How to compile command line utility for iPhone using XCode gcc

hello.c

echo 'main() { printf("Hello, world!\n"); }' > hello.c


compile hello.c

/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc-4.0 -arch armv6 -mthumb -isysroot /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS2.2.sdk -o hello hello.c


compile with framework

/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc-4.0 -arch armv6 -mthumb -isysroot /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS2.2.sdk -framework Foundation -framework CoreFoundation -lobjc -std=c99 main.m -o main


codesign in Mac, if you have developer or self-signed certificate (can't codesign it when in ssh session)

export CODESIGN_ALLOCATE=/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/codesign_allocate; codesign -f -s "iPhone Developer" hello


or you can codesign in iPhone, that is, send the binary to iPhone and then fake codesign it

ldid -S hello



This is how to use as (assembler) to compile hello.s to ARM thumb binary
/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/as -arch armv6 hello.s -o hello


# GAS filename : hello.s
# use as to compile
# /Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/as -arch armv6 hello.s -o hello
# use otool to disassemble
# otool -tv hello

  .globl _main
  .code 16
  .thumb_func _main
_main:
  push {r7, lr}
  add r7, sp, #0
  add r3, pc
  mov ip, r3
  mov r3, ip
  mov r0, r3
  pop {r7, pc}


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