[PATCH] kbuild: Handle builtin dtb files containing hyphens

[James Hogan <jhogan@kernel.org>]

On dtb files which contain hyphens, the dt_S_dtb command to build the
dtb.S files (which allow DTB files to be built into the kernel) results
in errors like the following:

bcm3368-netgear-cvg834g.dtb.S: Assembler messages:
bcm3368-netgear-cvg834g.dtb.S:5: Error: : no such section
bcm3368-netgear-cvg834g.dtb.S:5: Error: junk at end of line, first unrecognized character is `-'
bcm3368-netgear-cvg834g.dtb.S:6: Error: unrecognized opcode `__dtb_bcm3368-netgear-cvg834g_begin:'
bcm3368-netgear-cvg834g.dtb.S:8: Error: unrecognized opcode `__dtb_bcm3368-netgear-cvg834g_end:'
bcm3368-netgear-cvg834g.dtb.S:9: Error: : no such section
bcm3368-netgear-cvg834g.dtb.S:9: Error: junk at end of line, first unrecognized character is `-'

This is due to the hyphen being used in symbol names. Replace all
hyphens with underscores in the dt_S_dtb command to avoid this problem.

Quite a lot of dts files have hyphens, but its only a problem on MIPS
where such files can be built into the kernel. For example when
CONFIG_DT_NETGEAR_CVG834G=y, or on BMIPS kernels when the dtbs target is
used (in the latter case it admitedly shouldn't really build all the
dtb.o files, but thats a separate issue).

Fixes: 695835511f96 ("MIPS: BMIPS: rename bcm96358nb4ser to bcm6358-neufbox4-sercom")
Signed-off-by: James Hogan <jhogan@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kbuild@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.9+
---
 scripts/Makefile.lib | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 5589bae34af6..a6f538b31ad6 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -297,11 +297,11 @@ cmd_dt_S_dtb=						\
 	echo '\#include <asm-generic/vmlinux.lds.h>'; 	\
 	echo '.section .dtb.init.rodata,"a"';		\
 	echo '.balign STRUCT_ALIGNMENT';		\
-	echo '.global __dtb_$(*F)_begin';		\
-	echo '__dtb_$(*F)_begin:';			\
+	echo '.global __dtb_$(subst -,_,$(*F))_begin';	\
+	echo '__dtb_$(subst -,_,$(*F))_begin:';		\
 	echo '.incbin "$<" ';				\
-	echo '__dtb_$(*F)_end:';			\
-	echo '.global __dtb_$(*F)_end';			\
+	echo '__dtb_$(subst -,_,$(*F))_end:';		\
+	echo '.global __dtb_$(subst -,_,$(*F))_end';	\
 	echo '.balign STRUCT_ALIGNMENT'; 		\
 ) > $@
 
-- 
2.13.6