;********************************************************************* ;* Origin and Purpose * ;* * ;* All changes I made are hereby in the Public Domain. Commodore * ;* retains its copyright, if any, of the original code in the Rom * ;* Kernel manuals since this is a derivative work. -Jeff Rush * ;* * ;********************************************************************* ;* History * ;* * ;* 20Sep89 jrr Original crib from Amiga Rom Kernel Manual. * ;* 23Jul90 jrr Extensive descriptive prose added. * ;* * ;********************************************************************* TITLE Example Device Driver for Tutorial Use SMALLOBJ ; Use PC-Relative Addressing OPTIMON ; Enable C.A.P.E. 68K Optimizations SECTION TheOnlySection ;************ ;* Includes * ;************ NOLIST INCLUDE "exec/types.i" INCLUDE "exec/devices.i" INCLUDE "exec/initializers.i" INCLUDE "exec/memory.i" INCLUDE "exec/resident.i" INCLUDE "exec/io.i" INCLUDE "exec/ables.i" INCLUDE "exec/errors.i" INCLUDE "exec/tasks.i" INCLUDE "exec/semaphores.i" INCLUDE "hardware/intbits.i" INCLUDE "asmsupp.i" INCLUDE "Example.i" ; Device-Specific Definitions LIST ;****************** ;* Public Symbols * ;****************** XDEF CmdInvalid ; Handle an Unknown or Out-of-Range Command XDEF CmdReset ; Reset the Device XDEF CmdRead ; Read Data from the Device for Caller XDEF CmdWrite ; Write Data into the Device from Caller XDEF CmdUpdate ; Force Outbound Data from Caches onto Device XDEF CmdClear ; Discard All Pending Unread Data inside Device XDEF CmdStop ; Suspend Device Operations XDEF CmdStart ; Resume Device Operations XDEF CmdFlush ; Discard All Queued but Unprocessed I/O Requests ;******************** ;* External Symbols * ;******************** ; This Name is for Debugging Use, to Annotate Serial-Debug Output IFNE INFO_LEVEL ; If Any Debugging Enabled at All XREF subSysName ENDC ; Defined in Ex_Support.Asm XREF TermIO ; End of I/O Operation Exit Point ;********************************************************************* ;* 'Invalid' Command Routine * ;* * ;* This command causes the device to reply with an error of * ;* IOERR_NOCMD as defined in Exec/Errors.h indicating that the * ;* command is not supported. * ;* * ;* Inputs: * ;* A6 - Ptr to our Device node. * ;* A1 - Ptr to the caller's I/O request block. * ;* A3 - Ptr to the Unit Descriptor * ;* * ;* Outputs: * ;* IO_ERROR - Error code of operation. * ;* * ;********************************************************************* CmdInvalid: MOVE.B #IOERR_NOCMD,IO_ERROR(A1) ; Plug-In Error Code BRA TermIO ; Send Request Back to User ;********************************************************************* ;* 'Reset' Command Routine * ;* * ;* This command causes the device to abort all I/O requests, both * ;* those queued and in process and reset itself to its initialized * ;* state. * ;* * ;* Inputs: * ;* A6 - Ptr to our Device node. * ;* A1 - Ptr to the caller's I/O request block. * ;* A3 - Ptr to the Unit Descriptor * ;* * ;* Outputs: * ;* IO_ERROR - Zero if the reset succeeded, * ;* an error code otherwise. * ;* * ;********************************************************************* CmdReset: CLR.L IO_ACTUAL(A1) ; Zero Actual Count BRA TermIO ; Send Request Back to User ;********************************************************************* ;* 'Read' Command Routine * ;* * ;* This command causes the device to return data read from the * ;* hardware to the caller. * ;* * ;* Inputs: * ;* A6 - Ptr to our Device node. * ;* A1 - Ptr to the caller's I/O request block. * ;* A3 - Ptr to the Unit Descriptor * ;* * ;* Outputs: * ;* IO_ERROR - Error code of operation. * ;* * ;********************************************************************* CmdRead: IFGE INFO_LEVEL-200 MOVE.L IO_LENGTH(A1),-(SP) PUTMSG 200,<'%s/Rd len %ld'> ADDQ.L #4,SP ENDC MOVEM.L A2/A3,-(SP) ; Preserve Original Registers Across Function ; ; Check Ptr to User's Data Buffer for Word Alignment BTST.B #0,IO_DATA(A1) ; Is Data Buffer on an Odd Boundary? BNE.S CmdRead_LenErr ; Yes, Error! ; ; Perform Additional Checks and Calculations using IO_OFFSET and IO_LENGTH ; ; Perform Actual I/O Operation and Update IO_ACTUAL CmdRead_End: MOVEM.L (SP)+,A2/A3 ; Restore Original Registers BRA TermIO ; Send Request Back to User CmdRead_LenErr: MOVE.B #IOERR_BADLENGTH,IO_ERROR(A2) ; Signal an Error CLR.L IO_ACTUAL(A2) ; Report That No Data was Moved BRA.S CmdRead_End ;********************************************************************* ;* 'Write' Command Routine * ;* * ;* This command causes the device to take data supplied by the * ;* caller and send it to the hardware. * ;* * ;* Inputs: * ;* A6 - Ptr to our Device node. * ;* A1 - Ptr to the caller's I/O request block. * ;* A3 - Ptr to the Unit Descriptor * ;* * ;* Outputs: * ;* IO_ERROR - Error code of operation. * ;* * ;********************************************************************* CmdWrite: IFGE INFO_LEVEL-200 MOVE.L IO_LENGTH(A1),-(SP) PUTMSG 200,<'%s/Wr len %ld'> ADDQ.L #4,SP ENDC MOVEM.L A2/A3,-(SP) ; Preserve Original Registers Across Function ; ; Check Ptr to User's Data Buffer for Word Alignment BTST.B #0,IO_DATA(A1) ; Is Data Buffer on an Odd Boundary? BNE.S CmdWrite_LenErr ; Yes, Error! ; ; Perform Additional Checks and Calculations using IO_OFFSET and IO_LENGTH ; ; Perform Actual I/O Operation and Update IO_ACTUAL CmdWrite_End: MOVEM.L (SP)+,A2/A3 ; Restore Original Registers BRA TermIO ; Send Request Back to User CmdWrite_LenErr: MOVE.B #IOERR_BADLENGTH,IO_ERROR(A2) ; Signal an Error CLR.L IO_ACTUAL(A2) ; Report That No Data was Moved BRA.S CmdWrite_End ;********************************************************************* ;* 'Update' Command Routine * ;* * ;* This command causes the device to send any data waiting in an * ;* internal cache to the actual hardware. It does not return until * ;* all data is sent. * ;* * ;* Inputs: * ;* A6 - Ptr to our Device node. * ;* A1 - Ptr to the caller's I/O request block. * ;* A3 - Ptr to the Unit Descriptor * ;* * ;* Outputs: * ;* IO_ERROR - Error code of operation. * ;* * ;********************************************************************* CmdUpdate: CLR.L IO_ACTUAL(A1) ; Zero Actual Count BRA TermIO ; Send Request Back to User ;********************************************************************* ;* 'Clear' Command Routine * ;* * ;* This command causes the device to dump all pending unread data * ;* packets on the floor. All data available for reading is lost. * ;* * ;* Inputs: * ;* A6 - Ptr to our Device node. * ;* A1 - Ptr to the caller's I/O request block. * ;* A3 - Ptr to the Unit Descriptor * ;* * ;* Outputs: * ;* IO_ERROR - Error code of operation. * ;* * ;********************************************************************* CmdClear: CLR.L IO_ACTUAL(A1) ; Zero Actual Count BRA TermIO ; Send Request Back to User ;********************************************************************* ;* 'Stop' Command Routine * ;* * ;* This command suspends the processing of I/O requests in the * ;* queue, until a 'Start' command is received. The 'Stop' command * ;* is not stackable; e.g. no matter how many stops have been issued * ;* it only takes one 