Re: [PATCH] distroboot: Fix ubifs

["Pali Rohár" <pali@kernel.org>]

Hello!

On Wednesday 29 June 2022 15:36:57 Alexander Dahl wrote:
> Hello Pali,
> 
> had a look at this patch, and have some questions.  See below.
> 
> Am Dienstag, 31. Mai 2022, 10:32:36 CEST schrieb Pali Rohár:
> > Fix multiple issues in ubifs distroboot code:
> > 
> > U-Boot supports attaching only one MTD device as UBI at the time. So
> > always call 'ubifsmount ubi0:${bootubivol}' for mounting UBI volume
> > ${bootubivol}. Usage of 'ubi${devnum}' is incorrect as 'ubi part'
> > command attach MTD device always as UBI device ubi0.
> 
> Agreed.
> 
> > Set distroboot ${bootfstype} variable to ubifs in ubifs_boot command.
> > Distroboot scripts require ${bootfstype} variable to be properly set and it
> > is already set for all other boot types.
> 
> From grepping through u-boot source, I can not quite follow.  Where is that 
> variable set and where is it used?

For non-ubifs boot targets, env variable ${bootfstype} is set by
scan_dev_for_boot_part shell fragment. Then it calls user boot script
which can use ${bootfstype} variable. In most cases it is used for
constructing cmdline for kernel, mainly as "roofstype=${bootfstype}".

> > Set distroboot ${distro_bootpart} variable to ${bootubivol} value. UBI
> > device does not have partitions, but has volumes. Distroboot scripts
> > require something to be set in ${distro_bootpart} variable, so set it to
> > the UBI volume which is currently mounted by ubifs.
> > 
> > Set distroboot ${devnum} variable to fixed string "ubi0". ubifs code
> > differs from the other partition code that it requires "ubi" prefix before
> > number.
> 
> Okay.
> 
> > Explicitly unmount ubifs volume after loading all data from it. This allows
> > to detach UBI device from MTD device.
> 
> Okay.
> 
> > Move definition of MTD device with UBI and UBI volume with ubifs filesystem
> > from global env variables ${bootubipart} and ${bootubivol} into the
> > distroboot "func" macro, defined in board include config files. UBIFS
> > distroboot macros then set ${bootubipart} and ${bootubivol} local variables
> > for compatibility with existing distroboot scripts.
> 
> This might be problematic.  For a downstream board we use the 'bootubivol' env 
> variable to switch between different volumes for update purposes.  Means on 
> firmware update we modify U-Boot environment from Linux (fw_setenv) after 
> successfully updating the inactive volume.

Interesting... I even did not thought about such use case as it is not
possible to do it with other boot filesystems.

> > This last change allows to define more UBIFS target devices and make it
> > clear what is boot MTD/UBI device.
> 
> How would one switch the default UBI volume to be booted from then?

With this my change, it is probably not easily possible. One option is
to define more boot targets, e.g.:

  func(UBIFS, ubifs, 0, UBI, volume0)
  func(UBIFS, ubifs, 1, UBI, volume1)

And then change env ${boottargets} from ubifs0 to ubifs1, which can be
done via fs_setenv.

As with this change is finally possible to specify more ubifs targets
in BOOT_TARGET_DEVICES() u-boot macro.

This would be same as switching between other u-boot distroboot targets.

...

But I can understand that you want to have this (probably undocumented)
behavior of switching UBI volume via env variable ${bootubivol}.

So what about allowing both configuration in U-Boot, with stored boot
volume in ENV and with hardcoded boot volume in config file?

And which / how many boards use this functionality?

