Hi I have a general case about memory allocation in particular with that of the Vspace. I have been reading some documents and trying to compare how it is in Linux Kernel. Any program Virtual memory in a Linux kernel is as shown in picture below where all processes have 1GB of virtual memory which is mapped to kernel space for faster context switches and system calls. _____________________ | Kernel Space (1GB) | |_____________________| | | | User Mode Space | | (3 GB) | | | |_____________________| I have come across this this link http://os.inf.tu-dresden.de/pipermail/l4-hackers/2014/006262.html detailing a little about the sel4 memory management. But I haven't been able to completely comprehend it . I wanted to know if the seL4 kernel also has a similar mapping of kernel space. Regards Mark
Yes, I think the seL4 kernel is mapped into the virtual address space
of all processes. I think the exact separation between user mode space
and kernel space depends on the platform. For example, on the zynq7000
platform we have:
https://github.com/seL4/seL4/blob/master/src/plat/zynq7000/linker.lds
KERNEL_BASE = 0xe0000000;
PHYS_BASE = 0x00000000;
KERNEL_OFFSET = KERNEL_BASE - PHYS_BASE;
So there is ~3.5GB user mode space, ~500MB kernel space.
-Andrew
On Mon, Nov 21, 2016 at 7:13 PM, Mark Reus
Hi
I have a general case about memory allocation in particular with that of the Vspace. I have been reading some documents and trying to compare how it is in Linux Kernel. Any program Virtual memory in a Linux kernel is as shown in picture below where all processes have 1GB of virtual memory which is mapped to kernel space for faster context switches and system calls.
_____________________ | Kernel Space (1GB) | |_____________________| | | | User Mode Space | | (3 GB) | | | |_____________________|
I have come across this this link http://os.inf.tu-dresden.de/pipermail/l4-hackers/2014/006262.html detailing a little about the sel4 memory management. But I haven't been able to completely comprehend it . I wanted to know if the seL4 kernel also has a similar mapping of kernel space.
Regards Mark
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participants (2)
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Andrew Gacek
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Mark Reus