Layering of Simplified Kernel Code A ） 1 一R0 10 -IR1 ∩∩ u∩U∩∩ ←—R2 B locks cond var. 1/O 1 4一1R3 1 ←—R4 ←—R5 ←—IR6 〉 scheduler ctxt switching &.. —IR7 B:concurrent code with explicit interrupts How to verify ??Layering of Simplified Kernel Code scheduler & ctxt switching & ... . . . locks cond var. I/O . . . . . . . . . A B C 1 1 0 1 1 0 1 0 IR0 IR1 IR2 IR3 IR4 IR5 IR6 IR7 B: concurrent code with explicit interrupts How to verify ???