drivers/isdn/hysdn/hysdn_boot.c - linux - Git at Google

 /* $Id: hysdn_boot.c,v 1.4.6.4 2001/09/23 22:24:54 kai Exp $
  *
  * Linux driver for HYSDN cards
  * specific routines for booting and pof handling
  *
  * Author    Werner Cornelius (werner@titro.de) for Hypercope GmbH
  * Copyright 1999 by Werner Cornelius (werner@titro.de)
  *
  * This software may be used and distributed according to the terms
  * of the GNU General Public License, incorporated herein by reference.
  *
  */

 #include <linux/vmalloc.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>

 #include "hysdn_defs.h"
 #include "hysdn_pof.h"

 /********************************/
 /* defines for pof read handler */
 /********************************/
 #define POF_READ_FILE_HEAD  0
 #define POF_READ_TAG_HEAD   1
 #define POF_READ_TAG_DATA   2

 /************************************************************/
 /* definition of boot specific data area. This data is only */
 /* needed during boot and so allocated dynamically.         */
 /************************************************************/
 struct boot_data {
 	unsigned short Cryptor;	/* for use with Decrypt function */
 	unsigned short Nrecs;	/* records remaining in file */
 	unsigned char pof_state;/* actual state of read handler */
 	unsigned char is_crypted;/* card data is crypted */
 	int BufSize;		/* actual number of bytes bufferd */
 	int last_error;		/* last occurred error */
 	unsigned short pof_recid;/* actual pof recid */
 	unsigned long pof_reclen;/* total length of pof record data */
 	unsigned long pof_recoffset;/* actual offset inside pof record */
 	union {
 		unsigned char BootBuf[BOOT_BUF_SIZE];/* buffer as byte count */
 		tPofRecHdr PofRecHdr;	/* header for actual record/chunk */
 		tPofFileHdr PofFileHdr;		/* header from POF file */
 		tPofTimeStamp PofTime;	/* time information */
 	} buf;
 };

 /*****************************************************/
 /*  start decryption of successive POF file chuncks.  */
 /*                                                   */
 /*  to be called at start of POF file reading,       */
 /*  before starting any decryption on any POF record. */
 /*****************************************************/
 static void
 StartDecryption(struct boot_data *boot)
 {
 	boot->Cryptor = CRYPT_STARTTERM;
 }				/* StartDecryption */


 /***************************************************************/
 /* decrypt complete BootBuf                                    */
 /* NOTE: decryption must be applied to all or none boot tags - */
 /*       to HI and LO boot loader and (all) seq tags, because  */
 /*       global Cryptor is started for whole POF.              */
 /***************************************************************/
 static void
 DecryptBuf(struct boot_data *boot, int cnt)
 {
 	unsigned char *bufp = boot->buf.BootBuf;

 	while (cnt--) {
 		boot->Cryptor = (boot->Cryptor >> 1) ^ ((boot->Cryptor & 1U) ? CRYPT_FEEDTERM : 0);
 		*bufp++ ^= (unsigned char)boot->Cryptor;
 	}
 }				/* DecryptBuf */

 /********************************************************************************/
 /* pof_handle_data executes the required actions dependent on the active record */
 /* id. If successful 0 is returned, a negative value shows an error.           */
 /********************************************************************************/
 static int
 pof_handle_data(hysdn_card *card, int datlen)
 {
 	struct boot_data *boot = card->boot;	/* pointer to boot specific data */
 	long l;
 	unsigned char *imgp;
 	int img_len;

