sh4-ipl.c

this is ipl loader for hitachi SH4 processor.

/* sh4-ipl: Initial Program Loader for SH7750
 *
 *  Copyright (C) 2001 KOMORIYA Takeru
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * See the file "GPL" for more details.
 *
 * Contact to author:
 *   KOMORIYA Takeru, AAF Sendai Lab., Japan
 *   E-mail: [e-mail]
 *      URL: http://chmodx.dyndns.org/aaf/
 */

#include <stdio.h>
#include <stddef.h>

#include "sh7750.h"
#include "sh-sci.h"
#include "sh-intr.h"
#include "sh-cache.h"

/* Routines to handle hex data */

static const char hexchars[] = "0123456789abcdef";

char highhex(int  x)
{
  return hexchars[(x >> 4) & 0xf];
}

char lowhex(int  x)
{
  return hexchars[x & 0xf];
}

int
hex (char ch)
{
  if ((ch >= 'a') && (ch <= 'f'))
    return (ch - 'a' + 10);
  if ((ch >= '0') && (ch <= '9'))
    return (ch - '0');
  if ((ch >= 'A') && (ch <= 'F'))
    return (ch - 'A' + 10);
  return (-1);
}

/* read srec format data */
static int
read_srec (void)
{
  int i, mode, bytes, hi, low, addr;
  static int blink_ticks = 0;
  unsigned char data[32];
  unsigned char checksum;
  char *mem;
  void (*startpoint)(void);

  mode = scif_getcw () - '0';
  /* get bytes of line */
  hi = scif_getcw ();
  low = scif_getcw ();
  bytes = hex (hi) * 16 + hex (low);
  data[0] = bytes;

  for (i=1; i<=bytes; i++)
    {
      hi = scif_getcw ();
      low = scif_getcw ();
      data[i] = hex (hi) * 16 + hex (low);
    }

  while (scif_getcw () != '\n');

  /* Checksum */
  checksum = 0;
  for(i=0 ; i<bytes ; i++) checksum += data[i];
  checksum = 0xff - checksum;
  
  if(data[bytes] != checksum){
    /* Checksum error */
    scif_puts ("Checksum error\r\n");
    return 1; 
  }
  /* blink LED */
  if( blink_ticks++ % 50 == 0)
    PDTRB = PDTRB ^ 0x0008;

  switch (mode)
    {
    case 0:           /* header */
      scif_puts ("\r\n");
      break;
    case 1:           /* 16bit address */
      addr = ((int)data[1]<<8) + (int)data[2];
      mem = (char *)addr;
      for (i=0; i<bytes-3; i++)
	*mem++ = data[i+3];
      break;
    case 2:           /* 24bit address */
      addr = ((int)data[1]<<16) + ((int)data[2]<<8) + (int)data[3];
      mem = (char *)addr;
      for (i=0; i<bytes-4; i++)
	*mem++ = data[i+4];
      break;
    case 3:           /* 32bit address */
      addr = ((int)data[1]<<24) + ((int)data[2]<<16)
	+ ((int)data[3]<<8) + (int)data[4];
      mem = (char *)addr;
      for (i=0; i<bytes-5; i++)
	*mem++ = data[i+5];
      break;
    case 7:           /* start address(32bit) */
      startpoint = (void*)( ((unsigned long)(data[1])<<24)
			    + ((unsigned long)(data[2])<<16) 
			    + ((unsigned long)(data[3])<<8)
			    + (unsigned long)(data[4]) );
      scif_puts ("Start address: 0x");
      for (i=1; i<5; i++){
	scif_put_hex (data[i],2);
      }
      scif_puts ("\r\n");
      sh_cache_control(CACHE_DISABLE);
      scif_disable();
      PDTRB = PDTRB & ~0x0008;  /* LED OFF */
      startpoint ();            /* jump to user program */
      PDTRB = PDTRB | 0x0008;   /* LED ON */
      scif_init();
      sh_cache_control(CACHE_ENABLE);
      return 1;
    case 8:           /* start address(24bit) */
      startpoint = (void*)( ((unsigned long)(data[1])<<16)
			    + ((unsigned long)(data[2])<<8) 
			    + (unsigned long)(data[3]) );
      scif_puts ("Start address: 0x");
      for (i=1; i<4; i++){
	scif_put_hex (data[i],2);
      }
      scif_puts ("\r\n");
      sh_cache_control(CACHE_DISABLE);
      scif_disable();
      PDTRB = PDTRB & ~0x0008;  /* LED OFF */
      startpoint ();            /* jump to user program */
      PDTRB = PDTRB | 0x0008;   /* LED ON */
      scif_init();
      sh_cache_control(CACHE_ENABLE);
      return 1;
    case 9:           /* start address(16bit) */
      startpoint = (void*)( ((unsigned long)(data[1])<<8)
			    + (unsigned long)(data[2]) );
      scif_puts ("Start address: 0x");
      for (i=1; i<3; i++){
	scif_put_hex (data[i],2);
      }
      scif_puts ("\r\n");
      sh_cache_control(CACHE_DISABLE);
      scif_disable();
      PDTRB = PDTRB & ~0x0008;  /* LED OFF */
      startpoint ();            /* jump to user program */
      PDTRB = PDTRB | 0x0008;   /* LED ON */
      scif_init();
      sh_cache_control(CACHE_ENABLE);
      return 1;
    }
  return 0;
}

static const char * const banner = "\r\n\
SH4-IPL version 0.3, Copyright (C) 2001 KOMORIYA Takeru\r\n\
\r\n\
This software comes with ABSOLUTELY NO WARRANTY; for details type `w'.\r\n\
This is free software, and you are welcome to redistribute it under\r\n\
certain conditions; type `l' for details.\r\n\r\n";

static const char * const license_message = "\r\n\
SH4-IPL is free software; you can redistribute it and/or modify it under\r\n\
the terms of the GNU General Public License as published by \r\n\
the Free Software Foundatin; either version 2 of the License, or (at your \r\n\
option) any later version.\r\n\r\n";

static const char * const warranty_message = "\r\n\
SH4-IPL is distributed in the hope that it will be useful, but\r\n\
WITHOUT ANY WARRANTY; without even the implied warranty of\r\n\
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU\r\n\
General Public License for more details.\r\n\r\n";

static const char * const help_message = "\r\n\
SH4-IPL version 0.3, Copyright (C) 2001 KOMORIYA Takeru\r\n\
    Feed your program in Motrola 'srec' format.\r\n\
    ? --- Show this message (HELP)\r\n\
    l --- Show about license\r\n\
    w --- Show about (no)warranty\r\n\r\n\
";

static const char * const prompt = "> ";

void
start_main (void)
{
  char c;
  int showprompt = 1;

  /* initialize SCIF */
  scif_init();

  /* enable cache */
  sh_cache_control(CACHE_ENABLE);

  /* show banner */
  scif_puts (banner);

  /* LED ON */
  PCTRB = 0x000000c0;
  PDTRB = 0x0008;

  while (1)
    {
      if (showprompt)
	scif_puts (prompt);
      c = scif_getcw ();
      switch (c)
	{
	case '?':
	  /* Help */
	  scif_puts ("?");
	  scif_puts (help_message);
	  break;
	case 'l':
	  /* License */
	  scif_puts ("l");
	  scif_puts (license_message);
	  break;
	case 'S':
	  /* Read srec format data */
	  showprompt = read_srec();
	  break;
	case 'w':
	  /* Warranty */
	  scif_puts ("w");
	  scif_puts (warranty_message);
	  break;
	default:
	  scif_puts ("\r\n");
	  break;
	}
    }
}