2.2 ARM Processor operating mode

ARM Architecture Reference Manual

ARM Instruction Framework Manual

1. processor 7 Modes of Operation

Processor mode	Mode Number	Description
user usr	0b10000	normal Program execution mode
fiq FIQ	0b10001	supports A High-speed data transfer or channel process
supervisor Svc	0b10011	a protected Mode For the operating system
abort abt	0b10111	implements Virtual memory and/or memory protection
undefined und	0b11011	supports Software emulation of hardware coprocessors
System SYS	0b11111	Runs Privileged Operating system tasks (ARMV4 and above)

Linux applications running in USR mode

Linux kernel running in SVC mode

2.2 ARM Processor operating mode