Utility

; 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  => Utility

; *****************************************************************************
; Arthur Utility commands

SysModules_Info ROUT     ; start of ROM modules chain
        &       EndOfKernel-SysModules_Info

UtilityMod
        &       StartSuper-UtilityMod
        &       0                               ; no initialisation
        &       Util_Die-UtilityMod
        &       Util_Service-UtilityMod         ; code to register printer buffer with Buffer manager
        &       UtilModTitle-UtilityMod
        &       UtilHelpStr-UtilityMod
        &       UtilHelpTab-UtilityMod
        &       &F00000
        &       Util_SWI-UtilityMod
        &       Util_SWITab-UtilityMod
        &       0
 [ International_Help <> 0
        &       MessageFileName-UtilityMod
 |
        &       0
 ]
 [ :LNOT: No32bitCode
        &       UtilFlags-UtilityMod
 ]

Util_SWITab
        =       "ARM",0
        =       "IMB",0
        =       "IMBRange",0
        =       0
        ALIGN

Module_BaseAddr SETA UtilityMod

  [ ChocolateService
    ;service table
    ;
        ASSERT Service_MessageFileClosed < Service_BufferStarting
        ASSERT Service_BufferStarting    < Service_TerritoryStarted
        ASSERT Service_TerritoryStarted  < Service_DeviceFSCloseRequest
    ;

Util_ChocServTab
        DCD    0                            ;flags word
        DCD    Util_ChocService-UtilityMod  ;offset to handler
   [ CacheCommonErrors
        DCD    Service_MessageFileClosed
   ]
        DCD    Service_BufferStarting       ;service 1
   [ CacheCommonErrors
        DCD    Service_TerritoryStarted
   ]
        DCD    Service_DeviceFSCloseRequest ;service 2
        DCD    0                            ;terminator
        DCD    Util_ChocServTab-UtilityMod  ;table anchor
  ]
Util_Service ROUT
  [ ChocolateService
        MOV     r0, r0   ;magic instruction for new service table format
  ]
        TEQ     r1, #Service_BufferStarting
        TEQNE   r1, #Service_DeviceFSCloseRequest
  [ CacheCommonErrors
        TEQNE   r1, #Service_TerritoryStarted
        TEQNE   r1, #Service_MessageFileClosed
  ]
        MOVNE   pc, lr
  [ ChocolateService
    ;entry point excluding pre-rejection code
Util_ChocService
  ]
  [ CacheCommonErrors
        TEQ     r1, #Service_TerritoryStarted
        TEQNE   r1, #Service_MessageFileClosed
        BEQ     CacheCommonErrorsReinit
  ]
        TEQ     r1, #Service_BufferStarting
        BNE     %FT10
        Push    "r0-r3,lr"

; Register buffers with buffer manager in order of speed - first is fast

 [ MouseBufferManager
        MOV     r0, #BufferFlags_GenerateInputFull
        LDR     r1, =MouseBuff
        LDR     r2, =MouseBuff + MouseBuffSize
        MOV     r3, #Buff_Mouse
        SWI     XBuffer_Register                ; register mouse input buffer
 ]
        MOV     r0, #BufferFlags_GenerateInputFull :OR: BufferFlags_SendThresholdUpCalls
        LDR     r1, =RS423InBuff
        LDR     r2, =RS423InBuff + RS423InBuffSize
        MOV     r3, #Buff_RS423In
        SWI     XBuffer_Register                ; register serial input buffer

        MOV     r0, #BufferFlags_GenerateOutputEmpty
        LDR     r1, =RS423OutBuff
        LDR     r2, =RS423OutBuff + RS423OutBuffSize
        MOV     r3, #Buff_RS423Out
        SWI     XBuffer_Register                ; register serial output buffer

        LDR     r0, =ZeroPage                   ; used as index to PrinterBufferThing
        LDR     r1, [r0, #PrinterBufferAddr]    ; r1 -> start of buffer
        LDR     r2, [r0, #PrinterBufferSize]    ; r2 = size
        ADD     r2, r2, r1                      ; r2 -> end+1 of buffer
        MOV     r3, #Buff_Print
        MOV     r0, #BufferFlags_GenerateOutputEmpty
        SWI     XBuffer_Register                ; register the MOS's printer buffer

        Pull    "r0-r3,pc"

; service DeviceFSCloseRequest
; in:   r2 = handle we are requested to close
;       if r2 = PrinterActive (word) or SerialInHandle (byte) or SerialOutHandle (byte)
;       then zero appropriate variable and close file, then claim service
;       NB there is a disadvantage to doing it for SerialInHandle, in that it won't get
;       opened again, but we assume they accidentally left it in an fx2,2 state
;

