int01

int01 refers to interrupt vector 01 in the x86 architecture. This interrupt is triggered by a single-step execution, meaning it occurs after every instruction is executed. It is primarily used by debuggers to implement single-stepping functionality. When int01 is invoked, the processor generates a specific interrupt that can be handled by a predefined interrupt service routine. This routine can then perform actions such as examining the processor's state, displaying register values, or allowing the user to control program execution. The single-step interrupt is essential for debugging as it provides a granular level of control over program flow, enabling developers to trace execution step by step and identify the root cause of errors. While int01 is a fundamental part of x86 debugging, it is typically only active when a debugger has set the trap flag (TF) in the EFLAGS register.