Help for Marshalling
in [Compact Framework]
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From: Wrecked on 17 Dec 2006 23:57 Below is the unmanaged code written with evc++ ------------------------------------------------------------------------------------------------------------------------------- #include <windows.h> #include <windowsx.h> #include <aygshell.h> #include <msgqueue.h> #include <pnp.h> #include <diskio.h> #include <Pkfuncs.h> #include <sdcardddk.h> extern "C" _declspec(dllexport) void WINAPI OnRawRead(DWORD memory_location,unsigned char* lpOutBuf) { // TODO: Add your control notification handler code here HANDLE hDevice =CreateFile(L"DSK1:",GENERIC_READ,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL); SG_REQ lpInBuf; DWORD dwDummy = 3; //unsigned char *lpOutBuf; lpOutBuf = (unsigned char *)malloc(512); memset(lpOutBuf, 0x00, 512); // only to see the changes lpInBuf.sr_start = memory_location;//0xFF;//0x0018555; // physical sector to read lpInBuf.sr_num_sec = 1; // read 1 sector lpInBuf.sr_num_sg = 1; lpInBuf.sr_status = 0; //ERROR_SUCCESS; lpInBuf.sr_callback =NULL;// callbackDiskRead; lpInBuf.sr_sglist[0].sb_buf = ((LPBYTE) MapPtrToProcess(lpOutBuf,GetCurrentProcess())); lpInBuf.sr_sglist[0].sb_len = 512 * lpInBuf.sr_num_sec; BOOL bRet=DeviceIoControl(hDevice, // Handle to the device IOCTL_DISK_READ, // IOCTL for the operation &lpInBuf, // LP to a buffer (input data) sizeof(lpInBuf), // Size in Bytes of input data buffer lpOutBuf, // LP to a buffer for output data sizeof(lpOutBuf), // Size in Bytes of output buffer &dwDummy, // LP to variable (size of data in out buffer) NULL); CloseHandle(hDevice); } extern "C" _declspec(dllexport) void WINAPI OnRawWrite(DWORD memory_location,unsigned char* pBuffer) { HANDLE hDevice1 =CreateFile(L"DSK1:",GENERIC_WRITE,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL); SG_REQ lpInBuf1; DWORD dwDummy1 = 3; char *lpOutBuf1; lpOutBuf1 = (char *)malloc(512); memset(lpOutBuf1, 0x00, 512); // only to see the changes strcpy(( char*)lpOutBuf1,( char *)pBuffer); lpInBuf1.sr_start = memory_location; //0x0018555; // physical sector lpInBuf1.sr_num_sec = 1; // number of sectors sector lpInBuf1.sr_num_sg = 1; lpInBuf1.sr_status = 0; //ERROR_SUCCESS; lpInBuf1.sr_callback =NULL;// callbackDiskRead; lpInBuf1.sr_sglist[0].sb_buf = ((LPBYTE) MapPtrToProcess(lpOutBuf1,GetCurrentProcess())); lpInBuf1.sr_sglist[0].sb_len = 512 * lpInBuf1.sr_num_sec; BOOL bRet=DeviceIoControl(hDevice1, // Handle to the device IOCTL_DISK_WRITE, // IOCTL for the operation &lpInBuf1, // LP to a buffer (input data) sizeof(lpInBuf1), // Size in Bytes of input data buffer lpOutBuf1, // LP to a buffer for output data sizeof(lpOutBuf1), // Size in Bytes of output buffer &dwDummy1, // LP to variable (size of data in out buffer) NULL); CloseHandle(hDevice1); } ------------------------------------------------------------------------------------------------------------------------------- The functions do some basic rawread and rawwrite on an SD card. Now how can i use this code in the c# (managed code). Specifically i need to know how to marshal "char *". I did try out with the following code (the dll created by evc++ was SD_card_dll.dll. But it doesnt seam to work. [DllImport("SD_card_dll.dll")] public static extern void OnRawRead(int memory_location,ref IntPtr lpOutBuf); [DllImport("SD_card_dll.dll")] public static extern void OnRawWrite(int memory_location,ref IntPtr lpBuffer); } Thanks and Regards, Rithesh Student IIIT, Bangalore
