assembles short ARM instructions

arm_asm

#!/bin/sh
#
# assembles a short ARM assembly file/line and shows the opcode + disassembly
# useful for compiling one-liners into opcode
#
# usage:
#  arm_asm src-file.S             -> assembles src-file.S
#  echo "mov r1, r4" | arm_asm    -> assemble a single instruction
#

ASM_FILE=$1
GCC=${GCC:-/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc-4.2}

# check gcc
hash "$GCC" 2> /dev/null || {
	echo "unable to find gcc - please specify it in GCC"
	exit 2
}

# check for file, or read from stdin
ASM_FILE_TEMP=
if [ -z "$ASM_FILE" ]; then
	ASM_FILE_TEMP=`mktemp /var/tmp/testarm.XXXXXXXXXXX`
	cat > $ASM_FILE_TEMP
	ASM_FILE="$ASM_FILE_TEMP"
fi

# compile
OUTPUTS=
for ARMV in 6 7; do
	TMPOUT=`mktemp /var/tmp/testarm${ARMV}.XXXXXXXXXXX`
	$GCC -arch armv$ARMV -D_ARM_ARCH_$ARMV -c -o $TMPOUT -x assembler $ASM_FILE
	OUTPUTS="$OUTPUTS $TMPOUT"
done

# create fat binary and disassemble it
TMP_O_FAT=`mktemp /var/tmp/testarm_fat.XXXXXXXXXXX`
lipo -create $OUTPUTS -output $TMP_O_FAT
otool -t -v $TMP_O_FAT

rm -f $TMP_O_FAT $OUTPUTS $ASM_FILE_TEMP