Explain how iret instruction is executed

If the return is to another privilege level, the IRET instruction also pops the stack pointer and SS from the stack, before resuming program execution. If the return In the called task the execution of the IRET instruction at the end of the calledprocedure (when EFlags[NT] = 1) causes a switch back to the calling task and We can use this fact to get to ring 3 by pushing the required information to the stack and issuing an iret instruction. Make sure you have the The int instruction generates a software call to an interrupt handler. the base linear address of the IDT is defined by the contents of the IDTR. Interrupt procedures return via the iret instruction, which pops the flags and return address from the stack. The task executing iret is updated and saved in its task segment. Software can also generate interrupts by executing the INT n instruction. Intel 64 and IA-32 architectures for architecture-defined exceptions and interrupts. .. An execution of the IRET instruction unblocks NMIs even if the instruction causes In Real-Address Mode, the IRET instruction preforms a far return to the interrupted CS, and EFLAGS registers, respectively, and then resumes execution of the The following items define the state of the currently executing task: A return (initiated with an IRET instruction) when the NT flag in the EFLAGS register is set.Returns from interrupt procedures are handled with the IRET instruction, which a procedure defined in the "Operation" section for this instruction (except #GP). When the processor is executing in virtual-8086 mode, the IOPL determines the The IRET instruction is used at the end of an interrupt service procedure to return execution to the interrupted program. To do this return, the 8086 copies the saved value of IP from the stack to IP, the stored value of CS from the stack to CS, and the stored value of the flags back to the flag register. manner as it CALLs a procedure; the differences are explained in the following sections. The IRET instruction is used to exit from an interrupt procedure. privilege levels at which interrupt and exception handling procedures can execute.