Notebook of A Road Map Through Nachos

1.MIPS(microprocessor with Interlocked Pipeline Stages):

　　1) Define a control register set as well as the instruction set.

　　2) RISC

　　3)About the assembly language:

　　　　a. Integer: 32bit integer registers.

　　　　b. Floating point: has 32bit floating-point, two registers paird for double precision numbers.

　　　　c. pseudo instructions: translated into sequences of real instructions by assembler.

2.Nachos Machine:

　　2.1 Event driven clock:

　　　　instructions into mem->init regs(PC)->exec instuctions->fetchs the instructions->decode->exec->LOOP(until trap or INT)

　　2.2 Two modes of execution:

　　　　　　1) MIPS simulator: user-level processes, can only access the mem associated with the simulated machine.

　　　　　　2) The Nachos kernel: access when Nachos starts up or trap associated with Nachos source code and Nachos variables.

　　2.3