/*
	fileystems.c - aquire and print descriptions of all MOUNTed filesystems

	Copyright © 1990, Ethan Dicks, all rights reserved.  

This program is *not* in the public domain, but may be freely
redistributed on the condition that it is not sold, nor used in any
commercial or shareware package without the express written permission
of the author.  This program may be included in a freely redistributable
library, including, but not limited to the Fred Fish library collection.
In other words, selling this program is right out, but giving it away is
encouraged.

	V 1.0  27-Jan-1990
		- Obtain a pointer to the chain of DeviceNodes via the
		  DOSBase entry for RootNode, which contains a pointer
		  to the list of DeviceNodes.

	V 1.1  25-Feb-1990
		- Print out the device driver name

*/

/*

How it works...

The RootBlock structure pointed to by the DosLibrary structure
contains a BPTR to the DosInfo structure.  One of the elements of the
DosInfo structure is the DeviceNode.  This is a list of all "devices"
known to AmigaDOS; this list includes all volume names, device names
and logical names.  We are only interested in device names which have
filesystems associated with them.  The element dn_Type of the
DeviceNode is defined to be zero if this name is a device. 
Furthermore, we are only interested in DeviceNodes which have exec
tasks associated with them.  Once we have established that this
DeviceNode is appropriate, we print out its name (stored as a BSTR in
the element dn_Name) and check dn_Startup for a FileSysStartupMsg.  If
there is not one, we tell the user that and get the next DeviceNode,
until they are all gone.  If there is a FileSysStartupMsg, it contains
pointers to all sorts of interesting information: the name of the exec
device to call when accessing this device, the exec unit number, and a
pointer to a DosEnvec block.  The DosEnvec block contains the same
information you would find in a Mountlist entry.  We are concerned
with number of heads, number of sectors per track, starting track,
ending track and the proper memory type to request for buffers for
this device.  This information is collected and displayed, and then,
the dn_Next element of the DeviceNode is checked.  If is it non-zero,
it is a pointer to the next DeviceNode.  If it is zero, our work is
finished.

*/

# include <libraries/dosextens.h>
# include <libraries/filehandler.h>
# include <exec/memory.h>

void main()
{
extern struct DosLibrary *DOSBase;

struct RootNode *RootNode;
struct DosInfo *DosInfo;
struct FileSysStartupMsg *StartupMsg;
register struct DosEnvec *DosEnvec;
register struct DeviceNode *DeviceNode;

RootNode = (struct RootNode *)DOSBase->dl_Root;
DosInfo = (struct DosInfo *)BADDR(RootNode->rn_Info);

DeviceNode = (struct DeviceNode *)BADDR(DosInfo->di_DevInfo);

printf("\n");

while (DeviceNode)
	{
	if ( (DeviceNode->dn_Type == DLT_DEVICE) && DeviceNode->dn_Task)
		{
		printf("AmigaDOS device ");
		bcpl_print((char *)BADDR(DeviceNode->dn_Name));
		StartupMsg = (struct FileSysStartupMsg *)
		    BADDR(DeviceNode->dn_Startup);
		if (StartupMsg)
			{
			printf(": is unit %d of the exec device ",
			    StartupMsg->fssm_Unit);
			bcpl_print((char *)BADDR(StartupMsg->fssm_Device));
			printf(".\n");
			DosEnvec = (struct DosEnvec *)
			    BADDR(StartupMsg->fssm_Environ);
			printf(" Disk Geometry = %d X %d X %d (Cyls %d - %d)\n",
			   DosEnvec->de_Surfaces,
			   DosEnvec->de_BlocksPerTrack,
			   ( (DosEnvec->de_HighCyl - DosEnvec->de_LowCyl) + 1),
			   DosEnvec->de_LowCyl,
			   DosEnvec->de_HighCyl);
			printf(" BufMemType = %s  %s  %s\n",
			   ( (DosEnvec->de_BufMemType) & MEMF_PUBLIC ?
					"MEMF_PUBLIC" : ""),
			   ( (DosEnvec->de_BufMemType) & MEMF_CHIP ?
					"MEMF_CHIP" : ""),
			   ( (DosEnvec->de_BufMemType) & MEMF_FAST ?
					"MEMF_FAST" : ""));
			}
		else
			printf(": has no FileSysStartupMsg.\n");
		printf("\n");
		}
	DeviceNode = (struct DeviceNode *)BADDR(DeviceNode->dn_Next);
	}
}

/*
	bcpl_print - write a BCPL string to stdout
*/
bcpl_print(p)
char *p;	/* APTR to a valid BCPL string (length byte first) */
{
register int i;

for (i = *p++;i;i--)
	putchar(*p++);
return(0);
}