Fix multiboot for ACK-built images

Move the profiling buffer to the end of the data segment

kernel/Makefile

@@ -6,7 +6,7 @@ PROG=	kernel
 # first-stage, arch-dependent startup code
 SRCS=	mpx.S
 SRCS+=	start.c table.c main.c proc.c \
-	system.c clock.c utility.c debug.c profile.c interrupt.c \
+	system.c clock.c utility.c debug.c interrupt.c \
 	watchdog.c cpulocals.c
 
 .ifdef CONFIG_SMP
@@ -38,6 +38,10 @@ MAN=
 
 .include "system/Makefile.inc"
 .include "arch/${ARCH}/Makefile.inc"
+
+# These come last, so the profiling buffer is at the end of the data segment
+SRCS+= profile.c do_sprofile.c
+
 .include <bsd.prog.mk>
 
 debug.d: extracted-errno.h extracted-mfield.h extracted-mtype.h