subrout.s

：some examples of assembler level programming for the ARM（produces an ELF executable file which can

        AREA subrout, CODE, READONLY    ; name this block of code
        ENTRY                           ; mark first instruction
                                        ; to execute
start
        MOV     r0, #10                 ; Set up parameters
        MOV     r1, #3
        BL      doadd                   ; Call subroutine

stop    
        MOV     r0, #0x18               ; angel_SWIreason_ReportException
        LDR     r1, =0x20026            ; ADP_Stopped_ApplicationExit
        SWI     0x123456                ; ARM semihosting SWI

doadd   
        ADD     r0, r0, r1              ; Subroutine code
        MOV     pc, lr                  ; Return from subroutine.

        END                             ; Mark end of file