reactos/ntoskrnl/inbv/inbvport.c

/*
 * PROJECT:         ReactOS Kernel
 * LICENSE:         BSD - See COPYING.ARM in the top level directory
 * FILE:            ntoskrnl/inbv/inbvport.c
 * PURPOSE:         Serial Port Boot Driver for Headless Terminal Support
 * PROGRAMMERS:     ReactOS Portable Systems Group
 */

/* INCLUDES ******************************************************************/

#include <ntoskrnl.h>
#include <debug.h>

/* GLOBALS *******************************************************************/

CPPORT Port[4] =
{
	{NULL, 0, TRUE},
	{NULL, 0, TRUE},
	{NULL, 0, TRUE},
	{NULL, 0, TRUE}
};

/* FUNCTIONS *****************************************************************/

VOID
NTAPI
InbvPortEnableFifo(
	IN ULONG PortId,
	IN BOOLEAN Enable
	)
{
	/* Set FIFO as requested */
	CpEnableFifo(Port[PortId].Address, Enable);
}

VOID
NTAPI
InbvPortPutByte(
	IN ULONG PortId,
	IN BOOLEAN Output
	)
{
	/* Send the byte */
	CpPutByte(&Port[PortId], Output);
}

VOID
NTAPI
InbvPortTerminate(
	IN ULONG PortId
	)
{
	/* The port is now available */
	Port[PortId].Address = NULL;
}

BOOLEAN
NTAPI
InbvPortInitialize(
	IN ULONG BaudRate,
	IN ULONG PortNumber,
	IN PUCHAR PortAddress,
	OUT PULONG PortId,
	IN BOOLEAN IsMMIODevice
	)
{
	/* Not yet supported */
	ASSERT(IsMMIODevice == FALSE);

	/* Set default baud rate */
    if (BaudRate == 0) BaudRate = 19200;

	/* Check if port or address given */
	if (PortNumber)
	{
		/* Pick correct address for port */
	   if (!PortAddress)
		{
            switch (PortNumber)
			{
				case 1:
					PortAddress = (PUCHAR)0x3F8;
					break;

				case 2:
					PortAddress = (PUCHAR)0x2F8;
					break;

				case 3:
					PortAddress = (PUCHAR)0x3E8;
					break;

				default:
					PortNumber = 4;
					PortAddress = (PUCHAR)0x2E8;
			}
		}
    }
	else
	{
		/* Pick correct port for address */
		PortAddress = (PUCHAR)0x2F8;
		if (CpDoesPortExist(PortAddress))
		{
			PortNumber = 2;
        }
		else
		{
			PortAddress = (PUCHAR)0x3F8;
			if (!CpDoesPortExist(PortAddress)) return FALSE;
			PortNumber = 1;
 		}
	}

	/* Initialize the port unless it's already up, and then return it */
	if (Port[PortNumber - 1].Address) return FALSE;
	CpInitialize(&Port[PortNumber - 1], PortAddress, BaudRate);
	*PortId = PortNumber - 1;
	return TRUE;
}