10
        Push    "r0,r1,lr"
        LDR     lr, =ZeroPage
        MOV     r0, #0
        LDR     r1, [lr, #OsbyteVars + :INDEX: PrinterActive]
        TEQ     r1, r2
        STREQ   r0, [lr, #OsbyteVars + :INDEX: PrinterActive]
        BEQ     %FT20
        LDRB    r1, [lr, #OsbyteVars + :INDEX: SerialInHandle]
        TEQ     r1, r2
        STREQB  r0, [lr, #OsbyteVars + :INDEX: SerialInHandle]
        BEQ     %FT20
        LDRB    r1, [lr, #OsbyteVars + :INDEX: SerialOutHandle]
        TEQ     r1, r2
        Pull    "r0,r1,pc",NE                   ; if not any of these then exit preserving everything
        STRB    r0, [lr, #OsbyteVars + :INDEX: SerialOutHandle]
20
        SWI     XOS_Find                        ; close file, ignore errors (if we get an error it's closed anyway)
        MOV     r1, #Service_Serviced           ; indicate we closed it
        Pull    "r0,lr,pc"                      ; restore r0, junk r1, and exit


Util_Die   ROUT
           CMP   R10, #0
           MOVEQ PC, lr      ; non-fatal : can cope
           ADR   R0, %FT01
 [ International
           Push  "lr"
           BL    TranslateError
           Pull  "pc"
 |
           RETURNVS
 ]

01
           &     ErrorNumber_CantKill
 [ International
           =    "CantKill", 0
 |
           =    "Deleting the utility module is foolish", 0
 ]


UtilModTitle =  "UtilityModule", 0

UtilHelpStr  =  "MOS Utilities", 9, "$VersionNo", 0

  [ Oscli_HashedCommands
;
;***WARNING*** if commands are added or changed, UtilHashedCmdTab MUST be updated correspondingly
;
  ]
UtilHelpTab
           Command   Break,              0,  0, International_Help   ; just help
           Command   ChangeDynamicArea,255,  0, International_Help
           Command   Configure,        255,  0, Help_Is_Code_Flag :OR: International_Help
           Command   Commands,           0,  0, Help_Is_Code_Flag :OR: International_Help
           Command   Echo,             255,  0, International_Help
           Command   Error,            255,  1, International_Help
           Command   Eval,             255,  1, International_Help
           Command   FileCommands,       0,  0, Help_Is_Code_Flag :OR: International_Help
           Command   GOS,                0,  0, International_Help
           Command   IF,               255,  2, International_Help
           Command   Ignore,             1,  0, International_Help
           Command   Modules,            0,  0, Help_Is_Code_Flag :OR: International_Help
           Command   PowerOn,            0,  0, International_Help   ; just help
           Command   Reset,              0,  0, International_Help   ; just help
           Command   RMClear,            0,  0, International_Help
           Command   RMEnsure,         255,  2, International_Help
           Command   RMFaster,           1,  1, International_Help
           Command   RMInsert,           2,  1, International_Help
           Command   RMKill,             1,  1, International_Help
           Command   RMLoad,           255,  1, International_Help
           Command   RMReInit,         255,  1, International_Help
           Command   RMRun,            255,  1, International_Help
           Command   RMTidy,             0,  0, International_Help
           Command   ROMModules,         0,  0, International_Help
           Command   Set,              255,  2, International_Help
           Command   SetEval,          255,  2, International_Help
           Command   SetMacro,         255,  2, International_Help
           Command   Show,               1,  0, International_Help   ; *show = *show *
           Command   Status,           255,  0, International_Help
           Command   Syntax,             0,  0, International_Help
           Command   Time,               0,  0, International_Help
           Command   Unplug,             2,  0, International_Help
           Command   Unset,              1,  1, International_Help
           =   0

  [ Oscli_HashedCommands
;
; - Hashing table is 32 wide
; - Hashing function is:
;
;      hash = (sum of all chars of command, each upper-cased) & 0x1f
;
; - Order of commands in each hashed list is chosen as 'most common' first

