中秋假期已过，回来继续该博文主题。今天讲解第二种方法，将Logo图片的数据写入到Nand Flash中，在启动初始化LCD的时候，从固定的地址将数据读出并填充到显示缓存中。<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

       实验平台：WinCE6.0+Android6410 +4.3寸CLD。

       以下内容参考自CSDN论坛的一个帖子，不过里面的描述不是特别清楚，该主题博文进行了整理。为尊重原创，给出链接http://topic.csdn.net/u/20100126/14/ef1fc7c4-d8db-426b-b6bf-b74d74cdd05a.html。

      

       将Logo图片写Flash的思路继续细分，又可以分为几种不同的实现方法，今天先描述实现方法一，这是其中比较简单的一种方法，不需要修改bib文件等配置性文件，只需要修改代码即可。

       首先提几个问题：

       1、在什么时候将Logo数据写入Nand Flash？

       2、在什么时候读Nand Flash数据到显示缓存？

       3、要写的Logo的数据是什么？

       4、写入Flash的什么位置，又从什么位置读数据？

       5、写Flash的函数和读Flash的函数如何实现？

       上面几个问题弄清楚了，方法一基本就出来了。给出上面几个问题的解决方法：

       1、答：为了增加后期更加方便的升级开机启动Logo，在启动Eboot的主菜单中添加下载Logo的选项，如下图所示，选项G)便是通过USB下载Logo数据，同时将Logo数据写入到Nand Flash的某一位置上。
      
        2、答：在Eboot的初始化InitializeDisplay中，可以找到关于填充显示缓存的代码，改为从Flash的某一位置读取即可。

      3、答：关于写Logo的数据，可以是bin格式的，也可以是原始的bmp格式。其实bin格式的内容也都是通过读取bmp文件的位图阵列而生成的。两者的差别就在于一个在Eboot里面实现读取bmp的位图阵列，一个是在独立的应用程序中读取的。

      4、答：关于操作Nand Flash的位置问题，需要查看loader.h文件的相关代码，有关于Block的使用情况，如下所示。在这里为Logo数据分配一定的Block。
// NAND Boot (loads into SteppingStone) @ Block 0
#define NBOOT_BLOCK                                 0
#define NBOOT_BLOCK_SIZE                        1
#define NBOOT_SECTOR                                BLOCK_TO_SECTOR(NBOOT_BLOCK)

// TOC @ Block 1
#define TOC_BLOCK                                     1
#define TOC_BLOCK_SIZE                            1
#define TOC_SECTOR                                    BLOCK_TO_SECTOR(TOC_BLOCK)

// Eboot @ Block 2
#define EBOOT_BLOCK                                 2
#define EBOOT_SECTOR_SIZE                     FILE_TO_SECTOR_SIZE(EBOOT_RAM_IMAGE_SIZE)
#define EBOOT_BLOCK_SIZE                        SECTOR_TO_BLOCK(EBOOT_SECTOR_SIZE)
#define EBOOT_SECTOR                                BLOCK_TO_SECTOR(EBOOT_BLOCK)
       5、答：Flash的读写操作函数实现主要在nand.cpp文件中，具体实现可以参考函数ReadOSImageFromBootMedia和WriteOSImageToBootMedia。
      下面给出详细的修改步骤：

      1、首先修改loader.h文件，为Logo数据分配一定的Block空间。添加如下代码：
// Eboot @ Block 2
#define EBOOT_BLOCK                                 2
#define EBOOT_SECTOR_SIZE                     FILE_TO_SECTOR_SIZE(EBOOT_RAM_IMAGE_SIZE)
#define EBOOT_BLOCK_SIZE                        SECTOR_TO_BLOCK(EBOOT_SECTOR_SIZE)
#define EBOOT_SECTOR                                BLOCK_TO_SECTOR(EBOOT_BLOCK)

//-----------------------add by jazka 2011.09.04-------------------------
//-----------------------------start--------------------------------------
// Logo @ Block 6~
#define LOGO_BLOCK                    6
#define LOGO_BLOCK_SIZE                20
#define LOGO_SECTOR                            BLOCK_TO_SECTOR(LOGO_BLOCK)
//----------------------------- end ---------------------------------------

