您如何A）颠倒字符串，b）拆下手臂组件中的标点符号和空格 当前代码：
AREA, Program2, CODE, READONLY
ENTRY
ADR r1, source ;r1 points to the address i want to read/referencing
ADR r2, =0x40000000
L1 LDRB r3, [r1], #1 ;brackets around a register is like dereferencing a pointer, operand is at the memory location pointed to by r1, not actually at r1, after that one byte field is loaded into r3, r1 will then be incremented by 1 (what the #1 is)
STRB r3, [r2], #1; [] is indirection operator
CMP r3, #0 ;compare whats in r3 to a 0
BEQ stop ;if not equal unconditionally branch to L1 ? B L1
BNE L1
Stop b stop
source stingOne DCB “In User mode or System mode, if you attempt to read the SPSR, ”
stringTwo DCB “you will get an unpredictable value back, meaning the data cannot “
stringThree DCB “be used in any further operations.”, 0
END