gnupic: Thread: Re: [gnupic] GCC port for PIC

Cool!

I hope that finally means that I can start writing PIC programs in the trusty 
old Fortran77 !!!!!!!!

Yippeee!


Cheers

Dan / M0DFI


On Tuesday 04 April 2006 15:47, Colm O' Flaherty wrote:
> I just found out that there is an existing port of GCC for PIC.  Here is
> the contents of the mail I sent to the gcc mail list.. It may be of
> interest here as well...
>
> <GCC-MAIL>
> It seems that there is already a PIC port for gcc.. in the form of
> Microchips own MPLAB C30 compiler.. I didn't realise this (and google
> certainly didn't tell me) until I had started on the PIC14 port for gcc,
> and went to the Microchip website for some info, and searched on "C
> compiler" and then "gcc" out of curiosity... lo and behold, the source code
> for their port.. (based on gcc 3.3, it seems).
>
> It supports "Microchip 16-bit devices: PIC24, dsPIC30F and dsPIC33F"
>
> Microchip sells MPLAB C30 as a commercial product. On the "Buy It now"
> page, they have a link to the source code though, so I grabbed a copy... :)
>
> (Part Number: SW006012 - MPLAB C30 C Compiler for dsPIC30/33, PIC24: (GBP)
> � 513 )
>
> Colm
> </GCC-MAIL>
>
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: ####@####.####
> For additional commands, e-mail: ####@####.####

On 4/4/06, Colm O' Flaherty ####@####.#### wrote:

> It seems that there is already a PIC port for gcc.. in the form of
> Microchips own MPLAB C30 compiler.. I didn't realise this (and google
> certainly didn't tell me) until I had started on the PIC14 port for gcc, and
> went to the Microchip website for some info, and searched on "C compiler"
> and then "gcc" out of curiosity... lo and behold, the source code for their
> port.. (based on gcc 3.3, it seems).
>
> It supports "Microchip 16-bit devices: PIC24, dsPIC30F and dsPIC33F"

They are very very different from PIC14 and PIC16 and most likely
will not help you in porting gcc to PIC14 and PIC16.

By the way, you can built C30 under Linux. Just check the archive.
According to Microchip, it is not legal to use the library/header files/
linker scripts from the C30 package with the self-built C30 compiler
under Linux.
http://forum.microchip.com/tm.aspx?m=139510
http://forum.microchip.com/tm.aspx?m=139360


Regards,
Xiaofan

Now there's a blast from the past... I haven't heard/thought of Fortran
77 since '92. 

On Tue, 2006-04-04 at 15:54 +0100, Dan Andersson wrote:
> Cool!
> 
> I hope that finally means that I can start writing PIC programs in the trusty 
> old Fortran77 !!!!!!!!
> 
> Yippeee!
> 
> 
> Cheers
> 
> Dan / M0DFI
> 
> 
> On Tuesday 04 April 2006 15:47, Colm O' Flaherty wrote:
> > I just found out that there is an existing port of GCC for PIC.  Here is
> > the contents of the mail I sent to the gcc mail list.. It may be of
> > interest here as well...
> >
> > <GCC-MAIL>
> > It seems that there is already a PIC port for gcc.. in the form of
> > Microchips own MPLAB C30 compiler.. I didn't realise this (and google
> > certainly didn't tell me) until I had started on the PIC14 port for gcc,
> > and went to the Microchip website for some info, and searched on "C
> > compiler" and then "gcc" out of curiosity... lo and behold, the source code
> > for their port.. (based on gcc 3.3, it seems).
> >
> > It supports "Microchip 16-bit devices: PIC24, dsPIC30F and dsPIC33F"
> >
> > Microchip sells MPLAB C30 as a commercial product. On the "Buy It now"
> > page, they have a link to the source code though, so I grabbed a copy... :)
> >
> > (Part Number: SW006012 - MPLAB C30 C Compiler for dsPIC30/33, PIC24: (GBP)
> >  513 )
> >
> > Colm
> > </GCC-MAIL>
> >
> >
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: ####@####.####
> > For additional commands, e-mail: ####@####.####
> 
> 
> 
> 
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Xiaofan,

I'm dubious sure that what Microchip (in your links) say about the legality 
of using the library/header files/ linker scripts from the C30 package is 
actually correct, or just misinformed.  Their offering is based on the gnu 
cc compiler; is packaged and sold as a unit, and so *is* fully governed by 
the GPL.  They've even included the standard header in their source code..

