汇编写hello world

   .global main

   main:
           mov ip, sp
           stmfd sp!, {fp, ip, lr}
           sub fp, ip, #

           ldr r0, =he
           mov lr, pc
          b printf

          sub sp, fp, #
          ldmfd sp, {fp, sp, pc}

  he:
          .asciz "hello world\n"
          .align