S3C2450自动升级
S3C2450自动升级
在BSP包中，有两个bootloader文件夹，一个命名为bootloader,另一个命名为bootloader_update。Bootloader文件夹用于USB下载，调试用，bootloader_update用于生产，自动升级用。下面重点介绍bootloader_update文件夹。
Bootloader_update文件夹下有四个文件夹，分别是BLCOMMON，Eboot_boot，FAT_LIB以及IROM_SD_TOOL。BLCOMMON文件夹编译后生成oal_blcommon.lib文件，供Eboot_boot调用。FAT_LIB文件夹里面包含三个静态库文件FAT_LIB.lib，HSMMCEBOOT_LIB.lib以及SDREAD_UPDATE.lib。这些静态库封装了一些用于升级的函数。Eboot_boot文件夹编译后将会产生生产用的Eboot.bin文件，该文件即能够启动系统，也能够通过硬件平台的按键控制，实现自动升级。IROM_SD_TOOL文件夹编译后，会将前面的Eboot.bin文件封装成SD卡识别的程序，最终生成IROM_SD_EBOOT.nb0。通过三星提供的IROM_Fusing_Tool工具，将该文件烧到SD卡后，2450平台就能够实现从SD卡启动了。当然前提是硬件本身要设置跳线成SD卡启动。
主程序中(Eboot_boot文件夹)定义了三个重要的变量：AUTO_UPDATE_FROM_SD；
ERASE_ALL_FLASH_BLOCKS；
SHOW_UPDATE_LOGO。
当AUTO_UPDATE_FROM_SD为真时，Eboot将会进入升级程序，为假时将引导flash中的NK，启动系统。
当ERASE_ALL_FLASH_BLOCKS为真时，Eboot将会格式化flash，然后依次升级block0.nb0,eboot.bin,nk.bin，随后启动系统。
当SHOW_UPDATE_LOGO为真时，LCD上将会出现升级文件的提示，否则显示开机LOGO。
其中AUTO_UPDATE_FROM_SD标志位通过硬件平台的按键判断，当拨动电源键后在两秒之内回拨到LOCK位置，Eboot将识别到该LOCK标志，这时将AUTO_UPDATE_FROM_SD置高，程序进入升级状态。
ERASE_ALL_FLASH_BLOCKS标志位通过从SD卡中的update.txt文件中读取。
AUTO_UPDATE_FROM_SD的相关代码如下：
if(1 == UPDATA_ALL_IMAGE)
{
AUTO_UPDATE_FROM_SD =TRUE;
ERASE_ALL_FLASH_BLOCKS =TRUE;
SHOW_UPDATE_LOGO = TRUE;
}
else if( _FAT_Boot_ReadFile(_BOOT_TYPE_SD_BIN, _UPDATE_FILE_DETECT) ||auto_updatekey_isPressed() )
{
//自动升级健按下进行自动升级
AUTO_UPDATE_FROM_SD=TRUE;
}
else
{
AUTO_UPDATE_FROM_SD = FALSE;
}
其中_FAT_Boot_ReadFile()函数用于从SD卡中读取_UPDATE_FILE_DETECT文件，该字符串在最前面有如下定义：
#define _UPDATE_FILE_DETECT "DETECT BIN"
auto_updatekey_isPressed()函数用于检测拍照键是否按下，从这里可以看出，如果SD卡中存在detect.bin文件，则升级时不用再按住拍照键了。如果没有则必须按住拍照键。
Flash格式化的程序如下：
if(1)// format flash.
