Add DoModules to kernel build

There's upcoming work to build kernel variants without modules. Add
the infrastructure to support this.

kernel.spec

@@ -1106,6 +1106,8 @@ BuildKernel() {
     Flav=${Flavour:++${Flavour}}
     InstallName=${5:-vmlinuz}
 
+    DoModules=1
+
     # Pick the right config file for the kernel we're building
     Config=kernel-%{version}-%{_target_cpu}${Flavour:+-${Flavour}}.config
     DevelDir=/usr/src/kernels/%{KVERREL}${Flav}
@@ -1155,7 +1157,9 @@ BuildKernel() {
     # This ensures build-ids are unique to allow parallel debuginfo
     perl -p -i -e "s/^CONFIG_BUILD_SALT.*/CONFIG_BUILD_SALT=\"%{KVERREL}\"/" .config
     %{make} %{?make_opts} HOSTCFLAGS="%{?build_hostcflags}" HOSTLDFLAGS="%{?build_hostldflags}" ARCH=$Arch %{?_smp_mflags} $MakeTarget %{?sparse_mflags} %{?kernel_mflags}
-    %{make} %{?make_opts} HOSTCFLAGS="%{?build_hostcflags}" HOSTLDFLAGS="%{?build_hostldflags}" ARCH=$Arch %{?_smp_mflags} modules %{?sparse_mflags} || exit 1
+    if [ $DoModules -eq 1 ]; then
+	%{make} %{?make_opts} HOSTCFLAGS="%{?build_hostcflags}" HOSTLDFLAGS="%{?build_hostldflags}" ARCH=$Arch %{?_smp_mflags} modules %{?sparse_mflags} || exit 1
+    fi
 
     mkdir -p $RPM_BUILD_ROOT/%{image_install_path}
     mkdir -p $RPM_BUILD_ROOT/lib/modules/$KernelVer
@@ -1203,18 +1207,21 @@ BuildKernel() {
     sha512hmac $RPM_BUILD_ROOT/%{image_install_path}/$InstallName-$KernelVer | sed -e "s,$RPM_BUILD_ROOT,," > $RPM_BUILD_ROOT/%{image_install_path}/.vmlinuz-$KernelVer.hmac;
     cp $RPM_BUILD_ROOT/%{image_install_path}/.vmlinuz-$KernelVer.hmac $RPM_BUILD_ROOT/lib/modules/$KernelVer/.vmlinuz.hmac
 
-    # Override $(mod-fw) because we don't want it to install any firmware
+
-    # we'll get it from the linux-firmware package and we don't want conflicts
+    if [ $DoModules -eq 1 ]; then
-    %{make} %{?make_opts} ARCH=$Arch INSTALL_MOD_PATH=$RPM_BUILD_ROOT modules_install KERNELRELEASE=$KernelVer mod-fw=
+	# Override $(mod-fw) because we don't want it to install any firmware
+	# we'll get it from the linux-firmware package and we don't want conflicts
+	%{make} %{?make_opts} ARCH=$Arch INSTALL_MOD_PATH=$RPM_BUILD_ROOT modules_install KERNELRELEASE=$KernelVer mod-fw=
+    fi
 
     # add an a noop %%defattr statement 'cause rpm doesn't like empty file list files
     echo '%%defattr(-,-,-)' > ../kernel${Flavour:+-${Flavour}}-ldsoconf.list
     if [ $DoVDSO -ne 0 ]; then
         %{make} %{?make_opts} ARCH=$Arch INSTALL_MOD_PATH=$RPM_BUILD_ROOT vdso_install KERNELRELEASE=$KernelVer
         if [ -s ldconfig-kernel.conf ]; then
-            install -D -m 444 ldconfig-kernel.conf \
+             install -D -m 444 ldconfig-kernel.conf \
                 $RPM_BUILD_ROOT/etc/ld.so.conf.d/kernel-$KernelVer.conf
-            echo /etc/ld.so.conf.d/kernel-$KernelVer.conf >> ../kernel${Flavour:+-${Flavour}}-ldsoconf.list
+	     echo /etc/ld.so.conf.d/kernel-$KernelVer.conf >> ../kernel${Flavour:+-${Flavour}}-ldsoconf.list
         fi
         rm -rf $RPM_BUILD_ROOT/lib/modules/$KernelVer/vdso/.build-id
     fi
@@ -1387,22 +1394,36 @@ BuildKernel() {
     # don't include anything going into k-m-e in the file lists
     rm -rf lib/modules/$KernelVer/extra
 
-    # Find all the module files and filter them out into the core and modules
-    # lists.  This actually removes anything going into -modules from the dir.
-    find lib/modules/$KernelVer/kernel -name *.ko | sort -n > modules.list
-    cp $RPM_SOURCE_DIR/filter-*.sh .
-    %{SOURCE99} modules.list %{_target_cpu}
-    rm filter-*.sh
 
-    # Run depmod on the resulting module tree and make sure it isn't broken
+    if [ $DoModules -eq 1 ]; then
-    depmod -b . -aeF ./System.map $KernelVer &> depmod.out
+	# Find all the module files and filter them out into the core and
-    if [ -s depmod.out ]; then
+	# modules lists.  This actually removes anything going into -modules
-        echo "Depmod failure"
+	# from the dir.
-        cat depmod.out
+	find lib/modules/$KernelVer/kernel -name *.ko | sort -n > modules.list
-        exit 1
+	cp $RPM_SOURCE_DIR/filter-*.sh .
+	%{SOURCE99} modules.list %{_target_cpu}
+	rm filter-*.sh
+
+	# Run depmod on the resulting module tree and make sure it isn't broken
+	depmod -b . -aeF ./System.map $KernelVer &> depmod.out
+	if [ -s depmod.out ]; then
+	    echo "Depmod failure"
+	    cat depmod.out
+	    exit 1
+	else
+	    rm depmod.out
+	fi
     else
-        rm depmod.out
+	# Ensure important files/directories exist to let the packaging succeed
+	echo '%%defattr(-,-,-)' > modules.list
+	echo '%%defattr(-,-,-)' > k-d.list
+	mkdir -p lib/modules/$KernelVer/kernel
+	# Add files usually created by make modules, needed to prevent errors
+	# thrown by depmod during package installation
+	touch lib/modules/$KernelVer/modules.order
+	touch lib/modules/$KernelVer/modules.builtin
     fi
+
     # remove files that will be auto generated by depmod at rpm -i time
     pushd $RPM_BUILD_ROOT/lib/modules/$KernelVer/
         rm -f modules.{alias*,builtin.bin,dep*,*map,symbols*,devname,softdep}
@@ -1430,9 +1451,11 @@ BuildKernel() {
     rm -f $RPM_BUILD_ROOT/module-dirs.list
 
 %if %{signmodules}
-    # Save the signing keys so we can sign the modules in __modsign_install_post
+    if [ $DoModules -eq 1 ]; then
-    cp certs/signing_key.pem certs/signing_key.pem.sign${Flav}
+	# Save the signing keys so we can sign the modules in __modsign_install_post
-    cp certs/signing_key.x509 certs/signing_key.x509.sign${Flav}
+	cp certs/signing_key.pem certs/signing_key.pem.sign${Flav}
+	cp certs/signing_key.x509 certs/signing_key.x509.sign${Flav}
+    fi
 %endif
 
     # Move the devel headers out of the root file system