xen: allow architecture to choose how/whether to compress installed xen binary

This is a follow up to "xen: arm: make zImage the default target which we
install".

On ARM the xen.gz binary installed into /boot is not immediately useful because
bootloaders (e.g. u-boot) do not unconditionally support decompression (except
via the uImage wrapper, which we currently do not support via our build system)

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Jan Beulich <jbeulich@suse.com>

config/arm32.mk

@@ -2,6 +2,8 @@ CONFIG_ARM := y
 CONFIG_ARM_32 := y
 CONFIG_ARM_$(XEN_OS) := y
 
+CONFIG_XEN_INSTALL_SUFFIX :=
+
 # -march= -mcpu=
 
 # Explicitly specifiy 32-bit ARM ISA since toolchain default can be -mthumb:

config/arm64.mk

@@ -2,6 +2,8 @@ CONFIG_ARM := y
 CONFIG_ARM_64 := y
 CONFIG_ARM_$(XEN_OS) := y
 
+CONFIG_XEN_INSTALL_SUFFIX :=
+
 CFLAGS += #-marm -march= -mcpu= etc
 
 HAS_PL011 := y

config/x86_64.mk

@@ -8,6 +8,8 @@ CONFIG_MIGRATE := y
 CONFIG_XCUTILS := y
 CONFIG_IOEMU ?= y
 
+CONFIG_XEN_INSTALL_SUFFIX := .gz
+
 CFLAGS += -m64
 
 SunOS_LIBDIR = $(SunOS_LIBDIR_x86_64)

xen/Makefile

@@ -29,14 +29,14 @@ else
 endif
 
 .PHONY: _build
-_build: $(TARGET).gz
+_build: $(TARGET)$(CONFIG_XEN_INSTALL_SUFFIX)
 
 .PHONY: _install
 _install: D=$(DESTDIR)
 _install: T=$(notdir $(TARGET))
-_install: $(TARGET).gz
+_install: $(TARGET)$(CONFIG_XEN_INSTALL_SUFFIX)
 	[ -d $(D)/boot ] || $(INSTALL_DIR) $(D)/boot
-	$(INSTALL_DATA) $(TARGET).gz $(D)/boot/$(T)-$(XEN_FULLVERSION)
+	$(INSTALL_DATA) $(TARGET)$(CONFIG_XEN_INSTALL_SUFFIX) $(D)/boot/$(T)-$(XEN_FULLVERSION)
 	ln -f -s $(T)-$(XEN_FULLVERSION) $(D)/boot/$(T)-$(XEN_VERSION).$(XEN_SUBVERSION)
 	ln -f -s $(T)-$(XEN_FULLVERSION) $(D)/boot/$(T)-$(XEN_VERSION)
 	ln -f -s $(T)-$(XEN_FULLVERSION) $(D)/boot/$(T)