RPi1 is ARMv6, whereas the current Make.arm targets ARMv7.

@ihnorton I have modified it for RPi1
Make.arm

override LLVM_ASSERTIONS=1
LLVM_FLAGS+="--with-float=hard --with-fpu=vfp --enable-targets=arm --enable-optimized --enable-assertions"
override OPENBLAS_DYNAMIC_ARCH=0
override OPENBLAS_TARGET_ARCH=ARMV6
override USE_BLAS64=0
override LLVM_VER=3.5.1
override USE_SYSTEM_LIBM=1
override USE_SYSTEM_FFTW=1
override USE_SYSTEM_GMP=1
override USE_SYSTEM_MPFR=1
JCFLAGS += -fsigned-char

@vishnusuganth check out the RPI2 thread - I got it working by manually installing llvm 3.6.0.

@sbromberger Kudos! :)
How did you manually install llvm 3.6.0 ? Through apt-get or you took pre-built binaries from http://llvm.org/releases/download.html ?
They dont have pre-built binaries for ARMV6 :(

@vishnusuganth I went to llvm.org and downloaded the tar.xz archive, unpacked it into a local dev directory, and then went into /usr/local/bin, /usr/local/include, and /usr/local/lib and made symlinks to the files.

@sbromberger I guess you would have took the clang+llvm-3.6.0-armv7a-linux-gnueabihf.tar.xz archive.
I think I will have to build LLVM 3.6.0 from source for armv6.

Stuck with the same issue like what we faced in RPi2 !
I took the llvm-3.6.0 source code and built it seperately using:

./configure --build=arm-linux-gnueabihf --host=arm-linux-gnueabihf --target=arm-linux-gnueabihf --with-cpu=arm1176jzf-s --with-float=hard --with-abi=aapcs-vfp --with-fpu=vfp --enable-targets=arm --enable-optimized --enable-assertions`
make

LLVM build was successfull and added this to environment variables:

export PATH=/home/pi/llvm/Release+Asserts/bin/:$PATH
export LD_LIBRARY_PATH=/home/pi/llvm/Release+Asserts/lib/:$LD_LIBRARY_PATH

Then I started building julia with the following Make.arm ( as suggested by @sbromberger )

#override LLVM_ASSERTIONS=1
#LLVM_FLAGS+="--with-cpu=arm1176jzf-s --with-float=hard --with-abi=aapcs-vfp --with-fpu=vfp --enable-targets=arm --enable-optimized --enable-assertions"

override OPENBLAS_DYNAMIC_ARCH=0
override OPENBLAS_TARGET_ARCH=ARMV6
override USE_BLAS64=0

override USE_SYSTEM_LIBM=1
override USE_SYSTEM_FFTW=1
override USE_SYSTEM_GMP=1
override USE_SYSTEM_MPFR=1
override USE_SYSTEM_LAPACK=1

JCFLAGS += -fsigned-char

override USE_SYSTEM_LLVM=1
override USE_SYSTEM_BLAS=1

The build broke at:

constants.jl
error during bootstrap:
LoadError(at "sysimg.jl" line 269: LoadError(at "constants.jl" line 92: Base.AssertionError(msg="Float64(π) == Float64(big(π))")))

On commenting those three assert statements in constants.jl , the build went past and was successfull.
( NOTE: Previously build used to break with a segmentation fault error while running precompile.jl. But now I dont get that. )

But, while starting Julia

pi@raspberrypi ~julia $ ./julia
ERROR:inexacterror()

RPi1 needs to use JULIA_CPU_ARCH=arm1176jzf-s when building the sysimg, since otherwise llvm detects the processor incorrectly and doesn't know that it has VFP support.

@vtjnash @ViralBShah @sbromberger @physicsd00d @tkelman @ihnorton
Cool ! That worked ! :) Thanks a lot !
But you will need tons of patience to build on Raspberry Pi 1.
Build time:72 hours approx. ( LLVM - 48 hours & Julia - 24 )

Make.arm:

#override LLVM_ASSERTIONS=1
#LLVM_FLAGS+="--with-cpu=arm1176jzf-s --with-float=hard --with-abi=aapcs-vfp --with-fpu=vfp --enable-targets=arm --enable-optimized --enable-assertions"

override OPENBLAS_DYNAMIC_ARCH=0
override OPENBLAS_TARGET_ARCH=ARMV6
override USE_BLAS64=0

override USE_SYSTEM_LIBM=1
override USE_SYSTEM_FFTW=1
override USE_SYSTEM_GMP=1
override USE_SYSTEM_MPFR=1
override USE_SYSTEM_LAPACK=1

JCFLAGS += -fsigned-char

override USE_SYSTEM_LLVM=1
override USE_SYSTEM_BLAS=1

JULIA_CPU_ARCH=arm1176jzf-s

This is a good start :)

julia> versioninfo()
Julia Version 0.4.0-dev+4636
Commit 053780d* (2015-05-04 21:14 UTC)
Platform Info:
  System: Linux (arm-linux-gnueabihf)
  CPU: ARMv6-compatible processor rev 7 (v6l)
  WORD_SIZE: 32
  BLAS: libblas
  LAPACK: liblapack
  LIBM: libm
  LLVM: libLLVM-3.6.0

Did the tests pass?

We know they will not all pass. There are several testing related issues open.

@sbromberger Dint try ! They are known to fail !