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digitalmars.D - Cross compiler for embedded microcontrollers ?

reply "Jens Bauer" <doctor who.no> writes:
Hi,

Today is my first D-day. I haven't even written any d-code yet,
but I've got the compiler for my PPC-based Mac (yes, it's old).

I'm familiar with compiling toolchains for ARM Cortex-M0, M3 and
M4.
Is there any information on how to build a cross-gdc targetting
these architectures ?

Eg. the compiler will be built and run on my PowerMac, but I'd
like it to generate ARM Cortex-M3 code for instance.
Jan 15 2015
parent reply "Jens Bauer" <doctor who.no> writes:
It seems I've found it...

http://wiki.dlang.org/Bare_Metal_ARM_Cortex-M_GDC_Cross_Compiler

-It also seems I have to use gcc-4.9, as the gcc-4.8 branch does 
not seem to exist in the git repository ?
Jan 15 2015
parent reply Iain Buclaw via Digitalmars-d <digitalmars-d puremagic.com> writes:
On 15 January 2015 at 16:49, Jens Bauer via Digitalmars-d
<digitalmars-d puremagic.com> wrote:

 It seems I've found it...

 http://wiki.dlang.org/Bare_Metal_ARM_Cortex-M_GDC_Cross_Compiler

 -It also seems I have to use gcc-4.9, as the gcc-4.8 branch does not seem to
 exist in the git repository ?


That should be gdc-4.8, gdc-4.9
Jan 15 2015
parent reply "Jens Bauer" <doctor who.no> writes:
On Thursday, 15 January 2015 at 16:58:34 UTC, Iain Buclaw via 
Digitalmars-d wrote:

 On 15 January 2015 at 16:49, Jens Bauer via Digitalmars-d

 -It also seems I have to use gcc-4.9, as the gcc-4.8 branch 
 does not seem to exist in the git repository ?


 That should be gdc-4.8, gdc-4.9


I just tried again, and this time it looks like it's going to be 
successful.
Thank you for pointing out the mistake. :)
Jan 15 2015
parent reply "Jens Bauer" <doctor who.no> writes:
Build failed on final gcc.

I normally use newlib and multilib, because I'm developing for 
Cortex-M0, Cortex-M3 and Cortex-M4 and would like to be able to 
switch between those and use the same compiler.
But following the above mentioned instructions seem to suggest 
disabling multilib and using libgcc instead of newlib. Has anyone 
used newlib with a Cortex-M based GDC toolchain ?
Jan 16 2015
next sibling parent "Mike" <none none.com> writes:
On Friday, 16 January 2015 at 10:04:55 UTC, Jens Bauer wrote:

 Build failed on final gcc.

 I normally use newlib and multilib, because I'm developing for 
 Cortex-M0, Cortex-M3 and Cortex-M4 and would like to be able to 
 switch between those and use the same compiler.
 But following the above mentioned instructions seem to suggest 
 disabling multilib and using libgcc instead of newlib. Has 
 anyone used newlib with a Cortex-M based GDC toolchain ?


I wrote the those instructions on the wiki, but I don't have 
experience building a multilib toolchain, or building one with 
newlib.  I recommend going to 
https://launchpad.net/gcc-arm-embedded and downloading the source 
code package.  After extracting the archive, you'll find a three 
bash scripts that do the build.  It's an extremely complicated 
script, but inside you can find all the necessary commands for 
multilib and newlib builds.  That's the resource I used to figure 
it out and write those instructions.

My goal is to use D without having to rely on a C standard 
library, and I've demonstrated that it is feasible and even 
desirable.  Therefore, the instructions on the wiki don't include 
a C library like newlib.  I don't think D needs to leverage the C 
standard library, and as you're finding out, more dependencies = 
more problems.  I view libgcc as part of the toolchain itself, so 
I will be leveraging that in the future.

