**** libraries/filehandler.i **********************************************
*
*  device and file handler specific code for AmigaDOS
*
* Copyright (C) 1986,  Commodore-Amiga, Inc., All rights reserved.
*
* $Header: filehandler.i,v 33.4 86/05/21 19:14:20 neil Exp $
*
* $Locker:  $
*
****************************************************************************/

	IFND	LIBRARIES_FILEHANDLER_I
LIBRARIES_FILEHANDLER_I	SET	1

	IFND	  EXEC_TYPES_I
	INCLUDE "exec/types.i"
	ENDC	 !EXEC_TYPES_I

	IFND	  EXEC_PORTS_I
	INCLUDE "exec/ports.i"
	ENDC	 !EXEC_PORTS_I

	IFND	  LIBRARIES_DOS_I
	INCLUDE "libraries/dos.i"
	ENDC	 !LIBRARIES_DOS_I


** The disk "environment" is a longword array that describes the
** disk geometry.  It is variable sized, with the length at the beginning.
** Here are the constants for a standard geometry.

** these are the offsets into the array
DE_TABLESIZE	EQU	0	; standard value is 11
DE_SIZEBLOCK	EQU	1	; in longwords: standard value is 128
DE_SECORG	EQU	2	; not used; must be 0
DE_NUMHEADS	EQU	3	; # of heads (surfaces). drive specific
DE_SECSPERBLK	EQU	4	; not used; must be 1
DE_BLKSPERTRACK	EQU	5	; blocks per track. drive specific
DE_RESERVEDBLKS	EQU	6	; unavailable blocks at start.  usually 2
DE_PREFAC	EQU	7	; not used; must be 0
DE_INTERLEAVE	EQU	8	; usually 0
DE_LOWCYL	EQU	9	; starting cylinder. typically 0
DE_UPPERCYL	EQU	10	; max cylinder.  drive specific
DE_NUMBUFFERS	EQU	11	; starting # of buffers.  typically 5
DE_MEMBUFTYPE	EQU	12	; type of mem to allocate for buffers.
				;     default is 3, hard disks want 0


** The file system startup message is linked into a device node's startup
** field.  It contains a pointer to the above environment, plus the
** information needed to do an exec OpenDevice().

 STRUCTURE FileSysStartupMsg,0
    ULONG	fssm_Unit	; exec unit number for this device
    BSTR	fssm_Device	; null terminated bstring to the device name
    BPTR	fssm_Environ	; ptr to environment table (see above)
    ULONG	fssm_Flags	; flags for OpenDevice()
    LABEL	FileSysStartupMsg_SIZEOF


** The include file "libraries/dosextens.h" has a DeviceList structure.
** The "device list" can have one of three different things linked onto
** it.  Dosextens defines the structure for a volume.  DLT_DIRECTORY
** is for an assigned directory.  The following structure is for
** a dos "device" (DLT_DEVICE).

 STRUCTURE DeviceNode,0
    BPTR	dn_Next		; singly linked list
    ULONG	dn_Type		; always 0 for dos "devices"
    CPTR 	dn_Task		; standard dos "task" field.  If this is
				;     null when the node is accesses, a task
				;     will be started up
    BPTR	dn_Lock		; not used for devices -- leave null
    BSTR	dn_Handler	; filename to loadseg (if seglist is null)
    ULONG	dn_StackSize	; stacksize to use when starting task
    LONG	dn_Priority	; task priority when starting task
    BPTR	dn_Startup	; startup msg: FileSysStartupMsg for disks
    BPTR	dn_SegList	; code to run to start new task (if necessary).
				;     if null then dn_Handler will be loaded.
    BPTR	dn_GlobalVec	; BCPL global vector to use when starting
				;     a task.  -1 means that dn_SegList is not
				;     for a bcpl program, so the dos won't
				;     try and construct one.  0 tell the
				;     dos that you obey BCPL linkage rules,
				;     and that it should construct a global
				;     vector for you.
    BSTR	dn_Name		; the node name, e.g. '\3','D','F','3'
    LABEL	DeviceNode_SIZEOF


	ENDC	!LIBRARIES_FILEHANDLER_I