; Table MUST be reorganised if hashing function changed, or command set altered
;
           ALIGN
UtilHashedCmdTab
;
;    ! 0,"UtilHashedCmdTab  at ":CC::STR:(UtilHashedCmdTab)
;
;First, 1 word per table entry, giving offset to hashed list on each hash value
;
           DCD       0                        ;null list on this hash value
           DCD       UHC_hash01 - UtilityMod
           DCD       UHC_hash02 - UtilityMod
           DCD       0
           DCD       UHC_hash04 - UtilityMod
           DCD       0
           DCD       UHC_hash06 - UtilityMod
           DCD       UHC_hash07 - UtilityMod
           DCD       UHC_hash08 - UtilityMod
           DCD       UHC_hash09 - UtilityMod
           DCD       UHC_hash0A - UtilityMod
           DCD       UHC_hash0B - UtilityMod
           DCD       UHC_hash0C - UtilityMod
           DCD       0
           DCD       0
           DCD       UHC_hash0F - UtilityMod
           DCD       0
           DCD       UHC_hash11 - UtilityMod
           DCD       0
           DCD       0
           DCD       UHC_hash14 - UtilityMod
           DCD       0
           DCD       0
           DCD       0
           DCD       0
           DCD       UHC_hash19 - UtilityMod
           DCD       0
           DCD       UHC_hash1B - UtilityMod
           DCD       0
           DCD       0
           DCD       UHC_hash1E - UtilityMod
           DCD       UHC_hash1F - UtilityMod
;
; Now the hashed lists
;
UHC_hash01
           Command   Show,               1,  0, International_Help
           =   0
           ALIGN
UHC_hash02
           Command   Configure,        255,  0, Help_Is_Code_Flag :OR: International_Help
           =   0
           ALIGN
UHC_hash04
           Command   ChangeDynamicArea,255,  0, International_Help
           Command   RMFaster,           1,  1, International_Help
           Command   Status,           255,  0, International_Help
           Command   Ignore,             1,  0, International_Help
           =   0
           ALIGN
UHC_hash06
           Command   RMClear,            0,  0, International_Help
           =   0
           ALIGN
UHC_hash07
           Command   ROMModules,         0,  0, International_Help
           =   0
           ALIGN
UHC_hash08
           Command   Eval,             255,  1, International_Help
           =   0
           ALIGN
UHC_hash09
           Command   GOS,                0,  0, International_Help
           =   0
           ALIGN
UHC_hash0A
           Command   RMReInit,         255,  1, International_Help
           Command   Error,            255,  1, International_Help
           =   0
           ALIGN
UHC_hash0B
           Command   RMKill,             1,  1, International_Help
           =   0
           ALIGN
UHC_hash0C
           Command   Set,              255,  2, International_Help
           =   0
           ALIGN
UHC_hash0F
           Command   IF,               255,  2, International_Help
           Command   Unset,              1,  1, International_Help
           Command   Time,               0,  0, International_Help
           =   0
           ALIGN
UHC_hash11
           Command   RMEnsure,         255,  2, International_Help
           =   0
           ALIGN
UHC_hash14
           Command   SetEval,          255,  2, International_Help
           Command   RMRun,            255,  1, International_Help
           Command   RMInsert,           2,  1, International_Help
           =   0
           ALIGN
UHC_hash19
           Command   Modules,            0,  0, Help_Is_Code_Flag :OR: International_Help
           Command   RMTidy,             0,  0, International_Help
           =   0
           ALIGN
UHC_hash1B
           Command   Unplug,             2,  0, International_Help
           =   0
           ALIGN
UHC_hash1E
           Command   SetMacro,         255,  2, International_Help
           =   0
           ALIGN
UHC_hash1F
           Command   RMLoad,           255,  1, International_Help
           Command   Echo,             255,  0, International_Help
           =   0
           ALIGN

  ] ;Oscli_HashedCommands

Configure_Syntax     * Module_BaseAddr
Commands_Code        * Module_BaseAddr
Commands_Syntax      * Module_BaseAddr
Syntax_Code          * Module_BaseAddr
Syntax_Syntax        * Module_BaseAddr
Echo_Syntax          * Module_BaseAddr
Status_Syntax        * Module_BaseAddr
FileCommands_Code    * Module_BaseAddr
FileCommands_Syntax  * Module_BaseAddr
Reset_Code           * Module_BaseAddr
Reset_Syntax         * Module_BaseAddr
Break_Code           * Module_BaseAddr
Break_Syntax         * Module_BaseAddr
PowerOn_Code         * Module_BaseAddr
PowerOn_Syntax       * Module_BaseAddr

RMFaster_Code
           Push "lr"
           MOV R1, R0
           MOV R0, #ModHandReason_LookupName
           SWI XOS_Module
           Pull "PC", VS
           CMP   R3, #ROM                 ; HS if R3 >= ROM
           BLO   RMFast_notinROM
 [ :LNOT:ROMatTop
           CMP   R3, #ROMLimit
           BHS   RMFast_notinROM
 ]
           MOV   R1, R3
           LDR   R2, [R1, #-4]
           MOV   R0, #ModHandReason_CopyArea
           SWI   XOS_Module
           Pull  PC

RMFast_notinROM
           ADRL R0, ErrorBlock_RMNotFoundInROM
         [ International
           BL   TranslateError
         ]
           Pull lr
           RETURNVS

