[PATCH] firmware: fix missing firmware handling for external firmware

[Sascha Hauer]

Hi Marco,

On Wed, Jan 10, 2024 at 03:59:08PM +0100, Marco Felsch wrote:
> Currently we depend on the external firmware file since we need it for
> the sha256sum. But this dependency break the 'optional missing firmware'
> feature.
> 
> Fix this by dropping the firmware file prerequisite and instead evaluate
> the FWNAME_EXISTS variable. If the firmware file does not exist a dummy
> file is created and the build continues till the linking process (like
> we do for the other firmware).
> 
> Signed-off-by: Marco Felsch <m.felsch at pengutronix.de>
> ---
>  firmware/Makefile    | 6 +++---
>  images/Makefile      | 2 +-
>  scripts/Makefile.lib | 2 +-
>  3 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/firmware/Makefile b/firmware/Makefile
> index 51d98d54bf14..a07b31caec73 100644
> --- a/firmware/Makefile
> +++ b/firmware/Makefile
> @@ -41,7 +41,7 @@ fwobjdir := $(objtree)/firmware
>  pbl-y     := $(addsuffix .gen.o, $(pbl-firmware-y))
>  obj-pbl-y := $(addsuffix .gen.o, $(firmware-y))
>  
> -FWNAME    = $(patsubst $(obj)/%.extgen.S,%,$(patsubst $(obj)/%.gen.S,%,$@))
> +FWNAME    = $(patsubst $(obj)/%.sum,%,$(patsubst $(obj)/%.extgen.S,%,$(patsubst $(obj)/%.gen.S,%,$@)))

The purpose of this change is not clear to me. You replace the pattern
%.sum with %, but I don't see how this ever matches.

Dropping this change has no visible effect for me.

>  FWSTR     = $(subst /,_,$(subst .,_,$(subst -,_,$(FWNAME))))
>  FWNAME_EXISTS = $(if $(wildcard $(fwdir)/$(FWNAME)),1,0)
>  
> @@ -91,8 +91,8 @@ $(obj)/%.extgen.S: $(obj)/%.sha.bin FORCE
>  $(obj)/%.sha.bin: $(obj)/%.sum FORCE
>  	$(call if_changed,sha256bin)
>  
> -$(obj)/%.sum: $(obj)/% FORCE
> -	$(call if_changed,sha256sum)
> +$(obj)/%.sum: FORCE
> +	$(if $(findstring 1,$(FWNAME_EXISTS)), $(call if_changed,sha256sum,$(obj)/$*), @touch $@)
                                                                             ^^^

$(obj) should be $(fwdir) as this is the directory where the firmware
files are.

Sascha

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