;********************************************************************* ;* * ;* 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 ;************* ;* Constants * ;************* ;****************** ;* Public Symbols * ;****************** XDEF EndCode ; Label at End of Device Code XDEF LockGlobal ; Obtain Exclusive Access to Device Global Data XDEF UnlockGlobal ; Release Exclusive Access to Device Global Data XDEF PerformIO ; Common Fork or Dispatch to Handle Device Commands XDEF TermIO ; Common Join from Device Commands to Do Common Cleanup ;******************** ;* 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_Main.Asm XREF CmdTable ; Device Global Command Dispatch Table ;********************************************************************* ;* LockGlobal Helper Routine (for Open, Close, etc.) * ;* * ;* This functions uses a semaphore defined in the device global data * ;* to obtain exclusive access to the device global data area. It is * ;* used by DevOpen and DevClose to setup and takedown items that may * ;* break a Forbid(). Its use is optional and is not required if you * ;* have very simple opens/closes, *and* multiple copies of your unit * ;* tasks are not attempting to alter the device global area * ;* concurrently. They may all read it however, as long as no one is * ;* actually trying to -change- it while others are reading from it. * ;* * ;* Inputs: * ;* A6 - Ptr to our Device node. * ;* * ;* Outputs: * ;* None * ;* * ;* * All Registers are Preserved, Including D0-D1/A0-A1 * * ;* * ;* Notes: * ;* Calling task blocks until exclusive access can be granted. * ;* * ;********************************************************************* LockGlobal: ; ; Lock Device Global Data for Exclusive Access MOVEM.L D0-D1/A0-A1,-(SP) ; Preserve Registers During Lock LEA.L md_SemLock(A6),A0 ; Pickup Ptr to the Arbitration Semaphore LINKSYS ObtainSemaphore,md_SysLib(A6) ; Get Control of Device Node MOVEM.L (SP)+,D0-D1/A0-A1 ; Restore Registers RTS ;********************************************************************* ;* UnlockGlobal Helper Routine (for Open, Close, etc.) * ;* * ;* This functions uses a semaphore defined in the device global data * ;* to release exclusive access to the device global data area. It * ;* is used by DevOpen and DevClose to setup and takedown items that * ;* may break a Forbid(). Its use is optional and is not required if * ;* you have very simple opens/closes, *and* multiple copies of your * ;* unit tasks are not attempting to alter the device global area * ;* concurrently. They may all read it however, as long as no one is * ;* actually trying to -change- it while others are reading from it. * ;* * ;* Inputs: * ;* A6 - Ptr to our Device node. * ;* * ;* Outputs: * ;* None * ;* * ;* * All Registers are Preserved, Including D0-D1/A0-A1 * * ;* * ;* Notes: * ;* Calling task blocks until exclusive access can be granted. * ;* * ;********************************************************************* UnlockGlobal: ; ; Unlock Device Global Data from Exclusive Access MOVEM.L D0-D1/A0-A1,-(SP) ; Preserve Registers During Unlock LEA.L md_SemLock(A6),A0 ; Pickup Ptr to the Arbitration Semaphore LINKSYS ReleaseSemaphore,md_SysLib(A6) ; Release Control of Device Node MOVEM.L (SP)+,D0-D1/A0-A1 ; Restore Registers RTS ;********************************************************************* ;* PerformIO Helper Routine (for BeginIO) * ;* * ;* PerformIO actually dispatches an I/O request. It might be called * ;* from within the unit task, or directly from BeginIO (and thus on * ;* the callers's schedule). * ;* * ;* Inputs: * ;* A6 - Ptr to our Device node. * ;* A1 - Ptr to the caller's I/O request block as initialized by * ;* OpenDevice(). * ;* A3 - Ptr to the Unit Descriptor. * ;* * ;* (Bounds checking was done on the inputs by the caller) * ;* * ;* Outputs: * ;* IO_ERROR - Error code of operation (zero means success). * ;* * ;********************************************************************* PerformIO: IFGE INFO_LEVEL-150 CLR.L -(SP) ; Allocate and Clear a 32-bit Scratch Word MOVE.W IO_COMMAND(A1),2(SP) ; Pick up Command Code PUTMSG 150,<'%s/PerformIO -- %ld'> ; Output a Debugging Message ADDQ.L #4,SP ; Deallocate the 32-bit Scratch Word ENDC MOVEQ #0,D0 MOVE.B D0,IO_ERROR(A1) ; Initially Clear the Error Field¨to 'Ok' MOVE.B IO_COMMAND+1(A1),D0 ; Pick up Command Byte LSL.W #2,D0 ; Multiply by 4 to Get Table Offset LEA.L CmdTable(PC),A0 ; Pick up Base of Command Table in A0 MOVE.L 0(A0,D0.W),A0 ; Index into Table and Get Ptr to Handler Code ; ; Branch into Appropriate Handler Code for Desired Command ; A1 - Ptr to I/O Request Block ; A3 - Ptr to Unit Descriptor ; A6 - Ptr to Device Node JMP (A0) ;********************************************************************* ;* TermIO Helper Routine (for BeginIO) * ;* * ;* TermIO sends the I/O request back to the user. It knows not to * ;* mark the device as inactive if this was an immediate request or * ;* if the request was started from the unit task. * ;* * ;* Inputs: * ;* A6 - Ptr to our Device node. * ;* A1 - Ptr to the caller's I/O request block as initialized by * ;* OpenDevice(). * ;* A3 - Ptr to the Unit Descriptor. * ;* * ;* (Bounds checking was done on the inputs by the caller) * ;* * ;* Outputs: * ;* IO_ERROR - Error code of operation (zero means success). * ;* * ;********************************************************************* TermIO: PUTMSG 160,<'%s/TermIO'> MOVE.W IO_COMMAND(A1),D0 ; Pick up Command Code in D0 MOVE.L #IMMEDIATES,D1 ; Pick up Immediate Command Classification Mask BTST D0,D1 ; Test Command for an Immediate Type BNE.S TermIO_Immediate ; I/O was Immediate, Skip Task Handling Code BTST #UNITB_INTASK,UNIT_FLAGS(A3) ; Did I/O Come from Task? BNE.S TermIO_Immediate ; Yes, Don't Clear the Task-Active Flag BCLR #UNITB_ACTIVE,UNIT_FLAGS(A3) ; Clear the Task-Active Flag TermIO_Immediate: BTST #IOB_QUICK,IO_FLAGS(A1) ; Is the I/O Quick Bit Still Set? BNE.S TermIO_End ; Yes, Request Was Not Queued, Skip Reply Process ; ; Reply the Message Back to the Original Issuing Task LINKSYS ReplyMsg,md_SysLib(A6) ; Ptr to Message:A1 ; Note: The ReplyMsg() Function Sets the LN_TYPE to NT_REPLYMSG TermIO_End: RTS ;********************************************************************* ;* 'EndCode' is a marker that shows the end of your code. Make sure * ;* it does not span hunks and is not before the Romtag. * ;********************************************************************* EndCode: END