In short, the MPLAB C30 package *is* a derivative work of the GNU cc 
compiler, and so Microchip cannot impose additional licence constraints, as 
they seem to be doing. They are also required to make available the full 
source for their package (not just the gnu-gcc portion), including the 
source for the licence manager, etc.

As you rightly point out though, it might not be useful for getting a PIC14 
/ PIC16 port up and running, but its food for thought, and interesting from 
a coding point of view.. If you want a "free" / "open-source"  (ANSI 
compliant) C compiler, the number of options are increasing, especially for 
the newer chips. That can't be a bad thing.

<quote>
Subroutines for insn output for Microchip dsPIC30.
   Copyright (C) 1994, 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
   Contributed by John Elliott ####@####.####

This file is part of GNU CC.

GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 1, or (at your option)
any later version.
</quote>

Now this is what the GPL has to say that is relevant..

Preamble:

This General Public License applies to most of the Free Software
Foundation's software and to any other program whose authors commit to
using it.

...if you distribute copies of such a program, whether
gratis or for a fee, you must give the recipients all the rights that
you have.  You must make sure that they, too, receive or can get the
source code.  And you must show them these terms so they know their
rights.

Section 0

0. This License applies to any program or other work which contains
a notice placed by the copyright holder saying it may be distributed
under the terms of this General Public License.  The "Program", below,
refers to any such program or work, and a "work based on the Program"
means either the Program or any derivative work under copyright law:
that is to say, a work containing the Program or a portion of it,
either verbatim or with modifications and/or translated into another
language.

Section 1
You may charge a fee for the physical act of transferring a copy, and
you may at your option offer warranty protection in exchange for a fee

Section 2
2. You may modify your copy or copies of the Program or any portion
of it, thus forming a work based on the Program, and copy and
distribute such modifications or work under the terms of Section 1
above, provided that you also meet all of these conditions:

    a) You must cause the modified files to carry prominent notices
    stating that you changed the files and the date of any change.

    b) You must cause any work that you distribute or publish, that in
    whole or in part contains or is derived from the Program or any
    part thereof, to be licensed as a whole at no charge to all third
    parties under the terms of this License.
...
If
identifiable sections of that work are not derived from the Program,
and can be reasonably considered independent and separate works in
themselves, then this License, and its terms, do not apply to those
sections when you distribute them as separate works.  But when you
distribute the same sections as part of a whole which is a work based
on the Program, the distribution of the whole must be on the terms of
this License

Section 6
You may not impose any further
restrictions on the recipients' exercise of the rights granted herein.

Colm


>On 4/4/06, Colm O' Flaherty ####@####.#### wrote:
>
> > It seems that there is already a PIC port for gcc.. in the form of
> > Microchips own MPLAB C30 compiler.. I didn't realise this (and google
> > certainly didn't tell me) until I had started on the PIC14 port for gcc, 
>and
> > went to the Microchip website for some info, and searched on "C 
>compiler"
> > and then "gcc" out of curiosity... lo and behold, the source code for 
>their
> > port.. (based on gcc 3.3, it seems).
> >
> > It supports "Microchip 16-bit devices: PIC24, dsPIC30F and dsPIC33F"
>
>They are very very different from PIC14 and PIC16 and most likely
>will not help you in porting gcc to PIC14 and PIC16.
>
>By the way, you can built C30 under Linux. Just check the archive.
>According to Microchip, it is not legal to use the library/header files/
>linker scripts from the C30 package with the self-built C30 compiler
>under Linux.
>http://forum.microchip.com/tm.aspx?m=139510
>http://forum.microchip.com/tm.aspx?m=139360
>
>
>Regards,
>Xiaofan
>
>---------------------------------------------------------------------
>To unsubscribe, e-mail: ####@####.####
>For additional commands, e-mail: ####@####.####
>