{
//ADDED BY ZHOUPENG FOR TEST
ReadDeviceSerialNumber(Serial_Block_Number,pBuf8);
ReadDeviceSerialNumber(Smit_Device_Serial_Block_Number,pBuf9);
OALMSG(TRUE, (TEXT(" ++Format FIL (Erase All Blocks)/r/n")));
if (VFL_Close() != VFL_SUCCESS)
{
OALMSG(TRUE, (TEXT("[ERR] VFL_Close() Failure/r/n")));
}
if (WMR_Format_FIL() == FALSE32)
{
OALMSG(TRUE, (TEXT("[ERR] WMR_Format_FIL() Failure/r/n")));
}
if (WMR_Format_VFL() == FALSE32)
{
OALMSG(TRUE, (TEXT("[ERR] WMR_Format_VFL() Failure/r/n")));
}
if (WMR_Format_FTL() == FALSE32)
{
OALMSG(TRUE, (TEXT("[ERR] WMR_Format_FTL() Failure/r/n")));
}
OALMSG(TRUE, (TEXT("[INF] You can not use VFL before Format VFL/r/n")));
OALMSG(TRUE, (TEXT(" --Format FIL (Erase All Blocks)/r/n")));
WriteDeviceSerialNumber(Serial_Block_Number,pBuf8);
WriteDeviceSerialNumber(Smit_Device_Serial_Block_Number,pBuf9);
}
下载映像的函数如下：
static BOOL DownloadImage (LPDWORD pdwImageStart, LPDWORD pdwImageLength, LPDWORD pdwLaunchAddr)
{
BYTE hdr[BL_HDRSIG_SIZE];
DWORD dwRecLen, dwRecChk, dwRecAddr;
BOOL fIsFlash = FALSE;
LPBYTE lpDest = NULL;
int nPkgNum = 0;
BYTE nNumDownloadFiles = 1;
DWORD dwImageStart = 0;
DWORD dwImageLength = 0;
RegionInfo *pCurDownloadFile;
int i;
*pdwImageStart = *pdwImageLength = *pdwLaunchAddr = 0;
g_DownloadManifest.dwNumRegions = 0 ;
for( i = 0 ; i < BL_MAX_BIN_REGIONS ; i++)
{
g_DownloadManifest.Region[i].dwRegionStart = 0;
g_DownloadManifest.Region[i].dwRegionLength = 0;
g_DownloadManifest.Region[i].szFileName[0] = '/0';
}
do
{
// 将*.bin文件的前7个字节数据读入hdr(header)数组
if (!OEMReadData (BL_HDRSIG_SIZE, hdr))
{
EdbgOutputDebugString ("/r/nUnable to read image signature./r/n");
HALT (BLERR_MAGIC);
return (FALSE);
}
// An N000FF packet is manufactured by Platform Builder when we're
// downloading multiple files or when we're downloading a .nb0 file.
if (!memcmp (hdr, "N000FF/x0A", BL_HDRSIG_SIZE))//比较数据相等时memcmp返回0
{
// read the packet checksum.
//
if (!OEMReadData (sizeof (DWORD), (LPBYTE) &dwRecChk))
{
EdbgOutputDebugString("/r/nUnable to read download manifest checksum./r/n");
HALT (BLERR_MAGIC);
return (FALSE);
}
// read BIN region descriptions (start address and length).
//
if (!OEMReadData (sizeof (DWORD), (LPBYTE) &g_DownloadManifest.dwNumRegions) ||
!OEMReadData ((g_DownloadManifest.dwNumRegions * sizeof(RegionInfo)), (LPBYTE) &g_DownloadManifest.Region[0]))
{
EdbgOutputDebugString("/r/nUnable to read download manifest information./r/n");
HALT (BLERR_MAGIC);
return (FALSE);
}
// verify the packet checksum.
if (!VerifyChecksum((g_DownloadManifest.dwNumRegions * sizeof(RegionInfo)), (LPBYTE) &g_DownloadManifest.Region[0], dwRecChk))
{
EdbgOutputDebugString ("/r/nDownload manifest packet failed checksum verification./r/n");
HALT (BLERR_CHECKSUM);
return (FALSE);
}
if (g_pOEMMultiBINNotify)
{
g_pOEMMultiBINNotify((PDownloadManifest)&g_DownloadManifest);
}
// look for next download...
