nachos实验一代码

1、Test文件下: shell.c: #include syscall.hintmain() SpaceId newProc; OpenFileId input = ConsoleInput; OpenFileId output = ConsoleOutput; char ch, buffer60; int i;Write( ttn, 34, output); while( 1 ) Write( :, 20, output);i = 0;do Read(&bufferi, 1, input); while( bufferi+ != n );buffer-i = 0; if(Strncmp(buf

2、fer,exit,4)=0) Halt(); if( i 0 ) newProc = Exec(buffer);Join(newProc); Start.s :/* Start.s *Assembly language assist for user programs running on top of Nachos. * *Since we dont want to pull in the entire C library, we define *what we need for a user program here, namely Start and the system *calls.

3、 */#define IN_ASM#include syscall.h .text .align 2/* - * _start *Initialize running a C program, by calling main. * * NOTE: This has to be first, so that it gets loaded at location 0. *The Nachos kernel always starts a program by jumping to location 0. * - */.globl _start.ent_start_start:jalmainmove

4、$4,$0jalExit /* if we return from main, exit(0) */.end _start/* - * System call stubs: *Assembly language assist to make system calls to the Nachos kernel. *There is one stub per system call, that places the code for the *system call into register r2, and leaves the arguments to the *system call alo

5、ne (in other words, arg1 is in r4, arg2 is *in r5, arg3 is in r6, arg4 is in r7) * * The return value is in r2. This follows the standard C calling * convention on the MIPS. * - */.globl Halt.entHaltHalt:addiu $2,$0,SC_Haltsyscallj$31.end Halt.globl Add.entAddAdd:addiu $2,$0,SC_Addsyscallj $31.end A

6、dd.globl Exit.entExitExit:addiu $2,$0,SC_Exitsyscallj$31.end Exit.globl Exec.entExecExec:addiu $2,$0,SC_Execsyscallj$31.end Exec.globl ExecV.entExecVExecV:addiu $2,$0,SC_ExecVsyscallj$31.end ExecV.globl Join.entJoinJoin:addiu $2,$0,SC_Joinsyscallj$31.end Join.globl Create.entCreateCreate:addiu $2,$0

7、,SC_Createsyscallj$31.end Create.globl Remove.entRemoveRemove:addiu $2,$0,SC_Removesyscallj$31.end Remove.globl Open.entOpenOpen:addiu $2,$0,SC_Opensyscallj$31.end Open.globl Read.entReadRead:addiu $2,$0,SC_Readsyscallj$31.end Read.globl Write.entWriteWrite:addiu $2,$0,SC_Writesyscallj$31.end Write.

8、globl Close.entCloseClose:addiu $2,$0,SC_Closesyscallj$31.end Close.globl Seek.entSeekSeek:addiu $2,$0,SC_Seeksyscallj$31.end Seek.globl Delete.entDeleteDelete: addiu $2,$0,SC_Deletesyscallj$31.end Delete .globl ThreadFork .ent ThreadForkThreadFork: addiu $2,$0,SC_ThreadFork syscall j $31 .end Threa

9、dFork .globl ThreadYield .ent ThreadYieldThreadYield: addiu $2,$0,SC_ThreadYield syscall j $31 .end ThreadYield.globl ThreadExit.ent ThreadExitThreadExit:addiu $2, $0, SC_ThreadExitsyscallj $31.end ThreadExit.globl ThreadJoin.ent ThreadJoinThreadJoin:addiu $2, $0, SC_ThreadJoinsyscallj $31.end Threa

10、dJoin.globl getSpaceID.entgetSpaceIDgetSpaceID:addiu $2,$0,SC_getSpaceIDsyscallj$31.end getSpaceID.globl getThreadID.entgetThreadIDgetThreadID:addiu $2,$0,SC_getThreadIDsyscallj$31.end getThreadID.globl Ipc.ent IpcIpc: addiu $2,$0,SC_Ipcsyscallj $31.end Ipc.globl Clock.ent ClockClock:addiu $2,$0,SC_

