1 files changed, 21 insertions, 12 deletions

diff --git a/syscall.c b/syscall.c
index beadcbb..1d2eb54 100644
--- a/syscall.c
+++ b/syscall.c
@@ -42,13 +42,16 @@ fetcharg(int argno, int *ip)
   return fetchint(curproc[cpu()], esp + 8 + 4*argno, ip);
 }
 
-void
+int
 sys_fork()
 {
-  newproc();
+  struct proc *np;
+
+  np = newproc();
+  return np->pid;
 }
 
-void
+int
 sys_exit()
 {
   struct proc *p;
@@ -67,14 +70,16 @@ sys_exit()
       p->pid = 1;
 
   swtch();
+
+  return 0;
 }
 
-void
+int
 sys_wait()
 {
   struct proc *p;
   struct proc *cp = curproc[cpu()];
-  int any;
+  int any, pid;
 
   cprintf("waid pid %d ppid %d\n", cp->pid, cp->ppid);
 
@@ -84,28 +89,30 @@ sys_wait()
       if(p->state == ZOMBIE && p->ppid == cp->pid){
         kfree(p->mem, p->sz);
         kfree(p->kstack, KSTACKSIZE);
+        pid = p->pid;
         p->state = UNUSED;
         cprintf("%x collected %x\n", cp, p);
-        return;
+        return pid;
       }
       if(p->state != UNUSED && p->ppid == cp->pid)
         any = 1;
     }
     if(any == 0){
       cprintf("%x nothing to wait for\n", cp);
-      return;
+      return -1;
     }
     sleep(cp);
   }
 }
 
-void
+int
 sys_cons_putc()
 {
   int c;
 
   fetcharg(0, &c);
   cons_putc(c & 0xff);
+  return 0;
 }
 
 void
@@ -113,24 +120,26 @@ syscall()
 {
   struct proc *cp = curproc[cpu()];
   int num = cp->tf->tf_regs.reg_eax;
+  int ret = -1;
 
   cprintf("%x sys %d\n", cp, num);
   switch(num){
   case SYS_fork:
-    sys_fork();
+    ret = sys_fork();
     break;
   case SYS_exit:
-    sys_exit();
+    ret = sys_exit();
     break;
   case SYS_wait:
-    sys_wait();
+    ret = sys_wait();
     break;
   case SYS_cons_putc:
-    sys_cons_putc();
+    ret = sys_cons_putc();
     break;
   default:
     cprintf("unknown sys call %d\n", num);
     // XXX fault
     break;
   }
+  cp->tf->tf_regs.reg_eax = ret;
 }