memory.c

NXP公司ARM LPC23xx系列USB codeloader的编写

/*----------------------------------------------------------------------------
 *      Name:    MEMORY.C
 *      Purpose: USB Mass Storage Demo
 *      Version: V1.10
 *----------------------------------------------------------------------------
 *      This software is supplied "AS IS" without any warranties, express,
 *      implied or statutory, including but not limited to the implied
 *      warranties of fitness for purpose, satisfactory quality and
 *      noninfringement. Keil extends you a royalty-free right to reproduce
 *      and distribute executable files created using this software for use
 *      on Philips LPC2xxx microcontroller devices only. Nothing else gives
 *      you the right to use this software.
 *
 *      Copyright (c) 2005-2006 Keil Software.
 *---------------------------------------------------------------------------*/

#include <LPC23XX.H>                        /* LPC214x definitions */

#include "type.h"

#include "usb.h"
#include "usbcfg.h"
#include "usbhw.h"
#include "usbcore.h"
#include "mscuser.h"

#include "memory.h"
#include "sbl_iap.h"
#include "sbl_config.h"

extern BYTE  Fat_RootDir[FAT_SIZE + ROOT_DIR_SIZE];  /* RAM to store the file allocation table */
extern BYTE  RootDirEntry[DIR_ENTRY];                       /* Root directry entry constants */
extern BYTE  CRPEntry[DIR_ENTRY];
extern BOOL  user_flash_erased;

void enter_usb_isp(void);

/* Function that initializes LEDs                                                       */
void LED_Init(void) {
  PINSEL10 = 0;                         /* Ensure ETM interface is diabled, enable LEDs */
  FIO2DIR  = 0x000000FF;                /* P2.0..7 defined as Outputs                   */
  FIO2MASK = 0x00000000;
}

/* Main Program */

int main (void) {
  
  /* If CRP3 is enabled and user flash start sector is not blank, execute the user code */
  if( crp == CRP3 && user_code_present() )
  {
      execute_user_code();
  }

  /* check_isp_entry_pin() function does not return if isp entry is not requested */
  if( user_code_present() )
  {
      check_isp_entry_pin();
  }
  /* User code not present or isp entry requested */
  enter_usb_isp();
}

void enter_usb_isp(void)
{
  DWORD n,m,next_cluster;

  /* Set user_flash_erased flag to FALSE. This flag is used detect whether whole
     user flash needs to be erased or not when CRP2 or CRP3 is enabled */
	 user_flash_erased = FALSE;

  /* generate File Allocation Table to save Flash space */
  /* First Two FAT entries are reserved */
  Fat_RootDir[0]= 0xF8;
  Fat_RootDir[1]= 0xFF;
  Fat_RootDir[2]= 0xFF;
  /* Start cluster of a file is indicated by the Directory entry = 2 */
  m = 3;
  for ( n = 3;n < NO_OF_CLUSTERS;n+=2) {
	if( n == (NO_OF_CLUSTERS-1) )
	{
	  next_cluster = 0xFFF;
	}
	else
	{
	  next_cluster = n + 1;
	}
  	Fat_RootDir[m] = (BYTE)n & 0xFF;
  	Fat_RootDir[m+1] = (((BYTE)next_cluster & 0xF) << 4) | ((BYTE)(n>>8)&0xF);
  	Fat_RootDir[m+2] = (BYTE)(next_cluster >> 4) & 0xFF;
    
	m = m+3;
  }
  /* Copy root directory entries */
  for (n = 0; n < DIR_ENTRY ; n++) {             /* Copy Initial Disk Image */
    Fat_RootDir[(FAT_SIZE+n)] = RootDirEntry[n];  /*   from Flash to RAM     */
  }

  /* Update the disk volume label as per the CRP status */
  if ( crp != NOCRP )
  {
      if ( crp == CRP1 )
      {
          Fat_RootDir[(FAT_SIZE+3)] = '1';
      }
      if ( crp == CRP2 )
      {
          Fat_RootDir[(FAT_SIZE+3)] = '2';
      }
      if ( crp == CRP3 )
      {
          Fat_RootDir[(FAT_SIZE+3)] = '3';
      }
	  for (n = 4; n < 11 ; n++)
	  {
          Fat_RootDir[(FAT_SIZE+n)] = CRPEntry[n-4];
	  }
  }	   

  /* Correct file size entry for file firmware.bin */
  Fat_RootDir[FAT_SIZE+60] = (BYTE)(USER_FLASH_SIZE & 0xFF);
  Fat_RootDir[FAT_SIZE+61] = (BYTE)(USER_FLASH_SIZE >> 8);
  Fat_RootDir[FAT_SIZE+62] = (BYTE)(USER_FLASH_SIZE >> 16);
  Fat_RootDir[FAT_SIZE+63] = (BYTE)(USER_FLASH_SIZE >> 24);

  LED_Init();
  USB_Init();                               /* USB Initialization */
  USB_Connect(TRUE);                        /* USB Connect */

  while (1);                                /* Loop forever */
}