 	/* handle the different record types */
 	switch (boot->pof_recid) {

 	case TAG_TIMESTMP:
 		if (card->debug_flags & LOG_POF_RECORD)
 			hysdn_addlog(card, "POF created %s", boot->buf.PofTime.DateTimeText);
 		break;

 	case TAG_CBOOTDTA:
 		DecryptBuf(boot, datlen);	/* we need to encrypt the buffer */
 		/* fall through */
 	case TAG_BOOTDTA:
 		if (card->debug_flags & LOG_POF_RECORD)
 			hysdn_addlog(card, "POF got %s len=%d offs=0x%lx",
 				     (boot->pof_recid == TAG_CBOOTDTA) ? "CBOOTDATA" : "BOOTDTA",
 				     datlen, boot->pof_recoffset);

 		if (boot->pof_reclen != POF_BOOT_LOADER_TOTAL_SIZE) {
 			boot->last_error = EPOF_BAD_IMG_SIZE;	/* invalid length */
 			return (boot->last_error);
 		}
 		imgp = boot->buf.BootBuf;	/* start of buffer */
 		img_len = datlen;	/* maximum length to transfer */

 		l = POF_BOOT_LOADER_OFF_IN_PAGE -
 			(boot->pof_recoffset & (POF_BOOT_LOADER_PAGE_SIZE - 1));
 		if (l > 0) {
 			/* buffer needs to be truncated */
 			imgp += l;	/* advance pointer */
 			img_len -= l;	/* adjust len */
 		}
 		/* at this point no special handling for data wrapping over buffer */
 		/* is necessary, because the boot image always will be adjusted to */
 		/* match a page boundary inside the buffer.                        */
 		/* The buffer for the boot image on the card is filled in 2 cycles */
 		/* first the 1024 hi-words are put in the buffer, then the low 1024 */
 		/* word are handled in the same way with different offset.         */

 		if (img_len > 0) {
 			/* data available for copy */
 			if ((boot->last_error =
 			     card->writebootimg(card, imgp,
 						(boot->pof_recoffset > POF_BOOT_LOADER_PAGE_SIZE) ? 2 : 0)) < 0)
 				return (boot->last_error);
 		}
 		break;	/* end of case boot image hi/lo */

 	case TAG_CABSDATA:
 		DecryptBuf(boot, datlen);	/* we need to encrypt the buffer */
 		/* fall through */
 	case TAG_ABSDATA:
 		if (card->debug_flags & LOG_POF_RECORD)
 			hysdn_addlog(card, "POF got %s len=%d offs=0x%lx",
 				     (boot->pof_recid == TAG_CABSDATA) ? "CABSDATA" : "ABSDATA",
 				     datlen, boot->pof_recoffset);

 		if ((boot->last_error = card->writebootseq(card, boot->buf.BootBuf, datlen)) < 0)
 			return (boot->last_error);	/* error writing data */

 		if (boot->pof_recoffset + datlen >= boot->pof_reclen)
 			return (card->waitpofready(card));	/* data completely spooled, wait for ready */

 		break;	/* end of case boot seq data */

 	default:
 		if (card->debug_flags & LOG_POF_RECORD)
 			hysdn_addlog(card, "POF got data(id=0x%lx) len=%d offs=0x%lx", boot->pof_recid,
 				     datlen, boot->pof_recoffset);

 		break;	/* simply skip record */
 	}			/* switch boot->pof_recid */

 	return (0);
 }				/* pof_handle_data */


 /******************************************************************************/
 /* pof_write_buffer is called when the buffer has been filled with the needed */
 /* number of data bytes. The number delivered is additionally supplied for    */
 /* verification. The functions handles the data and returns the needed number */
 /* of bytes for the next action. If the returned value is 0 or less an error  */
 /* occurred and booting must be aborted.                                       */
 /******************************************************************************/
 int
 pof_write_buffer(hysdn_card *card, int datlen)
 {
 	struct boot_data *boot = card->boot;	/* pointer to boot specific data */

 	if (!boot)
 		return (-EFAULT);	/* invalid call */
 	if (boot->last_error < 0)
 		return (boot->last_error);	/* repeated error */

 	if (card->debug_flags & LOG_POF_WRITE)
 		hysdn_addlog(card, "POF write: got %d bytes ", datlen);

 	switch (boot->pof_state) {
 	case POF_READ_FILE_HEAD:
 		if (card->debug_flags & LOG_POF_WRITE)
 			hysdn_addlog(card, "POF write: checking file header");

