[Buildroot] [PATCH 1/1] package/rpi-firmware: add configurable kernel cmdline option

[Yann E. MORIN <yann.morin.1998@free.fr>]

Ivo, All,

On 2015-08-09 17:47 +0200, Ivo Slanina spake thusly:
> Raspberry Pi expects cmdline.txt file at boot partition, which defines
> kernel parameters. Buildroot stores this file in package/rpi-firmware
> directory and makes this configuration quite unconfortable. Basicaly
> user have to manually edit output/images/rpi-firmware/cmdline.txt for
> every build.
> 
> This patch adds option to specify content of cmdline.txt and store it
> in configuration file. This approach removes need to manually modify
> this file for every build and adds posibility to store its value
> in configuration file per project.
> 
> Signed-off-by: Ivo Slanina <ivo.slanina@gmail.com>

No. Such tweaking should be left for a post-build script.

And *if* we were to have a mean to set the kernel command line in
Buildroot, it should not be specific to the RPi. It should be a generic
solution, that could be used for all bootloaders. I.e. an entry in the
kernel menu.

But I'm not really a fan of this; post-build scripts have been
introduced just for this kind of local customisation. Others may
disagree, though...

Regards,
Yann E. MORIN.

> ---
>  package/rpi-firmware/Config.in       | 6 ++++++
>  package/rpi-firmware/cmdline.txt     | 1 -
>  package/rpi-firmware/rpi-firmware.mk | 2 +-
>  3 files changed, 7 insertions(+), 2 deletions(-)
>  delete mode 100644 package/rpi-firmware/cmdline.txt
> 
> diff --git a/package/rpi-firmware/Config.in b/package/rpi-firmware/Config.in
> index 405674f..978ecfd 100644
> --- a/package/rpi-firmware/Config.in
> +++ b/package/rpi-firmware/Config.in
> @@ -39,6 +39,12 @@ config BR2_PACKAGE_RPI_FIRMWARE_CD
>  
>  endchoice
>  
> +config BR2_PACKAGE_RPI_FIRMWARE_CMDLINE
> +	string "Kernel cmdline"
> +	default "root=/dev/mmcblk0p2 rootwait"
> +	help
> +	  Set this value to customize cmdline.txt file at boot partition.
> +
>  config BR2_PACKAGE_RPI_FIRMWARE_BOOT
>  	string
>  	default ""      if BR2_PACKAGE_RPI_FIRMWARE_DEFAULT
> diff --git a/package/rpi-firmware/cmdline.txt b/package/rpi-firmware/cmdline.txt
> deleted file mode 100644
> index 38aa378..0000000
> --- a/package/rpi-firmware/cmdline.txt
> +++ /dev/null
> @@ -1 +0,0 @@
> -root=/dev/mmcblk0p2 rootwait
> diff --git a/package/rpi-firmware/rpi-firmware.mk b/package/rpi-firmware/rpi-firmware.mk
> index 1ef15aa..9d22a69 100644
> --- a/package/rpi-firmware/rpi-firmware.mk
> +++ b/package/rpi-firmware/rpi-firmware.mk
> @@ -41,7 +41,7 @@ define RPI_FIRMWARE_INSTALL_IMAGES_CMDS
>  	$(INSTALL) -D -m 0644 $(@D)/boot/start$(BR2_PACKAGE_RPI_FIRMWARE_BOOT).elf $(BINARIES_DIR)/rpi-firmware/start.elf
>  	$(INSTALL) -D -m 0644 $(@D)/boot/fixup$(BR2_PACKAGE_RPI_FIRMWARE_BOOT).dat $(BINARIES_DIR)/rpi-firmware/fixup.dat
>  	$(INSTALL) -D -m 0644 package/rpi-firmware/config.txt $(BINARIES_DIR)/rpi-firmware/config.txt
> -	$(INSTALL) -D -m 0644 package/rpi-firmware/cmdline.txt $(BINARIES_DIR)/rpi-firmware/cmdline.txt
> +	echo $(BR2_PACKAGE_RPI_FIRMWARE_CMDLINE) > $(BINARIES_DIR)/rpi-firmware/cmdline.txt
>  	$(RPI_FIRMWARE_INSTALL_DTB)
>  	$(RPI_FIRMWARE_INSTALL_DTB_OVERLAYS)
>  endef
> -- 
> 2.1.4
> 
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