I want to participate in GSoC from RTEMS

[Madhusudan C.S]

Hi Joel,
           First of all thanks a lot for all the support and suggestions. I
am overwhelmed by the response. I am also very sorry for such a late
response. I am going through every mail the moment you post it to the list.
But I wanted to respond once I had a basic knowledge of what you were trying
to tell me. I nearly went through the whole wiki, now I am reading the pdf
that Daron sent me and online docs of 4.99.

    All your mails has helped me a lot to understand what is happening down
under. I have understood few things you have explained, though I haven't
understood all. I will ask you as and when I need I haven't understood
inline.

Before that, I wanted to get the RTEMS running to get the taste of how Time
Stamps are working now. So I checked out the CVS HEAD and then installed all
the prebuilt tools from ftp for F8-RTEMS-4.9. Since I have Ubuntu installed
on my PC, I converted those rpms to debs using alien and installed all the
prebuilt tools. When I did bootstrap and configure there were no errors as
such, I did all these for sparc CPU. When I did "make all" it said compiler
cannot create executables, as its given in the wiki I installed libc6-dev
package, since thats the Ubuntu version of libc-dev. But still the make
fails. Can someone help me please. If there is no other go, I will install
F8 through XEN. But somehow I want to get this working on Ubuntu, so in
later stages we can also provide debian packages along with rpms. I can help
you with this, maybe after SoC.

That project in particular requires more knowledge of C and more attention
> to detail than deep algorithmic knowledge.


 I have a fair knowledge of C. I hope I have the requirements you have
mentioned above.

Remember the issue is that
> RTEMS used to have all time based upon clock ticks, then we added
> nanosecond
> time granularity and kept the time in structure timespec.  It isn't easy
> or
> particularly efficient to do math on struct timespec so this project is
> adding the capability to configure on a per-target basis 64-bit time.
> You do
> have to implement it but since the math will be on the native type
> "unsigned
> long long" instead of int or long, that part isn't rough.
>

I did not understand what "per-target basis" means here. Can you please
explain?

The rougher side of the effort is in adding a supercore (cpukit/score)
> timestamp handler (e.g. roughly an opaque C "class") and going through
> the supercore and using that instead of struct timespec where appropriate.
>

I am reading the Documentation of Super Core to understand how the APIs are
structured.

As the Wiki description states, some times need to be native, others have to
> be in API formats.  Each case has to be evaluated so the conversions are
> minimized.


Ok I got a rough idea. But I still need to work on it.

Follow the code from one of the clock get time or set time routines down the
> layers to the lowest core methods and you will get a feel.  You will see
> routines
> with "convert" in their name or a name like "from XXX" or "to XXX" as
> the names.
> Start at cpukit/rtems/src/clockset.c for one case.  There are similar
> routines
> in cpukit/posix/src/clock*.c
>
> Does that make sense at all?


I went through the code in those files. I also quickly skimmed through the
code I have COed from HEAD and have got a rough idea of how the code is
structured. Now I am feeling somewhat better. But still to get a real feel
of how Timestamps are working now I want to get it compiled and see how they
work. Please help me.

Moreover thanks a lot to both Joel for all the above suggestions and Daron
for that timecounters pdf.



-- 
Thanks and regards,
Madhusudan.C.S




-- 
With regards,
Madhusudan.C.S

"When liberty is taken away by force it can be restored by force. When it is
relinquished voluntarily by default it can never be recovered"
- Dorothy Thompson
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