 		if (datlen != sizeof(tPofFileHdr)) {
 			boot->last_error = -EPOF_INTERNAL;
 			break;
 		}
 		if (boot->buf.PofFileHdr.Magic != TAGFILEMAGIC) {
 			boot->last_error = -EPOF_BAD_MAGIC;
 			break;
 		}
 		/* Setup the new state and vars */
 		boot->Nrecs = (unsigned short)(boot->buf.PofFileHdr.N_PofRecs);	/* limited to 65535 */
 		boot->pof_state = POF_READ_TAG_HEAD;	/* now start with single tags */
 		boot->last_error = sizeof(tPofRecHdr);	/* new length */
 		break;

 	case POF_READ_TAG_HEAD:
 		if (card->debug_flags & LOG_POF_WRITE)
 			hysdn_addlog(card, "POF write: checking tag header");

 		if (datlen != sizeof(tPofRecHdr)) {
 			boot->last_error = -EPOF_INTERNAL;
 			break;
 		}
 		boot->pof_recid = boot->buf.PofRecHdr.PofRecId;		/* actual pof recid */
 		boot->pof_reclen = boot->buf.PofRecHdr.PofRecDataLen;	/* total length */
 		boot->pof_recoffset = 0;	/* no starting offset */

 		if (card->debug_flags & LOG_POF_RECORD)
 			hysdn_addlog(card, "POF: got record id=0x%lx length=%ld ",
 				     boot->pof_recid, boot->pof_reclen);

 		boot->pof_state = POF_READ_TAG_DATA;	/* now start with tag data */
 		if (boot->pof_reclen < BOOT_BUF_SIZE)
 			boot->last_error = boot->pof_reclen;	/* limit size */
 		else
 			boot->last_error = BOOT_BUF_SIZE;	/* maximum */

 		if (!boot->last_error) {	/* no data inside record */
 			boot->pof_state = POF_READ_TAG_HEAD;	/* now start with single tags */
 			boot->last_error = sizeof(tPofRecHdr);	/* new length */
 		}
 		break;

 	case POF_READ_TAG_DATA:
 		if (card->debug_flags & LOG_POF_WRITE)
 			hysdn_addlog(card, "POF write: getting tag data");

 		if (datlen != boot->last_error) {
 			boot->last_error = -EPOF_INTERNAL;
 			break;
 		}
 		if ((boot->last_error = pof_handle_data(card, datlen)) < 0)
 			return (boot->last_error);	/* an error occurred */
 		boot->pof_recoffset += datlen;
 		if (boot->pof_recoffset >= boot->pof_reclen) {
 			boot->pof_state = POF_READ_TAG_HEAD;	/* now start with single tags */
 			boot->last_error = sizeof(tPofRecHdr);	/* new length */
 		} else {
 			if (boot->pof_reclen - boot->pof_recoffset < BOOT_BUF_SIZE)
 				boot->last_error = boot->pof_reclen - boot->pof_recoffset;	/* limit size */
 			else
 				boot->last_error = BOOT_BUF_SIZE;	/* maximum */
 		}
 		break;

 	default:
 		boot->last_error = -EPOF_INTERNAL;	/* unknown state */
 		break;
 	}			/* switch (boot->pof_state) */

 	return (boot->last_error);
 }				/* pof_write_buffer */


 /*******************************************************************************/
 /* pof_write_open is called when an open for boot on the cardlog device occurs. */
 /* The function returns the needed number of bytes for the next operation. If  */
 /* the returned number is less or equal 0 an error specified by this code      */
 /* occurred. Additionally the pointer to the buffer data area is set on success */
 /*******************************************************************************/
 int
 pof_write_open(hysdn_card *card, unsigned char **bufp)
 {
 	struct boot_data *boot;	/* pointer to boot specific data */