On 5 Apr 2006, at 08:23, Colm O' Flaherty wrote:
> I'm dubious sure that what Microchip (in your links) say about the  
> legality of using the library/header files/ linker scripts from the  
> C30 package is actually correct, or just misinformed.  Their  
> offering is based on the gnu cc compiler; is packaged and sold as a  
> unit, and so *is* fully governed by the GPL.  They've even included  
> the standard header in their source code..

They can put whatever license they want on their C library, library  
headers, and linker scripts if they wrote them from scratch, as they  
are not linked to any of the GCC libraries or executables. There is  
precedent for this - Rowley's Crossworks for ARM for example.

There's nothing to stop you using the compiler itself (which is  
GPLed) with an open source C library and your own linker scripts, but  
if they say you can't use their library and linker scripts without  
paying a license fee, you should respect their wishes.

> In short, the MPLAB C30 package *is* a derivative work of the GNU  
> cc compiler, and so Microchip cannot impose additional licence  
> constraints, as they seem to be doing. They are also required to  
> make available the full source for their package (not just the gnu- 
> gcc portion), including the source for the licence manager, etc.

That's incorrect. As long as the license manager program doesn't  
contain any GPL code, they don't need to place it under the GPL. The  
fact that it's distributed in a "package" along with some GPLed  
programs isn't relevant. See the stuff in the GPL about  
"aggregation". I'm not quite sure why you would want the source to  
the license manager though.

> Subroutines for insn output for Microchip dsPIC30.

This file appears to be a part of GCC itself, which is clearly GPLed.  
The issue is with the C library and linker scripts, not the compiler.

-- 
------------ Alex Holden - http://www.alexholden.net/ ------------
If it doesn't work, you're not hitting it with a big enough hammer

What the GPL says about aggregation:

<quote>
In addition, mere aggregation of another work not based on the Program
with the Program (or with a work based on the Program) on a volume of
a storage or distribution medium does not bring the other work under
the scope of this License.
</quote>

Fair enough, but this doesn't seem to me to be entirely relevant here.  This 
refers to someone creating a GNU PIC bundle (for example), with both GPL'ed 
software and non GPL'ed software aggregated on the same medium (CD).  All 
this clause says is that in doing this, you do not cause the non-GPL'ed 
software to fall under the GPL.

What about the following, as quoted earlier?  This seems to be directly 
applicable to the C30 compiler package, which has portions not directly 
based on gnu cc (the linker scripts, etc).  These are not distributed as 
separate works, but as part of the C30 compiler package, which is based on 
GNU CC.  This implies "the distribution of the whole must be on the terms of
this License".. ie, the entire of Microchips C30 compiler package must be on 
the terms of the GPL.

<quote>
These requirements apply to the modified work as a whole.  If
identifiable sections of that work are not derived from the Program,
and can be reasonably considered independent and separate works in
themselves, then this License, and its terms, do not apply to those
sections when you distribute them as separate works.  But when you
distribute the same sections as part of a whole which is a work based
on the Program, the distribution of the whole must be on the terms of
this License, whose permissions for other licensees extend to the
entire whole, and thus to each and every part regardless of who wrote it.
</quote>

As an aside, I'm not interested in the source of the licence manager per se, 
I'm just using it as an example of what source should be available (but 
doesn't seem to be) if, in fact, the entire C30 package falls under the GPL. 
  Thats what I'm interested in establishing now..

I'm not familiar with the ARM example.. Do you have more details?