nNumDownloadFiles = (BYTE)(g_DownloadManifest.dwNumRegions + 1); // +1 to account for this packet.
continue;
}
// Is this an old X000FF multi-bin packet header? It's no longer supported.
else if (!memcmp (hdr, "X000FF/x0A", BL_HDRSIG_SIZE))
{
EdbgOutputDebugString ("ERROR: The X000FF packet is an old-style multi-bin download manifest and it's no longer supported. /r/nPlease update your Platform Builder installation in you want to download multiple files./r/n");
HALT (BLERR_MAGIC);
return (FALSE);
}
// Is this a standard bin image? Check for the usual bin file signature.
else if (!memcmp (hdr, "B000FF/x0A", BL_HDRSIG_SIZE))//lqm:下载xip.bin,nk.bin,eboot.bin时在这里执行
{
g_bBINDownload = TRUE;
if (!OEMReadData (sizeof (DWORD), (LPBYTE) &dwImageStart)//读取*.bin前7个头字节后的一个DWORD到dwImageStart。*.bin记录了其映像起始地址
|| !OEMReadData (sizeof (DWORD), (LPBYTE) &dwImageLength))//读取上面接着的一个DWORD到dwImageLength。*.bin记录了其映像长度
{
EdbgOutputDebugString ("Unable to read image start/length/r/n");
HALT (BLERR_MAGIC);
return (FALSE);
}
}
// If the header signature isn't recognized, we'll assume the
// download file is a raw .nb0 file.
//
else
{
g_bBINDownload = FALSE;
}
if (!g_DownloadManifest.dwNumRegions)
{
g_DownloadManifest.dwNumRegions = 1; //声明*.bin有一条记录
g_DownloadManifest.Region[0].dwRegionStart = dwImageStart; //声明这条记录的起始地址
g_DownloadManifest.Region[0].dwRegionLength = dwImageLength;//声明这条记录的映像长度
// Provide the download manifest to the OEM.
if (g_pOEMMultiBINNotify)
{
g_pOEMMultiBINNotify((PDownloadManifest)&g_DownloadManifest);
}
}
// Locate the current download manifest entry (current download file).
pCurDownloadFile = &g_DownloadManifest.Region[g_DownloadManifest.dwNumRegions - nNumDownloadFiles];//当前下载文件指向*.bin开始
// give the OEM a chance to verify memory.内存校验
if (g_pOEMVerifyMemory && !g_pOEMVerifyMemory (pCurDownloadFile->dwRegionStart, pCurDownloadFile->dwRegionLength))
{
EdbgOutputDebugString ("!OEMVERIFYMEMORY: Invalid image/r/n");//lqm:很多情况下都会执行到这里!映像不能获得?
HALT (BLERR_OEMVERIFY);
return (FALSE);
}
// check for flash image. Start erasing if it is.
if ( (fIsFlash = OEMIsFlashAddr(pCurDownloadFile->dwRegionStart))//lqm:校验起始地址是否在Flash相应地址区域，如果是则擦除相应下载区域
&& !OEMStartEraseFlash (pCurDownloadFile->dwRegionStart, pCurDownloadFile->dwRegionLength))
{
EdbgOutputDebugString ("Invalid Flash Address/Length/r/n");
HALT (BLERR_FLASHADDR);
return (FALSE);
}
// if we're downloading a binary file, we've already downloaded part of the image when searching
// for a file header. copy what we've read so far to the destination buffer, then finish downloading.
if (!g_bBINDownload)
{
lpDest = OEMMapMemAddr (pCurDownloadFile->dwRegionStart, pCurDownloadFile->dwRegionStart);
memcpy(lpDest, hdr, BL_HDRSIG_SIZE);
// complete the file download...