 	if (card->boot) {
 		if (card->debug_flags & LOG_POF_OPEN)
 			hysdn_addlog(card, "POF open: already opened for boot");
 		return (-ERR_ALREADY_BOOT);	/* boot already active */
 	}
 	/* error no mem available */
 	if (!(boot = kzalloc(sizeof(struct boot_data), GFP_KERNEL))) {
 		if (card->debug_flags & LOG_MEM_ERR)
 			hysdn_addlog(card, "POF open: unable to allocate mem");
 		return (-EFAULT);
 	}
 	card->boot = boot;
 	card->state = CARD_STATE_BOOTING;

 	card->stopcard(card);	/* first stop the card */
 	if (card->testram(card)) {
 		if (card->debug_flags & LOG_POF_OPEN)
 			hysdn_addlog(card, "POF open: DPRAM test failure");
 		boot->last_error = -ERR_BOARD_DPRAM;
 		card->state = CARD_STATE_BOOTERR;	/* show boot error */
 		return (boot->last_error);
 	}
 	boot->BufSize = 0;	/* Buffer is empty */
 	boot->pof_state = POF_READ_FILE_HEAD;	/* read file header */
 	StartDecryption(boot);	/* if POF File should be encrypted */

 	if (card->debug_flags & LOG_POF_OPEN)
 		hysdn_addlog(card, "POF open: success");

 	*bufp = boot->buf.BootBuf;	/* point to buffer */
 	return (sizeof(tPofFileHdr));
 }				/* pof_write_open */

 /********************************************************************************/
 /* pof_write_close is called when an close of boot on the cardlog device occurs. */
 /* The return value must be 0 if everything has happened as desired.            */
 /********************************************************************************/
 int
 pof_write_close(hysdn_card *card)
 {
 	struct boot_data *boot = card->boot;	/* pointer to boot specific data */

 	if (!boot)
 		return (-EFAULT);	/* invalid call */

 	card->boot = NULL;	/* no boot active */
 	kfree(boot);

 	if (card->state == CARD_STATE_RUN)
 		card->set_errlog_state(card, 1);	/* activate error log */

 	if (card->debug_flags & LOG_POF_OPEN)
 		hysdn_addlog(card, "POF close: success");

 	return (0);
 }				/* pof_write_close */

 /*********************************************************************************/
 /* EvalSysrTokData checks additional records delivered with the Sysready Message */
 /* when POF has been booted. A return value of 0 is used if no error occurred.    */
 /*********************************************************************************/
 int
 EvalSysrTokData(hysdn_card *card, unsigned char *cp, int len)
 {
 	u_char *p;
 	u_char crc;

 	if (card->debug_flags & LOG_POF_RECORD)
 		hysdn_addlog(card, "SysReady Token data length %d", len);

 	if (len < 2) {
 		hysdn_addlog(card, "SysReady Token Data to short");
 		return (1);
 	}
 	for (p = cp, crc = 0; p < (cp + len - 2); p++)
 		if ((crc & 0x80))
 			crc = (((u_char) (crc << 1)) + 1) + *p;
 		else
 			crc = ((u_char) (crc << 1)) + *p;
 	crc = ~crc;
 	if (crc != *(cp + len - 1)) {
 		hysdn_addlog(card, "SysReady Token Data invalid CRC");
 		return (1);
 	}
 	len--;			/* don't check CRC byte */
 	while (len > 0) {

 		if (*cp == SYSR_TOK_END)
 			return (0);	/* End of Token stream */

 		if (len < (*(cp + 1) + 2)) {
 			hysdn_addlog(card, "token 0x%x invalid length %d", *cp, *(cp + 1));
 			return (1);
 		}
 		switch (*cp) {
 		case SYSR_TOK_B_CHAN:	/* 1 */
 			if (*(cp + 1) != 1)
 				return (1);	/* length invalid */
 			card->bchans = *(cp + 2);
 			break;

 		case SYSR_TOK_FAX_CHAN:	/* 2 */
 			if (*(cp + 1) != 1)
 				return (1);	/* length invalid */
 			card->faxchans = *(cp + 2);
 			break;

 		case SYSR_TOK_MAC_ADDR:	/* 3 */
 			if (*(cp + 1) != 6)
 				return (1);	/* length invalid */
 			memcpy(card->mac_addr, cp + 2, 6);
 			break;

