TCB capability problem

[ivyliolia]

Hi,
Is there anyone knows how to use RRawDisk class, which has the TCB capability, in a program?
My program uses RRawDisk to get a direct access to the external memory card. So I requested a devcert from Nokia with TCB capability, and I singed my application with that certificate. I can install the program but when I open the application, it returns the error "Unable to execute files for security reasons". I checked all my program, the only API that needs the special capability is RRawDisk. But it seems not working. I am pretty sure that this cerificate generated form Nokia is good and with TCB capability.
Is there anyone having this problem before and can kindly tell me how to fix this problem?
Many thanks.

[mitts]

TCB is the holiest of the capabilities, I'd be pretty surprised if you actually did get a certificate to use on your own site that actually gives you TCB. So I'd double-check that.

[ltomuta]

Do you have a GUI app with TCB or is it a GUI with virtually no capability that calls the services of a TCB empowered server ?

A GUI app cannot have TCB capability as most of the DLLs against which it must be linked have at best the "ALL-TCB" capability set. Remember to check emulator's logs for Platform Security related warnings/errors

You need to write a server application and have it provide raw disk access services to your client.

[Paul.Todd]

Make sure that you have included all the other capabilities you require in the mmp file and certificate