RMKill_Code
           MOV R6, #ModHandReason_Delete

Rmcommon   Push "lr"
           MOV r1, r0
           MOV r0, r6
           SWI   XOS_Module
           Pull "PC"

RMLoad_Code
           MOV R6, #ModHandReason_Load
           B   Rmcommon

RMRun_Code
           MOV R6, #ModHandReason_Run
           B   Rmcommon

RMTidy_Code
           MOV R6, #ModHandReason_Tidy
           B   Rmcommon

RMClear_Code
           MOV R6, #ModHandReason_Clear
           B   Rmcommon

RMReInit_Code
           MOV R6, #ModHandReason_ReInit
           B   Rmcommon

Modules_Help   ROUT
          Push  "r2, r3, lr"
          LDR   r2, =ZeroPage                      ; Try our own message file before Global.
          LDR   r0, [r2, #KernelMessagesBlock]
          TEQ   r0, #0
          ADDNE r0, r2, #KernelMessagesBlock+4
          ADRL  r1, modules_help1
        [ ZeroPage <> 0
          MOV   r2, #0
        ]
          SWI   XMessageTrans_Lookup
          SWIVC XMessageTrans_Dictionary
          MOVVC r1, r0
          MOVVC r0, r2
          SWIVC XOS_PrettyPrint
          Pull  "r2, r3, PC", VS
          LDR    R1, =ZeroPage+Module_List
03        LDR    R1, [R1]
          CMP    R1, #0
          BEQ    %FT05
          LDR    R0, [R1, #Module_code_pointer]
          BL     PrintTitle
          BVC    %BT03
05        MOVVC  R0, #0
          Pull  "r2, r3, PC"

PrintTitle ; of module at R0 : corrupts R0
        Push  "R1, lr"
        LDR    R1, [R0, #Module_HelpStr]
        CMP    R1, #0
        ADREQ  R0, NoRIT
      [ International
        BLEQ   Write0_Translated
        ADDNE  R0, R1, R0
        SWINE  XOS_PrettyPrint
      |
        ADDNE  R0, R1, R0
        SWI    XOS_PrettyPrint
      ]
        SWIVC  XOS_NewLine
        Pull  "R1, PC"

Modules_Code ROUT
        Push   "R7, lr"

      [ International
        BL     WriteS_Translated
        =      "Modules:No. Position Workspace Name", 10, 13, 0
        ALIGN
      |
        SWI     XOS_WriteS
        =      "No. Position Workspace Name", 10, 13, 0
        ALIGN
      ]
        Pull   "R7, PC", VS

        MOV     R1, #0
        MOV     R2, #0
        MOV     R6, #0
        MOV     R7, #0
06
        SWI     XOS_ReadEscapeState
        Pull    "R7, lr", CS
        BCS     AckEscape
        MOV     R0, #ModHandReason_GetNames
        SWI     XOS_Module
        BVC     %FT07
        CLRV
        Pull   "R7, pc"              ; back, clearing V

07
        Push   "R1, R2"
        CMP     R6, #0
        MOVNE   R1, #0
        BNE     %FT02
        ADD     R7, R7, #1
        MOV     R0, R7
        LDR     R1, =GeneralMOSBuffer
        MOV     R2, #256
        SWI     XOS_ConvertCardinal2
        SUB     R1, R1, R0          ; characters in buffer
02      CMP     R1, #3
        SWILT   XOS_WriteI+" "
        BVS     %FT03
        ADDLT   R1, R1, #1
        BLT     %BT02
03
        Pull   "R1, R2"
        BVS     %FT04
        CMP     R6, #0
        SWIEQ   XOS_Write0
        SWIVC   XOS_WriteI+" "
        MOV     R0, R3
        BLVC    HexR0LongWord
        SWIVC   XOS_WriteI+" "
        MOV     R0, R4
        BLVC    HexR0LongWord
        SWIVC   XOS_WriteI+" "
        SWIVC   XOS_WriteI+" "
        BLVC    %FT01         ; title out
        SWIVC   XOS_NewLine
        BVC     %BT06
04
        Pull   "R7, PC"
01
        Push   "lr"
        LDR     R0, [R3, #Module_Title]
        CMP     R0, #0
        ADDNE   R0, R3, R0
        ADREQ   R0, NoRIT
      [ International
        BLEQ    Write0_Translated
        SWINE   XOS_Write0
      |
        SWI     XOS_Write0
      ]
        Pull   "PC", VS
        CMP     R6, #0
        CMPEQ   R2, #0
        MOV     R6, R2
        Pull   "PC", EQ       ; only one incarnation
        SWI     XOS_WriteI + Postfix_Separator
        MOV     R0, R5
        SWIVC   XOS_Write0
        Pull   "PC"