Colm

>From: Alex Holden ####@####.####
>Reply-To: ####@####.####
>To: ####@####.####
>Subject: Re: [gnupic] GCC port for PIC
>Date: Wed, 5 Apr 2006 09:09:24 +0100
>
>On 5 Apr 2006, at 08:23, Colm O' Flaherty wrote:
>>I'm dubious sure that what Microchip (in your links) say about the  
>>legality of using the library/header files/ linker scripts from the  C30 
>>package is actually correct, or just misinformed.  Their  offering is 
>>based on the gnu cc compiler; is packaged and sold as a  unit, and so *is* 
>>fully governed by the GPL.  They've even included  the standard header in 
>>their source code..
>
>They can put whatever license they want on their C library, library  
>headers, and linker scripts if they wrote them from scratch, as they  are 
>not linked to any of the GCC libraries or executables. There is  precedent 
>for this - Rowley's Crossworks for ARM for example.
>
>There's nothing to stop you using the compiler itself (which is  GPLed) 
>with an open source C library and your own linker scripts, but  if they say 
>you can't use their library and linker scripts without  paying a license 
>fee, you should respect their wishes.
>
>>In short, the MPLAB C30 package *is* a derivative work of the GNU  cc 
>>compiler, and so Microchip cannot impose additional licence  constraints, 
>>as they seem to be doing. They are also required to  make available the 
>>full source for their package (not just the gnu- gcc portion), including 
>>the source for the licence manager, etc.
>
>That's incorrect. As long as the license manager program doesn't  contain 
>any GPL code, they don't need to place it under the GPL. The  fact that 
>it's distributed in a "package" along with some GPLed  programs isn't 
>relevant. See the stuff in the GPL about  "aggregation". I'm not quite sure 
>why you would want the source to  the license manager though.
>
>>Subroutines for insn output for Microchip dsPIC30.
>
>This file appears to be a part of GCC itself, which is clearly GPLed.  The 
>issue is with the C library and linker scripts, not the compiler.
>
>--
>------------ Alex Holden - http://www.alexholden.net/ ------------
>If it doesn't work, you're not hitting it with a big enough hammer
>
>
>
>---------------------------------------------------------------------
>To unsubscribe, e-mail: ####@####.####
>For additional commands, e-mail: ####@####.####
>

On 5 Apr 2006, at 11:47, Colm O' Flaherty wrote:
> <quote>
> In addition, mere aggregation of another work not based on the Program
> with the Program (or with a work based on the Program) on a volume of
> a storage or distribution medium does not bring the other work under
> the scope of this License.
> </quote>
> Fair enough, but this doesn't seem to me to be entirely relevant  
> here.  This refers to someone creating a GNU PIC bundle (for  
> example), with both GPL'ed software and non GPL'ed software  
> aggregated on the same medium (CD).  All this clause says is that  
> in doing this, you do not cause the non-GPL'ed software to fall  
> under the GPL.

It is relevant because in this case "another work" (Microchip's C  
library with associated header files) is not, as far as I am aware,  
based in any way on "the Program" (gcc). If they haven't used any  
GPLed code to create their library then the GPL doesn't apply to it.  
Bundling gcc and their C library into one package is simply aggregation.

> What about the following, as quoted earlier?  This seems to be  
> directly applicable to the C30 compiler package, which has portions  
> not directly based on gnu cc (the linker scripts, etc).  These are  
> not distributed as separate works, but as part of the C30 compiler  
> package, which is based on GNU CC.  This implies "the distribution  
> of the whole must be on the terms of
> this License".. ie, the entire of Microchips C30 compiler package  
> must be on the terms of the GPL.

The GPL applies to GPLed source code and binaries created by  
compiling/assembling that source code. It doesn't apply to other  
programs that are bundled together with them in a single package.

> These requirements apply to the modified work as a whole.

That means simply a program/library that is licensed under the GPL.  
It doesn't mean a tarball, zipfile, Windows installer, etc. that  
contains both GPLed programs and non-GPLed programs.

> I'm not familiar with the ARM example.. Do you have more details?

Rowley sell an ARM development environment that bundles ARM GCC with  
their own proprietary C library, linker scripts, and IDE.

