESCAPE to continue",0
        ALIGN
09
      |
        SWI     XOS_WriteS
        =       10,"CMOS RAM reset, press ESCAPE to continue",0
        ALIGN
      ]
10
        SWI     XOS_ReadEscapeState
        BCC     %BT10
        MOV     R0, #124
        SWI     XOS_Byte                ; Clear the condition
        SWI     XOS_WriteI+12           ; Clear the screen
12
        SWI     XOS_WriteS
        =       10, "$SystemName ", 0   ; now RISC OS (no +) again
        ALIGN

        MOV     R0, #8
        ORR     R0, R0, #&500
        SWI     XOS_Memory              ; returns amount of soft ROM (pages) in r1
        MOVVS   R1, #0

        LDR     R0, =ZeroPage
        LDR     R0, [R0, #RAMLIMIT]
        MLA     R0, R1, R2, R0          ; convert pages to bytes and add in

        MOV     R0, R0, LSR #20         ; /(1024*1024) down to megabytes
        LDR     R1, =GeneralMOSBuffer
        MOV     R2, #?GeneralMOSBuffer
        SWI     XOS_ConvertInteger4
        SWI     XOS_Write0
        SWI     XOS_WriteS
        =       "MB", 10,13, 10, 0      ; title complete
        ALIGN

        BL      ARM_PrintProcessorType
    |
        ! 0,    "Banner & printing of processor type disabled"
    ]

        MOV     r0, #0                  ; Set DomainId to 0 every reset
      [ ZeroPage = 0
        STR     r0, [r0, #DomainId]     ; before calling anyone
      |
        LDR     r1, =ZeroPage
        STR     r0, [r1, #DomainId]     ; before calling anyone
      ]

; issue reset service call

        MOV     R1, #Service_Reset
        SWI     XOS_ServiceCall

; now set up the default FIQ owner

        MOV     R1, #Service_ClaimFIQ
        SWI     XOS_ServiceCall

        MOV     R1, #Service_ReleaseFIQ
        SWI     XOS_ServiceCall

 [ SoftResets :LAND: STB
        ! 0, "!!!! SoftReset is true => resets close all open files !!!!"
        MOV     R0, #FSControl_Shut     ; Open files get closed at reset
        SWI     XOS_FSControl
 ]

        BL      PostInit

        MOV     r0, #&FD                ; read last reset type (again!)
        MOV     r1, #0
        MOV     r2, #&FF
        SWI     XOS_Byte
        CMP     r1, #SoftReset          ; a softie?
        SWINE   XOS_WriteI+7            ; go beep! Yaay!

        CMP     r1, #PowerOnReset
        BNE     %FT75

 [ HAL :LAND: CheckProtectionLink
        LDR     r1, =ZeroPage+HAL_StartFlags
        LDR     r1, [r1]
        TST     r1, #OSStartFlag_NoCMOSReset
        BNE     %FT75
 |
      [ CheckProtectionLink
        LDR     r1, =IOMD_MonitorType   ; check link bit again
        LDRB    r1, [r1]                ; no need to preload bus, since should
        TST     r1, #IOMD_ProtectionLinkBit ; be still there from earlier
        BEQ     %FT75                   ; zero => protected
      ]
 ]


; if any monitor key pressed, reconfigure, otherwise hang around for a bit
; till keys get a chance to come in again after being reset for the umpteenth
; time by yet another keyboard handler! SKS 07-Jun-88

        LDR     r3, =ZeroPage
        LDR     r3, [r3, #MetroGnome]
 [ EmulatorSupport
        ARM_on_emulator r0
        ADDEQ   r3, r3, #1
        ADDNE   r3, r3, #10             ; Hang about for a little while
 |
        ADD     r3, r3, #10             ; Hang about for a little while
 ]

KeypadStar_key  * -92

HorologicalDelayLoop1
        MOV     r0, #&79                        ; scan keyboard
        MOV     r1, #&FF                        ; starting at (&FF + 1) AND &FF
60
        ADD     r1, r1, #1
        AND     r1, r1, #&FF
        SWI     XOS_Byte
        TEQ     r1, #&FF                        ; if no key down
        BEQ     %FT70                           ; then check if we've run out of time

        ADR     r2, MonitorKeypadTable
62
        LDRB    r14, [r2], #2                   ; search for key in table
        TEQ     r14, #&FF
        BEQ     %FT70
        TEQ     r1, r14
        BNE     %BT62
        LDRB    r3, [r2, #-1]                   ; get corresponding CMOS bits
        MOV     r0, #ReadCMOS
        MOV     r1, #VduCMOS
        SWI     XOS_Byte
        BIC     r2, r2, #MonitorTypeBits
        ORR     r2, r2, r3
        MOV     r0, #WriteCMOS
        SWI     XOS_Byte

        TEQ     r3, #MonitorTypeAuto            ; if we're setting monitortype auto
        BNE     %FT64
        ADRL    r0, ModeCMOSTable +8            ; then configure mode auto
        LDR     r2, [r0, #-8]                   ; (load auto value)
        BL      WriteMultiField
        ADRL    r0, SyncCMOSTable +8            ; and configure sync auto
        LDR     r2, [r0, #-8]                   ; (load auto value)
        BL      WriteMultiField