From: " ctacke/>" on 18 Dec 2006 09:27 Well a char * would likely be a byte array, though your code is not conducive to that. You're using a strcpy on it, without knowing a length which is generally very unsafe (this is how many security holes in the desktop OS are created and exploited). You code appears to assume ASCII string input. Also not the best design for CE - especially when you need to marshal from managed code where strings are always Unicode. To keep with your definitions, change your P/Invoke to a byte[], then take your string data, pass it through Encoding.ASCII.GetBytes and pass that through. -- Chris Tacke OpenNETCF Consulting Managed Code in the Embedded World www.opennetcf.com -- "Wrecked" <rithesh.rg(a)gmail.com> wrote in message news:1166417850.957390.142050(a)79g2000cws.googlegroups.com... > Below is the unmanaged code written with evc++ > > > ------------------------------------------------------------------------------------------------------------------------------- > #include <windows.h> > #include <windowsx.h> > #include <aygshell.h> > #include <msgqueue.h> > #include <pnp.h> > #include <diskio.h> > #include <Pkfuncs.h> > #include <sdcardddk.h> > > > > extern "C" _declspec(dllexport) void WINAPI OnRawRead(DWORD > memory_location,unsigned char* lpOutBuf) > { > // TODO: Add your control notification handler code here > > HANDLE hDevice > =CreateFile(L"DSK1:",GENERIC_READ,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL); > SG_REQ lpInBuf; > DWORD dwDummy = 3; > //unsigned char *lpOutBuf; > lpOutBuf = (unsigned char *)malloc(512); > memset(lpOutBuf, 0x00, 512); // only to see the changes > lpInBuf.sr_start = memory_location;//0xFF;//0x0018555; // > physical sector to read > lpInBuf.sr_num_sec = 1; // read 1 sector > lpInBuf.sr_num_sg = 1; > lpInBuf.sr_status = 0; //ERROR_SUCCESS; > lpInBuf.sr_callback =NULL;// callbackDiskRead; > lpInBuf.sr_sglist[0].sb_buf = ((LPBYTE) > MapPtrToProcess(lpOutBuf,GetCurrentProcess())); > lpInBuf.sr_sglist[0].sb_len = 512 * lpInBuf.sr_num_sec; > > BOOL bRet=DeviceIoControl(hDevice, // Handle to the device > IOCTL_DISK_READ, // IOCTL for the operation > &lpInBuf, // LP to a buffer (input data) > sizeof(lpInBuf), // Size in Bytes of input data > buffer > lpOutBuf, // LP to a buffer for output data > sizeof(lpOutBuf), // Size in Bytes of output buffer > &dwDummy, // LP to variable (size of data in out > buffer) > NULL); > CloseHandle(hDevice); > > > } > > > extern "C" _declspec(dllexport) void WINAPI OnRawWrite(DWORD > memory_location,unsigned char* pBuffer) > { > HANDLE hDevice1 > =CreateFile(L"DSK1:",GENERIC_WRITE,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL); > SG_REQ lpInBuf1; > DWORD dwDummy1 = 3; > char *lpOutBuf1; > lpOutBuf1 = (char *)malloc(512); > memset(lpOutBuf1, 0x00, 512); // only to see the changes > > > strcpy(( char*)lpOutBuf1,( char *)pBuffer); > > lpInBuf1.sr_start = memory_location; //0x0018555; // physical > sector > lpInBuf1.sr_num_sec = 1; // number of sectors sector > lpInBuf1.sr_num_sg = 1; > lpInBuf1.sr_status = 0; //ERROR_SUCCESS; > lpInBuf1.sr_callback =NULL;// callbackDiskRead; > lpInBuf1.sr_sglist[0].sb_buf = ((LPBYTE) > MapPtrToProcess(lpOutBuf1,GetCurrentProcess())); > lpInBuf1.sr_sglist[0].sb_len = 512 * lpInBuf1.sr_num_sec; > > BOOL bRet=DeviceIoControl(hDevice1, // Handle to the device > IOCTL_DISK_WRITE, // IOCTL for the operation > &lpInBuf1, // LP to a buffer (input data) > sizeof(lpInBuf1), // Size in Bytes of input data > buffer > lpOutBuf1, // LP to a buffer for output data > sizeof(lpOutBuf1), // Size in Bytes of output buffer > &dwDummy1, // LP to variable (size of data in out > buffer) > NULL); > > CloseHandle(hDevice1); > > } > ------------------------------------------------------------------------------------------------------------------------------- > > > > > The functions do some basic rawread and rawwrite on an SD card. > Now how can i use this code in the c# (managed code). Specifically i > need to know how to marshal "char *". > > I did try out with the following code (the dll created by evc++ was > SD_card_dll.dll. But it doesnt seam to work. > > [DllImport("SD_card_dll.dll")] > public static extern void OnRawRead(int memory_location,ref > IntPtr lpOutBuf); > [DllImport("SD_card_dll.dll")] > public static extern void OnRawWrite(int memory_location,ref > IntPtr lpBuffer); > } > > Thanks and Regards, > Rithesh > > Student > IIIT, Bangalore >