 		default:
 			hysdn_addlog(card, "unknown token 0x%02x length %d", *cp, *(cp + 1));
 			break;
 		}
 		len -= (*(cp + 1) + 2);		/* adjust len */
 		cp += (*(cp + 1) + 2);	/* and pointer */
 	}

 	hysdn_addlog(card, "no end token found");
 	return (1);
 }				/* EvalSysrTokData */
	/* $Id: hysdn_boot.c,v 1.4.6.4 2001/09/23 22:24:54 kai Exp $
	*
	* Linux driver for HYSDN cards
	* specific routines for booting and pof handling
	*
	* Author Werner Cornelius (werner@titro.de) for Hypercope GmbH
	* Copyright 1999 by Werner Cornelius (werner@titro.de)
	*
	* This software may be used and distributed according to the terms
	* of the GNU General Public License, incorporated herein by reference.
	*
	*/

	#include <linux/vmalloc.h>
	#include <linux/slab.h>
	#include <linux/uaccess.h>

	#include "hysdn_defs.h"
	#include "hysdn_pof.h"

	/********************************/
	/* defines for pof read handler */
	/********************************/
	#define POF_READ_FILE_HEAD 0
	#define POF_READ_TAG_HEAD 1
	#define POF_READ_TAG_DATA 2

	/************************************************************/
	/* definition of boot specific data area. This data is only */
	/* needed during boot and so allocated dynamically. */
	/************************************************************/
	struct boot_data {
	unsigned short Cryptor; /* for use with Decrypt function */
	unsigned short Nrecs; /* records remaining in file */
	unsigned char pof_state;/* actual state of read handler */
	unsigned char is_crypted;/* card data is crypted */
	int BufSize; /* actual number of bytes bufferd */
	int last_error; /* last occurred error */
	unsigned short pof_recid;/* actual pof recid */
	unsigned long pof_reclen;/* total length of pof record data */
	unsigned long pof_recoffset;/* actual offset inside pof record */
	union {
	unsigned char BootBuf[BOOT_BUF_SIZE];/* buffer as byte count */
	tPofRecHdr PofRecHdr; /* header for actual record/chunk */
	tPofFileHdr PofFileHdr; /* header from POF file */
	tPofTimeStamp PofTime; /* time information */
	} buf;
	};

	/*****************************************************/
	/* start decryption of successive POF file chuncks. */
	/* */
	/* to be called at start of POF file reading, */
	/* before starting any decryption on any POF record. */
	/*****************************************************/
	static void
	StartDecryption(struct boot_data *boot)
	{
	boot->Cryptor = CRYPT_STARTTERM;
	} /* StartDecryption */


	/***************************************************************/
	/* decrypt complete BootBuf */
	/* NOTE: decryption must be applied to all or none boot tags - */
	/* to HI and LO boot loader and (all) seq tags, because */
	/* global Cryptor is started for whole POF. */
	/***************************************************************/
	static void
	DecryptBuf(struct boot_data *boot, int cnt)
	{
	unsigned char *bufp = boot->buf.BootBuf;

	while (cnt--) {
	boot->Cryptor = (boot->Cryptor >> 1) ^ ((boot->Cryptor & 1U) ? CRYPT_FEEDTERM : 0);
	*bufp++ ^= (unsigned char)boot->Cryptor;
	}
	} /* DecryptBuf */

	/********************************************************************************/
	/* pof_handle_data executes the required actions dependent on the active record */
	/* id. If successful 0 is returned, a negative value shows an error. */
	/********************************************************************************/
	static int
	pof_handle_data(hysdn_card *card, int datlen)
	{
	struct boot_data boot = card->boot; / pointer to boot specific data */
	long l;
	unsigned char *imgp;
	int img_len;

