Re: [ptxdist] [RFC] u-boot: Build in default envinronment from file

[Ladislav Michl <oss-lists@triops.cz>]

On Fri, Jun 05, 2026 at 04:34:04PM +0200, Michael Olbrich wrote:
> On Mon, Jun 01, 2026 at 03:42:49PM +0200, Ladislav Michl wrote:
> > Incorporating default envinroment from external file makes changes to it
> > much easier compared to creating patch for u-boot creating config file
> > with CONFIG_EXTRA_ENV_SETTINGS macro.
> > This however requires xxd tool, so question is where to get it from?
> > 1. leave to user, similar as HOST_SYSTEM_BC is made
> 
> I think we can go with this one.
> 
> > 2. add HOST_XXD, make it depend on HOST_VIM to reuse archive and compile
> >    just xxd
> > 3. patch u-boot to not use xxd
> > 
> > Except for the last case we would need something like 
> > select HOST_XXD if U_BOOT_DEFAULT_ENV
> > in the Kconfig.
> > 
> > Also, do we want envinronment file name configurable?
> 
> No, there is no good reason for something like that.
> 
> > Thanks for the suggestions,
> > 	ladis
> > 
> > ---
> >  platforms/u-boot.in |  9 +++++++++
> >  rules/u-boot.make   | 23 +++++++++++++++++++++++
> >  2 files changed, 32 insertions(+)
> > 
> > diff --git a/platforms/u-boot.in b/platforms/u-boot.in
> > index d263135ca..c1abe3930 100644
> > --- a/platforms/u-boot.in
> > +++ b/platforms/u-boot.in
> > @@ -73,6 +73,15 @@ config U_BOOT_CONFIGFILE_KCONFIG
> >  	help
> >  	  This entry specifies the .config file used to compile U-Boot.
> >  
> > +config U_BOOT_DEFAULT_ENV
> > +	prompt "compile in default environment from file"
> > +	bool
> > +	help
> > +	  Text file uboot-defaultenv.txt in the platform config directory
> > +	  describing the builtin default environment.
> > +	  The file should have lines in the form var=value, one per line.
> > +	  Blank lines and lines starting with a # are ignored.
> > +
> >  endif
> >  
> >  if U_BOOT_CONFIGSYSTEM_LEGACY
> > diff --git a/rules/u-boot.make b/rules/u-boot.make
> > index d3ea65cf2..1966ba9b6 100644
> > --- a/rules/u-boot.make
> > +++ b/rules/u-boot.make
> > @@ -39,6 +39,11 @@ endif
> >  U_BOOT_INJECT_PATH	:= ${PTXDIST_SYSROOT_TARGET}/usr/lib/firmware
> >  U_BOOT_INJECT_OOT	:= $(call ptx/ifdef, PTXCONF_U_BOOT_BUILD_OOT,YES,NO)
> >  
> > +ifdef PTXCONF_U_BOOT_DEFAULT_ENV
> > +U_BOOT_DEFAULT_ENV_TXT	:= $(call ptx/in-platformconfigdir, uboot-defaultenv.txt)
> > +$(call ptx/cfghash-file, U_BOOT, $(U_BOOT_DEFAULT_ENV_TXT))
> > +endif
> > +
> >  ifdef PTXCONF_U_BOOT_BOOT_SCRIPT
> >  U_BOOT_BOOT_SCRIPT_TXT := $(call ptx/in-platformconfigdir, uboot.scr)
> >  U_BOOT_BOOT_SCRIPT_BIN := $(call remove_quotes, \
> > @@ -119,6 +124,24 @@ endif
> >  
> >  $(STATEDIR)/u-boot.compile:
> >  	@$(call targetinfo)
> > +ifdef PTXCONF_U_BOOT_DEFAULT_ENV
> > +	@rm -rf $(U_BOOT_BUILD_DIR)/.ptxdist-defaultenv
> 
> Did you test this with PTXCONF_U_BOOT_BUILD_OOT enabled?

In fact I tested only OOT build...

> > +	@ln -s $(U_BOOT_DEFAULT_ENV_TXT) $(U_BOOT_BUILD_DIR)/.ptxdist-defaultenv
> > +#	# pre-2025.10
> > +	@sed -i -e 's,^.*CONFIG_USE_DEFAULT_ENV_FILE.*$$,CONFIG_USE_DEFAULT_ENV_FILE=y,g' \
> > +		$(U_BOOT_BUILD_DIR)/.config
> > +	@sed -i -e '/\\<CONFIG_DEFAULT_ENV_FILE\\>/d' \
> > +		$(U_BOOT_BUILD_DIR)/.config
> > +	@sed -i -e '/CONFIG_USE_DEFAULT_ENV_FILE=y/a CONFIG_DEFAULT_ENV_FILE=".ptxdist-defaultenv"' \
> > +		$(U_BOOT_BUILD_DIR)/.config
> > +#	# 2025.10 and later
> > +	@sed -i -e 's,^.*CONFIG_ENV_USE_DEFAULT_ENV_TEXT_FILE.*$$,CONFIG_ENV_USE_DEFAULT_ENV_TEXT_FILE=y,g' \
> > +		$(U_BOOT_BUILD_DIR)/.config
> > +	@sed -i -e '/\\<CONFIG_ENV_DEFAULT_ENV_TEXT_FILE\\>/d' \
> > +		$(U_BOOT_BUILD_DIR)/.config
> > +	@sed -i -e '/CONFIG_ENV_USE_DEFAULT_ENV_TEXT_FILE=y/a CONFIG_ENV_DEFAULT_ENV_TEXT_FILE=".ptxdist-defaultenv"' \
> > +		$(U_BOOT_BUILD_DIR)/.config
> 
> I'd like to avoid patching the config like that. I know we do it in barebox
> as well, but:

Indeed, barebox was my inspiration.

> 1. it's an absolute path that cannot be in the config
> 2. only the variable with the path, not enabling it as well
> 3. legacy, so changing it will break things.
> 
> Please just check here, that the correct options are set and describe what
> needs to be done in the menu help.

Just to be clear: are you suggesting to propose a filename user will
set in u-boot config and the only thing ptxdist does then is to provide
a symling of that name? So I can delete all those nice sed regular
expressions... ;-) What is the suggested default environment name then?

> Michael
> 
> > +endif
> >  	@$(call world/compile, U_BOOT)
> >  ifdef PTXCONF_U_BOOT_VERIFY_SIGNATURE
> >  	@mv $(U_BOOT_BUILD_DIR)/u-boot.dtb $(U_BOOT_BUILD_DIR)/u-boot-pubkey.dtb
> > -- 
> > 2.47.3
> > 
> > 
> > 
> 
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