From: Wrecked on 18 Dec 2006 09:47 Hello Chris, >From one of the previous discussions i understand that i could as well use OpenNetCF to use createfile and deviceIocontrol in the StreamInterfaceDriver. Kindly if u could throw some light on how this could be done, it would be great. I couldnt find much documentation for this. All i could know about this class was one could use this abstract base class to create wrappers around Stream Interface Drivers that are not supported by the CF. I am not able to figure out how i could pass SG_REQ structure. It would help me a lot to use the functions OpenNetCF since then i wouldnt have to worry about deploying my project on phones with different architectures. I am not an expert on .net CF, a skeleton flow of how i could write this would be of great help. Thanks and Regards, Rithesh Student, IIIT, Bangalore <ctacke/> wrote: > Well a char * would likely be a byte array, though your code is not > conducive to that. You're using a strcpy on it, without knowing a length > which is generally very unsafe (this is how many security holes in the > desktop OS are created and exploited). > > You code appears to assume ASCII string input. Also not the best design for > CE - especially when you need to marshal from managed code where strings are > always Unicode. > > To keep with your definitions, change your P/Invoke to a byte[], then take > your string data, pass it through Encoding.ASCII.GetBytes and pass that > through. > > > -- > Chris Tacke > OpenNETCF Consulting > Managed Code in the Embedded World > www.opennetcf.com > -- > > > > "Wrecked" <rithesh.rg(a)gmail.com> wrote in message > news:1166417850.957390.142050(a)79g2000cws.googlegroups.com... > > Below is the unmanaged code written with evc++ > > > > > > ------------------------------------------------------------------------------------------------------------------------------- > > #include <windows.h> > > #include <windowsx.h> > > #include <aygshell.h> > > #include <msgqueue.h> > > #include <pnp.h> > > #include <diskio.h> > > #include <Pkfuncs.h> > > #include <sdcardddk.h> > > > > > > > > extern "C" _declspec(dllexport) void WINAPI OnRawRead(DWORD > > memory_location,unsigned char* lpOutBuf) > > { > > // TODO: Add your control notification handler code here > > > > HANDLE hDevice > > =CreateFile(L"DSK1:",GENERIC_READ,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL); > > SG_REQ lpInBuf; > > DWORD dwDummy = 3; > > //unsigned char *lpOutBuf; > > lpOutBuf = (unsigned char *)malloc(512); > > memset(lpOutBuf, 0x00, 512); // only to see the changes > > lpInBuf.sr_start = memory_location;//0xFF;//0x0018555; // > > physical sector to read > > lpInBuf.sr_num_sec = 1; // read 1 sector > > lpInBuf.sr_num_sg = 1; > > lpInBuf.sr_status = 0; //ERROR_SUCCESS; > > lpInBuf.sr_callback =NULL;// callbackDiskRead; > > lpInBuf.sr_sglist[0].sb_buf = ((LPBYTE) > > MapPtrToProcess(lpOutBuf,GetCurrentProcess())); > > lpInBuf.sr_sglist[0].sb_len = 512 * lpInBuf.sr_num_sec; > > > > BOOL bRet=DeviceIoControl(hDevice, // Handle to the device > > IOCTL_DISK_READ, // IOCTL for the operation > > &lpInBuf, // LP to a buffer (input data) > > sizeof(lpInBuf), // Size in Bytes of input data > > buffer > > lpOutBuf, // LP to a buffer for output data > > sizeof(lpOutBuf), // Size in Bytes of output buffer > > &dwDummy, // LP to variable (size of data in out > > buffer) > > NULL); > > CloseHandle(hDevice); > > > > > > } > > > > > > extern "C" _declspec(dllexport) void WINAPI OnRawWrite(DWORD > > memory_location,unsigned char* pBuffer) > > { > > HANDLE hDevice1 > > =CreateFile(L"DSK1:",GENERIC_WRITE,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL); > > SG_REQ lpInBuf1; > > DWORD