64
    [ DoInitialiseMode :LOR: :LNOT: Embedded_UI
        BL      InitialiseMode

      [ International
        SWI     XOS_WriteI+10
        BVS     %FT65
        BL      WriteS_Translated
        =       "MonType:Monitor type reconfigured",10,13,10,0
        ALIGN
65
      |
        SWI     XOS_WriteS
        =       10,"Monitor type reconfigured",10,13,10,0
        ALIGN
      ]
    ]
        B       %FT75

BranchThroughZeroInstruction2
 [ ProcessorVectors
        LDR     PC, .+ProcVec_Branch0
 |
        B       .+Branch0_Trampoline
 ]

MonitorKeypadTable      ; internal key number, CMOS bits
        =       106, MonitorType0
        =       107, MonitorType1
        =       124, MonitorType2
        =       108, MonitorType3
        =       122, MonitorType4
        =       123, MonitorType5
        =       26,  MonitorType6
        =       27,  MonitorType7
        =       42,  MonitorType8
        =       43,  MonitorType9
        =       76,  MonitorTypeAuto    ; keypad dot
        =       &FF
        ALIGN 32

      [ International
MessageFileName DCB     "Resources:$.Resources.Kernel.Messages",0
        ALIGN
      ]

 [ StrongARM :LAND: :LNOT: HAL
cputable
        DCD &6000,0,0
        DCD &6100,1,0
        DCD &7000,2,0
        DCD &7100,3,0
        DCD &8100,4,2_11101
        DCD &a100,5,2_11011 ;corrected for 3.71 (SA does not abort for vector reads in 26-bit mode)
        DCD &7500,6,0
        DCD &7501,7,0
        DCD -1

Processor_Type
        MOV     r0,#IOMD_Base
        LDRB    r1,[r0,#IOMD_ID0]
        CMP     r1,#&E7
        LDRB    r1,[r0,#IOMD_ID1]
        CMPEQ   r1,#&D4
        BEQ     PT_RiscPC               ; E7,D4 means Risc PC
        CMP     r1,#&5B
        MOVEQ   r0,#&7500               ; 5B means 7500
        BEQ     PT_lookup
        CMP     r1,#&AA
        MOVEQ   r0,#&7500
        ORREQ   r0,r0,#&0001            ; AA means 7500FE - mark as 7501
        BEQ     PT_lookup
PT_RiscPC
        ReadCop  R0,CR_ID               ; see data sheets for values
        ; ARM 600 funny
        TST     R0,#&f000
        MOVEQ   R0,R0, LSL #4
        AND     R0,R0,#&ff00
PT_lookup
        ADR     R1,cputable
66
        LDR     R2,[R1],#4
        TEQ     R2,#0
        MOVMI   R0,#0
        STRMI   R2,[R0,#ProcessorType]
        MOVMI   PC,LR
        TEQ     R2,R0
        ADDNE   R1,R1,#8
        BNE     %BT66
        LDMIA   R1,{R0,R2}
        MOV     R1,#0
        STRB    R0,[R1,#ProcessorType]
        STR     R2,[R1,#ProcessorFlags]
        MOV     PC,LR
 ]

70
        LDR     r14, =ZeroPage
        LDR     r14, [r14, #MetroGnome]
        CMP     r14, r3
        BLO     HorologicalDelayLoop1
75


; Deal with SHIFT pressed/SHIFT-BREAK configured:
; do appropriate FSControl if wanted

        Pull    "R0"                    ; first check kbd there

        CMP     R0, #0
        BEQ     AutoBootCosNoKbd

        MOV     R0, #&FF
        MOV     R1, #0
        MOV     R2, #&FF                ; read shifty state
        SWI     XOS_Byte
        AND     R0, R1, #8              ; picka da bit
        EOR     R0, R0, #8              ; invert sense
        Pull    "R1"
        CMP     R1, #0
        MOVNE   R1, #8
        EORS    R1, R1, R0
        BEQ     %FT80

Hortoculture_Kicking
        MOV     R0, #FSControl_BootupFS
        SWI     XOS_FSControl
        BVC     %FT80

        Push    "r3,r4"
        ADD     r1, r0, #4              ; Set Boot$Error if it failed (Desktop will report it).
        ADR     r0, str_booterror
        MOV     r2, #1024               ; Big enough that terminator will be reached.
        MOV     r3, #0
        MOV     r4, #VarType_String
        SWI     XOS_SetVarVal
        SUBVS   r0, r1, #4              ; If setting Boot$Error failed then report original error as before.
        BLVS    PrintError
        SWIVS   XOS_NewLine
        Pull    "r3,r4"
80
; if either * pressed, drop into * prompt, otherwise hang around for a bit
; till keys get a chance to come in again after being reset for the umpteenth
; time by yet another keyboard handler! SKS 01-Jun-88