	/* handle the different record types */
	switch (boot->pof_recid) {

	case TAG_TIMESTMP:
	if (card->debug_flags & LOG_POF_RECORD)
	hysdn_addlog(card, "POF created %s", boot->buf.PofTime.DateTimeText);
	break;

	case TAG_CBOOTDTA:
	DecryptBuf(boot, datlen); /* we need to encrypt the buffer */
	/* fall through */
	case TAG_BOOTDTA:
	if (card->debug_flags & LOG_POF_RECORD)
	hysdn_addlog(card, "POF got %s len=%d offs=0x%lx",
	(boot->pof_recid == TAG_CBOOTDTA) ? "CBOOTDATA" : "BOOTDTA",
	datlen, boot->pof_recoffset);

	if (boot->pof_reclen != POF_BOOT_LOADER_TOTAL_SIZE) {
	boot->last_error = EPOF_BAD_IMG_SIZE; /* invalid length */
	return (boot->last_error);
	}
	imgp = boot->buf.BootBuf; /* start of buffer */
	img_len = datlen; /* maximum length to transfer */

	l = POF_BOOT_LOADER_OFF_IN_PAGE -
	(boot->pof_recoffset & (POF_BOOT_LOADER_PAGE_SIZE - 1));
	if (l > 0) {
	/* buffer needs to be truncated */
	imgp += l; /* advance pointer */
	img_len -= l; /* adjust len */
	}
	/* at this point no special handling for data wrapping over buffer */
	/* is necessary, because the boot image always will be adjusted to */
	/* match a page boundary inside the buffer. */
	/* The buffer for the boot image on the card is filled in 2 cycles */
	/* first the 1024 hi-words are put in the buffer, then the low 1024 */
	/* word are handled in the same way with different offset. */

	if (img_len > 0) {
	/* data available for copy */
	if ((boot->last_error =
	card->writebootimg(card, imgp,
	(boot->pof_recoffset > POF_BOOT_LOADER_PAGE_SIZE) ? 2 : 0)) < 0)
	return (boot->last_error);
	}
	break; /* end of case boot image hi/lo */

	case TAG_CABSDATA:
	DecryptBuf(boot, datlen); /* we need to encrypt the buffer */
	/* fall through */
	case TAG_ABSDATA:
	if (card->debug_flags & LOG_POF_RECORD)
	hysdn_addlog(card, "POF got %s len=%d offs=0x%lx",
	(boot->pof_recid == TAG_CABSDATA) ? "CABSDATA" : "ABSDATA",
	datlen, boot->pof_recoffset);

	if ((boot->last_error = card->writebootseq(card, boot->buf.BootBuf, datlen)) < 0)
	return (boot->last_error); /* error writing data */

	if (boot->pof_recoffset + datlen >= boot->pof_reclen)
	return (card->waitpofready(card)); /* data completely spooled, wait for ready */

	break; /* end of case boot seq data */

	default:
	if (card->debug_flags & LOG_POF_RECORD)
	hysdn_addlog(card, "POF got data(id=0x%lx) len=%d offs=0x%lx", boot->pof_recid,
	datlen, boot->pof_recoffset);

	break; /* simply skip record */
	} /* switch boot->pof_recid */

	return (0);
	} /* pof_handle_data */


	/******************************************************************************/
	/* pof_write_buffer is called when the buffer has been filled with the needed */
	/* number of data bytes. The number delivered is additionally supplied for */
	/* verification. The functions handles the data and returns the needed number */
	/* of bytes for the next action. If the returned value is 0 or less an error */
	/* occurred and booting must be aborted. */
	/******************************************************************************/
	int
	pof_write_buffer(hysdn_card *card, int datlen)
	{
	struct boot_data boot = card->boot; / pointer to boot specific data */

	if (!boot)
	return (-EFAULT); /* invalid call */
	if (boot->last_error < 0)
	return (boot->last_error); /* repeated error */

	if (card->debug_flags & LOG_POF_WRITE)
	hysdn_addlog(card, "POF write: got %d bytes ", datlen);

	switch (boot->pof_state) {
	case POF_READ_FILE_HEAD:
	if (card->debug_flags & LOG_POF_WRITE)
	hysdn_addlog(card, "POF write: checking file header");

