I would like to report the following information regarding compiling OpenMPI on Debian ARMv6. I won't submit this as a patch because I don't believe that "delete all 'dmb' instructions" can be considered a well developed patch. But this information may be of use to someone down the line.
I was able to compile the upstream openmpi-1.5.4 distribution on a Debian6 armv6l qemu emulation. http://www.open-mpi.org/software/ompi/v1.4/downloads/openmpi-1.4.5.tar.bz2 You have to make 3 changes to the package 1) Delete all references to the RISC instruction 'dmb' 2) Modify the 'configure' file to include an 'armv6' option 3) Compile with CFLAGS=-march=armv6 ## 1) make the following edits to these three files ./opal/asm/generated/atomic-local.s delete all dmb instructions ./opal/asm/base/ARM.asm delete all dmb instructions ./opal/include/opal/sys/arm/atomic.h change the lines: #if OPAL_WANT_SMP_LOCKS #define MB() __asm__ __volatile__ ("dmb" : : : "memory") #define RMB() __asm__ __volatile__ ("dmb" : : : "memory") #define WMB() __asm__ __volatile__ ("dmb" : : : "memory") #else #define MB() #define RMB() #define WMB() #endif to read: #define MB() #define RMB() #define WMB() ## 2) add the following to the 'configure' file at line 26946 of 171183 goto line 26946, there should be an 'alpha-' section above and an 'armv7' below insert the following armv6*) ompi_cv_asm_arch="ARM" OPAL_ASM_SUPPORT_64BIT=0 OMPI_GCC_INLINE_ASSIGN='"mov %0, #0" : "=&r"(ret)' ;; ## 3) compile and install with the following CFLAGS CFLAGS=-march=armv6 ./configure CFLAGS=-march=armv6 make sudo make install more information about my build at http://rhinohide.wordpress.com/2012/02/26/openmpi-on-raspberry-pi/
