diff --git a/tools/Makefile b/tools/Makefile
index f4f81939..cfd2db1b 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -8,6 +8,7 @@ DEFINES=
 NASM = nasm
 NASMFLAGS = -fbin
 EXECFILES = $(shell find ../newlib/examples -perm -u+r+x -type f) 
+CORENUM ?= 1
 
 # other implicit rules
 %.o : %.c
@@ -36,7 +37,7 @@ reset_vector.bin: reset_vector.o
 	ld --oformat binary -Ttext 0 -melf_i386 -o $@ $<
 
 scc_bootinfo.asm: bootinfo.sh initrd.img
-	./bootinfo.sh 0x01000000 initrd.img 1 533 0 > scc_bootinfo.asm
+	./bootinfo.sh 0x01000000 initrd.img $(CORENUM) 533 `seq 0 $$(($(CORENUM) - 1))` > scc_bootinfo.asm
 
 scc_bootinfo.bin: scc_bootinfo.asm
 	$(NASM) $(NASMFLAGS) -o $@ $<