.global Main
.text
Main:

/*into system mode*/
mrs r0,CPSR
bic r0,r0,#0x1f    /*把R0后面5位全部清0*/
orr r0,r0,#0x1f    /*把R0后面5位賦值為11111*/
msr CPSR,r0        /*把R0賦值給CPSR并根據標志位切換狀態*/
mov r0,#1
mov r1,#2
mov r2,#3
mov r3,#4
mov r4,#5
mov r5,#6
mov r6,#7
mov r7,#8
mov r8,#9
mov r9,#10
mov r10,#11
mov r11,#12
mov r12,#13
mov r13,#14
mov r14,#15

/*into FIQ mode*/
mrs r0,CPSR
bic r0,r0,#0x1f
orr r0,r0,#0x11
msr CPSR,r0
mov r8,#16
mov r9,#17
mov r10,#18
mov r11,#19
mov r12,#20
mov r13,#21
mov r14,#22


/*into SVC mode*/
mrs r0,CPSR
bic r0,r0,#0x1f
orr r0,r0,#0x13
msr CPSR,r0
mov r13,#23
mov r14,#24


/*into ABORT mode*/
mrs r0,CPSR
bic r0,r0,#0x1f
orr r0,r0,#0x17
msr CPSR,r0
mov r13,#25
mov r14,#26

/*into IRQ mode*/
mrs r0,CPSR
bic r0,r0,#0x1f
orr r0,r0,#0x12
msr CPSR,r0
mov r13,#27
mov r14,#28

/*into UNDEF mode*/
mrs r0,CPSR
bic r0,r0,#0x1f
orr r0,r0,#0x1B
msr CPSR,r0
mov r13,#29
mov r14,#30


pt:
  b pt
.end