Книга: Microsoft Windows Embedded CE 6.0 Exam Preparation Kit

Entering the Suspend State

Entering the Suspend State

When entering the Suspend state, Windows Embedded CE performs the following sequence of steps:

1. GWES notifies the Taskbar about the power down event.

2. The system aborts calibration if in the calibration screen.

3. The system stops the Windows message queues. After step 3, the system enters single-thread mode, which prevents function calls that rely on blocking operations.

4. The system checks if the startup user interface (UI) must appear on resume.

5. The system saves video memory to RAM.

6. The system calls SetSystemPowerState (NULL, POWER_STATE_SUSPEND, POWER_FORCE).

7. Power Manager:

 a. Calls the FileSystemPowerFunction to power off the drivers related to the file system.

 b. Calls PowerOffSystem to inform the kernel to do the final power down.

 c. Calls Sleep(0) to invoke the scheduler.

8. Kernel:

 a. Unloads GWES process.

 b. Unloads Filesys.exe.

 c. Calls OEMPowerOff.

9. OEMPowerOff configures the interrupts and puts the CPU in Suspend state.

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