Hi Kevin,
First, thank you for your reply very much. But I cannot understand those very well. Generally speaking, how does the OS personality get and know all caps for its own? More accurate, take the init process for example(which I am focusing on), how does it know which cap it has? I think it has to resort to the kernel, as the init process is created by the kernel, and I assume the kernel will set up caps for it.
Thanks again. Yuxin
On Fri, Oct 17, 2014 at 1:36 AM, Kevin Elphinstone < Kevin.Elphinstone@nicta.com.au> wrote:
In general, seL4 provides low-level mechanisms, not high-level abstractions.
The vm model and process model are high-level abstractions of an OS personality on seL4, and as such, the OS personality is expected to keep the information required to implement those abstractions.
So I would expect the OS personality running on seL4 to keep track of the frame caps used to create VM objects/address-spaces, which threads are in what processes, etc..
There are some libraries that ease building OS personalities, which are the ones you are using. Those libraries walk a thin line between helpful libraries to aid the construction of OS personalities, and largely defining the OS personality.
We make no claims as to the line striking the right balance, this is evolving over time, with tension pulling the line in either direction.
So if my understanding of the current support libraries is correct, what you’re after is part of the book-keeping you should be managing when creating your OS personality on seL4 – it is not provide by the libraries nor seL4.
Kevin*From:* Devel [mailto:devel-bounces@sel4.systems] *On Behalf Of *Yuxin Ren *Sent:* Friday, 17 October 2014 5:21 AM *To:* devel@sel4.systems *Subject:* [seL4] How to get a capability of a virtual address
Hi All,
In sel4, how can a process/thread get the capability of its virtual address?
I know there is function
*vspace_get_cap*(*vspace_t* ***vspace, *void* ***vaddr)
But how can I know the current vspace the process/thread is in?
Thank you very much.
Yuxin
The information in this e-mail may be confidential and subject to legal professional privilege and/or copyright. National ICT Australia Limited accepts no liability for any damage caused by this email or its attachments.