-- 
------------ Alex Holden - http://www.alexholden.net/ ------------
If it doesn't work, you're not hitting it with a big enough hammer

Alex,

When you say..

>If they haven't used any  GPLed code to create their library then the GPL 
>doesn't apply to it.  Bundling gcc and their C library into one package is 
>simply aggregation.

I just don't follow that logic at all.. It seems to completely ignore the 
GPL clause that says the following  (How the distribution happens seems to 
be the key).

<quote>
These requirements apply to the modified work as a whole.  If
identifiable sections of that work are not derived from the Program,
and can be reasonably considered independent and separate works in
themselves, then this License, and its terms, do not apply to those
sections when you distribute them as separate works.  But when you
distribute the same sections as part of a whole which is a work based
on the Program, the distribution of the whole must be on the terms of
this License, whose permissions for other licensees extend to the
entire whole, and thus to each and every part regardless of who wrote it.
</quote>

But hey, we can agree to differ, right?  :)

This discussion might also be better placed in the gcc list forum than 
here..  (Its relevant here, but more relevant there).

Colm


>From: Alex Holden ####@####.####
>Reply-To: ####@####.####
>To: ####@####.####
>Subject: Re: [gnupic] GCC port for PIC
>Date: Wed, 5 Apr 2006 12:04:28 +0100
>
>On 5 Apr 2006, at 11:47, Colm O' Flaherty wrote:
>><quote>
>>In addition, mere aggregation of another work not based on the Program
>>with the Program (or with a work based on the Program) on a volume of
>>a storage or distribution medium does not bring the other work under
>>the scope of this License.
>></quote>
>>Fair enough, but this doesn't seem to me to be entirely relevant  here.  
>>This refers to someone creating a GNU PIC bundle (for  example), with both 
>>GPL'ed software and non GPL'ed software  aggregated on the same medium 
>>(CD).  All this clause says is that  in doing this, you do not cause the 
>>non-GPL'ed software to fall  under the GPL.
>
>It is relevant because in this case "another work" (Microchip's C  library 
>with associated header files) is not, as far as I am aware,  based in any 
>way on "the Program" (gcc). If they haven't used any  GPLed code to create 
>their library then the GPL doesn't apply to it.  Bundling gcc and their C 
>library into one package is simply aggregation.
>
>>What about the following, as quoted earlier?  This seems to be  directly 
>>applicable to the C30 compiler package, which has portions  not directly 
>>based on gnu cc (the linker scripts, etc).  These are  not distributed as 
>>separate works, but as part of the C30 compiler  package, which is based 
>>on GNU CC.  This implies "the distribution  of the whole must be on the 
>>terms of
>>this License".. ie, the entire of Microchips C30 compiler package  must be 
>>on the terms of the GPL.
>
>The GPL applies to GPLed source code and binaries created by  
>compiling/assembling that source code. It doesn't apply to other  programs 
>that are bundled together with them in a single package.
>
>>These requirements apply to the modified work as a whole.
>
>That means simply a program/library that is licensed under the GPL.  It 
>doesn't mean a tarball, zipfile, Windows installer, etc. that  contains 
>both GPLed programs and non-GPLed programs.
>
>>I'm not familiar with the ARM example.. Do you have more details?
>
>Rowley sell an ARM development environment that bundles ARM GCC with  their 
>own proprietary C library, linker scripts, and IDE.
>
>--
>------------ Alex Holden - http://www.alexholden.net/ ------------
>If it doesn't work, you're not hitting it with a big enough hammer
>
>
>
>---------------------------------------------------------------------
>To unsubscribe, e-mail: ####@####.####
>For additional commands, e-mail: ####@####.####
>

On 5 Apr 2006, at 12:31, Colm O' Flaherty wrote:
>> If they haven't used any  GPLed code to create their library then  
>> the GPL doesn't apply to it.  Bundling gcc and their C library  
>> into one package is simply aggregation.
> I just don't follow that logic at all.. It seems to completely  
> ignore the GPL clause that says the following  (How the  
> distribution happens seems to be the key).
> <quote>
> These requirements apply to the modified work as a whole.

