firmware_loader: builtin: fail build on empty firmware

If an empty firmware file is supplied via CONFIG_EXTRA_FIRMWARE, the
build currently succeeds but creates an empty section. While the
firmware loader will not return such sections it is better to avoid
adding them in the first place.

Add a compile-time size check to the filechk_fwbin macro to abort the
build early if a 0-size firmware is encountered.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Link: https://patch.msgid.link/20260426043041.649202-2-dmitry.torokhov@gmail.com
[ Use 'exit 1' to properly fail the build. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
This commit is contained in:
Dmitry Torokhov 2026-04-25 21:30:39 -07:00 committed by Danilo Krummrich
parent d059966c0c
commit 1160c2208f

View File

@ -16,20 +16,24 @@ ASM_ALIGN = $(if $(CONFIG_64BIT),3,2)
PROGBITS = $(if $(CONFIG_ARM),%,@)progbits
filechk_fwbin = \
echo "/* Generated by $(src)/Makefile */" ;\
echo " .section .rodata" ;\
echo " .p2align 4" ;\
echo "_fw_$(FWSTR)_bin:" ;\
echo " .incbin \"$(fwdir)/$(FWNAME)\"" ;\
echo "_fw_end:" ;\
echo " .section .rodata.str,\"aMS\",$(PROGBITS),1" ;\
echo " .p2align $(ASM_ALIGN)" ;\
echo "_fw_$(FWSTR)_name:" ;\
echo " .string \"$(FWNAME)\"" ;\
echo " .section .builtin_fw,\"a\",$(PROGBITS)" ;\
echo " .p2align $(ASM_ALIGN)" ;\
echo " $(ASM_WORD) _fw_$(FWSTR)_name" ;\
echo " $(ASM_WORD) _fw_$(FWSTR)_bin" ;\
if [ ! -s "$(fwdir)/$(FWNAME)" ]; then \
echo "error: empty firmware: $(fwdir)/$(FWNAME)" >&2 ;\
exit 1 ;\
fi ;\
echo "/* Generated by $(src)/Makefile */" ;\
echo " .section .rodata" ;\
echo " .p2align 4" ;\
echo "_fw_$(FWSTR)_bin:" ;\
echo " .incbin \"$(fwdir)/$(FWNAME)\"" ;\
echo "_fw_end:" ;\
echo " .section .rodata.str,\"aMS\",$(PROGBITS),1" ;\
echo " .p2align $(ASM_ALIGN)" ;\
echo "_fw_$(FWSTR)_name:" ;\
echo " .string \"$(FWNAME)\"" ;\
echo " .section .builtin_fw,\"a\",$(PROGBITS)" ;\
echo " .p2align $(ASM_ALIGN)" ;\
echo " $(ASM_WORD) _fw_$(FWSTR)_name" ;\
echo " $(ASM_WORD) _fw_$(FWSTR)_bin" ;\
echo " $(ASM_WORD) _fw_end - _fw_$(FWSTR)_bin"
$(obj)/%.gen.S: FORCE