Persistent storage and the registry

re: Persistent storage and the registry

ce_base — Thu, 03 Nov 2005 22:03:45 GMT

I don't know why your blog didn't automatically cross-reference my post, so I'm adding my own cross-reference:

http://blogs.msdn.com/ce_base/archive/2005/09/26/474069.aspx

re: Persistent storage and the registry

ChunFai — Fri, 24 Feb 2006 12:04:07 GMT

I tried to modify the key HKLM\software\microsoft\speech to disable Cyberon Voice Tag but whenever I reboot my phone the modification is reverted. Any idea?

re: Persistent storage and the registry

Matthew — Mon, 03 Apr 2006 23:22:19 GMT

I believe there is some highly errornous information in this post. Rebooting via ExitWindowEx() does indeed flush the fliesystem cach and the registrty. However, rebooting via KernelIoCtl() DOES NOT. That method has been discouraged for several versions of the operating system and, under the proper conditions, could cause data loss even on the RAM-based object store of prior versions. For versions prior to 5, where ExitWindowsEx() is not available, the SetSystemPoertState() call is a safe alternative to KernelIoCtl().

re: Persistent storage and the registry

Scott Yost — Thu, 27 Jul 2006 21:16:03 GMT

Matthew - Have you tried that on WM5? I've written code to set a reg key and then reboot via IOCTL and verified that the registry key persists. (and if you set the reg key and then immediately pull battery, the change is lost)

re: Persistent storage and the registry

ce_base — Thu, 26 Oct 2006 20:47:16 GMT

To follow up on Matthew / Scott's discussion of rebooting via IOCTL -- in Windows Mobile 5 we hacked IOCTL_HAL_REBOOT to call into the safe power down which flushes the registry and other cached data. We still want to discourage people from using the IOCTL, but we made it as safe as we could. Because too many people were still relying on the IOCTL instead of better methods.

Sue

re: Persistent storage and the registry

temez — Wed, 11 Jul 2007 13:31:23 GMT

I wonder what's wrong. Some of my registry changes always disappear if the battery runs low or the device reboots. I've tried calling RegFlushKey() and resetting the device. Still some of the keys always disappear. The weird part is that some settings do persist, some don't.

I wonder if there's something wrong with HTC's TyTN that I'm debugging on or if it has something to do with calling RegFlushKey() from withing SetupDLL.