再次学习flash驱动——挖掘不能发现nand flash盘符的原因

作者：wogoyixikexie@gliet 2008-12-05

昨晚看以前优龙的老4.2BSP的flash驱动，发现和我现在不能发现这个盘符的驱动有些差别。下面这个函数是flash驱动加载的时候要执行的，作用是检测flash有没有坏块。我发现我在新的flash驱动中犯了严重的错误。等下会在代码中说明。

DWORD FMD_GetBlockStatus(BLOCK_ID blockID)

{

SECTOR_ADDR Sector = (blockID * NAND_PAGE_CNT);

SectorInfo SI;

DWORD dwResult = 0;



//我在新的flash驱动根本没有这句关键代码，这句的作用是把NK和bootloader

//占用的flash 的block标记为坏块，这样起到保护的作用

//其实这个并不完整，因为这样会检测超出最大block数目正确的做法是

//if(blockID<0x280||blockID>flash总block数目-1)//这样就不会越界了。

if(blockID<0x280)//

return BLOCK_STATUS_BAD;

if (IsBlockBad(blockID))

return BLOCK_STATUS_BAD;

if (!FMD_ReadSector(Sector, NULL, &SI, 1))

return BLOCK_STATUS_UNKNOWN;

if (!(SI.bOEMReserved & OEM_BLOCK_READONLY))

dwResult |= BLOCK_STATUS_READONLY;

if (!(SI.bOEMReserved & OEM_BLOCK_RESERVED))

dwResult |= BLOCK_STATUS_RESERVED;

return(dwResult);

}



我还发现一些注册表的问题。

这是4.2可发现盘符的BSP的flash注册表部分

[HKEY_LOCAL_MACHINE/System/StorageManager/Profiles/FlashDrv]

"DriverPath"="Drivers//BuiltIn//FlashDrv"

"DefaultFileSystem"="FATFS"//这在失败哪里是没有的，居然是binfs不可思议。

"PartitionDriver"="mspart.dll"

"AutoMount"=dword:1

"AutoPart"=dword:1

"AutoFormat"=dword:1//这个也没有，这个会对没有格式化过的flash自动格式化。

"Folder"="nand flash"

"Name"="Microsoft Flash Disk"

"BootPhase"=dword:0

"Flags"=dword:1000//这个有什么用？

"Ioctl"=dword:4//这个有什么用？



少了那几个东西，对于使用优龙的BIOS来说，是不能发现盘符的。



在这里重新回到优龙ADS bootloader的话题，我仔细看过，里面的确没有binfs以及FAT分区功能。

那经过上面注册表之后为什么就实现分区了呢？



——————查看CSDN老帖，有：

有几个问题求教，望高手们赐教：
1 用CreatePartition函数会自动生成MBR和分区表吗？
2 我用DeviceIoControl函数时，好象只能对某个分区进行读写。我想用CreateFile，第一个参数应该指定一个物理设备名，对于Nand Flash应该指定为什么字符串啊？

================================

是可以生成mbr，以及mbr里的partition table的。

参见C:/WINCE420/PRIVATE/WINCEOS/COREOS/STORAGE/DOSPART/part.cpp代码

============================================================================================

C:/WINCE500/PRIVATE/WINCEOS/COREOS/STORAGE/DOSPART/helper.cpp(747):BOOL WriteMBR(DriverState *state, SECTORNUM snSectorNum, SECTORNUM snNumSectors, BYTE fileSysType, BOOL bCreateMBR)

//重新创建MBR，这个不知道在哪里被调用了，但是可以解释优龙的问题。

/*****************************************************************************

* WriteMBR - adds a partition entry to the master boot record. The partition

* table is traversed to find the placement for this partition. Entries within

* the MBR are sorted by the start sector.

