Guards against errors that are hard to track down:

- if crt0s is empty (eg. because crt0-y is still used),
  break the build, and say where that behaviour changed
- if a stage is unusable for cbfstool because it's placed
  outside the ROM space (linked to 0 is somewhat notorious),
  warn about it, give some hints and exit instead of crashing.

Signed-off-by: Patrick Georgi <patrick.georgi@coresystems.de>
Acked-by: Stefan Reinauer <stefan.reinauer@coresystems.de>


git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5077 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

src/arch/i386/Makefile.inc

@@ -62,6 +62,10 @@ $(obj)/coreboot.a: $(objs)
 #######################################################################
 # done
 
+# crt0s should be set by now
+ifeq ($(crt0s),)
+$(error crt0s are empty. If your board still uses crt0-y and ldscript-y: It shouldn't, we moved away from that in r5065)
+endif
 endif
 
 ifeq ($(CONFIG_TINY_BOOTBLOCK),y)