> Greets
> Alex
> 
> > All board include config files are adjusted to use this new scheme of
> > specifying boot MTD/UBI device.
> > 
> > Signed-off-by: Pali Rohár <pali@kernel.org>
> > ---
> > CI test passed on https://github.com/u-boot/u-boot/pull/179
> > ---
> >  include/config_distro_bootcmd.h    | 27 ++++++++++++++++-----------
> >  include/configs/am335x_guardian.h  |  3 +--
> >  include/configs/colibri-imx6ull.h  |  1 -
> >  include/configs/colibri_imx7.h     |  1 -
> >  include/configs/kontron-sl-mx6ul.h |  2 +-
> >  include/configs/mys_6ulx.h         |  2 +-
> >  include/configs/npi_imx6ull.h      |  2 +-
> >  include/configs/omap3_beagle.h     |  4 +---
> >  include/configs/omap3_evm.h        |  4 +---
> >  include/configs/pcl063.h           |  2 +-
> >  include/configs/stm32mp15_common.h |  2 +-
> >  include/configs/uniphier.h         |  2 +-
> >  12 files changed, 25 insertions(+), 27 deletions(-)
> > 
> > diff --git a/include/config_distro_bootcmd.h
> > b/include/config_distro_bootcmd.h index c55023889cab..c6e9c497413d 100644
> > --- a/include/config_distro_bootcmd.h
> > +++ b/include/config_distro_bootcmd.h
> > @@ -70,18 +70,23 @@
> >  #ifdef CONFIG_CMD_UBIFS
> >  #define BOOTENV_SHARED_UBIFS \
> >  	"ubifs_boot=" \
> > -		"env exists bootubipart || " \
> > -			"env set bootubipart UBI; " \
> > -		"env exists bootubivol || " \
> > -			"env set bootubivol boot; " \
> >  		"if ubi part ${bootubipart} && " \
> > -			"ubifsmount ubi${devnum}:${bootubivol}; " \
> > +			"ubifsmount ubi0:${bootubivol}; " \
> >  		"then " \
> >  			"devtype=ubi; " \
> > +			"devnum=ubi0; " \
> > +			"bootfstype=ubifs; " \
> > +			"distro_bootpart=${bootubivol}; " \
> >  			"run scan_dev_for_boot; " \
> > +			"ubifsumount; " \
> >  		"fi\0"
> > -#define BOOTENV_DEV_UBIFS	BOOTENV_DEV_BLKDEV
> > -#define BOOTENV_DEV_NAME_UBIFS	BOOTENV_DEV_NAME_BLKDEV
> > +#define BOOTENV_DEV_UBIFS(devtypeu, devtypel, instance, bootubipart,
> > bootubivol) \ +	"bootcmd_ubifs" #instance "=" \
> > +		"bootubipart=" #bootubipart "; " \
> > +		"bootubivol=" #bootubivol "; " \
> > +		"run ubifs_boot\0"
> > +#define BOOTENV_DEV_NAME_UBIFS(devtypeu, devtypel, instance, bootubipart,
> > bootubivol) \ +	#devtypel #instance " "
> >  #else
> >  #define BOOTENV_SHARED_UBIFS
> >  #define BOOTENV_DEV_UBIFS \
> > @@ -411,13 +416,13 @@
> >  	BOOT_TARGET_DEVICES_references_PXE_without_CONFIG_CMD_DHCP_or_PXE
> >  #endif
> > 
> > -#define BOOTENV_DEV_NAME(devtypeu, devtypel, instance) \
> > -	BOOTENV_DEV_NAME_##devtypeu(devtypeu, devtypel, instance)
> > +#define BOOTENV_DEV_NAME(devtypeu, devtypel, instance, ...) \
> > +	BOOTENV_DEV_NAME_##devtypeu(devtypeu, devtypel, instance, ## __VA_ARGS__)
> >  #define BOOTENV_BOOT_TARGETS \
> >  	"boot_targets=" BOOT_TARGET_DEVICES(BOOTENV_DEV_NAME) "\0"
> > 
> > -#define BOOTENV_DEV(devtypeu, devtypel, instance) \
> > -	BOOTENV_DEV_##devtypeu(devtypeu, devtypel, instance)
> > +#define BOOTENV_DEV(devtypeu, devtypel, instance, ...) \