*

* Input: state - structure for this store

* snSectorNum - start sector number for this partition

* snNumSectors - number of sectors in this partition

* fileSysType - partition type

* bCreateMBR - TRUE to generate a new MBR, FALSE to add to the

* existing MBR

*

* Output: none

*

* Return: TRUE if successfully written, FALSE for failures, ERROR_DISK_FULL

* will be set if no room in the MBR

*

*****************************************************************************/

BOOL WriteMBR(DriverState *state, SECTORNUM snSectorNum, SECTORNUM snNumSectors, BYTE fileSysType, BOOL bCreateMBR)

{

PBYTE buffer = NULL;

PPARTENTRY tmpbuffer, tmpbuffer1;

BOOL bResult;

int i, partIndex, partNum = -1;

// don't create the MBR, it already exists so use it 这个要特别注意，检测是否已经分区，没有就重新写入MBR

if (!bCreateMBR)

{

bResult = ReadSectors (state, 0, 1, &buffer);

if (!bResult)

return FALSE;

for (i = 0, partIndex = 0, tmpbuffer = (PPARTENTRY)(buffer + PARTTABLE_OFFSET); i < 4; i++, tmpbuffer++)

{

if (tmpbuffer->Part_TotalSectors == 0)

{

partNum = i;

break;

}

// find the index of the partition located just before this one

if (snSectorNum > tmpbuffer->Part_StartSector)

partIndex = i + 1;

}

if (partNum == -1)

{

// we return this error code so the caller can tell that there's no room in the MBR

LocalFree(buffer);

SetLastError(ERROR_DISK_FULL);

return FALSE;

}

// these indexes would be equal if we are adding to the end of the table

if (partIndex != partNum)

{

// this partition needs to be added in the order that it appears on the disk - so this may involve

// shifting some of the existing partition entries to open up the partition entry where this belongs

tmpbuffer = (PPARTENTRY)(buffer + PARTTABLE_OFFSET + (partNum * sizeof(PARTENTRY)));

tmpbuffer1 = (PPARTENTRY)(buffer + PARTTABLE_OFFSET + ((partNum -1) * sizeof(PARTENTRY)));

for (; partNum > partIndex; partNum--)

{

memcpy(tmpbuffer, tmpbuffer1, sizeof(PARTENTRY));

tmpbuffer--;

tmpbuffer1--;

}

}

}

else

{

buffer = (PBYTE)LocalAlloc(LMEM_ZEROINIT, state->diskInfo.di_bytes_per_sect);

if (!buffer)

return FALSE;

// add header and trailer info to the MBR

*(WORD *)(buffer + BOOT_SIGNATURE) = BOOTSECTRAILSIGH;

buffer[0] = 0xE9;

buffer[1] = 0xfd;

buffer[2] = 0xff;

partNum = 0;

}

tmpbuffer = (PPARTENTRY)(buffer + PARTTABLE_OFFSET + partNum * (int)sizeof(PARTENTRY));

// create the partition entry for the extended partition

bResult = ConvertLBAtoCHS (state, snSectorNum, &tmpbuffer->Part_FirstTrack, &tmpbuffer->Part_FirstHead, &tmpbuffer->Part_FirstSector);

tmpbuffer->Part_FileSystem = fileSysType;

tmpbuffer->Part_StartSector = (DWORD)snSectorNum;

tmpbuffer->Part_TotalSectors = (DWORD)snNumSectors;

bResult = ConvertLBAtoCHS (state, tmpbuffer->Part_StartSector + tmpbuffer->Part_TotalSectors -1, &tmpbuffer->Part_LastTrack, &tmpbuffer->Part_LastHead, &tmpbuffer->Part_LastSector);

bResult = WriteSectors(state, 0, 1, buffer);

LocalFree(buffer);

return bResult;

}

如果eboot不格式化FAT分区，就要在flash驱动中把NK所占block标记为坏块。才行。

但是如何让系统自动格式化位binfs我就不知道怎么搞了。这个不行的。因为当时已经存在NK了，不能再格式化了。
哈哈，终于弄明白优龙为何不支持binfs了。
哈哈，现在如果在ADS增加binfs格式化那么就好办了。

转载请标明:作者wogoyixikexie@gliet.桂林电子科技大学一系科协。如有错误，希望能够留言指出。