ry.c

开源的BIOS启动软件

/*
 * Receive file with YMODEM file transfer protocol
 *
 * Note:  This code uses 8 bit checksum which may not be compatible with 
 *        some programs claiming to support YMODEM transfers.
 *
 * 1999/11/24  Nicolas Pitre <[e-mail]>:
 *	Integrated into EBSA285's BIOS for ARM Linux.
 *
 */


#include <bios/stdio.h>
#include <bios/string.h>
#include <bios/time.h>
#include <bios/timer.h>
#include <bios/boot.h>
#include <bios/bootdev.h>


#define SERBASE 0x42000160
#define OK 0
#define ERROR (-1)
#define FALSE 0
#define TRUE 1
#define CAN ('X'&037)
#define SOH 1
#define STX 2
#define EOT 4
#define ACK 6
#define NAK 025
#define TIMEOUT (-2)
#define RETRYMAX 15
#define WCEOT (-10)


static long Bytesleft;
static int Blklen;
static char secbuf[1024];
static unsigned long *pout;


static void tx( int c )
{
  while (*((volatile int *)(SERBASE + 0x18)) & (1<<5));
  *((volatile int *)(SERBASE)) = c;
}

static int rx(int timeout)
{
  int c;
  unsigned int expire = centisecs + timeout * 100;

  while( centisecs <= expire ){
    if ( ! (*((volatile int *)(SERBASE + 0x18)) & (1<<4)) ) {
      c = *((volatile int *)(SERBASE));
      return c & 0xff;
    }
  }
  return TIMEOUT;
}

static inline void putsec (char *p, int n)
{
  n += 3;
  n >>= 2;
  while( n-- )
    *pout++ = *((unsigned long *)p)++;
}

static int procheader (char *name)
{
  register char *p;

  Bytesleft = 0x7fffffff;
  p = name + 1 + strnlen (name, 128);
  if (*p)
    Bytesleft = atol(p);
  return OK;
}

static int wcgetsec (char *rxbuf)
{
  register int checksum, wcj, firstch;
  register char *p;
  int sectcurr, errors;
  for (errors = 0; errors < RETRYMAX; errors++)
    {
      if ((firstch = rx(5)) == STX)
	{
	  Blklen = 1024;
	  goto get2;
	}
      if (firstch == SOH)
	{
	  Blklen = 128;
	get2:
	  sectcurr = rx(2);
	  checksum = 0;
	  if ((sectcurr + (rx(2))) == 0377)
	    {
	      for (p = rxbuf, wcj = Blklen; --wcj >= 0;)
		{
		  if ((firstch = rx(2)) < 0)
		    goto bilge;
		  checksum += (*p++ = firstch);
		}
	      if ((firstch = rx(2)) < 0)
		goto bilge;
	      if (((checksum - firstch) & 0377) == 0)
		return sectcurr;
	    }
	}
      else if (firstch == EOT)
	return WCEOT;
      else if (firstch == CAN)
	return ERROR;
    bilge:
      while (rx(2) != TIMEOUT);
      tx(NAK);
    }
  return ERROR;
}

static int wcrxpn (char *rpn)
{
  register int c;

   
et_tu:
  tx(NAK);
  while ((c = wcgetsec (rpn)) != 0)
    {
      if (c == WCEOT)
	{
	  tx(ACK);
	  rx(2);
	  goto et_tu;
	}
      return ERROR;
    }
  tx(ACK);
  return OK;
}

static int wcrx ()
{
  register int sectnum, sectcurr, sendchar, cblklen;

  sectnum = 0;
  sendchar = NAK;
  for (;;)
    {
      tx(sendchar);
      sectcurr = wcgetsec (secbuf);
      if (sectcurr == ((sectnum + 1) & 0377))
	{
	  sectnum++;
	  cblklen = Bytesleft > Blklen ? Blklen : Bytesleft;
	  putsec (secbuf, cblklen);
	  if ((Bytesleft -= cblklen) < 0)
	    Bytesleft = 0;
	  sendchar = ACK;
	}
      else if (sectcurr == (sectnum & 0377))
	sendchar = ACK;
      else if (sectcurr == WCEOT)
	{
	  tx(ACK);
	  return OK;
	}
      else if (sectcurr == ERROR)
	return ERROR;
      else
	return ERROR;
    }
}

static int wcreceive ()
{
  for (;;)
    {
      if (wcrxpn (secbuf) == ERROR)
	break;
      if (secbuf[0] == 0)
	return OK;
      if (procheader (secbuf) == ERROR || wcrx () == ERROR)
	break;
    }
  return ERROR;
}

static int serial_load( void )
{
  int res;

  printf( "\nNow send file with y-modem (^X to abort) ...\n" );
  pout = (unsigned long *)load_addr;
  res = wcreceive();
  wait_cs( 50 );
  printf( "\nTransfer %s, press any key.\n", 
          (res == OK) ? "complete" : "failed" );
  getc();
  return res;
}

static int serial_dummy( void )
{
  return 0;
}

struct bootdev boot_serial = {
        "serial",
        serial_dummy,
        serial_dummy,
        serial_load,
        serial_dummy
};