dwDummy1 = 3; > > char *lpOutBuf1; > > lpOutBuf1 = (char *)malloc(512); > > memset(lpOutBuf1, 0x00, 512); // only to see the changes > > > > > > strcpy(( char*)lpOutBuf1,( char *)pBuffer); > > > > lpInBuf1.sr_start = memory_location; //0x0018555; // physical > > sector > > lpInBuf1.sr_num_sec = 1; // number of sectors sector > > lpInBuf1.sr_num_sg = 1; > > lpInBuf1.sr_status = 0; //ERROR_SUCCESS; > > lpInBuf1.sr_callback =NULL;// callbackDiskRead; > > lpInBuf1.sr_sglist[0].sb_buf = ((LPBYTE) > > MapPtrToProcess(lpOutBuf1,GetCurrentProcess())); > > lpInBuf1.sr_sglist[0].sb_len = 512 * lpInBuf1.sr_num_sec; > > > > BOOL bRet=DeviceIoControl(hDevice1, // Handle to the device > > IOCTL_DISK_WRITE, // IOCTL for the operation > > &lpInBuf1, // LP to a buffer (input data) > > sizeof(lpInBuf1), // Size in Bytes of input data > > buffer > > lpOutBuf1, // LP to a buffer for output data > > sizeof(lpOutBuf1), // Size in Bytes of output buffer > > &dwDummy1, // LP to variable (size of data in out > > buffer) > > NULL); > > > > CloseHandle(hDevice1); > > > > } > > ------------------------------------------------------------------------------------------------------------------------------- > > > > > > > > > > The functions do some basic rawread and rawwrite on an SD card. > > Now how can i use this code in the c# (managed code). Specifically i > > need to know how to marshal "char *". > > > > I did try out with the following code (the dll created by evc++ was > > SD_card_dll.dll. But it doesnt seam to work. > > > > [DllImport("SD_card_dll.dll")] > > public static extern void OnRawRead(int memory_location,ref > > IntPtr lpOutBuf); > > [DllImport("SD_card_dll.dll")] > > public static extern void OnRawWrite(int memory_location,ref > > IntPtr lpBuffer); > > } > > > > Thanks and Regards, > > Rithesh > > > > Student > > IIIT, Bangalore > >
From: " ctacke/>" on 18 Dec 2006 10:19 You'd simply derive from StreamInterfaceDriver and set the prefix to DSK1: and that gives you the foundation. Create a function for reading and have it call its internal Read, and the same for Write. For reading or writing any specific structure, you need to define the sructure (or class) and then pass it, following hte rules of CF marshaling appropriate for your version. -- Chris Tacke OpenNETCF Consulting Managed Code in the Embedded World www.opennetcf.com -- "Wrecked" <rithesh.rg(a)gmail.com> wrote in message news:1166453269.094586.65330(a)80g2000cwy.googlegroups.com... > Hello Chris, > >>From one of the previous discussions i understand that i could as well > use OpenNetCF to use createfile and deviceIocontrol in the > StreamInterfaceDriver. Kindly if u could throw some light on how this > could be done, it would be great. I couldnt find much documentation for > this. > All i could know about this class was one could use this abstract base > class to create wrappers around Stream Interface Drivers that are not > supported by the CF. I am not able to figure out how i could pass > SG_REQ structure. > > It would help me a lot to use the functions OpenNetCF since then i > wouldnt have to worry about deploying my project on phones with > different architectures. I am not an expert on .net CF, a skeleton flow > of how i could write this would be of great help. > > Thanks and Regards, > Rithesh > Student, > IIIT, Bangalore > > <ctacke/> wrote: >> Well a char * would likely be a byte array, though your code is not >> conducive to that. You're using a strcpy on it, without knowing a length >> which is generally very unsafe (this is how many security holes in the >> desktop OS are created and exploited). >> >> You code appears to assume ASCII string input. Also not the best design >> for >> CE - especially when you need to marshal from managed code where strings >> are >> always Unicode. >> >> To keep with your definitions, change your P/Invoke to a byte[], then >> take >> your string data, pass it through Encoding.ASCII.GetBytes and pass that >> through. >> >> >> -- >> Chris Tacke >> OpenNETCF Consulting >> Managed Code in the Embedded World >> www.opennetcf.com >> -- >> >> >> >> "Wrecked" <rithesh.rg(a)gmail.com> wrote in message >> news:1166417850.957390.142050(a)79g2000cws.googlegroups.com... >> > Below is the unmanaged code written with evc++ >> > >> > >> > ------------------------------------------------------------------------------------------------------------------------------- >> > #include <windows.h> >> > #include <windowsx.h> >> > #include <aygshell.h> >> > #include <msgqueue.h> >> > #include <pnp.h> >> > #include <diskio.h> >> > #include <Pkfuncs.h> >> > #include <sdcardddk.h> >> > >> > >> > >> > extern "C" _declspec(dllexport) void WINAPI OnRawRead(DWORD >> > memory_location,unsigned char* lpOutBuf) >> > { >> > // TODO: Add your control notification handler code here >> > >> > HANDLE hDevice >> > =CreateFile(L"DSK1:",GENERIC_READ,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL); >> > SG_REQ lpInBuf; >> > DWORD dwDummy = 3; >> > //unsigned char *lpOutBuf; >> > lpOutBuf = (unsigned char *)malloc(512); >> > memset(lpOutBuf, 0x00, 512); // only to see the changes >> > lpInBuf.sr_start = memory_location;//0xFF;//0x0018555; // >> > physical sector to read >> > lpInBuf.sr_num_sec = 1; // read 1 sector >> > lpInBuf.sr_num_sg = 1; >> > lpInBuf.sr_status = 0; //ERROR_SUCCESS; >> > lpInBuf.sr_callback =NULL;// callbackDiskRead; >> > lpInBuf.sr_sglist[0].sb_buf = ((LPBYTE) >> > MapPtrToProcess(lpOutBuf,GetCurrentProcess())); >> > lpInBuf.sr_sglist[0].sb_len = 512 * lpInBuf.sr_num_sec; >> > >> > BOOL bRet=DeviceIoControl(hDevice, // Handle to the device >> > IOCTL_DISK_READ, // IOCTL for the operation >> > &lpInBuf, // LP to a buffer (input data) >> > sizeof(lpInBuf), // Size in Bytes of input data >> > buffer >> > lpOutBuf, // LP to a buffer for output data >> > sizeof(lpOutBuf), // Size in Bytes of output buffer >> > &dwDummy, // LP to variable (size of data in out >> > buffer) >> > NULL); >> > CloseHandle(hDevice); >> > >> > >> > } >> > >> > >> > extern "C" _declspec(dllexport) void WINAPI OnRawWrite(DWORD >> > memory_location,unsigned char* pBuffer) >> > { >> > HANDLE hDevice1 >> > =CreateFile(L"DSK1:",GENERIC_WRITE,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL); >> > SG_REQ lpInBuf1; >> > DWORD dwDummy1 = 3; >> > char *lpOutBuf1; >> > lpOutBuf1 = (char *)malloc(512); >> > memset(lpOutBuf1, 0x00, 512); // only to see the changes >> > >> > >> > strcpy(( char*)lpOutBuf1,( char *)pBuffer); >> > >> > lpInBuf1.sr_start = memory_location; //0x0018555; // physical >> > sector >> > lpInBuf1.sr_num_sec = 1; // number of sectors sector >> > lpInBuf1.sr_num_sg = 1; >> > lpInBuf1.sr_status = 0; //ERROR_SUCCESS; >> > lpInBuf1.sr_callback =NULL;// callbackDiskRead; >> > lpInBuf1.sr_sglist[0].sb_buf = ((LPBYTE) >> > MapPtrToProcess(lpOutBuf1,GetCurrentProcess())); >> > lpInBuf1.sr_sglist[0].sb_len = 512 * lpInBuf1.sr_num_sec; >> > >> > BOOL bRet=DeviceIoControl(hDevice1, // Handle to the device >> > IOCTL_DISK_WRITE, // IOCTL for the operation >> > &lpInBuf1, // LP to a buffer (input data) >> > sizeof(lpInBuf1), // Size in Bytes of input data >> > buffer >> > lpOutBuf1, // LP to a buffer for output data >> > sizeof(lpOutBuf1), // Size in Bytes of output buffer >> > &dwDummy1, // LP to variable (size of data in out >> > buffer) >> > NULL); >> > >> > CloseHandle(hDevice1); >> > >> > } >> > ------------------------------------------------------------------------------------------------------------------------------- >> > >> > >> > >> > >> > The functions do some basic rawread and rawwrite on an SD card. >> > Now how can i use this code in the c# (managed code). Specifically i >> > need to know how to marshal "char *". >> > >> > I did try out with the following code (the dll created by evc++ was >> > SD_card_dll.dll. But it doesnt seam to work. >> > >> > [DllImport("SD_card_dll.dll")] >> > public static extern void OnRawRead(int memory_location,ref >> > IntPtr lpOutBuf); >> > [DllImport("SD_card_dll.dll")] >> > public static extern void OnRawWrite(int memory_location,ref >> > IntPtr lpBuffer); >> > } >> > >> > Thanks and Regards, >> > Rithesh >> > >> > Student >> > IIIT, Bangalore >> > >