//-----------------------modify by jazka 2011.09.04-----------------------
//-----------------------------start---------------------------------------
//#define RESERVED_BOOT_BLOCKS                (NBOOT_BLOCK_SIZE + TOC_BLOCK_SIZE + EBOOT_BLOCK_SIZE)
#define RESERVED_BOOT_BLOCKS                (NBOOT_BLOCK_SIZE + TOC_BLOCK_SIZE + EBOOT_BLOCK_SIZE + LOGO_BLOCK_SIZE)
从上面可以看出从Block6开始，为Logo分配了20个Block的Flash空间，这样可以存放64KB*20=1280KB大小的Logo数据，即<?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />1M以内的图片数据。由于Logo占用了一定的Block空间，所以后面Nk的起始位置RESERVED_BOOT_BLOCKS需要向后移动。

       2、在Eboot启动主菜单中增加下载Logo数据的相应的选项。修改的代码如下：
EdbgOutputDebugString ( "F) Low-level format the Smart Media card\r\n");
    //add by jazka 2011.09.05
    //-----------------------------start---------------------------------
    EdbgOutputDebugString ( "G) DOWNLOAD Logo now(USB)\r\n");
    //----------------------------- end ---------------------------------
                EdbgOutputDebugString ( "L) LAUNCH existing Boot Media p_w_picpath\r\n");
                EdbgOutputDebugString ( "R) Read Configuration \r\n");
                EdbgOutputDebugString ( "U) DOWNLOAD p_w_picpath now(USB)\r\n");
                EdbgOutputDebugString ( "W) Write Configuration Right Now\r\n");
                EdbgOutputDebugString ( "\r\nEnter your selection: ");

                while (! ( ( (KeySelect >= '0') && (KeySelect <= '9') ) ||
                                     ( (KeySelect == 'A') || (KeySelect == 'a') ) ||
                                     ( (KeySelect == 'B') || (KeySelect == 'b') ) ||
                                     ( (KeySelect == 'C') || (KeySelect == 'c') ) ||
                                     ( (KeySelect == 'D') || (KeySelect == 'd') ) ||
                                     ( (KeySelect == 'E') || (KeySelect == 'e') ) ||
                                     ( (KeySelect == 'F') || (KeySelect == 'f') ) ||
             ( (KeySelect == 'G') || (KeySelect == 'g') ) ||                 //add by jazak 2011.09.05
                                     ( (KeySelect == 'L') || (KeySelect == 'l') ) ||
                                     ( (KeySelect == 'R') || (KeySelect == 'r') ) ||
                                     ( (KeySelect == 'U') || (KeySelect == 'u') ) ||
                                     ( (KeySelect == 'W') || (KeySelect == 'w') ) ))
                {
                        KeySelect = OEMReadDebugByte();
                }
//add by jazka 2011.09.05
    //--------------------------start-----------------------------
    case 'G':
    case 'g':
      {
        OALMSG(TRUE, (TEXT("Please send the Logo through USB.\r\n")));
        g_bUSBDownload = TRUE;

        {
          DWORD dwStartAddr = 0;
          LPBYTE lpDes = NULL;        
          lpDes = (LPBYTE)(FILE_CACHE_START);

          if (!OEMReadData(LCD_WIDTH*LCD_HEIGHT*2, lpDes))
          {
            OALMSG(TRUE, (TEXT("Error when sending the Logo through USB.\r\n")));
            SpinForever();
          }

          dwStartAddr = (DWORD)lpDes;

          if (!WriteLogoToBootMedia(dwStartAddr, (DWORD)(LCD_WIDTH*LCD_HEIGHT*2), dwStartAddr))
          {
            OALMSG(TRUE, (TEXT("Error when WriteLogoToBootMedia.\r\n")));
            SpinForever();
          }
        }
      }
      break;
    //-------------------------- end -----------------------------
这里把g_bUSBDownload设置为TRUE，以便后面选择USB进行下载。由于USB下载的速度和写Flash速度不匹配，所以先下载到内存中，然后在一下子写入Flash中（这部分详解见博客http://jazka.blog.51cto.com/809003/605776）。WriteLogoToBootMedia便是Flash的写函数，后面给出实现。

