Resume State

When a resume occurs the kernel is the first to execute. A device will only resume from a halted state if an interrupt occurs and the CPU has been programmed to wake when an interrupt occurs.

To resume a device

  1. The kernel performs the following clean-up tasks before resuming normal scheduling:
    • If this is an SHx, it calls OEMFlushCache.
    • Calls InitClock to re-initialize timer hardware to a 1 ms tick.
    • Calls Filesys.exe with a power on notification.
    • Calls GWES with a power on notification.
    • Initializes the KITL interrupt if one is in use.
  2. Power manager then calls FileSystemPowerFunction with the (FSNOTIFY_POWER_ON) argument.
  3. On the resume, GWES performs the following tasks:
    • Restores video memory from RAM.
    • Powers on the Window Manager.
    • Sets the screen contrast.
    • Shows the Startup UI screen, if required.
    • Posts a message to the Taskbar to tell it the device has resumed by send a WM_POWERBROADCAST message with PBT_APMRESUMESUSPEND parameter.
    • Sends the same message to the User notification subsystem.
    • Triggers applications that have requested to be triggered on resume.

See Also

Kernel States

Last updated on Wednesday, April 13, 2005

© 2005 Microsoft Corporation. All rights reserved.