      [ International
NoRIT   =   "Untitled:<Untitled>", 0
      |
NoRIT   =   "<Untitled>", 0
      ]
starstr =   "*", 13
        ALIGN



Show_Code
        CMP     r1, #0                  ; *show only?
        ADREQ   r0, starstr
        Entry   "r0,r7",8+256
        MRS     r7, CPSR

        ADD     r6, sp, #8              ; initial buffer for var expansions
        MOV     lr, #256+4
        STR     lr, [sp, #4]            ; fake heap block size
        MOV     lr, #&ffffffff
        STR     lr, [sp, #0]            ; inhibit page mode off on exit

        ; Read current VDU status and save it away
        MOVVC   r0, #117
        SWIVC   XOS_Byte
        STRVC   R1, [sp, #0]
        SWIVC   XOS_WriteI+14           ; paged mode on.
        BVS     ShowBang

        MOV     r3, #0          ; enumeration pointer
01
        LDR     r0, [sp, #Proc_RegOffset + 0*4]        ; wildcard
10
        MOV     r1, r6          ; 'heap' block
        LDR     r2, [r6, #-4]   ; block size
        SUB     r2, r2, #4
        MOV     r4, #0          ; no expansion
        SWI     XOS_ReadVarVal
        BVS     Show_ErrorReading

        ; Varname
        MOV     r0, r3
        SWI     XOS_Write0
        BVS     ShowBang

        ; (Number) or (Macro) as appropriate
        CMP     R4, #VarType_String
        BEQ     skipvalprt
      [ :LNOT: International
        SWI     XOS_WriteS
        =       " (", 0
        ALIGN
        BVS     ShowBang
      ]
        CMP     R4, #VarType_Number
        MOVEQ   R2, #256
        LDREQ   R0, [R1]
        SWIEQ   XOS_BinaryToDecimal
        ADREQ   R0, %FT02
        ADRHI   R0, %FT03
      [ International
        BLVC    Write0_Translated
      |
        SWIVC   XOS_Write0
        SWIVC   XOS_WriteI+")"
      ]
        BVS     ShowBang
skipvalprt
        ; " : "
        SWI     XOS_WriteS
        =       " : ", 0
        ALIGN
        BVS     ShowBang

        ; Now output the value's value
        MOV     R5, #-1
05      ADD     R5, R5, #1
        CMP     R5, R2
        BEQ     %FT06
        SWI     XOS_ReadEscapeState
        BLCS    AckEscape
        BVS     ShowBang
        LDRB    R0, [R1, R5]
        CMP     R0, #&7F
        MOVEQ   R0, #"?"-"@"
        CMP     R0, #31
        ADDLE   R0, R0, #"@"
        SWILE   XOS_WriteI+"|"
        BVS     ShowBang

        CMP     R0, #"|"
        CMPNE   R0, #""""
        CMPNE   R0, #"<"
        SWINE   XOS_WriteC
        BVS     ShowBang
        BNE     %BT05

        CMP     R4, #VarType_Macro
        SWINE   XOS_WriteI+"|"
        SWIVC   XOS_WriteC
        BVC     %BT05
ShowBang
        STR     r0, [sp, #Proc_RegOffset + 0*4]
        ORR     r7, r7, #V_bit                          ; CPSR in

Show_Exit
        ; Release buffer if necessary
        ADD     lr, sp, #8              ; stack buffer
        TEQ     r6, lr
        MOVNE   r0, #ModHandReason_Free
        MOVNE   r2, r6
        SWINE   XOS_Module

        ; Switch paged mode off if necessary
        LDR     lr, [sp, #0]
        TST     lr, #5
        SWIEQ   XOS_WriteI+15  ; paged mode off

        MSR     CPSR_f, r7
        EXIT

06      SWI     XOS_NewLine
        BVS     ShowBang
        B       %BT01

      [ International
02
        =       "Number:(Number)", 0
03
        =       "Macro:(Macro)", 0
      |
02
        =       "Number", 0
03
        =       "Macro", 0
      ]
        ALIGN

Show_ErrorReading
        ; Error from OS_ReadVarVal:
        ; VarCantFind - end of *show
        ; BuffOverflow - try and extend buffer
        ; other - return as error
        LDR     r5, [r0]
        LDR     lr, =ErrorNumber_VarCantFind
        TEQ     r5, lr
        BEQ     Show_Exit
        LDR     lr, =ErrorNumber_BuffOverflow
        TEQ     r5, lr
        BNE     ShowBang