       3、修改LCD初始化函数InitializeDisplay，修改代码如下：
// Fill Framebuffer
#if(SMDK6410_LCD_MODULE == LCD_MODULE_UT_LCD35A)
        memcpy((void *)EBOOT_FRAMEBUFFER_UA_START, (void *)InitialImage_rgb16_320x240, 320*240*2);
#elif        (LCD_BPP == 16)
        {
    //delete by jazka 2011.08.31    修改开机启动界面
             /* int i;
                unsigned short *pFB;
                pFB = (unsigned short *)EBOOT_FRAMEBUFFER_UA_START;

                for (i=0; i<LCD_WIDTH*LCD_HEIGHT; i++)
    {
                        //*pFB++ = 0x0000;//0x001F;                // Blue
      //*pFB++ = 0x001F;                                             //modify by jazka 2011.07.22
      *pFB++ = InitialImage_rgb16_480x272[i];
    }
    */

    //add by jazka 2011.08.31
    //memcpy((void *)EBOOT_FRAMEBUFFER_UA_START, (void *)InitialImage_rgb16_480x272, 480*272*2);

    //modify by jazka 2011.09.07
    DWORD dwReadAddr = (DWORD)EBOOT_FRAMEBUFFER_UA_START;
    if (!DisplayLogoFromBootMedia(dwReadAddr, (DWORD)LCD_WIDTH*LCD_HEIGHT*2, dwReadAddr))
    {
      int i;
      unsigned short *pFB;
      pFB = (unsigned short *)EBOOT_FRAMEBUFFER_UA_START;

      for (i=0; i<LCD_WIDTH*LCD_HEIGHT; i++)
        *pFB++ = 0x0000;//0x001F;                // Blue
    }
DisplayLogoFromBootMedia函数便是Flash的度函数，这里将读出的数据写入到显示缓存EBOOT_FRAMEBUFFER_US_START中，该函数的实现后面给出。

      4、修改nand.cpp文件，添加WriteLogoToBootMedia和DisplayLogoFromBootMedia两个函数的实现。
/*
  Write the Logo data to Nand Flash
  add by jazka 2011.09.05
*/
BOOL WriteLogoToBootMedia(DWORD dwImageStart, DWORD dwImageLength, DWORD dwLaunchAddr)
{
  DWORD dwBlock,dwNumBlocks;
  LPBYTE pbBuffer;
  SectorInfo si;

  OALMSG(TRUE, (TEXT("+WriteLogoToBootMedia\r\n")));

  dwBlock = LOGO_BLOCK;
  pbBuffer = (LPBYTE)dwImageStart;

  OALMSG(TRUE, (TEXT("^^^^^^^^ 0x%x ^^^^^^^^\r\n"), (unsigned short *)pbBuffer));

  dwNumBlocks = (dwImageLength/(g_FlashInfo.wDataBytesPerSector*g_FlashInfo.wSectorsPerBlock)) +    
                                                 (dwImageLength%(g_FlashInfo.wDataBytesPerSector*g_FlashInfo.wSectorsPerBlock) ? 1: 0);

  OALMSG(TRUE, (TEXT("dwImageLength = 0x%x \r\n"), dwImageLength));
  OALMSG(TRUE, (TEXT("dwNumBlocks = 0x%x \r\n"), dwNumBlocks));

  while (dwNumBlocks--)
  {
    OALMSG(TRUE, (TEXT("dwBlock(0x%x) X "), dwBlock));
    OALMSG(TRUE, (TEXT("g_FlashInfo.wSectorsPerBlock(0x%x)"), g_FlashInfo.wSectorsPerBlock));
    OALMSG(TRUE, (TEXT(" = 0x%x \r\n"), dwBlock*g_FlashInfo.wSectorsPerBlock));

    FMD_ReadSector(dwBlock*g_FlashInfo.wSectorsPerBlock, NULL, &si, 1);

    // Stepldr & Eboot p_w_picpath in nand flash
    // block mark as BLOCK_STATUS_RESERVED & BLOCK_STATUS_READONLY & BLOCK_STATUS_BAD
    if ((si.bBadBlock == 0x0) && (si.bOEMReserved !=3 ))
    {
      ++dwBlock;
      ++dwNumBlocks;                // Compensate for fact that we didn't write any blocks.
      continue;
    }

    if (!ReadBlock(dwBlock, NULL, g_pSectorInfoBuf))
    {
      OALMSG(OAL_ERROR, (TEXT("WriteData: failed to read block (0x%x).\r\n"), dwBlock));
      return(FALSE);
    }

    if (!FMD_EraseBlock(dwBlock))
    {
      OALMSG(OAL_ERROR, (TEXT("WriteData: failed to erase block (0x%x).\r\n"), dwBlock));
      return FALSE;
    }

    if (!WriteBlock(dwBlock, pbBuffer, g_pSectorInfoBuf))
    {
      OALMSG(OAL_ERROR, (TEXT("WriteData: failed to write block (0x%x).\r\n"), dwBlock));
      return(FALSE);
    }

