tools/firmware/Makfile: Respect caller's CONFIG_PV_SHIM

This makes it easier to disable the shim build.  (In Debian we need to
build the shim separately because it needs different compiler flags
and a different XEN_COMPILE_ARCH.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/config/Tools.mk.in b/config/Tools.mk.in
index 23df47af8d90d107dac8de3b93f307eb628f1aae..7a3e5773c5e7f69fc1d37887d37e5994308b3a93 100644 (file)
--- a/config/Tools.mk.in
+++ b/config/Tools.mk.in
@@ -76,4 +76,4 @@ ARGP_LDFLAGS        := @argp_ldflags@
 
 FILE_OFFSET_BITS    := @FILE_OFFSET_BITS@
 
-CONFIG_PV_SHIM      := @pvshim@
+CONFIG_PV_SHIM      ?= @pvshim@