	if (datlen != sizeof(tPofFileHdr)) {
	boot->last_error = -EPOF_INTERNAL;
	break;
	}
	if (boot->buf.PofFileHdr.Magic != TAGFILEMAGIC) {
	boot->last_error = -EPOF_BAD_MAGIC;
	break;
	}
	/* Setup the new state and vars */
	boot->Nrecs = (unsigned short)(boot->buf.PofFileHdr.N_PofRecs); /* limited to 65535 */
	boot->pof_state = POF_READ_TAG_HEAD; /* now start with single tags */
	boot->last_error = sizeof(tPofRecHdr); /* new length */
	break;

	case POF_READ_TAG_HEAD:
	if (card->debug_flags & LOG_POF_WRITE)
	hysdn_addlog(card, "POF write: checking tag header");

	if (datlen != sizeof(tPofRecHdr)) {
	boot->last_error = -EPOF_INTERNAL;
	break;
	}
	boot->pof_recid = boot->buf.PofRecHdr.PofRecId; /* actual pof recid */
	boot->pof_reclen = boot->buf.PofRecHdr.PofRecDataLen; /* total length */
	boot->pof_recoffset = 0; /* no starting offset */

	if (card->debug_flags & LOG_POF_RECORD)
	hysdn_addlog(card, "POF: got record id=0x%lx length=%ld ",
	boot->pof_recid, boot->pof_reclen);

	boot->pof_state = POF_READ_TAG_DATA; /* now start with tag data */
	if (boot->pof_reclen < BOOT_BUF_SIZE)
	boot->last_error = boot->pof_reclen; /* limit size */
	else
	boot->last_error = BOOT_BUF_SIZE; /* maximum */

	if (!boot->last_error) { /* no data inside record */
	boot->pof_state = POF_READ_TAG_HEAD; /* now start with single tags */
	boot->last_error = sizeof(tPofRecHdr); /* new length */
	}
	break;

	case POF_READ_TAG_DATA:
	if (card->debug_flags & LOG_POF_WRITE)
	hysdn_addlog(card, "POF write: getting tag data");

	if (datlen != boot->last_error) {
	boot->last_error = -EPOF_INTERNAL;
	break;
	}
	if ((boot->last_error = pof_handle_data(card, datlen)) < 0)
	return (boot->last_error); /* an error occurred */
	boot->pof_recoffset += datlen;
	if (boot->pof_recoffset >= boot->pof_reclen) {
	boot->pof_state = POF_READ_TAG_HEAD; /* now start with single tags */
	boot->last_error = sizeof(tPofRecHdr); /* new length */
	} else {
	if (boot->pof_reclen - boot->pof_recoffset < BOOT_BUF_SIZE)
	boot->last_error = boot->pof_reclen - boot->pof_recoffset; /* limit size */
	else
	boot->last_error = BOOT_BUF_SIZE; /* maximum */
	}
	break;

	default:
	boot->last_error = -EPOF_INTERNAL; /* unknown state */
	break;
	} /* switch (boot->pof_state) */

	return (boot->last_error);
	} /* pof_write_buffer */


	/*******************************************************************************/
	/* pof_write_open is called when an open for boot on the cardlog device occurs. */
	/* The function returns the needed number of bytes for the next operation. If */
	/* the returned number is less or equal 0 an error specified by this code */
	/* occurred. Additionally the pointer to the buffer data area is set on success */
	/*******************************************************************************/
	int
	pof_write_open(hysdn_card card, unsigned char *bufp)
	{
	struct boot_data boot; / pointer to boot specific data */

	if (card->boot) {
	if (card->debug_flags & LOG_POF_OPEN)
	hysdn_addlog(card, "POF open: already opened for boot");
	return (-ERR_ALREADY_BOOT); /* boot already active */
	}
	/* error no mem available */
	if (!(boot = kzalloc(sizeof(struct boot_data), GFP_KERNEL))) {
	if (card->debug_flags & LOG_MEM_ERR)
	hysdn_addlog(card, "POF open: unable to allocate mem");
	return (-EFAULT);
	}
	card->boot = boot;
	card->state = CARD_STATE_BOOTING;

