fix a problem with end. make uartputc() wait until h/w is ready.

1 files changed, 2 insertions, 4 deletions

diff --git a/kalloc.c b/kalloc.c
index cfbbae4..1ed1c49 100644
--- a/kalloc.c
+++ b/kalloc.c
@@ -27,8 +27,6 @@ void
 kinit()
 {
   initlock(&kmem.lock, "kmem");
-  if(PHYSTOP > RAMDISK)
-    panic("kinit");
   freerange(end, (void*)PHYSTOP);
 }
 
@@ -76,7 +74,7 @@ kalloc(void)
   if(r)
     kmem.freelist = r->next;
   release(&kmem.lock);
-  memset((char*)r, 5, PGSIZE); // fill with junk
+  if(r)
+    memset((char*)r, 5, PGSIZE); // fill with junk
   return (void*)r;
 }
-