bootstrap clone sys call

Makefile

@@ -180,6 +180,7 @@ UPROGS=\
 	$U/_bcachetest\
 	$U/_alloctest\
 	$U/_specialtest\
+	$U/_dhagatest\
 	# $U/_symlinktest\
 
 fs.img: mkfs/mkfs README user/xargstest.sh $(UPROGS)

kernel/syscall.c

@@ -106,6 +106,7 @@ extern uint64 sys_write(void);
 extern uint64 sys_uptime(void);
 extern uint64 sys_ntas(void);
 extern uint64 sys_nfree(void);
+extern uint64 sys_clone(void);
 
 static uint64 (*syscalls[])(void) = {
 [SYS_fork]    sys_fork,
@@ -131,6 +132,7 @@ static uint64 (*syscalls[])(void) = {
 [SYS_close]   sys_close,
 [SYS_ntas]    sys_ntas,
 [SYS_nfree]   sys_nfree,
+[SYS_clone]   sys_clone
 };
 
 void

kernel/syscall.h

@@ -24,3 +24,6 @@
 // System calls for labs
 #define SYS_ntas   22
 #define SYS_nfree  23
+
+// DHAGA calls
+#define SYS_clone  24

kernel/sysproc.c

@@ -95,3 +95,9 @@ sys_uptime(void)
   release(&tickslock);
   return xticks;
 }
+
+uint64
+sys_clone(void)
+{
+  return 0;
+}

user/dhagatest.c

@@ -0,0 +1,22 @@
+#include "kernel/types.h"
+#include "kernel/stat.h"
+#include "user/user.h"
+
+void
+dhagatest()
+{
+    if(clone((void *)0,0)!=0)
+    {
+        printf("clone should return zero\n");
+        exit(1);
+    }
+
+    printf("all tests passing\n");
+}
+
+int
+main(void)
+{
+  dhagatest();
+  exit(0);
+}

user/user.h

@@ -28,6 +28,7 @@ int crash(const char*, int);
 int mount(char*, char *);
 int umount(char*);
 int nfree();
+int clone(void*, int);
 
 // ulib.c
 int stat(const char*, struct stat*);

user/usys.pl

@@ -38,3 +38,4 @@ sub entry {
 entry("uptime");
 entry("ntas");
 entry("nfree");
+entry("clone");