Re: [avr32-libc-devel] Building AVR32-Libc with GNU tool chain

[Kaushik, P. <Pra...@at...>]

Hi Eric,

>-----Original Message-----
>From: Weddington, Eric 
>Sent: Thursday, July 22, 2010 9:53 PM
>To: Kaushik, Praveen_Kumar
>Cc: 'avr...@li...'; Joerg Wunsch
>Subject: RE: [avr32-libc-devel] Building AVR32-Libc with GNU tool chain

 

>> -----Original Message-----
>> From: Kaushik, Praveen_Kumar 
>> Sent: Thursday, July 22, 2010 12:56 AM
>> To: Weddington, Eric
>> Cc: avr...@li...
>> Subject: RE: [avr32-libc-devel] Building AVR32-Libc with GNU 
>> tool chain
>> 

>> The switch name --with-newlib might not be appropriate but 
>> this does not say that we are going to use Newlib as C 
>> library but instead it is for because the libstdc++ depends 
>> on certain functions provided by Newlib which might not be 
>> part of standard C library.


>You said that libstdc++ depends on certain functions provided by Newlib >which might not be part of the standard C library. Do you know exactly >which functions libstdc++ needs from Newlib that aren't part of the >standard C library?

When I was building avr32-libc for first time, I got errors for absence of few functions while building libstdc++. When I looked for those functions few of those were not part of the standard C library but were still provided by Newlib. I gave dummy declarations for those functions and went on   building the library.

The following header files are also not part of standard C library:

unistd.h:
required for declaration of lseek() 

sys/types.h:
required for various 'type' definitions

sys/stat.h:
required for definitions of some macros and declaration of fstat()

Apart from these,
In stdio.h:
function fdopen() is required but is not a part of standards.
function vsnprintf() conforms to C99 but not to C89.

The above list might not be comprehensive but with the inclusion of these files, I was able to build libstdc++ and AVR32 tool chain using avr32-libc.

I came across the discussion on GCC's mailing list about the name of the switch '--with-newlib'. The discussion is very long but I think the following pages can be a quick reference for why the name --with-newlib is used,

http://www.mailinglistarchive.com/gc...@gc.../msg18539.html


Only the last two paragraphs on this page will be useful:-
http://www.mailinglistarchive.com/gc...@gc.../msg18544.html


Regards,
Praveen Kaushik