// read data block
if (!OEMReadData ((pCurDownloadFile->dwRegionLength - BL_HDRSIG_SIZE), (lpDest + BL_HDRSIG_SIZE)))
{
EdbgOutputDebugString ("ERROR: failed when reading raw binary file./r/n");
HALT (BLERR_CORRUPTED_DATA);
return (FALSE);
}
}
// we're downloading a .bin file - download each .bin record in turn...
else//开始下载*.bin文件到DRAM中。
{
while (OEMReadData (sizeof (DWORD), (LPBYTE) &dwRecAddr) && //读取*.bin的第n条记录的地址.
OEMReadData (sizeof (DWORD), (LPBYTE) &dwRecLen) && //读取*.bin的第n条记录的长度.
OEMReadData (sizeof (DWORD), (LPBYTE) &dwRecChk)) //读取*.bin的第n条记录的校验和.
{
// last record of .bin file uses sentinel values for address and checksum.
// 最后一条记录表示结束.其地址和校验和均为0.
if (!dwRecAddr && !dwRecChk)
{
break;//读到最后一条记录时跳出循环
}
// map the record address (FLASH data is cached, for example)
// 将存入的记录地址映射到指针地址lpDest
lpDest = OEMMapMemAddr (pCurDownloadFile->dwRegionStart, dwRecAddr);
// read data block
if (!OEMReadData (dwRecLen, lpDest))//读取*.bin的第n条记录的内容到lpDest.这里先把*.bin的数据读到DRAM中。
{
EdbgOutputDebugString ("****** Data record %d corrupted, ABORT!!! ******/r/n", nPkgNum);
HALT (BLERR_CORRUPTED_DATA);
return (FALSE);
}
if (!VerifyChecksum (dwRecLen, lpDest, dwRecChk))//每读取一条记录则校验一次数据
{
EdbgOutputDebugString ("****** Checksum failure on record %d, ABORT!!! ******/r/n", nPkgNum);
HALT (BLERR_CHECKSUM);
return (FALSE);
}
// Look for ROMHDR to compute ROM offset. NOTE: romimage guarantees that the record containing
// the TOC signature and pointer will always come before the record that contains the ROMHDR contents.
//
if (dwRecLen == sizeof(ROMHDR) && (*(LPDWORD) OEMMapMemAddr(pCurDownloadFile->dwRegionStart, pCurDownloadFile->dwRegionStart + ROM_SIGNATURE_OFFSET) == ROM_SIGNATURE))
{
DWORD dwTempOffset = (dwRecAddr - *(LPDWORD)OEMMapMemAddr(pCurDownloadFile->dwRegionStart, pCurDownloadFile->dwRegionStart + ROM_SIGNATURE_OFFSET + sizeof(ULONG)));
ROMHDR *pROMHdr = (ROMHDR *)lpDest;
// Check to make sure this record really contains the ROMHDR.
//
if ((pROMHdr->physfirst == (pCurDownloadFile->dwRegionStart - dwTempOffset)) &&
(pROMHdr->physlast == (pCurDownloadFile->dwRegionStart - dwTempOffset + pCurDownloadFile->dwRegionLength)) &&
(DWORD)(HIWORD(pROMHdr->dllfirst << 16) <= pROMHdr->dlllast) &&
(DWORD)(LOWORD(pROMHdr->dllfirst << 16) <= pROMHdr->dlllast))
{
g_dwROMOffset = dwTempOffset;
EdbgOutputDebugString("rom_offset=0x%x./r/n", g_dwROMOffset);
}
}
// verify partial checksum
OEMShowProgress (nPkgNum ++);
// lqm added Progress in LCD.10-01-22
while( nPkgNum>=8 )
{
nPkgNum = 0;
LcdDrawString(">");
}
// end added.