        ; try and extend the buffer
        CLRV
        MOV     r1, r3                  ; actual name so retry gets this node exactly
        ADD     lr, sp, #8              ; stack buffer
        TEQ     r6, lr
        MOV     r0, #ModHandReason_Free
        MOV     r2, r6
        MOV     r6, lr                  ; to prevent any attempt at freeing in ShowBang
        SWINE   XOS_Module
        BVS     ShowBang

        MOV     r0, r1
        MOV     r1, #ARM_CC_Mask
        MOV     r2, #-1                 ; To sence size
        MOV     r3, #0                  ; 1st var
        MOV     r4, #0                  ; unexpanded
        SWI     XOS_ReadVarVal
        CLRV                            ; error will be buffer overflow
        MOV     r1, r3                  ; varname again
        MVN     r3, r2
        ADD     r3, r3, #&ff            ; round up to 256 byte boundary
        BIC     r3, r3, #&ff
        MOV     r0, #ModHandReason_Claim
        SWI     XOS_Module
        BVS     ShowBang
        MOV     r6, r2
        MOV     r0, r1
        MOV     r3, #0                  ; restart from that node
        B       %BT10

Set_Code ROUT
        MOV    R4, #VarType_String
01
        Push  "lr"

        ; space terminated name in R0

        ; Skip name in R1
        MOV    R1, R0
02      LDRB   R2, [R1], #1
        CMP    R2, #" "
        BNE    %BT02

        ; Then skip spaces
03      LDRB   R2, [R1], #1
        CMP    R2, #" "
        BEQ    %BT03
        SUB    R1, R1, #1

        ; r2 +ve to set, r3 = 0 for 1st var
        MOV    R2, #1
        MOV    R3, #0
        SWI    XOS_SetVarVal
        Pull  "PC"

        LTORG

SetMacro_Code MOV    R4, #VarType_Macro
        B  %BT01

SetEval_Code MOV    R4, #VarType_Expanded
        B  %BT01

Unset_Code ROUT
        Push  "lr"
        MOV    R2, #-1
        MOV    R3, #0
01      SWI    XOS_SetVarVal
        BVC    %BT01
        CLRV
        Pull  "pc"

Echo_Code ROUT
        Push  "lr"
        MOV    R2, #GS_NoQuoteMess
        SWI    XOS_GSInit
01      SWI    XOS_GSRead
        BVS    %FT02
        MOVCC  R3, R0
        MOVCC  R0, R1
        SWICC  XOS_WriteC
        BVS    %FT02
        MOVCC  R0, R3
        BCC    %BT01
        SWI    XOS_NewLine
02
        Pull  "PC"

Commands_Help  ROUT
        Push  "R0, lr"         ; keep buffer pointer
        ADRL   R0, commands_helpstr
        MOV    R1, #0
KeyHelpCommon                  ; also used by *Configure
        Push   r1
; R2 & R3 can be junked here?
        MOV    r1, r0
        LDR    r2, =ZeroPage   ; Try our own message file before Global.
        LDR    r0, [r2, #KernelMessagesBlock]
        TEQ    r0, #0
        ADDNE  r0, r2, #KernelMessagesBlock+4
      [ ZeroPage <> 0
        MOV    r2, #0
      ]
        SWI    XMessageTrans_Lookup
        SWIVC  XMessageTrans_Dictionary
        MOVVC  r1, r0
        MOVVC  r0, r2
        SWIVC  XOS_PrettyPrint
        Pull   "r1,lr,PC", VS  ; if error, pull R1, junk stacked R0 and exit
        Pull   "r1,r3"         ; restore r1 and get buffer pointer
        MOV    r0, #0
        ADRL   R2, SysCommsModule
        BL     OneModuleK
        BVS    %FT10
        LDR    R6, =ZeroPage+Module_List
12      LDR    R6, [R6]
        CMP    R6, #0
        BEQ    %FT10
        LDR    R2, [R6, #Module_code_pointer]
        BL     OneModuleK
        BVC    %BT12
10      MOVVC  R0, #0
        Pull  "PC"

FileCommands_Help
        Push  "R0, lr"
        ADRL   R0, fscommands_helpstr
        MOV    R1, #FS_Command_Flag
        B      KeyHelpCommon

; take module code pointer in r2
;                    flags in r1
;    HelpBufferSize buffer in r3
;          string to print in r0

OneModuleK     ROUT
        Push  "r2-r7, lr"
        LDR    R4, [R2, #Module_HC_Table]
        CMP    R4, #0
        Pull  "r2-r7, PC", EQ       ; no table
        MOV    R7, #&80000000       ; flag
        MOV    R5, #0               ; buffer offset

