Hi,
On Fri Jul 17, 2015 at 10:36:35 +0200, Mahdi Aichouch wrote:
The memory regions are exclusive. Specifying exactly which physical
memory an L4Linux is getting is currently not possible but I guess you're using the numbers just as an example?
Yes, I am giving these numbers as an example. However, is it possible to know what are the start address and the end address of a physical memory partition allocated to a L4Linux instance?
Yes, this is done in L4Linux as it is for example required for device drivers. virt_to_phys will yield the proper physical memory address. L4Linux is also printing the virt-phys pairs on bootup.
The memory is completely mapped initially, so no page fault should
happen. As probably nobody will take it away again it should also stay like this.
Does this apply also to user-level programs executed on top of L4Linux.
User-level programs are paged normally. Any possible page fault avoidance needs to be done with Linux means.
You can put showpfexc=1 on the cmdline to see any in-kernel page fault.
There shouldn't be any (except in the outside wrapper code as I see
which can be changed by launching L4Linux with the eager_map flag).
Could please give some explanation about what is the wrapper code? And Where to set the "eager_map flag" option?
With the wrapper code I mean the glue layer that gates between the internal Linux system and the outside L4Re system. See arch/l4/boot.
L4.default_loader:start({ ldr_flags = L4.Ldr_flags.eager_map }, ...);
Adam