Good afternoon, everyone. There is a piece of code that should switch the CPU operation mode, but it does not do this. Of course, I'm misunderstanding something. Please help me resolve this misunderstanding.When running the script, the CPSR value is 0x10 16 (USR)
In the MSR line CPSR, R1
the value 0x12 should be written to the CPSR, which corresponds to the IRQ mode, but this does not happen. After executing this line (in gdb)
0x00010060 <+12>: msr CPSR_fc, r1
The CPSR value remains the same. Help me figure it out. Thank you.
Code:
.data.bss.text.global _start_start: MRS R0, CPSR BIC R1, R0, #0x1F ORR R1, R1, #0x12 // 0x12 == 10010 (IRQ) MSR CPSR, R1 end: MOV R7, #1 SWI 0In the MSR line CPSR, R1
the value 0x12 should be written to the CPSR, which corresponds to the IRQ mode, but this does not happen. After executing this line (in gdb)
0x00010060 <+12>: msr CPSR_fc, r1
The CPSR value remains the same. Help me figure it out. Thank you.
Statistics: Posted by dio4 — Sat Apr 20, 2024 6:43 am — Replies 1 — Views 40