}
}
if (g_bBINDownload)
{
// Does this .bin file contain a TOC?
if (*(LPDWORD) OEMMapMemAddr(pCurDownloadFile->dwRegionStart, pCurDownloadFile->dwRegionStart + ROM_SIGNATURE_OFFSET) == ROM_SIGNATURE) //+ ksk 20051219
{
// Contain the kernel?
if (IsKernelRegion(pCurDownloadFile->dwRegionStart, pCurDownloadFile->dwRegionLength))
{
*pdwImageStart = pCurDownloadFile->dwRegionStart;
*pdwImageLength = pCurDownloadFile->dwRegionLength;
*pdwLaunchAddr = dwRecLen;
}
}
// No TOC - not made by romimage. However, if we're downloading more than one
// .bin file, it's probably chain.bin which doesn't have a TOC (and which isn't
// going to be downloaded on its own) and we should ignore it.
//
else if (g_DownloadManifest.dwNumRegions == 1)
{
*pdwImageStart = pCurDownloadFile->dwRegionStart;
*pdwImageLength = pCurDownloadFile->dwRegionLength;
*pdwLaunchAddr = dwRecLen;
}
}
else // Raw binary file.
{
*pdwImageStart = pCurDownloadFile->dwRegionStart;
*pdwLaunchAddr = pCurDownloadFile->dwRegionStart;
*pdwImageLength = pCurDownloadFile->dwRegionLength;
}
// write to flash if it's flash image
if (fIsFlash)
{
// finish the flash erase
if (!OEMFinishEraseFlash ())
{
HALT (BLERR_FLASH_ERASE);
return (FALSE);
}
// Before writing the image to flash, optionally check the image signature.
if (g_bBINDownload && g_pOEMCheckSignature)
{
if (!g_pOEMCheckSignature(pCurDownloadFile->dwRegionStart, g_dwROMOffset, *pdwLaunchAddr, TRUE))
HALT(BLERR_CAT_SIGNATURE);
}
}
}
while (--nNumDownloadFiles);
if (fIsFlash)
{
nNumDownloadFiles = (BYTE)g_DownloadManifest.dwNumRegions;
while (nNumDownloadFiles--)
{
if (!OEMWriteFlash (g_DownloadManifest.Region[nNumDownloadFiles].dwRegionStart, g_DownloadManifest.Region[nNumDownloadFiles].dwRegionLength))
{
HALT (BLERR_FLASH_WRITE);
return (FALSE);
}
}
}
return (TRUE);
}
上面程序中有如下代码：
OEMShowProgress (nPkgNum ++);
while( nPkgNum>=8 )
{
nPkgNum = 0;
LcdDrawString(">");
}
该程序放在反复从SD卡中读取xip.bin的一条条记录的while循环中，这里是为了在升级界面上显示升级的进度。LcdDrawString(“>”)函数是调用了LcdDraw.c中的函数，用于在LCD上绘图。
这里一定要了解xip.bin的文件格式，否则很难理解整个数据流的流程。
Xip.bin以及NK.bin的组成：
组成：标记(7)+Image开始地址(1)+Image长度(1)
记录0地址+记录0长+记录0校验和+记录0内容(文件内容)
记录1地址+记录1长+记录1校验和+记录1内容(文件内容)
......
结束符号
从上面的程序可以看出，
if (!OEMReadData (BL_HDRSIG_SIZE, hdr))
{
EdbgOutputDebugString ("/r/nUnable to read image signature./r/n");
HALT (BLERR_MAGIC);
return (FALSE);
}
即是将xip.bin的前7个字节的数据读到数组hdr，供后面分析所读的文件的类型。
if (!OEMReadData (sizeof (DWORD), (LPBYTE) &dwImageStart)//读取*.bin前7个头字节后的一个DWORD到dwImageStart。*.bin记录了其映像起始地址
|| !OEMReadData (sizeof (DWORD), (LPBYTE) &dwImageLength))//读取上面接着的一个DWORD到dwImageLength。*.bin记录了其映像长度
{
EdbgOutputDebugString ("Unable to read image start/length/r/n");
HALT (BLERR_MAGIC);
return (FALSE);
}
则是将紧接着前7个字节的两个WORD数据读到dwImageStart和dwImageLength。随后的
while (OEMReadData (sizeof (DWORD), (LPBYTE) &dwRecAddr) &&
//读取*.bin的第n条记录的地址.
