[PATCH] i386/virtualpok BSP, virtual BSP to be used with POK, build with enable-paravirt

Philipp Eppelt philipp.eppelt at mailbox.tu-dresden.de
Tue Jan 14 14:58:19 UTC 2014

On 01/14/2014 12:32 PM, Chris Johns wrote:
> On 14/01/2014 12:40 am, Philipp Eppelt wrote:
>> On 01/12/2014 10:19 PM, Chris Johns wrote:
>>> On 13/01/2014 2:39 am, Philipp Eppelt wrote:
>>>> On 01/11/2014 11:50 PM, Chris Johns wrote:
>>>>> On 12/01/2014 12:45 am, Philipp Eppelt wrote:
>>>>>> On 01/10/2014 10:27 PM, Chris Johns wrote:
>>>>>>> On 7/01/2014 9:14 pm, Philipp Eppelt wrote:
>>>>>>>> On 01/07/2014 04:25 AM, Chris Johns wrote:
>>>>>>> Does this include headers ?
>>>>>> POK separates kernel and partition code. The kernel code is not
>>>>>> affected
>>>>>> by the partitions running on top. And each partition has the
>>>>>> 'knowledge'
>>>>>> of how to communicate with the kernel. libpart.a consits of this
>>>>>> communication code or 'partition base code' and the implementation of
>>>>>> the functions in virtualizationlayercpu.h and
>>>>>> virtualizationlayerbsp.h.
>>>>>> Or what do you mean with headers?
>>>>> Where do the virtualizationlayercpu.h and virtualizationlayerbsp.h
>>>>> come
>>>>> from and live ?
>>>> In libbsp/i386/virtualpok/include. The files are part of this patch.
>>> What is used to build the library externally ?
>>> I do not think having headers in RTEMS for a library built outside is a
>>> good idea. An interface change in the library not reflected in RTEMS
>>> headers will be difficult to find.
>> The header files define the virtualization layer in RTEMS. They are not
>> part of POK.
> Yet the code is built by POK. I am a little confused by this.
>> The header files define the functions a host has to
>> implement to run this particular RTEMS BSP.
> Sure.
>> All hardware interactions a BSP/CPU does go through this layer and are
>> handled on the host system. RTEMS defines the function necessary and POK
>> is providing the implementation via libpart.a.
> How does POK see these definitions so it can build the library ?
Copy & Paste.
I kept the two systems separated and I think gcc, couldn't resolve links.

>> For examples, the console driver calls _BSP_Virtual_Char_read/write,
>> defined in virtualizationlayerbsp.h.
>> The implementation is done in POK and passed to RTEMS at compile time
>> via libpart.a
> What is the interface used in POK to build this RTEMS interface ?
What do you mean?

The header files are written for RTEMS, so the compiler has something to
work with. The linker uses the library provided by POK to resolve the
undefined references.
The POK implementation includes a copy of these header files. Hence, the
linker can match the names.


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