Re: GNAT ARM on Mac OS X?

[Simon Wright <simon@pushface.org>]

Jerry Petrey <gpetrey@earthlink.net> writes:

> On 11/5/2014 6:57 AM, Simon Wright wrote:
>> Maciej Sobczak <see.my.homepage@gmail.com> writes:
>>
>>> I have just checked the libre.adacore.com site and noticed that
>>> there is no GNAT package for the ARM targets, hosted on Mac OS
>>> X. Only Windows and Linux hosts are supported.
>>>
>>> Do you have any information on the possible plans for such a
>>> package?
>>
>> It looks as though it might be an interesting project.
>>
>> The GNAT GPL 2014 package (I looked at the Linux version) is
>> configured for arm-eabi and has zfp (zero footprint) and Ravenscar
>> RTS's.
>>
>> I see that Farnell have the STM32F4DISCOVERY for £11.71 + p&p, looks
>> like an inexpensive way to start.
>>
>
> It is a very interesting project.  I have Ada running on about a dozen
> different ARM M4/M3 boards now and it is very nice. You can see my
> article in Electronic Design magazine
> (http://electronicdesign.com/dev-tools/armed-and-ready) for some help
> in getting things set up.  Unfortunately it is only available for
> Windows and Linux - I have only used the Windows version.  The
> STMF429DISCOVERY board is an exceptional deal and has a graphics
> LCD. I recently completed a basic driver in Ada for the LCD display
> which makes this a very useful platform for development as I can catch
> and display exceptions on the display.

OK, getting there! I now have an STM32F429I Discovery board, and am
getting to grips with it.

I have an arm-eabi GNAT GPL 2014 toolchain running on Mac OS X
Mavericks, produced by cobbling together AdaCore's linux-elf distro and
various build tips from around the web (the best was [1]).

There are various oddities:

(1) during the second build, you have to configure with --disable-libada
(because you don't want the full RTS), which makes you run

  make                  # build the base compiler, gnatmake, gnatbind
  make cross-gnattools  # build the other gnat* tools    
  make                  # rename the gnat* tools to gnat*-cross (!!!)
  make install          # renames gnat*-cross to arm-eabi-gnat*

This may change in newer base GCCs (GNAT GPL 2014 is based on 4.7.4).

(2) There has to be an RTS or gprbuild won't see the compiler. I don't
know how this is determined.

I started out copying the Linux distro's rts-zfp RTS to
lib/gcc/arm-eabi/4.7.4/, but that didn't work, so I made symlinks from
lib/gcc/arm-eabi/4.7.4/rts-zfp/adalib,adainclude to the level above. OK!

I see that the Linux distro has the Ravenscar RTS in
lib/gnat/arm-eabi/ravenscar-sfp-stm32f4, perhaps that's the clue.

(3) The stlink utilities work just fine, I had a problem misreading the
flash load address as 0x80000000 rather than 0x8000000 and would have
expected some error message instead of an immediate failure!

st-flash requires a bin format rather than hex or elf, so I used
hex2bin[2] for the former (good for getting the demo back on the card!)
and

   arm-eabi-objcopy -O binary demo demo.bin

for the latter.

(4) Thanks for your pointer to [3] for the updated Ravenscar BSP for
the STM32F429I Discovery!


I now have the LEDs demo twinkling away beside me. This lot needs a
writeup ..


[1]
http://istarc.wordpress.com/2014/07/21/stm32f4-build-your-toolchain-from-scratch/
[2] https://sourceforge.net/projects/hex2bin/
[3] https://github.com/gnlnops/gnat-stm32f429i-disco