diff --git a/util/genbuild_h/genbuild_h.sh b/util/genbuild_h/genbuild_h.sh
index 10ca0c5fa3..c898fb6e3f 100755
--- a/util/genbuild_h/genbuild_h.sh
+++ b/util/genbuild_h/genbuild_h.sh
@@ -5,6 +5,7 @@
 DATE=""
 GITREV=""
 TIMESOURCE=""
+XGCCPATH="${XGCCPATH:-util/crossgcc/xgcc/bin/}"
 
 export LANG=C
 export LC_ALL=C
@@ -47,8 +48,15 @@ NetBSD|OpenBSD|DragonFly|FreeBSD|Darwin)
 esac
 }
 
-IASL=util/crossgcc/xgcc/bin/iasl
+# Look for IASL in XGCCPATH and xcompile.  Unfortunately,
+# xcompile isn't available on the first build.
+# If neither of those gives a valid iasl, check the path.
+IASL="${XGCCPATH}iasl"
 eval $(grep ^IASL:= "$XCOMPILE" 2>/dev/null | sed s,:=,=,)
+if [ ! -x "${IASL}" ]; then
+	IASL=$(command -v iasl)
+fi
+IASLVERSION="$(${IASL} -v | grep version | sed 's/.*version //')" >/dev/null
 
 #Print out the information that goes into build.h
 printf "/* build system definitions (autogenerated) */\n"
@@ -72,5 +80,5 @@ printf "#define COREBOOT_BUILD_EPOCH \"$(our_date "$DATE" +%s)\"\n"
 printf "#define COREBOOT_DMI_DATE \"$(our_date "$DATE" +%m/%d/%Y)\"\n"
 printf "\n"
 printf "#define COREBOOT_COMPILE_TIME \"$(our_date "$DATE" +%T)\"\n"
-printf "#define ASL_VERSION 0x%d\n" `$IASL -v | grep version | sed 's/.*version //'`
+printf "#define ASL_VERSION 0x%d\n" "${IASLVERSION}"
 printf "#endif\n"