I require to access NVRAM variable in my driver, So on Windows 8 I am using API ExGetFirmwareEnvironmentVariable, but unfortunately that API is not available on Windows 7.
Further GetFirmwareEnvironmentVariableW which is a usermode API is available starting from Windows XP SP1, but surprisingly there is no documented API available in kernel.
So I have gone through ntoskrnl eports on Windows 7 and found NtGetEnvironmentVariableEx API which seems to be helpful for me. NtGetEnvironmentVariableEx is available from Windows Vista SP1 onwords. But unfortunately it is not documented.
So can I use it to solve my perpose on Windows 7? If yes what is the prototype of NtGetEnvironmentVariableEx? If not can anyone help me to access NVRAM variable in my driver atleast on Windows 7?
lkd> !error 0C0000002 Error code: (NTSTATUS) 0xc0000002 (3221225474) - {Not Implemented} The requested operation is not implemented.
if this is required for your debugging or some sort of non production code use scour the net for alex ionescu’s native nt toolkit
iirc takes a guid and returns an attribute
On 7/15/13, xxxxx@yahoo.com wrote: > Hi All, > > I require to access NVRAM variable in my driver, So on Windows 8 I am using > API ExGetFirmwareEnvironmentVariable, but unfortunately that API is not > available on Windows 7. > > Further GetFirmwareEnvironmentVariableW which is a usermode API is available > starting from Windows XP SP1, but surprisingly there is no documented API > available in kernel. > > So I have gone through ntoskrnl eports on Windows 7 and found > NtGetEnvironmentVariableEx API which seems to be helpful for me. > NtGetEnvironmentVariableEx is available from Windows Vista SP1 onwords. But > unfortunately it is not documented. > > So can I use it to solve my perpose on Windows 7? If yes what is the > prototype of NtGetEnvironmentVariableEx? If not can anyone help me to access > NVRAM variable in my driver atleast on Windows 7? > > Thanks & Regards, > Amit > > > > — > NTDEV is sponsored by OSR > > Visit the list at: http://www.osronline.com/showlists.cfm?list=ntdev > > OSR is HIRING!! See http://www.osr.com/careers > > For our schedule of WDF, WDM, debugging and other seminars visit: > http://www.osr.com/seminars > > To unsubscribe, visit the List Server section of OSR Online at > http://www.osronline.com/page.cfm?name=ListServer >
> Thanks for reply Raj, Currently I don’t care about XP,
> I am more consern about Windows 7.
I believe Win7 will be just as unsupported as WinXP. EFI really kicked
in for Windows starting in Win8, perhaps a bit earlier on some 64-bit
server buildss.
You might need to write a driver to do it yourself, if possible, in
older OS versions.
this answer is just for records
i wrote a blanket statement earlier that
GetFirmwareEnvironmentVariableW is not available in xp
it will simply return Error Not Implemented
i browsed through the documents after posting that and the documents state that
this api is available in windows xp sp1 onwards if the os was NOT
booted with legacy bios
On 7/16/13, Blibbet wrote: >> Thanks for reply Raj, Currently I don’t care about XP, > > I am more consern about Windows 7. > > I believe Win7 will be just as unsupported as WinXP. EFI really kicked > in for Windows starting in Win8, perhaps a bit earlier on some 64-bit > server buildss. > > You might need to write a driver to do it yourself, if possible, in > older OS versions. > > > — > NTDEV is sponsored by OSR > > Visit the list at: http://www.osronline.com/showlists.cfm?list=ntdev > > OSR is HIRING!! See http://www.osr.com/careers > > For our schedule of WDF, WDM, debugging and other seminars visit: > http://www.osr.com/seminars > > To unsubscribe, visit the List Server section of OSR Online at > http://www.osronline.com/page.cfm?name=ListServer >