> > +	BOOTENV_DEV_##devtypeu(devtypeu, devtypel, instance, ## __VA_ARGS__)
> >  #define BOOTENV \
> >  	BOOTENV_SHARED_HOST \
> >  	BOOTENV_SHARED_MMC \
> > diff --git a/include/configs/am335x_guardian.h
> > b/include/configs/am335x_guardian.h index b92703205cde..340715dad5c6 100644
> > --- a/include/configs/am335x_guardian.h
> > +++ b/include/configs/am335x_guardian.h
> > @@ -29,7 +29,7 @@
> >  	"ramdisk_addr_r=0x88080000\0" \
> > 
> >  #define BOOT_TARGET_DEVICES(func) \
> > -	func(UBIFS, ubifs, 0)
> > +	func(UBIFS, ubifs, 0, UBI, rootfs)
> > 
> >  #define AM335XX_BOARD_FDTFILE "fdtfile=" CONFIG_DEFAULT_DEVICE_TREE
> > ".dtb\0"
> > 
> > @@ -54,7 +54,6 @@
> >  	GUARDIAN_DEFAULT_PROD_ENV \
> >  	"autoload=no\0" \
> >  	"backlight_brightness=50\0" \
> > -	"bootubivol=rootfs\0" \
> >  	"distro_bootcmd=" \
> >  		"setenv rootflags \"bulk_read,chk_data_crc\"; " \
> >  		"setenv ethact usb_ether; " \
> > diff --git a/include/configs/colibri-imx6ull.h
> > b/include/configs/colibri-imx6ull.h index 9e5212acb2ee..a0a0e1767fe0 100644
> > --- a/include/configs/colibri-imx6ull.h
> > +++ b/include/configs/colibri-imx6ull.h
> > @@ -91,7 +91,6 @@
> >  	UBI_BOOTCMD \
> >  	UBOOT_UPDATE \
> >  	"boot_script_dhcp=boot.scr\0" \
> > -	"bootubipart=ubi\0" \
> >  	"console=ttymxc0\0" \
> >  	"defargs=user_debug=30\0" \
> >  	"fdt_board=eval-v3\0" \
> > diff --git a/include/configs/colibri_imx7.h b/include/configs/colibri_imx7.h
> > index 3dba7bcef258..3cad17777975 100644
> > --- a/include/configs/colibri_imx7.h
> > +++ b/include/configs/colibri_imx7.h
> > @@ -131,7 +131,6 @@
> >  	UBOOT_UPDATE \
> >  	"boot_file=zImage\0" \
> >  	"boot_script_dhcp=boot.scr\0" \
> > -	"bootubipart=ubi\0" \
> >  	"console=ttymxc0\0" \
> >  	"defargs=\0" \
> >  	"fdt_board=eval-v3\0" \
> > diff --git a/include/configs/kontron-sl-mx6ul.h
> > b/include/configs/kontron-sl-mx6ul.h index 7bc402d578e8..b4808d2bbf75
> > 100644
> > --- a/include/configs/kontron-sl-mx6ul.h
> > +++ b/include/configs/kontron-sl-mx6ul.h
> > @@ -45,7 +45,7 @@
> >  #define BOOT_TARGET_DEVICES(func) \
> >  	func(MMC, mmc, 1) \
> >  	func(MMC, mmc, 0) \
> > -	func(UBIFS, ubifs, 0) \
> > +	func(UBIFS, ubifs, 0, UBI, boot) \
> >  	func(USB, usb, 0) \
> >  	func(PXE, pxe, na) \
> >  	func(DHCP, dhcp, na)
> > diff --git a/include/configs/mys_6ulx.h b/include/configs/mys_6ulx.h
> > index 6801fc109eae..663820177a3e 100644
> > --- a/include/configs/mys_6ulx.h
> > +++ b/include/configs/mys_6ulx.h
> > @@ -59,7 +59,7 @@
> > 
> >  #define BOOT_TARGET_DEVICES(func) \
> >  	func(MMC, mmc, 0) \
> > -	func(UBIFS, ubifs, 0) \
> > +	func(UBIFS, ubifs, 0, UBI, boot) \
> >  	func(PXE, pxe, na) \
> >  	func(DHCP, dhcp, na)
> > 
> > diff --git a/include/configs/npi_imx6ull.h b/include/configs/npi_imx6ull.h
> > index c250fa650603..ebb887544e08 100644
> > --- a/include/configs/npi_imx6ull.h
> > +++ b/include/configs/npi_imx6ull.h
> > @@ -67,7 +67,7 @@
> > 