11、Clocksyscallj $31.end Clock/* dummy function to keep gcc happy */ .globl _main .ent _main_main: j $31 .end _main.globl Strncmp.ent StrncmpStrncmp: addiu $2,$0,SC_Strncmp syscall j $31 .end Strncmp .globl Exit .ent ExitUserprog文件夹下Exception.cc: / exception.cc /Entry point into the Nachos kernel from

12、user programs./There are two kinds of things that can cause control to/transfer back to here from user code:/syscall - The user code explicitly requests to call a procedure/in the Nachos kernel. Right now, the only function we support is/Halt./exceptions - The user code does something that the CPU c

13、ant handle./For instance, accessing memory that doesnt exist, arithmetic errors,/etc. /Interrupts (which can also cause control to transfer from user/code into the Nachos kernel) are handled elsewhere./ For now, this only handles the Halt() system call./ Everything else core dumps./ Copyright (c) 19

14、92-1996 The Regents of the University of California./ All rights reserved. See copyright.h for copyright notice and limitation / of liability and disclaimer of warranty provisions.#include copyright.h#include main.h#include syscall.h#include ksyscall.h/-/ ExceptionHandler/ Entry point into the Nacho

15、s kernel. Called when a user program/is executing, and either does a syscall, or generates an addressing/or arithmetic exception./ For system calls, the following is the calling convention:/ system call code - r2/arg1 - r4/arg2 - r5/arg3 - r6/arg4 - r7/The result of the system call, if any, must be

16、put back into r2. / If you are handling a system call, dont forget to increment the pc/ before returning. (Or else youll loop making the same system call forever!)/which is the kind of exception. The list of possible exceptions /is in machine.h./-voidExceptionHandler(ExceptionType which) int type =

17、kernel-machine-ReadRegister(2); DEBUG(dbgSys, Received Exception which type: type n); switch (which) case SyscallException: switch(type) case SC_Halt:DEBUG(dbgSys, Shutdown, initiated by user program.n);SysHalt();ASSERTNOTREACHED();break;case SC_Write:DEBUG(dbgSys,Write from buffer to consoleOutputm

18、achine-ReadRegister(4)machine-ReadRegister(5)machine-ReadRegister(6)machine-ReadRegister(5);OpenFileId printOut;printOut= (OpenFileId)kernel-machine-ReadRegister(6);int addressOne;addressOne=(int)kernel-machine-ReadRegister(4);int i;i=0;dokernel-machine-ReadMem(addressOne+,1,(int*)&wbufferi+); while

19、(imachine-WriteRegister(2,n1);kernel-machine-WriteRegister(PrevPCReg,kernel-machine-ReadRegister(PCReg);kernel-machine-WriteRegister(PCReg, kernel-machine-ReadRegister(PCReg) +4);kernel-machine-WriteRegister(NextPCReg,kernel-machine-ReadRegister(PCReg)+4); return;ASSERTNOTREACHED();break;case SC_Rea

20、d:DEBUG(dbgSys, read from buffer machine-ReadRegister(4) machine-ReadRegister(5)machine-ReadRegister(6) machine-ReadRegister(5);OpenFileId enterIn;enterIn = (OpenFileId)kernel-machine-ReadRegister(6);char addressTwo;addressTwo = (char)kernel-machine-ReadRegister(4);int local ;local= (int)kernel-mach

21、ine-ReadRegister(4);int n2 ;n2= SysRead(&addressTwo,rsize,enterIn);kernel-machine-WriteMem(local,1,(int)addressTwo);kernel-machine-WriteRegister(2,n2); kernel-machine-WriteRegister(PrevPCReg,kernel-machine-ReadRegister(PCReg);kernel-machine-WriteRegister(PCReg, kernel-machine-ReadRegister(PCReg) +4)

22、;kernel-machine-WriteRegister(NextPCReg,kernel-machine-ReadRegister(PCReg)+4);return;ASSERTNOTREACHED();break;case SC_Exec:DEBUG(dbgSys,execute a commandmachine-ReadRegister(4)machine-ReadRegister(4);int c;c = 0;dokernel-machine-ReadMem(addressThree+,1,(int*)&ebufferc+); while(cmachine-WriteRegister

