1 #include <stdio.h>

2 #include "syscall.h"

3 #include "intr.h"

4 #include "proc.h"

5 #include "sched.h"

6 #include "timer.h"

7

8 static int (*sys_func[NUM_SYSCALLS])();

9

10 static void syscall(int inum);

11

12 static int sys_hello(void);

13

14 void init_syscall(void)

15 {

16 sys_func[SYS_HELLO] = sys_hello;

17 sys_func[SYS_SLEEP] = sys_sleep; /* timer.c */

18 sys_func[SYS_FORK] = sys_fork; /* proc.c */

19 sys_func[SYS_EXIT] = sys_exit; /* proc.c */

20 sys_func[SYS_WAITPID] = sys_waitpid; /* proc.c */

21 sys_func[SYS_GETPID] = sys_getpid; /* proc.c */

22 sys_func[SYS_GETPPID] = sys_getppid; /* proc.c */

23

24 interrupt(SYSCALL_INT, syscall);

25 }

26

27 static void syscall(int inum)

28 {

29 struct intr_frame *frm;

30 int idx;

31

32 frm = get_intr_frame();

33 idx = frm->regs.eax;

34

35 if(idx < 0 || idx >= NUM_SYSCALLS) {

36 printf("invalid syscall: %d\n", idx);

37 return;

38 }

39

40 /* the return value goes into the interrupt frame copy of the user's eax

41 * so that it'll be restored into eax before returning to userland.

42 */

43 frm->regs.eax = sys_func[idx](frm->regs.ebx, frm->regs.ecx, frm->regs.edx, frm->regs.esi, frm->regs.edi);

44

45 /* we don't necessarily want to return to the same process

46 * might have blocked or exited or whatever, so call schedule

47 * to decide what's going to run next.

48 */

49 schedule();

50 }

51

52 static int sys_hello(void)

53 {

54 printf("process %d says hello!\n", get_current_pid());

55 return 0;

56 }