	card->stopcard(card); /* first stop the card */
	if (card->testram(card)) {
	if (card->debug_flags & LOG_POF_OPEN)
	hysdn_addlog(card, "POF open: DPRAM test failure");
	boot->last_error = -ERR_BOARD_DPRAM;
	card->state = CARD_STATE_BOOTERR; /* show boot error */
	return (boot->last_error);
	}
	boot->BufSize = 0; /* Buffer is empty */
	boot->pof_state = POF_READ_FILE_HEAD; /* read file header */
	StartDecryption(boot); /* if POF File should be encrypted */

	if (card->debug_flags & LOG_POF_OPEN)
	hysdn_addlog(card, "POF open: success");

	bufp = boot->buf.BootBuf; / point to buffer */
	return (sizeof(tPofFileHdr));
	} /* pof_write_open */

	/********************************************************************************/
	/* pof_write_close is called when an close of boot on the cardlog device occurs. */
	/* The return value must be 0 if everything has happened as desired. */
	/********************************************************************************/
	int
	pof_write_close(hysdn_card *card)
	{
	struct boot_data boot = card->boot; / pointer to boot specific data */

	if (!boot)
	return (-EFAULT); /* invalid call */

	card->boot = NULL; /* no boot active */
	kfree(boot);

	if (card->state == CARD_STATE_RUN)
	card->set_errlog_state(card, 1); /* activate error log */

	if (card->debug_flags & LOG_POF_OPEN)
	hysdn_addlog(card, "POF close: success");

	return (0);
	} /* pof_write_close */

	/*********************************************************************************/
	/* EvalSysrTokData checks additional records delivered with the Sysready Message */
	/* when POF has been booted. A return value of 0 is used if no error occurred. */
	/*********************************************************************************/
	int
	EvalSysrTokData(hysdn_card card, unsigned char cp, int len)
	{
	u_char *p;
	u_char crc;

	if (card->debug_flags & LOG_POF_RECORD)
	hysdn_addlog(card, "SysReady Token data length %d", len);

	if (len < 2) {
	hysdn_addlog(card, "SysReady Token Data to short");
	return (1);
	}
	for (p = cp, crc = 0; p < (cp + len - 2); p++)
	if ((crc & 0x80))
	crc = (((u_char) (crc << 1)) + 1) + *p;
	else
	crc = ((u_char) (crc << 1)) + *p;
	crc = ~crc;
	if (crc != *(cp + len - 1)) {
	hysdn_addlog(card, "SysReady Token Data invalid CRC");
	return (1);
	}
	len--; /* don't check CRC byte */
	while (len > 0) {

	if (*cp == SYSR_TOK_END)
	return (0); /* End of Token stream */

	if (len < (*(cp + 1) + 2)) {
	hysdn_addlog(card, "token 0x%x invalid length %d", cp, (cp + 1));
	return (1);
	}
	switch (*cp) {
	case SYSR_TOK_B_CHAN: /* 1 */
	if (*(cp + 1) != 1)
	return (1); /* length invalid */
	card->bchans = *(cp + 2);
	break;

	case SYSR_TOK_FAX_CHAN: /* 2 */
	if (*(cp + 1) != 1)
	return (1); /* length invalid */
	card->faxchans = *(cp + 2);
	break;

	case SYSR_TOK_MAC_ADDR: /* 3 */
	if (*(cp + 1) != 6)
	return (1); /* length invalid */
	memcpy(card->mac_addr, cp + 2, 6);
	break;

	default:
	hysdn_addlog(card, "unknown token 0x%02x length %d", cp, (cp + 1));
	break;
	}
	len -= ((cp + 1) + 2); / adjust len */
	cp += ((cp + 1) + 2); / and pointer */
	}

	hysdn_addlog(card, "no end token found");
	return (1);
	} /* EvalSysrTokData */