OEMReadData (sizeof (DWORD), (LPBYTE) &dwRecLen) &&
//读取*.bin的第n条记录的长度.
OEMReadData (sizeof (DWORD), (LPBYTE) &dwRecChk))
//读取*.bin的第n条记录的校验和.
则开始一条条的解析xip.bin的记录。
if (!OEMReadData (dwRecLen, lpDest))
{
EdbgOutputDebugString ("****** Data record %d corrupted, ABORT!!! ******/r/n", nPkgNum);
HALT (BLERR_CORRUPTED_DATA);
return (FALSE);
}
用于将读取到的第N条记录存放到lpDest.
分析要下载的文件并写入flash的代码如下：
void OEMLaunch( DWORD dwImageStart, DWORD dwImageLength, DWORD dwLaunchAddr, const ROMHDR *pRomHdr )
{
DWORD dwPhysLaunchAddr;
OALMSG(1, (TEXT("+OEMLaunch./r/n")));
// If the user requested that a disk image (stored in RAM now) be written to the SmartMedia card, so it now.
if (g_bDownloadImage) // && (g_pBootCfg->ConfigFlags & TARGET_TYPE_NAND))
{
// Since this platform only supports RAM images, the image cache address is the same as the image RAM address.
switch (g_ImageType)
{
case IMAGE_TYPE_STEPLDR://stepldr.bin
if (!WriteRawImageToBootMedia(dwImageStart, dwImageLength, dwLaunchAddr))
{
OALMSG(OAL_ERROR, (TEXT("ERROR: OEMLaunch: Failed to store image to Smart Media./r/n")));
goto CleanUp;
}
OALMSG(TRUE, (TEXT("INFO: Step loader image stored to Smart Media. Please Reboot. Halting.../r/n")));
if (g_bAutoDownload == TRUE)
{
return ;
}
while(1);
break;
case IMAGE_TYPE_LOADER://eboot.bin
g_pTOC->id[0].dwLoadAddress = dwImageStart;
g_pTOC->id[0].dwTtlSectors = FILE_TO_SECTOR_SIZE(dwImageLength);
if (!WriteRawImageToBootMedia(dwImageStart, dwImageLength, dwLaunchAddr))
{
OALMSG(OAL_ERROR, (TEXT("ERROR: OEMLaunch: Failed to store image to Smart Media./r/n")));
goto CleanUp;
}
if (dwLaunchAddr && (g_pTOC->id[0].dwJumpAddress != dwLaunchAddr))
{
g_pTOC->id[0].dwJumpAddress = dwLaunchAddr;
#if 0 // don't write TOC after download Eboot
if ( !TOC_Write() ) {
EdbgOutputDebugString("*** OEMLaunch ERROR: TOC_Write failed! Next boot may not load from disk *** /r/n");
}
TOC_Print();
#endif // by hmseo - 061123
}
OALMSG(TRUE, (TEXT("INFO: Eboot image stored to Smart Media. Please Reboot. Halting.../r/n")));
if (g_bAutoDownload == TRUE)
{
return ;
}
while(1);
break;
case IMAGE_TYPE_RAMIMAGE://NK.bin
OALMSG(1, (TEXT("+IMAGE_TYPE_RAMIMAGE dwImageStart:%08x.,dwLaunchAddr : %08x/r/n"),dwImageStart,dwLaunchAddr));
g_pTOC->id[g_dwTocEntry].dwLoadAddress = dwImageStart;
g_pTOC->id[g_dwTocEntry].dwTtlSectors = FILE_TO_SECTOR_SIZE(dwImageLength);
// 将NK.bin写到flash.