You seem to be interpreting "the modified work as a whole" to mean  
the installer (zipfile, tarball, whatever) and everything contained  
in it. I disagree. The "modified work as a whole" in this case is  
simply GCC, not the other libraries and programs that Microchip have  
bundled with it.

-- 
------------ Alex Holden - http://www.alexholden.net/ ------------
If it doesn't work, you're not hitting it with a big enough hammer

>You seem to be interpreting "the modified work as a whole" to mean  the 
>installer (zipfile, tarball, whatever) and everything contained  in it. I 
>disagree. The "modified work as a whole" in this case is  simply GCC, not 
>the other libraries and programs that Microchip have  bundled with it.

I think thats a good summary of our interpretations...   The PICC-gcc 
compiler (as opposed to the C30 package which contains it) is certainly a 
"modified work".. no argument there.  Why isn't the C30 package (and its 
distributed in such a fashion) which contains the PIC-gcc compiler also a 
"modified work" then?  It seems to fit the criteria.

<quote>
This License applies to any program or other work which contains
a notice placed by the copyright holder saying it may be distributed
under the terms of this General Public License.  The "Program", below,
refers to any such program or work, and a "work based on the Program"
means either the Program or any derivative work under copyright law:
that is to say, a work containing the Program or a portion of it,
either verbatim or with modifications and/or translated into another
language.
</quote>

Note: 'a "work based on the Program" means either the Program or any 
derivative work under copyright law:that is to say, a work containing the 
Program or a portion of it'. Isn't C30 a work that contain GNU CC??  Whats 
special about C30 that means that the clause above doesn't apply to it?

And why would the GPL say "These requirements apply to the modified work as 
a whole." if you don't mean the package that contains GNU CC?

Some info from the FSF itself on the GPL.. I don't see anything in here that 
would explain how, in this case, the linker scripts (etc) are not covered by 
the GPL.  Everything seems to indicate that these additional elements (which 
are released as part of C30, which incorporates a modified version of 
GNU-CC) *are* covered by the GPL, and are, as a result, free for general 
use. (and cannot have a more restrictive licence placed on them by 
Microchip).

http://www.fsf.org/licensing/licenses/gpl-faq.html#GPLRequireSourcePostedPublic
See the following:
- Does the GPL allow me to distribute a modified or beta version under a 
nondisclosure agreement?
- I heard that someone got a copy of a GPL'ed program under another license. 
Is this possible?
- If I add a module to a GPL-covered program, do I have to use the GPL as 
the license for my module?
- What is the difference between "mere aggregation" and "combining two 
modules into one program"?

Colm

>From: Alex Holden ####@####.####
>Reply-To: ####@####.####
>To: ####@####.####
>Subject: Re: [gnupic] GCC port for PIC
>Date: Wed, 5 Apr 2006 12:50:06 +0100
>
>On 5 Apr 2006, at 12:31, Colm O' Flaherty wrote:
>>>If they haven't used any  GPLed code to create their library then  the 
>>>GPL doesn't apply to it.  Bundling gcc and their C library  into one 
>>>package is simply aggregation.
>>I just don't follow that logic at all.. It seems to completely  ignore the 
>>GPL clause that says the following  (How the  distribution happens seems 
>>to be the key).
>><quote>
>>These requirements apply to the modified work as a whole.
>
>You seem to be interpreting "the modified work as a whole" to mean  the 
>installer (zipfile, tarball, whatever) and everything contained  in it. I 
>disagree. The "modified work as a whole" in this case is  simply GCC, not 
>the other libraries and programs that Microchip have  bundled with it.
>
>--
>------------ Alex Holden - http://www.alexholden.net/ ------------
>If it doesn't work, you're not hitting it with a big enough hammer
>
>
>
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>To unsubscribe, e-mail: ####@####.####
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