moved boot.asm into kernel/boot, added kernel/boot/Makefile using new subdir.mak

git-svn-id: svn://anubis/hos/trunk@20 5b3e749e-e535-0410-8002-a9bb6afbdfca

kernel/Makefile

@@ -17,6 +17,7 @@ endif
 export NASM     := nasm
 
 WD              := $(shell pwd)
+export HOS_TOPLEVEL := $(WD)
 LDSCRIPT        := link.ld
 KERNEL          := hos
 export CPPFLAGS := -I$(WD)/include
@@ -34,7 +35,7 @@ $(KERNEL).gz: $(KERNEL)
 	gzip -c $< > $@
 
 $(KERNEL): $(SUBDIRS)
-	$(LD) $(LDFLAGS) -o $@ $(SUBDIRS:%=%/%.o)
+	$(LD) $(LDFLAGS) -o $@ $(foreach subdir,$(SUBDIRS),$(subdir)/$(subdir).o)
 
 .PHONY: $(SUBDIRS)
 $(SUBDIRS):