    ++dwBlock;
    pbBuffer += g_FlashInfo.dwBytesPerBlock;
    OALMSG(TRUE, (TEXT("dwBytesPerBlock : %d\r\n"), g_FlashInfo.dwBytesPerBlock));
  }

  OALMSG(TRUE, (TEXT("_WriteLogoToBootMedia\r\n")));

  return TRUE;
}
/*
  Read the Logo data from Nand Flash
  add by jazka 2011.09.05
*/
BOOL DisplayLogoFromBootMedia(DWORD dwImageStart, DWORD dwImageLength, DWORD dwLaunchAddr)
{
  unsigned int * pFB32 = (unsigned int *)EBOOT_FRAMEBUFFER_UA_START;
  unsigned int * dst = pFB32;        
  //unsigned int * p = NULL;
  SectorInfo si;

  DWORD dwBlock,dwNumBlocks;

  OALMSG(TRUE, (TEXT("+ReadLogoFromBootMedia\r\n")));

  dwBlock = LOGO_BLOCK;

  OALMSG(TRUE, (TEXT("dwImageLength = 0x%x \r\n"), dwImageLength));
  OALMSG(TRUE, (TEXT("dwImageLength = 0x%x \r\n"), g_FlashInfo.wDataBytesPerSector));
  OALMSG(TRUE, (TEXT("dwImageLength = 0x%x \r\n"), g_FlashInfo.wSectorsPerBlock));

  if (0 == g_FlashInfo.wDataBytesPerSector || 0 == g_FlashInfo.wSectorsPerBlock)
  {
    return FALSE;
  }

  dwNumBlocks = (dwImageLength / (g_FlashInfo.wDataBytesPerSector*g_FlashInfo.wSectorsPerBlock)) +
                (dwImageLength%(g_FlashInfo.wDataBytesPerSector*g_FlashInfo.wSectorsPerBlock) ? 1: 0);
  OALMSG(TRUE, (TEXT("dwNumBlocks = 0x%x \r\n"), dwNumBlocks));

  while (dwNumBlocks--)
  {    
    OALMSG(TRUE, (TEXT("dwBlock(0x%x) X "), dwBlock));
    OALMSG(TRUE, (TEXT("g_FlashInfo.wSectorsPerBlock(0x%x)"), g_FlashInfo.wSectorsPerBlock));
    OALMSG(TRUE, (TEXT(" = 0x%x \r\n"), dwBlock*g_FlashInfo.wSectorsPerBlock));

    //BOOL ReadBlock(DWORD dwBlock, LPBYTE pbBlock, PSectorInfo pSectorInfoTable)
    if (!ReadBlock(dwBlock, (LPBYTE)dst, g_pSectorInfoBuf))
    {
      OALMSG(OAL_ERROR, (TEXT("WriteData: failed to read block (0x%x).\r\n"), dwBlock));
      return(FALSE);    
    }
    dst += g_FlashInfo.dwBytesPerBlock/4;
    ++dwBlock;
  }
  OALMSG(TRUE, (TEXT("_ReadLogoFromBootMedia\r\n")));

  return TRUE;
}
       5、关于Logo数据的文件bin的生成，网上有很多工具可以实现，其实可以自己写一个应用程序完成该功能。本人编写了24位Bmp文件生成RGB565格式的bin文件的程序，这部分代码也可以在nand.app中写成一个函数，在写入Flash时调用转换为相应的RGB565数据即可，这样更新Logo时可以更直接。注意下载时的数据量是现在的3倍。

       这里就不给出源代码了，如果需要，请留言。

       今天就到这里，改天上实现方法二：将Logo.bin做成和Eboot.bin一样的格式，这样下载Eboot.bin的很多代码就可以直接使用。