Thanks Anton Burtsev <aburtsev@uci.edu>

da3b931d · Frans Kaashoek · a4ee6f7d · da3b931d
--- a/kalloc.c
+++ b/kalloc.c
@@ -11,6 +11,7 @@

 void freerange(void *vstart, void *vend);
 extern char end[]; // first address after kernel loaded from ELF file
+                   // defined by the kernel linker script in kernel.ld

 struct run {
  struct run *next;