if (!WriteOSImageToBootMedia(dwImageStart, dwImageLength, dwLaunchAddr))
{
OALMSG(OAL_ERROR, (TEXT("ERROR: OEMLaunch: Failed to store image to Smart Media./r/n")));
goto CleanUp;
}
EdbgOutputDebugString("INFO1:dwLaunchAdd : %08x g_pTOC->id[0].dwJumpAddress :%08x, g_pTOC->id[1].dwJumpAddress :%08x/r /r/n", dwLaunchAddr, g_pTOC->id[0].dwJumpAddress,g_pTOC->id[1].dwJumpAddress);
if (dwLaunchAddr && (g_pTOC->id[g_dwTocEntry].dwJumpAddress != dwLaunchAddr))
{
g_pTOC->id[g_dwTocEntry].dwJumpAddress = dwLaunchAddr;
if ( !TOC_Write() ) //写TOC文件
{
EdbgOutputDebugString("*** OEMLaunch ERROR: TOC_Write failed! Next boot may not load from disk *** /r/n");
}
//masked by denis_wei for test 2009-02-05 TOC_Print();
}
else
{
dwLaunchAddr= g_pTOC->id[g_dwTocEntry].dwJumpAddress;
EdbgOutputDebugString("INFO2: using TOC[%d] dwJumpAddress: 0x%x/r/n", g_dwTocEntry, dwLaunchAddr);
}
break;
}
if(ERASE_ALL_FLASH_BLOCKS)//lqm added.10-01-22
{
LcdSetStringPosition(1,15);// lqm added.10-01-22
LcdDrawString("Starting WINCE,Please Wait......");// lqm added.10-01-22
//LcdSetStringPosition(1,16);// lqm added.10-01-22
}
if ( !ReadOSImageFromBootMedia( ) )//从FLASH读取映像到DRAM.
{
OALMSG(OAL_ERROR, (TEXT("OEMPlatformInit ERROR: Failed to load kernel region into RAM./r/n")));
SpinForever();
}
}
OALMSG(1, (TEXT("waitforconnect/r/n")));
if (dwLaunchAddr && (g_pTOC->id[g_dwTocEntry].dwJumpAddress != dwLaunchAddr))
{
g_pTOC->id[g_dwTocEntry].dwJumpAddress = dwLaunchAddr;
}
else
{
dwLaunchAddr= g_pTOC->id[g_dwTocEntry].dwJumpAddress;
OALMSG(OAL_INFO, (TEXT("INFO: using TOC[%d] dwJumpAddress: 0x%x/r/n"), g_dwTocEntry, dwLaunchAddr));
}
// Jump to downloaded image (use the physical address since we'll be turning the MMU off)...
//
dwPhysLaunchAddr = (DWORD)OALVAtoPA((void *)dwLaunchAddr);
OALMSG(TRUE, (TEXT("INFO: OEMLaunch: Jumping to Physical Address 0x%Xh (Virtual Address 0x%Xh).../r/n/r/n/r/n"), dwPhysLaunchAddr, dwLaunchAddr));
// Jump...
if( g_bAutoDownload == TRUE )
{
OALMSG(TRUE, (TEXT("INFO: auto update (BLOCK0IMAGE EBOOT NK) SUCCESS!/r/n")));}
Launch(dwPhysLaunchAddr);//跳到指定物理地址运行程序.
CleanUp:
OALMSG(TRUE, (TEXT("ERROR: OEMLaunch: Halting.../r/n")));
SpinForever();
}
在上面代码中，如下代码用于将已经读入DRAM的数据烧写到flash.
if (!WriteOSImageToBootMedia(dwImageStart, dwImageLength, dwLaunchAddr))
{
OALMSG(OAL_ERROR, (TEXT("ERROR: OEMLaunch: Failed to store image to Smart Media./r/n")));
goto CleanUp;
}
整个bootloader代码量大，但是细下心来慢慢分析，其实不难理解。这里就不一一分析了。