Index: /trunk/Config.kmk
===================================================================
--- /trunk/Config.kmk	(revision 16008)
+++ /trunk/Config.kmk	(revision 16009)
@@ -1249,8 +1249,20 @@
 
 # Bruce's C compile is a C-compiler for BIOS-related 8086 code
-VBOX_BCC       ?= $(PATH_DEVTOOLS_BLD)/bin/bcc$(HOSTSUFF_EXE) -B $(PATH_DEVTOOLS_BLD)/bin/
+ifndef VBOX_BCC
+ if exist $(PATH_DEVTOOLS_BLD)/bin/bcc$(HOSTSUFF_EXE)
+VBOX_BCC       := $(PATH_DEVTOOLS_BLD)/bin/bcc$(HOSTSUFF_EXE) -B $(PATH_DEVTOOLS_BLD)/bin/
+ else
+VBOX_BCC       := bcc$(HOSTSUFF_EXE)
+ endif
+endif
 
 # Assembler for BIOS-related 8086 code
-VBOX_AS86      ?= $(PATH_DEVTOOLS_BLD)/bin/as86$(HOSTSUFF_EXE)
+ifndef VBOX_AS86
+ if exist $(PATH_DEVTOOLS_BLD)/bin/as86$(HOSTSUFF_EXE)
+VBOX_AS86      := $(PATH_DEVTOOLS_BLD)/bin/as86$(HOSTSUFF_EXE)
+ else
+VBOX_AS86      := as86$(HOSTSUFF_EXE)
+ endif
+endif
 
 # libxslt XSLT processor. (see PATH_TOOL_YASM for explanation why it's temporarily located in bin.)