23、(2,SysExec(ebuffer);kernel-machine-WriteRegister(PrevPCReg,kernel-machine-ReadRegister(PCReg);kernel-machine-WriteRegister(PCReg, kernel-machine-ReadRegister(PCReg) +4);kernel-machine-WriteRegister(NextPCReg,kernel-machine-ReadRegister(PCReg)+4);return;ASSERTNOTREACHED();break;case SC_Join:DEBUG(dbg

24、Sys,jion machine-ReadRegister(4)machine-WriteRegister(2,SysJoin(SpaceId)kernel-machine-ReadRegister(4);kernel-machine-WriteRegister(PrevPCReg,kernel-machine-ReadRegister(PCReg);kernel-machine-WriteRegister(PCReg, kernel-machine-ReadRegister(PCReg) +4);kernel-machine-WriteRegister(NextPCReg,kernel-ma

25、chine-ReadRegister(PCReg)+4);return;ASSERTNOTREACHED();break;case SC_Strncmp:DEBUG(dbgSys, compare two string machine-ReadRegister(4) machine-ReadRegister(5) machine-ReadRegister(6) machine-ReadRegister(4);int addressFive;addressFive = kernel-machine-ReadRegister(5);char str1buffer60;char str2buffer

26、60;int d,e;d= 0;e=0;dokernel-machine-ReadMem(addressFour+,1,(int*)&str1bufferd+); while(dmachine-ReadMem(addressFive+,1,(int*)&str2buffere+);while(emachine-ReadRegister(6);kernel-machine-WriteRegister(2,n3);kernel-machine-WriteRegister(PrevPCReg,kernel-machine-ReadRegister(PCReg);kernel-machine-Writ

27、eRegister(PCReg, kernel-machine-ReadRegister(PCReg) +4);kernel-machine-WriteRegister(NextPCReg,kernel-machine-ReadRegister(PCReg)+4);return;ASSERTNOTREACHED();break; case SC_Add:DEBUG(dbgSys, Add machine-ReadRegister(4) + machine-ReadRegister(5) machine-ReadRegister(4),/* int op2 */(int)kernel-machi

28、ne-ReadRegister(5);DEBUG(dbgSys, Add returning with result machine-WriteRegister(2, (int)result);/* Modify return point */ /* set previous programm counter (debugging only)*/ kernel-machine-WriteRegister(PrevPCReg, kernel-machine-ReadRegister(PCReg); /* set programm counter to next instruction (all

29、Instructions are 4 byte wide)*/ kernel-machine-WriteRegister(PCReg, kernel-machine-ReadRegister(PCReg) + 4); /* set next programm counter for brach execution */ kernel-machine-WriteRegister(NextPCReg, kernel-machine-ReadRegister(PCReg)+4);return;ASSERTNOTREACHED();break; default:cerr Unexpected syst

30、em call type n;break; break; default: cerr Unexpected user mode exception (int)which n; break; ASSERTNOTREACHED();Ksyscall.h : /* * * userprog/ksyscall.h * * Kernel interface for systemcalls * * by Marcus Voelp (c) Universitaet Karlsruhe * */#ifndef _USERPROG_KSYSCALL_H_ #define _USERPROG_KSYSCALL_H

31、_ #include kernel.h#include #include #include #include #include #include #include #include #include #include #include #include #include #define SHELL /bin/sh int SysWrite(char*buffer ,int size,OpenFileId id) return write(id,buffer,(size_t)size);int SysRead(char*buffer ,int size,OpenFileId id) return

32、 read(id, buffer, (size_t)size);SpaceId SysExec(char* exec_name)pid_t child;child = vfork();if(child = 0)execl (SHELL, SHELL, -c, exec_name, NULL); _exit (EXIT_FAILURE);else if(child interrupt-Halt();int SysAdd(int op1, int op2) return op1 + op2;#endif /* ! _USERPROG_KSYSCALL_H_ */Syscall.h: /* sysc