        ADD    R2, R2, R4           ; point at table start.
03      MOV    R6, R2
        LDRB   R4, [R2]
        CMP    R4, #0
        BEQ    %FT06

04      LDRB   R4, [R6], #1
        CMP    R4, #0
        BNE    %BT04
        ADD    lr, R6, #3
        BIC    lr, lr, #3           ; align but leave r6 at end of command for below (05)
        LDR    R4, [lr, #0]         ; code offset
        CMP    r1, #-1              ; fudge?
        BEQ    %FT78
        CMP    R4, #0
        ADDEQ  R2, lr, #16
        BEQ    %BT03
        LDRB   R4, [lr, #7]
        BIC    R4, R4, #(Help_Is_Code_Flag:OR:International_Help) :SHR: 24
        CMP    R4, R1, LSR #24      ; move flags into bottom byte
79      ADDNE  R2, lr, #16
        BNE    %BT03
        TST    R7, #&80000000
        BEQ    %FT05
        SWI    XOS_NewLine
        SWIVC  XOS_NewLine
        BVS    %FT77
        MOV    r4, r0
        CMP    r0, #0
        BEQ    OneModuleK_PrintTitle ; Don't trust MessageTrans to preserve Z
        SWI    XMessageTrans_Dictionary
        STMDB  sp!, {r1}
        MOVVC  r1, r0
        MOVVC  r0, r4
        SWIVC  XOS_PrettyPrint
        LDMIA  sp!, {r1}
        B      %FT77
OneModuleK_PrintTitle
        LDR    r0, [stack]
        BL     PrintTitle
77
        MOVVC  r0, r4
        Pull  "r2-r7, PC", VS
        BIC    R7, R7, #&80000000
05
        SUB    lr, r6, r2
        RSB    r4, r5, #HelpBufferSize
        CMP    r4, lr                   ; have we got enough space for command+tab
        BCS    %FT07
        MOV    r4, #0                   ; no, so 0 terminate what we've got and print it
        SUB    r5, r5, #1               ; write 0 over trailing tab
        STRB   r4, [r3, r5]
        MOV    r4, r0
        MOV    r0, r3
        SWI    XOS_PrettyPrint
        SWIVC  XOS_NewLine
        Pull   "r2-r7,pc",VS
        MOV    r0, r4
        MOV    r5, #0                   ; start again with empty buffer
07
        LDRB   r4, [r2], #1             ; copy command
        CMP    r4, #0
        STRNEB r4, [r3, r5]
        ADDNE  r5, r5, #1
        BNE    %BT07
        MOV    r4, #TAB                 ; add tab
        STRB   r4, [r3, r5]
        ADD    r5, r5, #1
        ADD    r2, r2, #3+16            ; align and move on to next command
        BIC    r2, r2, #3
        B      %BT03

78      CMP    r4, #0
        B      %BT79

06      TST    R7, #&80000000
        Pull  "r2-r7, PC", NE
        Push  "R0"
        MOV    R0, #0
        SUB    R5, R5, #1
        STRB   R0, [R5, R3]
        MOV    R0, R3
        SWI    XOS_PrettyPrint
        STRVS  r0, [stack]
        Pull  "R0, r2-r7, PC"

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

GOS_Code
        Push    lr
        MOV     r2, r0
        addr    R1, UtilModTitle
        MOV     R0, #ModHandReason_Enter
        SWI     XOS_Module
        Pull    pc

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

; Deal with UtilityModule SWIs.
;
; The UtilityModule provides "OS-independent" SWIs. At present these are:
;
; SWI &F00000 (ARM_IMB)
; SWI &F00001 (ARM_IMBRange)
;
; as specified by the ARMv5 ARM (section 2.7.4 Prefetching and self-modifying
; code)

Util_SWI
        CMP     r11, #1
        BLO     SyncCodeAreasFull       ; (00) will do tail-call return from SWI
        BHI     Util_SWINotKnown        ; (02..3F)

; Ranged wotsit                           (01)
        Push    "r1,r2,lr"
        SUB     r2, r1, #4              ; convert from exclusive to inclusive
        MOV     r1, r0
        BL      SyncCodeAreasRange
        Pull    "r1,r2,pc"

Util_SWINotKnown
        ADR     r0, ErrorBlock_ModuleBadSWI
      [ International
        addr    r4, UtilModTitle
        B       TranslateError_UseR4
      |
        RETURNVS
      ]

        MakeErrorBlock ModuleBadSWI

; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
; ChangeDynamicArea - moved here from the Task Manager as embedded devices
; tend not to have the Task Manager
; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

rmaarea         *       1               ; RMA area
screenarea      *       2               ; screen area
spritearea      *       3               ; sprite area
fontarea        *       4               ; font cache dynamic area number
ramfsarea       *       5               ; RAM disc area

