[PATCH v2 3/3] x86/boot: Add option to add modules.img to {fd,hd,iso}image

["H. Peter Anvin" <hpa@zytor.com>]

From: "H. Peter Anvin (Intel)" <hpa@zytor.com>

Make it easy to generate a disk image which includes the all-modules
initramfs image.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
---
 arch/x86/Makefile      |  3 ++-
 arch/x86/boot/Makefile | 20 ++++++++++++++++----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 943f26a32834..74f4e66568d7 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -309,7 +309,8 @@ define archhelp
   echo  '  isoimage		- Create a boot CD-ROM image (arch/x86/boot/image.iso)'
   echo  '			  bzdisk/fdimage*/hdimage/isoimage also accept:'
   echo  '			  FDARGS="..."  arguments for the booted kernel'
-  echo  '                  	  FDINITRD=file initrd for the booted kernel'
+  echo  '			  FDINITRD=file initrd for the booted kernel'
+  echo  '			  FDMODS=1 to include all modules as an initrd'
   echo  ''
   echo  '  kvm_guest.config	- Enable Kconfig items for running this kernel as a KVM guest'
   echo  '  xen.config		- Enable Kconfig items for running this kernel as a Xen guest'
diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile
index dfbc26a8e924..a4f8c66a63d0 100644
--- a/arch/x86/boot/Makefile
+++ b/arch/x86/boot/Makefile
@@ -116,11 +116,23 @@ $(obj)/compressed/vmlinux: FORCE
 
 # Set this if you want to pass append arguments to the
 # bzdisk/fdimage/hdimage/isoimage kernel
-FDARGS =
+FDARGS   :=
 # Set this if you want one or more initrds included in the image
-FDINITRD =
+FDINITRD :=
+# Set this to 1 if you want usr/modules.img included in the image
+FDMODS   :=
 
-imgdeps = $(obj)/bzImage $(obj)/mtools.conf $(src)/genimage.sh
+imgdeps   := $(obj)/bzImage $(obj)/mtools.conf $(src)/genimage.sh
+fdinitrds := $(FDINITRD)
+
+ifneq ($(FDMODS),)
+imgdeps   += $(objtree)/usr/modules.img
+fdinitrds += $(objtree)/usr/modules.img
+
+$(objtree)/usr/modules.img:
+	$(Q)$(MAKE) -f $(srctree)/Makefile usr/modules.img
+KBUILD_MODULES := 1
+endif
 
 $(obj)/mtools.conf: $(src)/mtools.conf.in
 	sed -e 's|@OBJ@|$(obj)|g' < $< > $@
@@ -131,7 +143,7 @@ targets += mtools.conf
 # external dependencies.
 quiet_cmd_genimage = GENIMAGE $3
 cmd_genimage = $(BASH) $(srctree)/$(src)/genimage.sh $2 $3 $(obj)/bzImage \
-		$(obj)/mtools.conf '$(FDARGS)' $(FDINITRD)
+		$(obj)/mtools.conf '$(FDARGS)' $(fdinitrds)
 
 PHONY += bzdisk fdimage fdimage144 fdimage288 hdimage isoimage install
 
-- 
2.30.2