33、alls.h * Nachos system call interface. These are Nachos kernel operations * that can be invoked from user programs, by trapping to the kernel *via the syscall instruction. * *This file is included by user programs and by the Nachos kernel. * * Copyright (c) 1992-1993 The Regents of the University of

34、 California. * All rights reserved. See copyright.h for copyright notice and limitation * of liability and disclaimer of warranty provisions. */#ifndef SYSCALLS_H#define SYSCALLS_H#include copyright.h#include errno.h/* system call codes - used by the stubs to tell the kernel which system call * is b

35、eing asked for */#define SC_Halt0#define SC_Exit1#define SC_Exec2#define SC_Join3#define SC_Create4#define SC_Remove 5#define SC_Open6#define SC_Read7#define SC_Write8#define SC_Seek 9#define SC_Close10#define SC_Delete 11#define SC_ThreadFork12#define SC_ThreadYield13#define SC_ExecV14#define SC_Th

36、readExit 15#define SC_ThreadJoin 16#define SC_getSpaceID 17#define SC_getThreadID 18#define SC_Ipc 19#define SC_Clock 20#define SC_Add42#define SC_Strncmp 43#ifndef IN_ASM/* The system call interface. These are the operations the Nachos * kernel needs to support, to be able to run user programs. * *

37、 Each of these is invoked by a user program by simply calling the * procedure; an assembly language stub stuffs the system call code * into a register, and traps to the kernel. The kernel procedures * are then invoked in the Nachos kernel, after appropriate error checking, * from the system call ent

38、ry point in exception.cc. */* Stop Nachos, and print out performance stats */void Halt();int Strncmp(char *buffer,char*str,int size); /* * Add the two operants and return the result */ int Add(int op1, int op2);/* Address space control operations: Exit, Exec, Execv, and Join */* This user program is

39、 done (status = 0 means exited normally). */void Exit(int status);/* A unique identifier for an executing user program (address space) */typedef int SpaceId;/* A unique identifier for a thread within a task */typedef int ThreadId;/* Run the specified executable, with no args */* This can be implemen

40、ted as a call to ExecV. */ SpaceId Exec(char* exec_name);/* Run the executable, stored in the Nachos file argv0, with * parameters stored in argv1.argc-1 and return the * address space identifier */SpaceId ExecV(int argc, char* argv); /* Only return once the user program id has finished. * Return th

41、e exit status. */int Join(SpaceId id); /* File system operations: Create, Remove, Open, Read, Write, Close * These functions are patterned after UNIX - files represent * both files *and* hardware I/O devices. * * Note that the Nachos file system has a stub implementation, which * can be used to supp

42、ort these system calls if the regular Nachos * file system has not been implemented. */ /* A unique identifier for an open Nachos file. */typedef int OpenFileId;/* when an address space starts up, it has two open files, representing * keyboard input and display output (in UNIX terms, stdin and stdou

43、t). * Read and Write can be used directly on these, without first opening * the console device. */#define ConsoleInput0 #define ConsoleOutput1 /* Create a Nachos file, with name name */* Note: Create does not open the file. */* Return 1 on success, negative error code on failure */int Create(char *n

44、ame);/* Remove a Nachos file, with name name */int Remove(char *name);/* Open the Nachos file name, and return an OpenFileId that can * be used to read and write to the file. mode gives the requested * operation mode for this file. */#define RO 1#define RW 2#define APPEND 3OpenFileId Open(char *name

45、, int mode);/* Write size bytes from buffer to the open file. * Return the number of bytes actually read on success. * On failure, a negative error code is returned. */int Write(char *buffer, int size, OpenFileId id);/* Read size bytes from the open file into buffer. * Return the number of bytes actually read - if the open file isnt * long enough, or if it is an I/O device, and there arent enough * characters to read, return whatever is available (for I/O devices, * you should always wait until you can return at least one c