                ^       0
vec_fontsize    #       4               ; fields in output vector
vec_spritesize  #       4
vec_ramfssize   #       4
vec_rmasize	#	4
vec_screensize	#	4
ss_outputvec    *       &100

Keydef  DCB     "FontSize/K,SpriteSize/K,RamFSSize/K,RMASize/K,ScreenSize/K"
        DCB     0
        ALIGN

; NB: R12 -> private word (don't use workspace, as it may not be present)

ChangeDynamicArea_Code  ROUT
        Push    "R11,LR"
        MOV     R11,sp                  ; remember stack for later
;
        SUB     sp,sp,#ss_outputvec     ; local workspace
;
; scan the comand line by calling OS_ReadArgs
;
        MOV     R1,R0                   ; R1 = input string
        ADR     R0,Keydef               ; R0 = key defion string
        MOV     R2,sp                   ; R2 = output vector
        MOV     R3,#ss_outputvec        ; R3 = max output vector length
        SWI     XOS_ReadArgs
;
; scan the resulting vector for known fields
;
        MOVVC   R0,#rmaarea
        LDRVC   R1,[sp,#vec_rmasize]
        BLVC    changeR0R1              ; R0 = area number, R1 = size required

        MOVVC   R0,#screenarea
        LDRVC   R1,[sp,#vec_screensize]
        BLVC    changeR0R1              ; R0 = area number, R1 = size required

        MOVVC   R0,#fontarea
        LDRVC   R1,[sp,#vec_fontsize]
        BLVC    changeR0R1              ; R0 = area number, R1 = size required

        MOVVC   R0,#spritearea
        LDRVC   R1,[sp,#vec_spritesize]
        BLVC    changeR0R1              ; R0 = area number, R1 = size required

        MOVVC   R0,#ramfsarea           ; NB: do RAMFS last so others get done if it fails
        LDRVC   R1,[sp,#vec_ramfssize]
        BLVC    changeR0R1              ; R0 = area number, R1 = size required

        MOV     sp,R11                  ; restore stack
        Pull    "R11,PC"

; In    R0 = dynamic area number
;       R1 -> string specifying size required (<=0 => don't bother)
; Out   calls OS_ChangeDynamicArea, which gives Service_MemoryMoved
;       this is intercepted, and sets [memoryupdated]
;       this causes a pollword event:
;           which calls set_memory for all memory slots
;           if the RAM disc slot size changes to/from 0
;               [ramfsflag] is set
;               unless dragging the ram slot bar:
;                   reramfsfiler re-ialises the RAMFSFiler
;                   otherwise it waits till the bar is dropped

changeR0R1      ROUT
        Push    "R0-R3,LR"

        CMP     R1,#0
        Pull    "R0-R3,PC",EQ

        SWI     XOS_ReadDynamicArea     ; R1 = current size of area
        MOVVC   R3,R1

        LDRVC   R1,[sp,#1*4]
        BLVC    getK                    ; R1 = new amount required

        LDRVC   R0,[sp,#0*4]
        SUBVC   R1,R1,R3                ; R1 = change required
        SWIVC   XOS_ChangeDynamicArea

        STRVS   R0,[sp]
        Pull    "R0-R3,PC"


; In    R1 --> string
; Out   R1 = parameter value (number)
; Errors: "Bad number"
;

getK    ROUT
        Push    "R2-R3,LR"
;
        MOV     R0,#10
        SWI     XOS_ReadUnsigned
        Pull    "R2-R3,PC",VS
;
        LDRB    R3,[R1]
        UpperCase R3, R14
        TEQ     R3,#"K"                 ; if terminator is "K" or "k",
        ADDEQ   R1,R1,#1
        MOVEQ   R2,R2,LSL #10           ; multiply by 1024
        TEQ     R3,#"M"                 ; if terminator is "M" or "m",
        ADDEQ   R1,R1,#1
        MOVEQ   R2,R2,LSL #20           ; multiply by 1048576
        TEQ     R3,#"G"                 ; if terminator is "G" or "g",
        ADDEQ   R1,R1,#1
        MOVEQ   R2,R2,LSL #30           ; multiply by 1073741824
;
        LDRB    R14,[R1]                ; check terminator
        RSBS    R14,R14,#" "+1          ; ensure GT set if OK
        ADRLEL  R0,ErrorBlock_BadNumb   ; "Number not recognised"
      [ International
        BLLE    TranslateError
      ]
;
        MOVVC   R1,R2                   ; R1 = answer
        Pull    "R2-R3,PC"


 [ :LNOT: No32bitCode
UtilFlags DCD ModuleFlag_32bit
 ]

        END