Arm处理器寄存器介绍及汇编基础

1. ARM处理器支持7种工作模式

· User (usr): 　　　　 The normal ARM program execution state
· FIQ (fiq):　　　 　　Designed to support a data transfer or channel process
· IRQ (irq): 　　　　   Used for general-purpose interrupt handling
· Supervisor (svc): 　  Protected mode for the operating system
· Abort mode (abt): 　 Entered after a data or instruction prefetch abort
· System (sys): 　　　A privileged user mode for the operating system
· Undefined (und): 　  Entered when an undefined instruction is executed

2. ARM状态寄存器（CPRS）

3. ARM寻址方式

①立即数寻址： ADD R0, R1, #0x01

②寄存器寻址：ADD R0, R1, R2

③寄存器间接寻址：LDR R0, [R2];

④基址变址寻址：LDR R0, [R1,#4]

⑤相对寻址：BL

4. ARM汇编指令介绍