[ntdev][basic]Question on Escape call.

NTDEV
1

Hello experts,
[I am new to this world so my question might be basic.]
I have been asked to write an API to query our existing display driver.
I came to know Escape/IOCTL are available options to accomplish this. I have
decided to go with Escape call but I did not see any option to set the query
as buffered/direct/Neither as we have in IOCTLs. Please let me know if it is
not available in case of Escape calls. What is the default behavior of a
Escape call, is it buffered? Asking this to decide how to return output data
from driver.

Any input will be highly appreciable.

Thanks & regards
Ravi

2

Ravi Gupta wrote:

Hello experts,
[I am new to this world so my question might be basic.]
I have been asked to write an API to query our existing display
driver. I came to know Escape/IOCTL are available options to
accomplish this. I have decided to go with Escape call but I did not
see any option to set the query as buffered/direct/Neither as we have
in IOCTLs. Please let me know if it is not available in case of Escape
calls. What is the default behavior of a Escape call, is it buffered?
Asking this to decide how to return output data from driver.

Any input will be highly appreciable.

I’m trying to find a reference for this, but as far as I know, DrvEscape
is handled like a buffered ioctl. The system allocates kernel buffers
of the same size, and copies the user data on the way in and out.

–
Tim Roberts, xxxxx@probo.com
Providenza & Boekelheide, Inc.