From: Wrecked on 18 Dec 2006 10:50
Hello Chris, Thanks again for your help. I am still trying to hook up with C# and excuse me if u find my questions too simple. I couldnt exactly follow - "set the prefix to DSK1:", kindly could u be a bit more specific as how i could do that. Staying with c#, to access specific locations on DSK1 to read/write(i.e after creating an handle to it - which i am yet to figure out how), could i use PhysicalAddressPointer(int,int) and then use ReadByte/WriteByte in PhysicalAddressPointer class. Is this also an alternative to DeviceIoControl and Createfile functions. Thanks and Regards, Rithesh Student, IIIT, Bangalore <ctacke/> wrote: > You'd simply derive from StreamInterfaceDriver and set the prefix to DSK1: > and that gives you the foundation. Create a function for reading and have > it call its internal Read, and the same for Write. > > For reading or writing any specific structure, you need to define the > sructure (or class) and then pass it, following hte rules of CF marshaling > appropriate for your version. > > > -- > Chris Tacke > OpenNETCF Consulting > Managed Code in the Embedded World > www.opennetcf.com > -- > > > "Wrecked" <rithesh.rg(a)gmail.com> wrote in message > news:1166453269.094586.65330(a)80g2000cwy.googlegroups.com... > > Hello Chris, > > > >>From one of the previous discussions i understand that i could as well > > use OpenNetCF to use createfile and deviceIocontrol in the > > StreamInterfaceDriver. Kindly if u could throw some light on how this > > could be done, it would be great. I couldnt find much documentation for > > this. > > All i could know about this class was one could use this abstract base > > class to create wrappers around Stream Interface Drivers that are not > > supported by the CF. I am not able to figure out how i could pass > > SG_REQ structure. > > > > It would help me a lot to use the functions OpenNetCF since then i > > wouldnt have to worry about deploying my project on phones with > > different architectures. I am not an expert on .net CF, a skeleton flow > > of how i could write this would be of great help. > > > > Thanks and Regards, > > Rithesh > > Student, > > IIIT, Bangalore > > > > <ctacke/> wrote: > >> Well a char * would likely be a byte array, though your code is not > >> conducive to that. You're using a strcpy on it, without knowing a length > >> which is generally very unsafe (this is how many security holes in the > >> desktop OS are created and exploited). > >> > >> You code appears to assume ASCII string input. Also not the best design > >> for > >> CE - especially when you need to marshal from managed code where strings > >> are > >> always Unicode. > >> > >> To keep with your definitions, change your P/Invoke to a byte[], then > >> take > >> your string data, pass it through Encoding.ASCII.GetBytes and pass that > >> through. > >> > >> > >> -- > >> Chris Tacke > >> OpenNETCF Consulting > >> Managed Code in the Embedded World > >> www.opennetcf.com > >> -- > >> > >> > >> > >> "Wrecked" <rithesh.rg(a)gmail.com> wrote in message > >> news:1166417850.957390.142050(a)79g2000cws.googlegroups.com... > >> > Below is the unmanaged code written with evc++ > >> > > >> > > >> > ------------------------------------------------------------------------------------------------------------------------------- > >> > #include <windows.h> > >> > #include <windowsx.h> > >> > #include <aygshell.h> > >> > #include <msgqueue.h> > >> > #include <pnp.h> > >> > #include <diskio.h> > >> > #include <Pkfuncs.h> > >> > #include <sdcardddk.h> > >> > > >> > > >> > > >> > extern "C" _declspec(dllexport) void WINAPI OnRawRead(DWORD > >> > memory_location,unsigned char* lpOutBuf) > >> > { > >> > // TODO: Add your control notification handler code here > >> > > >> > HANDLE hDevice > >> > =CreateFile(L"DSK1:",GENERIC_READ,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL); > >> > SG_REQ lpInBuf; > >> > DWORD dwDummy = 3; > >> > //unsigned char *lpOutBuf; > >> > lpOutBuf = (unsigned char *)malloc(512); > >> > memset(lpOutBuf, 0x00, 512); // only to see the changes > >> > lpInBuf.sr_start = memory_location;//0xFF;//0x0018555; // > >> > physical sector to read > >> > lpInBuf.sr_num_sec = 1; // read 1 sector > >> > lpInBuf.sr_num_sg = 1; > >> > lpInBuf.sr_status = 0; //ERROR_SUCCESS; > >> > lpInBuf.sr_callback =NULL;// callbackDiskRead; > >> > lpInBuf.sr_sglist[0].sb_buf = ((LPBYTE) > >> > MapPtrToProcess(lpOutBuf,GetCurrentProcess())); > >> > lpInBuf.sr_sglist[0].sb_len = 512 * lpInBuf.sr_num_sec; > >> > > >> > BOOL bRet=DeviceIoControl(hDevice, // Handle to the device > >> > IOCTL_DISK_READ, // IOCTL for the operation > >> > &lpInBuf, // LP to a buffer (input data) > >> > sizeof(lpInBuf), // Size in Bytes of input data > >> > buffer > >> > lpOutBuf, // LP to a buffer for output data > >> > sizeof(lpOutBuf), // Size in Bytes of output buffer > >> > &dwDummy, // LP to variable (size of data in out > >> > buffer) > >> > NULL); > >> > CloseHandle(hDevice); > >> > > >> > > >> > } > >> > > >> > > >> > extern "C" _declspec(dllexport) void WINAPI OnRawWrite(DWORD > >> > memory_location,unsigned char* pBuffer) > >> > { > >> > HANDLE hDevice1 > >> > =CreateFile(L"DSK1:",GENERIC_WRITE,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL); > >> > SG_REQ lpInBuf1; > >> > DWORD dwDummy1 = 3; > >> > char *lpOutBuf1; > >> > lpOutBuf1 = (char *)malloc(512); > >> > memset(lpOutBuf1, 0x00, 512); // only to see the changes > >> > > >> > > >> > strcpy(( char*)lpOutBuf1,( char *)pBuffer); > >> > > >> > lpInBuf1.sr_start = memory_location; //0x0018555; // physical > >> > sector > >> > lpInBuf1.sr_num_sec = 1; // number of sectors sector > >> > lpInBuf1.sr_num_sg = 1; > >> > lpInBuf1.sr_status = 0; //ERROR_SUCCESS; > >> > lpInBuf1.sr_callback =NULL;// callbackDiskRead; > >> > lpInBuf1.sr_sglist[0].sb_buf = ((LPBYTE) > >> > MapPtrToProcess(lpOutBuf1,GetCurrentProcess())); > >> > lpInBuf1.sr_sglist[0].sb_len = 512 * lpInBuf1.sr_num_sec; > >> > > >> > BOOL bRet=DeviceIoControl(hDevice1, // Handle to the device > >> > IOCTL_DISK_WRITE, // IOCTL for the operation > >> > &lpInBuf1, // LP to a buffer (input data) > >> > sizeof(lpInBuf1), // Size in Bytes of input data > >> > buffer > >> > lpOutBuf1, // LP to a buffer for output data > >> > sizeof(lpOutBuf1), // Size in Bytes of output buffer > >> > &dwDummy1, // LP to variable (size of data in out > >> > buffer) > >> > NULL); > >> > > >> > CloseHandle(hDevice1); > >> > > >> > } > >> > ------------------------------------------------------------------------------------------------------------------------------- > >> > > >> > > >> > > >> > > >> > The functions do some basic rawread and rawwrite on an SD card. > >> > Now how can i use this code in the c# (managed code). Specifically i > >> > need to know how to marshal "char *". > >> > > >> > I did try out with the following code (the dll created by evc++ was > >> > SD_card_dll.dll. But it doesnt seam to work. > >> > > >> > [DllImport("SD_card_dll.dll")] > >> > public static extern void OnRawRead(int memory_location,ref > >> > IntPtr lpOutBuf); > >> > [DllImport("SD_card_dll.dll")] > >> > public static extern void OnRawWrite(int memory_location,ref > >> > IntPtr lpBuffer); > >> > } > >> > > >> > Thanks and Regards, > >> > Rithesh > >> > > >> > Student > >> > IIIT, Bangalore > >> > > > |