flashvmem.c

采用ST20 CPU的机顶盒的烧写程序

/*
 * File     : flashvmem.c
 * Synopsys : OS21 virtual memory FLASH access functions.
 *
 * Copyright 2006 STMicroelectronics Limited.  All right reserved.
 *
 * FLASH memory access functions which use the OS21 vmem API.  These functions
 * are unsuitable for use in a multi-threaded application (static variables are
 * not protected).
 */

#include <stdio.h>
#include <stdlib.h>

#include "flash.h"
#ifdef __ST200__
#include "tlbhelper.h"
#endif

/* Globals used in accessing FLASH */
static unsigned int uncachedFlashBase = 0;
static unsigned int cachedFlashBase = 0;

/* Based on FLASH_BASE, work out what size we will map for FLASH */
static unsigned int getMappedFlashSize(void)
{
  static unsigned int mappedFlashSize = 0;
  if (!mappedFlashSize)
  {
    /* We decide to use from FLASH_BASE to the next 256MB aligned address.  If
       FLASH_BASE is 256MB aligned this should be TLB entry efficient.
     */
    unsigned int mask = 0x0FFFFFFF;
    while (mask)
    {
      if ((mask & FLASH_START) == 0)
      {
        mappedFlashSize = mask + 1;
        break;
      }
      mask = mask >> 1;
    }
  }
  return mappedFlashSize;
}

/* Function for getting the uncached base address of FLASH */
unsigned int getUncachedFlashBase(void)
{
  if (!uncachedFlashBase)
  {
    uncachedFlashBase = (unsigned int)vmem_create((void*)FLASH_START, getMappedFlashSize(), (void*)0, VMEM_CREATE_UNCACHED);
    if (!uncachedFlashBase)
    {
      fprintf(stderr, "flashdir: Unable to obtain uncached virtual memory mapping for FLASH\n");
      exit(1);
    }
  }
  return uncachedFlashBase;
}

/* Function for getting the cached base address of FLASH */
unsigned int getCachedFlashBase(void)
{
  if (!cachedFlashBase)
  {
    cachedFlashBase = (unsigned int)vmem_create((void*)FLASH_START, getMappedFlashSize(), (void*)0, VMEM_CREATE_CACHED);
    if (!cachedFlashBase)
    {
      fprintf(stderr, "flashdir: Unable to obtain cached virtual memory mapping for FLASH\n");
      exit(1);
    }
  }
  return cachedFlashBase;
}

/* Function for converting a physical FLASH address to uncached */
unsigned int physToUncachedFlashAddr(unsigned int addr)
{
  return getUncachedFlashBase() + (addr - FLASH_START);
}

/* Function for converting a physical FLASH address to cached */
unsigned int physToCachedFlashAddr(unsigned int addr)
{
  return getCachedFlashBase() + (addr - FLASH_START);
}

/* Unmap any vmem mapped FLASH regions implicitly created by the
   get<mode>FlashBase functions.
 */
void unmapFlash()
{
  if (uncachedFlashBase)
    vmem_delete((void*)uncachedFlashBase);
  if (cachedFlashBase)
    vmem_delete((void*)cachedFlashBase);
}


/*
 * Perform core specific memory initialisation.
 */
void init_flash_access(void)
{
#if defined(__ST231__)
  /* Enable speculative loads over the flash region so we can use the Toolset
     library functions on it safely (they are compiled with speculation on by
     default).
   */
  if (ensureSCURegion((void*)(FLASH_START & 0xF0000000), 0x10000000))
  {
    fprintf(stderr, "Failed to cover Flash region for speculative loads\n");
    exit(1);
  }
#endif
}