If you want to use the the C library, though, check out minlibd: 
https://bitbucket.org/timosi/minlibd.  That project has some 
documentation for building a toolchain:  
https://bitbucket.org/timosi/minlibd/wiki/gdc_cross_compiler

The other option would be to use crosstools-ng:  
http://crosstool-ng.org/.  But, I had a hell of time with that 
last time I tried:  
http://forum.dlang.org/post/ptedovhanscsgshlemlb forum.dlang.org

Mike
Jan 16 2015
prev sibling next sibling parent "Mike" <none none.com> writes:
On Friday, 16 January 2015 at 10:04:55 UTC, Jens Bauer wrote:

 Build failed on final gcc.

 But following the above mentioned instructions seem to suggest 
 disabling multilib and using libgcc instead of newlib.


Also, libgcc is not a replacement for newlib. I'm not an expert 
on the toolchain but my understanding is that libgcc contains the 
implementations for some of GCC's builtins.  Like I said in my 
last post, it's really part of the toolchain itself.

https://gcc.gnu.org/onlinedocs/gccint/Libgcc.html

Mike
Jan 16 2015
prev sibling parent reply "Timo Sintonen" <t.sintonen luukku.com> writes:
On Friday, 16 January 2015 at 10:04:55 UTC, Jens Bauer wrote:


 Has anyone used newlib with a Cortex-M based GDC toolchain ?


As Mike pointed out, my minlibd project is a good starting point. 
It contains a fully functional example for stm32f4


 Build failed on final gcc.

 I normally use newlib and multilib, because I'm developing for 
 Cortex-M0, Cortex-M3 and Cortex-M4 and would like to be able to 
 switch between those and use the same compiler.
 But following the above mentioned instructions seem to suggest 
 disabling multilib and using libgcc instead of newlib.


Libgcc is not libc

Libgcc is gcc internal library. It contains functions for those c 
language features that can not be represented as a simple machine 
instruction pattern. The compiler generates calls to these 
functions and users should never call these directly.
Libc contains the standard c library functions like fopen and 
printf. Glibc is the original gnu libc. Newlib is a smaller 
alternative for libc and better suitable for small systems. Libc 
or newlib is needed to build the compiler but the application 
needs it only if its features are used. I have not needed libc in 
my cortex programs.

Both libgcc and libc are included automatically unless --nostdlib 
option is used or if there is a custom linker script.

The multilib building is a bit tricky. I have not succeeded to 
build m0/m3/m4 libraries at the same time. Gcc developers have 
always assumed that there is no Arm processor with fpu and thumb. 
Now we have Cortex-m4...

If you have succeeded with building the libraries please share 
your experiences. If you have failed, please ask this in 
gcc-users list and report here in d.gnu list what they answered.
Jan 16 2015
parent "Jens Bauer" <doctor who.no> writes:
Thank you both Mike and Timo for clearing these things up. :)
(I had the impression that multilib replaced glibcc, not the 
other way round - but clearly that's not what it was about).

I've spent around 3 years on getting my toolchain working (!)
-This is because I'm on a PowerPC based Mac. I can't just run 
some "do-it-for-you" script that other people uses for their 
toolchains; they all fail.

So I had to do everything the hard way.

I have multilib working, but I don't have it working with a 
toolchain that includes GDC.

My toolchain is still alpha, and it will not work on Mac Pro with 
clang, but it might be useful for people wanting alternatives to 
the other toolchains.
So hereby the first public reference to it:

http://toolchain.gpio.dk/

Caveat: I may be experimentally changing it while you're viewing 
it, so  you may get real annoyed with me, if you're in the middle 
of a build, and I've been messing with the Web-page and making 
draft-changes there. The original purpose of the page was to have 
a step-by-step guide for myself.

Note: Although it's "prepared" for gdc, there's no steps 
(currently) for a successful build of gcc with gdc. But I do 
believe that one day, there will be a lot of people using D for 
embedded instead of C, as it's a far more suitable language for 
small devices.
Jan 17 2015