        LDR     r3, =ZeroPage
        LDR     r3, [r3, #MetroGnome]
 [ EmulatorSupport
        ARM_on_emulator r1
        ADDEQ   r3, r3, #1
        ADDNE   r3, r3, #10             ; Hang about for a little while
 |
        ADD     r3, r3, #10             ; Hang about for a little while
 ]

HorologicalDelayLoop2
        MOV     r1, #KeypadStar_key :AND: &FF
        BL      IsKeyPressedAtReset
        BEQ     DoStartSuper            ; EQ -> start up supervisor

        LDR     r0, =ZeroPage
        LDR     r0, [r0, #MetroGnome]
        CMP     r0, r3
        BLO     HorologicalDelayLoop2


; Start configured language module if keypad-* wasn't pressed

        MOV     R0, #ReadCMOS
        MOV     R1, #LanguageCMOS
        SWI     XOS_Byte

        MOV     R0, #ModHandReason_GetNames
        SUB     R1, R2, #1
        MOV     R2, #0                  ; preferred incarnation
        SWI     XOS_Module
        ADRVSL  R3, UtilityMod
        LDR     R2, [R3, #Module_Title]
        CMP     R2, #0
        ADDNE   R1, R3, R2
DoStartSuper
        ADREQL  R1, UtilModTitle        ; ALWAYS enter via SWI: sets CAO etc.
        MOV     R0, #ModHandReason_Enter
        ADRL    R2, crstring            ; no environment
        SWI     XOS_Module
        CMP     r0, r0                  ; set EQ if failed to enter config.lang
        B       DoStartSuper            ; -> force Super entry


str_booterror   DCB     "Boot$Error",0
                ALIGN


AutoBootCosNoKbd
    [ :LNOT: Embedded_UI
      [ International
        SWI     XOS_WriteI+7
        BVS     %FT81
        BL      WriteS_Translated
        =       "NoKbd:No keyboard present - autobooting", 10,13,0
        ALIGN
81
      |
        SWI     XOS_WriteS
        =       7, "No keyboard present - autobooting", 10,13,0
        ALIGN
      ]
    ]
        B       Hortoculture_Kicking


RealIRQHandler
 [ ProcessorVectors
        LDR     PC, .-&18+ProcVec_IRQ
 |
        B     Initial_IRQ_Code+.-&18
 ]

; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
; In    r1 = INKEY -ve key code to look for

; Out   EQ: key pressed
;       NE: key not pressed

IsKeyPressedAtReset Entry "r0-r2"

        MOV     r0, #129
        MOV     r2, #&FF
        SWI     XOS_Byte
        TEQ     r1, #&FF
        TEQEQ   r2, #&FF
        EXIT

; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

    [ AddTubeBashers
TubeDumpR0     ROUT
        EntryS  "R1, R2"
        ADR   lr, HexTable
        TubeChar r0, r1, "MOV r1, #"" """
        MOV    R1, #7
01      MOV    R0, R0, ROR #28
        AND    R2, R0, #&F
        TubeChar R0, R1, "LDRB R1, [lr, R2]"
        SUBS   R1, R1, #1
        BPL    %BT01
        TubeChar r0, r1, "MOV r1, #"" """
        EXITS

TubeNewl
        EntryS
        TubeChar R0, R1, "MOV R1, #10"
        TubeChar R0, R1, "MOV R1, #13"
        EXITS

HexTable = "0123456789ABCDEF"

    ]

; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

 [ HAL
LookForHALRTC
        Push "R0-R2,R8,R12,R14"
        LDR     R0, =ZeroPage
        LDR     R0, [R0, #RTCFitted]
        CMP     R0, #0
        Pull "R0-R2,R8,R12,PC",NE ; We already have an RTC
        LDR     R0, =(0:SHL:16)+HALDeviceType_SysPeri+HALDeviceSysPeri_RTC
        MOV     R1, #0
        MOV     R8, #OSHW_DeviceEnumerate
01
        SWI     XOS_Hardware
        Pull "R0-R2,R8,R12,PC",VS
        CMP     R1, #-1
        Pull "R0-R2,R8,R12,PC",EQ
        LDR     R14, [R2, #HALDevice_Location]
        ; Currently, we only support devices located on IIC bus 0
        CMP     R14, #HALDeviceBus_Ser+HALDeviceSerBus_IIC
        BNE     %BT01
        ; Try activating
        Push "R0-R3"
        MOV     R0, R2
        MOV     LR, PC
        LDR     PC, [R2, #HALDevice_Activate]
        CMP     R0, #1
        Pull "R0-R3"
        BNE     %BT01
        DebugTX "HAL RTC detected!"
        LDR     R0, =ZeroPage
        STR     R2, [R0, #RTCFitted]
        ; Read the time from the RTC into RealTime, and fixup YearCMOS if needed
        BYTEWS  WsPtr
        BL      CheckYear
        DebugTX "Leaving LookForHALRTC"
        Pull "R0-R2,R8,R12,PC"
 ]

        END