Windows 2000 wdm: no display driver calls the HwVidStartIo of my miniport driver

Question

I am writing a graphic miniport driver for Windows NT 4.0 - 5.1. I am stuck in the situation, that HwVidStartIo of my miniport driver never gets called.

I would expect that a display driver triggers the function calls by sending requests to videoprt.sys and then videoprt.sys calls my HwVidStartIo. But somehow no display driver cares about my miniport driver.

Do I need to announce or register my miniport driver to a display driver somehow?

When the system boots the flow is like this:

1. DriverEntry gets called
2. HwVidFindAdapter gets called
3. HwVidFindAdapter returns NO_ERROR/0x00
4. HwVidFindAdapter gets called
5. HwVidFindAdapter returns ERROR_INVALID_PARAMETER/0x57
6. HwVidFindAdapter gets called
7. HwVidFindAdapter returns ERROR_INVALID_PARAMETER/0x57
8. HwVidFindAdapter gets called
9. HwVidFindAdapter returns NO_ERROR/0x00
10. DriverEntry returns 0x00 (return value of VideoPortInitialize)
11. HwVidInitialize gets called
12. HwVidInitialize returns true/0x01
13. HwVidInitialize gets called
14. HwVidInitialize returns true/0x01

Answer 1

Ok, I figured it out.

My .inf-file stated:

StartType = 3 ; 3 == SERVICE_DEMAND_START

Which might be fine for plug and play drivers. But mine is not plug and play compatible. So I had to change it to

StartType = 1 ; 1 == SERVICE_SYSTEM_START

Finally I can move on.