[powerpc,powerpcspe,ppc64] Fix cross-build (Closes: #903096)

- Introduce linux-bootwrapper-<abiname> package containing boot wrapper
  tools for the host architecture
- linux-image: Install symlinks to boot wrapper tools instead of the
  native tools built by kbuild

debian/changelog

@@ -241,6 +241,11 @@ linux (4.17.4-1) UNRELEASED; urgency=medium
     - powerpc/lib/sstep: Fix building for powerpcspe
     - powerpc/lib/Makefile: Don't pull in quad.o for 32-bit kernels
     - linux-perf: Disable building for powerpcspe
+  * [powerpc,powerpcspe,ppc64] Fix cross-build (Closes: #903096):
+    - Introduce linux-bootwrapper-<abiname> package containing boot wrapper
+      tools for the host architecture
+    - linux-image: Install symlinks to boot wrapper tools instead of the
+      native tools built by kbuild
 
  -- Sjoerd Simons <sjoerd@debian.org>  Wed, 04 Jul 2018 10:25:57 +0200
 

debian/rules.d/Makefile

@@ -6,6 +6,11 @@ SUBDIRS = \
 	scripts \
 	tools
 
+DEB_HOST_ARCH := $(shell dpkg-architecture -qDEB_HOST_ARCH)
+ifneq ($(filter powerpc powerpcspe ppc64,$(DEB_HOST_ARCH)),)
+	SUBDIRS += arch/powerpc/boot
+endif
+
 include $(top_rulesdir)/Makefile.inc
 
 # Build userland headers first

debian/rules.d/arch/powerpc/boot/Makefile

@@ -0,0 +1,11 @@
+PROGS = \
+	addnote \
+	hack-coff \
+	mktree
+
+SCRIPTS = \
+	wrapper
+
+include $(top_rulesdir)/Makefile.inc
+
+CPPFLAGS += -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64

debian/rules.real

@@ -85,6 +85,9 @@ ifneq ($(DO_TOOLS_VERSIONED),False)
       binary-arch-arch: install-perf
     endif
   endif
+  ifneq ($(filter powerpc powerpcspe ppc64,$(DEB_HOST_ARCH)),)
+    binary-arch-arch: install-bootwrapper
+  endif
 endif
 ifneq ($(DO_TOOLS_UNVERSIONED),False)
   binary-arch-arch: install-usbip install-cpupower install-liblockdep
@@ -455,10 +458,20 @@ ifneq ($(filter arm64 armel armhf,$(ARCH)),)
 	+$(MAKE_CLEAN) -C $(DIR) dtbs_install INSTALL_DTBS_PATH=$(CURDIR)/$(DT_INSTALL_DIR)
 endif
 ifneq ($(filter powerpc powerpcspe ppc64,$(ARCH)),)
+# Install wrapper code and DT source, but not the wrapper script or
+# the executables it calls.  Kbuild will always build these executable
+# as native code, which is wrong for a cross-built package.  Install
+# symlinks to the versions in the linux-bootwrapper package instead.
+	rm -rf '$(DIR)_bootwrapper'
 	+$(MAKE_CLEAN) -C '$(DIR)' bootwrapper_install \
-	  WRAPPER_OBJDIR='$(CURDIR)/$(DT_INSTALL_DIR)' \
-	  WRAPPER_DTSDIR='$(CURDIR)/$(DT_INSTALL_DIR)'/dts \
-	  WRAPPER_BINDIR='$(CURDIR)/$(DT_INSTALL_DIR)'
+		WRAPPER_OBJDIR='$(CURDIR)/$(DT_INSTALL_DIR)' \
+		WRAPPER_DTSDIR='$(CURDIR)/$(DT_INSTALL_DIR)/dts' \
+		WRAPPER_BINDIR='$(CURDIR)/$(DIR)_bootwrapper'
+	for prog in '$(DIR)_bootwrapper'/*; do \
+		prog="$$(basename $$prog)"; \
+		ln -s ../linux-bootwrapper-$(ABINAME)/$$prog \
+			'$(DT_INSTALL_DIR)'/$$prog; \
+	done
 endif
 
 install-image_$(ARCH)_$(FEATURESET)_$(FLAVOUR)_bug:
@@ -765,4 +778,22 @@ endif
 	dh_md5sums
 	dh_builddeb
 
+install-bootwrapper: PACKAGE_NAME = linux-bootwrapper-$(ABINAME)
+install-bootwrapper: DH_OPTIONS = -p$(PACKAGE_NAME)
+install-bootwrapper: DIR = $(CURDIR)/debian/$(PACKAGE_NAME)
+install-bootwrapper: $(STAMPS_DIR)/build-tools
+	dh_testdir
+	dh_testroot
+	dh_prep
+	$(call make-tools,arch/powerpc/boot) install DESTDIR=$(DIR) installdir=/usr/lib/$(PACKAGE_NAME)
+	dh_installchangelogs
+	dh_strip
+	dh_compress
+	dh_fixperms
+	dh_installdeb
+	dh_shlibdeps
+	dh_gencontrol
+	dh_md5sums
+	dh_builddeb
+
 # vim: filetype=make

debian/templates/control.image.in

@@ -1,6 +1,6 @@
 Package: linux-image-@abiname@@localversion@
 Build-Profiles: <!stage1>
-Depends: kmod, linux-base (>= 4.3~), ${misc:Depends}
+Depends: kmod, linux-base (>= 4.3~), linux-bootwrapper-@abiname@ [powerpc powerpcspe ppc64], ${misc:Depends}
 Recommends: firmware-linux-free, ${kernel:Recommends}
 Suggests: linux-doc-@version@, debian-kernel-handbook
 Description: Linux @upstreamversion@ for @class@

debian/templates/control.tools-versioned.in

@@ -22,3 +22,12 @@ Description: Performance analysis tools for Linux @version@
  .
  The linux-base package contains a 'perf' command which will invoke the
  appropriate version for the running kernel.
+
+Package: linux-bootwrapper-@abiname@
+Build-Profiles: <!stage1 !pkg.linux.notools>
+Architecture: powerpc powerpcspe ppc64
+Depends: ${shlibs:Depends}, ${misc:Depends}
+Multi-Arch: foreign
+Description: Boot wrapper tools for Linux @version@ on PowerPC
+ This package provides the 'wrapper' script and related tools needed
+ to process the Linux kernel image for use with some PowerPC platforms.