On Fri, Oct 11, 2019 at 8:55 AM Sebastian Huber < sebastian.hu...@embedded-brains.de> wrote:
> On 11/10/2019 15:46, Joel Sherrill wrote: > > Hi > > > > I'm trying to find the right multilib for the ARM Deos BSP. They compile > > their native > > ARINC 653 applications with these: > > > > arm-eabi-gcc -MP -MMD -nostdinc -gdwarf-2 -fno-exceptions > > -mabi=aapcs-linux -march=armv7-a -mfloat-abi=hard -mfpu=vfpv3-d16 > > -mthumb -mthumb-interwork -O0 -fno-threadsafe-statics > > -fno-use-cxa-atexit -fno-rtti > > I am not sure if -mabi=aapcs-linux is a nop or dangerous. Why do they > use this option. > I deleted this from the RTEMS builds. I recall determining it is the default for us but don't hold me to that. > > The -mthumb-interwork is superfluous. > Thanks. > > The -fno-exceptions and -fno-rtti make more sense if you build libstdc++ > also with it. > They custom build their C++ support and I should have deleted those as I am just concerned about CPU related C flags. > > > > > Neither arm-eabi nor arm-rtems will link this. arm-eabi picks a variant > > for crtn0.o but doesn't seem to find a libm even though one is there in > > the same multilib path and ends up with the math function undefined. > > arm-rtems is just missing the multlib info as best I can tell. > > > > > /data/home/joel/test-gcc/install-master/bin/../lib/gcc/arm-rtems5/10.0.0/../../../../arm-rtems5/bin/ld: > > > error: /tmp/cc8zsaRc.o uses VFP register arguments, armtest does not > > > /data/home/joel/test-gcc/install-master/bin/../lib/gcc/arm-rtems5/10.0.0/../../../../arm-rtems5/bin/ld: > > > failed to merge target specific data of file /tmp/cc8zsaRc.o > > > > I have attached my simple example. Do we have a multlib that should be > > matching this or does one need to be added? > > > > Assistance definitely appreciated. > > GCC 8, 9 and 10 are not supported by the ARM BSPs right now. > +1 I'm building with the gcc master so the patch can be against that if one is needed. > > You can try this with GCC 10: > > -mthumb -march=armv7-a+simd -mfloat-abi=hard > That definitely links! Thank you! Is there something comparable for the gcc 7.4.1 we are actually using? > > Why do they use -mfpu=vfpv3-d16? This seems to be quite a non-standard > ARMv7-A chip. > I don't know how they got to this. They don't have any custom ARM CPUs. Mostly the same type of things we are used to -- Zynq, MPSoc, and the NXP Layerscape. This is definitely something I will have to discuss with them. > > -- > Sebastian Huber, embedded brains GmbH > > Address : Dornierstr. 4, D-82178 Puchheim, Germany > Phone : +49 89 189 47 41-16 > Fax : +49 89 189 47 41-09 > E-Mail : sebastian.hu...@embedded-brains.de > PGP : Public key available on request. > > Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG. >
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