Re: Allocating and accessing physically contiguous memory in user mode in WinCE 6.0 Beta

Do you mean that there is no way to allocate and use a physically
contiguous memory region from user mode in 6.0 beta ?
"no way" is a bit strong a phrase and not quite true. It's generally true
for normal processes. However CE 6 supports the concept of User mode drivers
which operate in the context of a user mode process that is created by the
kernel. This process can call the CEDDK functions that do allocations and
hardware access as needed and the kernel will allow the access to a set of
addresses defined by a protected registry key created by the device OEM. So
do what should have been driver level functionality in your application
doesn't really fit the CE6 memory/security model. However, there is a
theoretical alternative that is pretty close. The process that the kernel
starts for user mode drivers is something that you, the OEM, can specify!
Thus you can alter your application to load as the user mode driver host
process and then it ends up with access to the APIs in CEDDK for mapping
hardware etc...


--
Steve Maillet
EmbeddedFusion
www.EmbeddedFusion.com
smaillet at EmbeddedFusion dot com


.

Relevant Pages

  • Re: When to write as a device driver instead of just a library.
    ... > one write the code as a device driver as opposed to a plain simple ... In general if it can be done in user mode, ... or major advantages to a kernel mode implementation, ... If you communicate with a device that way, ...
    (comp.os.linux.development.system)
  • Re: USB performance bug since kernel 2.6.13 (CRITICAL???)
    ... user mode for this sort of thing. ... kernel mode drivers in this regard. ... Recall that each transaction ...
    (Linux-Kernel)
  • Re: (basics) driver - library
    ... layout DLLs) that are used in both user mode and kernel mode. ... ProjectDriver: aaa.sys (Driver, Configuration Type: Makefile) ...
    (microsoft.public.development.device.drivers)
  • Re: Unexpected Error With CE.BIB file
    ... runs in kernel mode which corrupts the kernel ... in user mode can't access kernel mode space, ... Anything running in kernel mode can access both user and kernel space. ... Move the component that loads hidparse into kernel space, ...
    (microsoft.public.windowsce.platbuilder)
  • Re: Kernel malloc/realloc?
    ... > YOU related this thread to user-mode reallocation. ... The weord "kernel" in the thread title should make it quite clear what this ... How can i learn how to realloc a memory buffer in "kernel" mode by looking ... unrelated to this thread) and it maps to the user mode HeapXXX windows API, ...
    (microsoft.public.development.device.drivers)
Loading