syscall.c

#include "userprog/syscall.h"
#include <stdio.h>
#include <syscall-nr.h>
#include "system_calls.h"
#include "threads/interrupt.h"
#include "threads/thread.h"


/* System call numbers. */
typedef enum syscall_t {
    /* Projects 2 and later. */
    SYSCALL_HALT,                   /* Halt the operating system. */
    SYSCALL_EXIT,                   /* Terminate this process. */
    SYSCALL_EXEC,                   /* Start another process. */
    SYSCALL_WAIT,                   /* Wait for a child process to die. */
    SYSCALL_CREATE,                 /* Create a file. */
    SYSCALL_REMOVE,                 /* Delete a file. */
    SYSCALL_OPEN,                   /* Open a file. */
    SYSCALL_FILESIZE,               /* Obtain a file's size. */
    SYSCALL_READ,                   /* Read from a file. */
    SYSCALL_WRITE,                  /* Write to a file. */
    SYSCALL_SEEK,                   /* Change position in a file. */
    SYSCALL_TELL,                   /* Report current position in a file. */
    SYSCALL_CLOSE,                  /* Close a file. */

    /* Project 3 and optionally project 4. */
    SYSCALL_MMAP,                   /* Map a file into memory. */
    SYSCALL_MUNMAP,                 /* Remove a memory mapping. */

    /* Project 4 only. */
    SYSCALL_CHDIR,                  /* Change the current directory. */
    SYSCALL_MKDIR,                  /* Create a directory. */
    SYSCALL_READDIR,                /* Reads a directory entry. */
    SYSCALL_ISDIR,                  /* Tests if a fd represents a directory. */
    SYSCALL_INUMBER                 /* Returns the inode number for a fd. */
} syscall_t;

static void syscall_handler (struct intr_frame *);

void
syscall_init (void) 
{
  intr_register_int (0x30, 3, INTR_ON, syscall_handler, "syscall");
}


static void
syscall_handler (struct intr_frame *f UNUSED)
{
  /*
   * the syscall number is addressed by f->esp (pointer to void)
   * here we cast it to a pointer to int and then dereference that
   * to get the system call number
   * --Joshua Saxby
   */
  int syscall_number = *((int*)f->esp);
  switch (syscall_number) {
  case SYSCALL_HALT:
    syscall_halt(f);
    break;
  case SYSCALL_EXIT:
    syscall_exit(f);
    break;
  case SYSCALL_EXEC:
    syscall_exec(f);
    break;
  case SYSCALL_WAIT:
    syscall_wait(f);
    break;
  case SYSCALL_CREATE:
    syscall_create(f);
    break;
  case SYSCALL_WRITE:
    syscall_write(f);
    break;
  case SYSCALL_OPEN:
    syscall_open(f);
	break;
  default:
    printf ("WARNING: Invalid Syscall (%d)\n", syscall_number);
    thread_exit ();
  }
}