[tboot-devel] [PATCH 1/1] Config.mk, safestringlib/makefile : allow tool overrides

[Christopher C. <chr...@gm...>]

To simplify integration of tboot into build systems such as
OpenEmbeddded, use softer assignments and appends to define
the build tool and flag variables.

Signed-off-by: Christopher Clark <chr...@gm...>

This patch is based on an OpenXT patch by Eric Chanudet:
https://github.com/OpenXT/xenclient-oe/blob/fc13893594f684baea65b7ee09066a8ddb840b4d/recipes-security/tboot/tboot-1.9.9/0001-config-Allow-build-system-integration.patch

diff -r 0db8feeba423 -r dcec96ce7d2c Config.mk
--- a/Config.mk	Thu Dec 12 12:09:20 2019 +0100
+++ b/Config.mk	Fri Jan 24 10:03:42 2020 -0800
@@ -45,22 +45,22 @@
 	            $(call cc-option,$(CC),-Wlogical-op,) \
 	            -Wno-missing-field-initializers
 
-AS         = as
-LD         = ld
-CC         = gcc
-CPP        = cpp
-AR         = ar
-RANLIB     = ranlib
-NM         = nm
-STRIP      = strip
-OBJCOPY    = objcopy
-OBJDUMP    = objdump
+AS         ?= as
+LD         ?= ld
+CC         ?= gcc
+CPP        ?= cpp
+AR         ?= ar
+RANLIB     ?= ranlib
+NM         ?= nm
+STRIP      ?= strip
+OBJCOPY    ?= objcopy
+OBJDUMP    ?= objdump
 
 ifeq ($(debug),n)
-INSTALL_STRIP = -s
+INSTALL_STRIP ?= -s
 endif
 
-INSTALL      = install
+INSTALL      ?= install
 INSTALL_DIR  = $(INSTALL) -d -m0755 -p
 INSTALL_DATA = $(INSTALL) -m0644 -p
 INSTALL_PROG = $(INSTALL) $(INSTALL_STRIP) -m0755 -p
diff -r 0db8feeba423 -r dcec96ce7d2c safestringlib/makefile
--- a/safestringlib/makefile	Thu Dec 12 12:09:20 2019 +0100
+++ b/safestringlib/makefile	Fri Jan 24 10:03:42 2020 -0800
@@ -1,7 +1,7 @@
 IDIR = include
-CC=gcc
-CFLAGS=-I$(IDIR) -fstack-protector-strong -fPIE -fPIC -O2 -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security -DSTDC_HEADERS
-LDFLAGS=-z noexecstack -z relo -z now
+CC ?= gcc
+CFLAGS += -I$(IDIR) -fstack-protector-strong -fPIE -fPIC -O2 -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security -DSTDC_HEADERS
+LDFLAGS += -z noexecstack -z relo -z now
 
 ODIR=obj
 OTDIR=objtest