'Start' to restart processing. * ;* * ;* Inputs: * ;* A6 - Ptr to our Device node. * ;* A1 - Ptr to the caller's I/O request block. * ;* A3 - Ptr to the Unit Descriptor * ;* * ;* Outputs: * ;* IO_ERROR - Error code of operation. * ;* * ;********************************************************************* CmdStop: PUTMSG 30,<'%s/MyStop: called'> BSET #MDUB_STOPPED,UNIT_FLAGS(A3) BRA TermIO ; Send Request Back to User ;********************************************************************* ;* 'Start' Command Routine * ;* * ;* This command restarts or unsuspends the processing of queued I/O * ;* requests. * ;* * ;* Inputs: * ;* A6 - Ptr to our Device node. * ;* A1 - Ptr to the caller's I/O request block. * ;* A3 - Ptr to the Unit Descriptor * ;* * ;* Outputs: * ;* IO_ERROR - Error code of operation. * ;* * ;********************************************************************* CmdStart: PUTMSG 30,<'%s/Start: called'> BSR InternalStart BRA TermIO ; Send Request Back to User InternalStart: MOVE.L A1,-(SP) ; Preserve Original A1 Across Function BCLR #MDUB_STOPPED,UNIT_FLAGS(A3) ; Turn Processing Back On ; ;!!!!! What if there is no unit task for this unit??? ; ; Kick the Unit Task to Start It Moving Again MOVE.B MP_SIGBIT(A3),D1 CLEAR D0 BSET D1,D0 ; Prepare a Signal Mask MOVE.L MP_SIGTASK(A3),A1 ; Pickup Task to Signal LINKSYS Signal,md_SysLib(A6) ; Issue Signal to Unit MOVE.L (SP)+,A1 ; Restore Original A1 RTS ;********************************************************************* ;* 'Flush' Command Routine * ;* * ;* This command causes the device to dump all pending I/O requests * ;* currently queued for the device on the floor. All data that * ;* would have been written is lost and all such I/O requests are * ;* aborted and returned to their issuer. It does -not- affect I/O * ;* requests actually in progress. * ;* * ;* Inputs: * ;* A6 - Ptr to our Device node. * ;* A1 - Ptr to the caller's I/O request block. * ;* A3 - Ptr to the Unit Descriptor * ;* * ;* Outputs: * ;* IO_ERROR - Error code of operation. * ;* * ;* Notes: * ;* Some funny magic goes on with the STOPPED bit in here. The * ;* 'Stop' command is defined as not being reentrant. We therefore * ;* save the old state of the bit and then restore it later. This * ;* keeps us from needing to Disable() in 'Flush'. It also fails * ;* miserably if someone does a start in the middle of a flush. * ;* * ;********************************************************************* CmdFlush: PUTMSG 30,<'%s/Flush: called'> MOVEM.L D2/A1/A6,-(SP) ; Preserve Original Registers MOVE.L md_SysLib(A6),A6 ; Pickup Ptr to Exec Library BSET #MDUB_STOPPED,UNIT_FLAGS(A3) ; Stop Unit SNE D2 ; Save Stop-Status in D2 until Later Flush_Loop: MOVE.L A3,A0 ; Pickup Ptr to Message Port at Front of Unit Descriptor CALLSYS GetMsg ; Steal a Message from the Unit Task's Message Port TST.L D0 ; Did We Obtain a Message? BEQ.S Flush_End ; Nope, Flush is Finished MOVE.L D0,A1 ; Prepare to Abort I/O Request MOVE.B #IOERR_ABORTED,IO_ERROR(A1) ; Set I/O Abort Error Code into Request CALLSYS ReplyMsg ; Send Message Back to User BRA.S Flush_Loop ; Go Process Additional Messages Flush_End: MOVE.L D2,D0 ; Pickup Original Stop-Status in D0 MOVEM.L (SP)+,D2/A1/A6 ; Restore Original Registers TST.B D0 ; Was the Device Stopped When We Were Entered? BEQ.S 1$ ; Yes, Leave It Stopped BSR InternalStart ; No, Restart It Again 1$: BRA TermIO ; Send Request Back to User ;********************************************************************* ;* * ;********************************************************************* END