gnupic: Thread: Re: [gnupic] Re: PIC32 C32 GCC Source Code Released

On Nov 9, 2007 7:03 AM, John Steele Scott ####@####.#### wrote:
> > Thanks. But then I have to question the legality of Microchip's
> > distributing a code size limit C32 binary since it uses GNU GPLed
> > source codes. I am not a lawyer but this is kind of strange.
> > That is why I asked in the forum in the first place.
> > http://forum.microchip.com/tm.aspx?m=292995
>
> C32 could take the same approach. If there is a pic32 license manager
> program, grep the source to see if GCC ever executes it.

There is no license manager this time.

> The reply James Grosbach gave you in the Microchip forum suggests that the
> size limitation is imposed by the runtime library somehow, but I don't see
> how that would work. On the other hand, I can imagine that the easiest
> place to impose this restriction would be in a linker script.

I am seeking further clarification in that thread.

And I can actually build C32 with newlib but newlib itself failed to be built.
So if someone here can port newlib over, then we have a working C32.

I downloaded the following and extract the source, newlib is there.
http://www.mips.com/products/software-tools/software-tools/mips-sde-lite/

And then I copy the newlib directory to the PIC32 C32 source code
directory and interestingly C32 gcc can be built. newlib failed to be
built. So I think it might need some efforts to port newlib over.

mcuee@ubuntu710:~/Desktop/PIC32/src$
./configure --target=$TARGET --prefix=$PREFIX --without-headers --with-newlib
--with-gnu-as --with-gnu-ld --enable-languages=c

mcuee@ubuntu710:~/Desktop/PIC32/src$
make all-gcc

mcuee@ubuntu710:~/Desktop/PIC32/src$
sudo make install-gcc

mcuee@ubuntu710:~/Desktop/PIC32/src$ ls /opt/pic32mx/bin/
pic32mx-addr2line pic32mx-bin2hex pic32mx-gcc pic32mx-gcov
pic32mx-objcopy pic32mx-readelf pic32mx-strip
pic32mx-ar pic32mx-c++filt pic32mx-gcc-3.4.4 pic32mx-ld
pic32mx-objdump pic32mx-size
pic32mx-as pic32mx-cpp pic32mx-gccbug pic32mx-nm
pic32mx-ranlib pic32mx-strings

mcuee@ubuntu710:~/Desktop/PIC32/src$ pic32mx-gcc --v
Reading specs from /opt/pic32mx/lib/gcc/pic32mx/3.4.4/specs
Configured with: : (reconfigured) ./configure --target=pic32mx
--prefix=/opt/pic32mx --without-headers --with-newlib --with-gnu-as
--with-gnu-ld : (reconfigured) ./configure --target=pic32mx
--prefix=/opt/pic32mx --with-newlib --with-gnu-as --with-gnu-ld :
(reconfigured) ./configure --target=pic32mx --prefix=/opt/pic32mx
--without-headers --with-newlib --with-gnu-as --with-gnu-ld
--enable-languages=c
Thread model: single
gcc version 3.4.4 MPLAB C32 v1.00-20071024

Xiaofan

On Nov 9, 2007 7:03 AM, John Steele Scott ####@####.#### wrote:
> > Thanks. But then I have to question the legality of Microchip's
> > distributing a code size limit C32 binary since it uses GNU GPLed
> > source codes. I am not a lawyer but this is kind of strange.
> > That is why I asked in the forum in the first place.
> > http://forum.microchip.com/tm.aspx?m=292995
>
> The reply James Grosbach gave you in the Microchip forum suggests that the
> size limitation is imposed by the runtime library somehow, but I don't see
> how that would work. On the other hand, I can imagine that the easiest
> place to impose this restriction would be in a linker script.
>

I got the answer again and it seems that James is right and the
distributed executables have no restrictions on code size.
As I run the Upgrader.exe to update the default starter
version (16k) to the student version (64k), it seems that he is right,
I can see that the library files are updated.

I tested his patch and configuration and it works.

So if some hackers can port newlib over to PIC32, it is actually possible
to lift the code size limit.

Xiaofan

On Nov 9, 2007 7:03 AM, John Steele Scott ####@####.#### wrote:

> The reply James Grosbach gave you in the Microchip forum suggests that the
> size limitation is imposed by the runtime library somehow, but I don't see
> how that would work.

Just wanted to test his assertion, how could I write a simple program which
can be easily increased to more than 64KB code size? Maybe this
is a stupid question but I just could not think of an easy way now.

Xiaofan

Xiaofan Chen escribió:
 > On Nov 9, 2007 7:03 AM, John Steele Scott ####@####.#### wrote:
 >
 > > The reply James Grosbach gave you in the Microchip forum suggests 
that the
 > > size limitation is imposed by the runtime library somehow, but I 
don't see
 > > how that would work.
 >
 > Just wanted to test his assertion, how could I write a simple program 
which
 > can be easily increased to more than 64KB code size? Maybe this
 > is a stupid question but I just could not think of an easy way now.

A macro calling n-times an inline function?
A big rom array?


-- 
------------------------------
Mauricio Giovagnini (Maunix)
www.maunix.com.ar
Cordoba, Arg.

On Nov 20, 2007 2:30 AM, Mauricio Giovagnini ####@####.#### wrote:
>  >
>  > Just wanted to test his assertion, how could I write a simple
> > program which can be easily increased to more than 64KB code size?
> > Maybe this is a stupid question but I just could not think of an easy way now.
>
> A macro calling n-times an inline function?
> A big rom array?

The test shows that the linker will fail once the code size increases. It
is confirmed in Microchip forum as well.
http://forum.microchip.com/tm.aspx?m=292995&mpage=2

Xiaofan

On Wed, Dec 12, 2007 at 7:49 AM, Xiaofan Chen ####@####.#### wrote:
> On Nov 20, 2007 2:30 AM, Mauricio Giovagnini ####@####.#### wrote:
> >  >
> >  > Just wanted to test his assertion, how could I write a simple
> > > program which can be easily increased to more than 64KB code size?
> > > Maybe this is a stupid question but I just could not think of an easy way now.
> >
> > A macro calling n-times an inline function?
> > A big rom array?
>
> The test shows that the linker will fail once the code size increases. It
> is confirmed in Microchip forum as well.
> http://forum.microchip.com/tm.aspx?m=292995&mpage=2
>

The same limit actually applies even if you do not use the C compiler but
only the assembler.

Details here:
http://forum.microchip.com/tm.aspx?m=326497



Xiaofan