nachos实验一代码(共23页).doc

《nachos实验一代码(共23页).doc》由会员分享，可在线阅读，更多相关《nachos实验一代码(共23页).doc（23页珍藏版）》请在淘文阁 - 分享文档赚钱的网站上搜索。

1、精选优质文档-倾情为你奉上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; i

2、f(Strncmp(buffer,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 s

3、ystem *calls. */#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_star

4、t:jalmainmove$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 *sy

5、stem call alone (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_Addsysca

6、llj $31.end Add.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.entCreateCreat

7、e:addiu $2,$0,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,$0,SC_Writesyscallj$

8、31.end Write.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 $

9、31 .end ThreadFork .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

10、$31.end ThreadJoin.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:ad

11、diu $2,$0,SC_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

12、 kernel from 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 t

13、hat the CPU cant 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./ Cop

14、yright (c) 1992-1996 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 i

15、nto the Nachos 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

16、any, must be 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

17、) int type = 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 c

18、onsoleOutputmachine-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*)&wbuf

19、feri+); while(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();brea

20、k;case SC_Read: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= (in

21、t)kernel-machine-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-ReadRegist

22、er(PCReg) +4);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-

23、WriteRegister(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_J

24、oin:DEBUG(dbgSys,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(NextPC

25、Reg,kernel-machine-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;ch

26、ar str2buffer60;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

27、-machine-WriteRegister(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

28、)kernel-machine-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 inst

29、ruction (all 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 Un

30、expected system 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 _USERPR

31、OG_KSYSCALL_H_ #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,OpenFile

32、Id id) return 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_ */Sysca

33、ll.h: /* syscalls.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

34、University of 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 syste

35、m call * is being 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_ThreadExit 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