thanks mtasm

Makefile

@@ -82,6 +82,13 @@ ASFLAGS = -m32 -gdwarf-2 -Wa,-divide
 # FreeBSD ld wants ``elf_i386_fbsd''
 LDFLAGS += -m $(shell $(LD) -V | grep elf_i386 2>/dev/null | head -n 1)
 
+# Disable PIE when possible (for Ubuntu 16.10 toolchain)
+ifneq ($(shell $(CC) -dumpspecs 2>/dev/null | grep -e '[^f]no-pie'),)
+CFLAGS += -fno-pie -no-pie
+endif
+ifneq ($(shell $(CC) -dumpspecs 2>/dev/null | grep -e '[^f]nopie'),)
+CFLAGS += -fno-pie -nopie
+endif
 
 xv6.img: bootblock kernel
 	dd if=/dev/zero of=xv6.img count=10000

mmu.h

@@ -181,5 +181,3 @@ struct gatedesc {
 
 #endif
 
-//PAGEBREAK!
-// Blank page.

runoff.list

@@ -7,6 +7,7 @@ x86.h
 asm.h
 mmu.h
 elf.h
+date.h
 
 # entering xv6
 entry.S
@@ -75,3 +76,5 @@ sh.c
 bootasm.S
 bootmain.c
 
+# link
+kernel.ld