[SOLVED] msp430-gcc: "Only cross-compile builds are support"

tomtom69 · n00b Joined: 09 Nov 2010 Posts: 70

Hi,

I would like to develop programs (embedded, no linux on target) using a MSP430 launchpad board. To do this I need a cross compiler. Gentoo portage delivers the msp430-gcc package, which seems to be the right choice for this.
But when I try to emerge dev-embedded/msp430-gcc I get the following error message:

>>> Running pre-merge checks for dev-embedded/msp430-gcc-4.6.2_p20120330
* ERROR: dev-embedded/msp430-gcc-4.6.2_p20120330 failed (pretend phase):
* Only cross-compile builds are supported

This looks strange, because cross-compiling looks to me like what I need.
Host is amd64 stable (I needed to add "=dev-embedded/msp430-gcc-4.6.2_p20120330 ~amd64" to /etc/portage/package.keywords to be able to emerge msp430-gcc).

I did not find any howto about cross-compiling for embedded targets. Does anyone know what to do to get msp430-gcc installed on my machine?

tom

Genone · Posted: Wed Apr 11, 2012 9:35 am Post subject:

http://www.gentoo.org/proj/en/base/embedded/cross-development.xml

tomtom69 · n00b Joined: 09 Nov 2010 Posts: 70

Thank you for your answer, Genone.

I tried to follow this guide, however I do not know which target (-t) to specify:
"Target (-t) takes a tuple ARCH-VENDOR-OS-LIBC; see 'crossdev -t help'"
OK, so I looked at the help page for crossdev.
"Architectures" does not contain MSP430. MSP430 is mentioned in "Special Targets".
But what to do with the other things like OS and VENDOR in the tuple?
I tried "-t mps430" and "-t msp430-newlib", because I do not use any OS (which would be ridiculous on a MCU with 8kB flash and 1kB RAM), but both do not work.

Genone · Posted: Thu Apr 12, 2012 8:26 am Post subject:

tomtom69 · n00b Joined: 09 Nov 2010 Posts: 70

Yes, it was only a typo...

Anyone here with uC experience?

radhermit · Developer Joined: 15 Apr 2010 Posts: 7

tomtom69 · n00b Joined: 09 Nov 2010 Posts: 70

-t msp430 works now:
It was necessary to add "--ov-output /usr/portage/". I first tried "--ov-output msptest" which did not work.
I built the toolchain now, but it does not work as expected:

$ msp430-gcc -Os -Wall -g -mmcu=msp430x2012 -o main.elf main.o
/usr/libexec/gcc/msp430/ld: cannot open linker script file memory.x: No such file or directory
collect2: ld gab 1 als Ende-Status zurück

Looks like it is related this bug:
https://bugs.gentoo.org/show_bug.cgi?id=147155

I tried to re-emerge msp430mcu and set the symlinks according to the bug report, but the problem remains.
The package msp430mcu contains the *.x files in /usr/msp430/lib/ldscripts/$MCUTYPE/

Where does msp430-ld look for the linker script files?

tomtom69 · n00b Joined: 09 Nov 2010 Posts: 70

ld works now.
I took the demo file for the launchpad which specifies -mmcu=msp430x2012, but the cross compiler does not have this mcu type.
Changed this to -mmcu=msp430g2553 and now gcc runs without error messages. :-)

The demo code does not run yet because it uses a different gcc version or header files, but this should not be a problem.

radhermit · Developer Joined: 15 Apr 2010 Posts: 7

tomtom69 · n00b Joined: 09 Nov 2010 Posts: 70

I do not have any overlays installed, so PORTDIR_OVERLAY does not exist - this is why crossdev insists on the --ov-output parameter
(as far as I understood the crossdev guide there is no need for overlays any more to get a working cross compiler).

The legacy.map file is really a great help when converting makefiles or projects.

Thanks for your help! :-)