Re: What does L4_Sigma0_GetPage_RcvWindow?

[Martin Christian]
> I haven't found any documentation about the sigma0 functions,
> neither in the reference manual, nor in the header file sigma0.h
> itself. Maybe you could add that in the next revision of the
> reference manual?

I was the one who added the header file for the sigma0 functions.  It
wasn't meant (at the time at least) to be part of the L4 API, and it
was therefore not added to the spec.  Probably a good idea to add it.
It's just a few functions afterall.

> But for now I would be quite happy, if someone could explain what

> L4_Fpage_t L4_Sigma0_GetPage_RcvWindow(
>   L4_ThreadId_t s0,
>   L4_Fpage_t f,
>   L4_Fpage_t RcvWindow
> )

> does or point me to a document that explains the sigma0 helper
> functions? My understanding is: Tell s0 to map "f" in his address
> space to RcvWindow in my address space. The return value should then
> be within RcvWindow. If s0==NilThread ask sigma0 for the page.

Parameters are as follows:

  s0 - thread ID of sigma0, or calculated by lookup in the KIP if a
       nilid is specified.

  f -  the memory region to allocate (i.e., the fpage in sigma0's
       address space).  Size and location taken from the fpage.  A
       location of -1 indicates allocation from an arbitrary
       (unallocated) location of regular memory.

  RcvWindow - The receive window in which to receive the mapping.

The function returns the fpage mapped into the address space, or
nilpage if operation failed.

	eSk