shared memory Beispiel?

Mathias Krause mkrause at
Thu Sep 1 19:48:33 CEST 2005

Adam Lackorzynski wrote:
>>To map it into L4Linux 2.6, you have to reserve a range of virtual memory
>>inside the Linux server (Adam, which function should someone use for this?)
>>and then map it into that reserved region via l4dm_map_ds() (see dm_phys
>>manual). Since L4Linux 2.6 makes havy use of L4env functionality, this
>>function is available. Make sure that the whole dataspace is mapped into
>>L4Linux since there is no region manager.
> The Linux server is a 'normal' L4Env application so mapping memory
> works as usual. Depending on what one wants to do it may be necessary to
> make the memory region known to Linux. But if it's (just) a driver one
> can simply use it.

So a l4rm_attach() in L4Linux is just fine? No conflicts with virtual 
Currently I do a l4dm_mem_open() plus l4dm_share() in the driver task 
followed by a l4rm_attach() on this dataspace in L4Linux. But I fear 
that the mapped virtual address range maybe get accidentally reused by 
L4Linux? So my question is if I need to inform L4Linux about my mapping 
or if the region mapper just handles this fine?
If I need to could you please tell me how I should do this?

 > Look at the stub drivers in 2.6, they just do that.

Neither the oshkosh nor the l4or driver stub make use of the functions I 
mentioned? Maybe I do something wrong? :/


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