> >  #define BOOT_TARGET_DEVICES(func) \
> >  	func(MMC, mmc, 0) \
> > -	func(UBIFS, ubifs, 0) \
> > +	func(UBIFS, ubifs, 0, UBI, boot) \
> >  	func(PXE, pxe, na) \
> >  	func(DHCP, dhcp, na)
> > 
> > diff --git a/include/configs/omap3_beagle.h b/include/configs/omap3_beagle.h
> > index 158773acedb9..f5da08cf3359 100644
> > --- a/include/configs/omap3_beagle.h
> > +++ b/include/configs/omap3_beagle.h
> > @@ -65,7 +65,7 @@
> >  #define BOOT_TARGET_DEVICES(func) \
> >  	func(MMC, mmc, 0) \
> >  	func(LEGACY_MMC, legacy_mmc, 0) \
> > -	func(UBIFS, ubifs, 0) \
> > +	func(UBIFS, ubifs, 0, rootfs, rootfs) \
> >  	func(NAND, nand, 0)
> > 
> >  #else /* !CONFIG_MTD_RAW_NAND */
> > @@ -87,8 +87,6 @@
> >  	"bootenv=uEnv.txt\0" \
> >  	"bootfile=zImage\0" \
> >  	"bootpart=0:2\0" \
> > -	"bootubivol=rootfs\0" \
> > -	"bootubipart=rootfs\0" \
> >  	"usbtty=cdc_acm\0" \
> >  	"mpurate=auto\0" \
> >  	"buddy=none\0" \
> > diff --git a/include/configs/omap3_evm.h b/include/configs/omap3_evm.h
> > index eeb9ef8c741a..cc98e03096ab 100644
> > --- a/include/configs/omap3_evm.h
> > +++ b/include/configs/omap3_evm.h
> > @@ -60,7 +60,7 @@
> >  #define BOOT_TARGET_DEVICES(func) \
> >  	func(MMC, mmc, 0) \
> >  	func(LEGACY_MMC, legacy_mmc, 0) \
> > -	func(UBIFS, ubifs, 0) \
> > +	func(UBIFS, ubifs, 0, rootfs, rootfs) \
> >  	func(NAND, nand, 0)
> > 
> >  #else /* !CONFIG_MTD_RAW_NAND */
> > @@ -88,8 +88,6 @@
> >  	"bootenv=uEnv.txt\0" \
> >  	"bootfile=zImage\0" \
> >  	"bootpart=0:2\0" \
> > -	"bootubivol=rootfs\0" \
> > -	"bootubipart=rootfs\0" \
> >  	"optargs=\0" \
> >  	"nandroot=ubi0:rootfs ubi.mtd=rootfs rw noinitrd\0" \
> >  	"nandrootfstype=ubifs rootwait\0" \
> > diff --git a/include/configs/pcl063.h b/include/configs/pcl063.h
> > index 31b7d07a24cd..c3f7e7eb2c4b 100644
> > --- a/include/configs/pcl063.h
> > +++ b/include/configs/pcl063.h
> > @@ -71,7 +71,7 @@
> > 
> >  #define BOOT_TARGET_DEVICES(func) \
> >  	func(MMC, mmc, 0) \
> > -	func(UBIFS, ubifs, 0) \
> > +	func(UBIFS, ubifs, 0, UBI, boot) \
> >  	func(PXE, pxe, na) \
> >  	func(DHCP, dhcp, na)
> > 
> > diff --git a/include/configs/stm32mp15_common.h
> > b/include/configs/stm32mp15_common.h index 6b40cdb01779..68ea56e69c98
> > 100644
> > --- a/include/configs/stm32mp15_common.h
> > +++ b/include/configs/stm32mp15_common.h
> > @@ -77,7 +77,7 @@
> >  #endif
> > 
> >  #ifdef CONFIG_CMD_UBIFS
> > -#define BOOT_TARGET_UBIFS(func)	func(UBIFS, ubifs, 0)
> > +#define BOOT_TARGET_UBIFS(func)	func(UBIFS, ubifs, 0, UBI, boot)
> >  #else
> >  #define BOOT_TARGET_UBIFS(func)
> >  #endif
> > diff --git a/include/configs/uniphier.h b/include/configs/uniphier.h
> > index f813f88cdd7a..640a29067d85 100644
> > --- a/include/configs/uniphier.h
> > +++ b/include/configs/uniphier.h
> > @@ -20,7 +20,7 @@
> >  #endif
> > 
> >  #ifdef CONFIG_CMD_UBIFS
> > -#define BOOT_TARGET_DEVICE_UBIFS(func)	func(UBIFS, ubifs, 0)
> > +#define BOOT_TARGET_DEVICE_UBIFS(func)	func(UBIFS, ubifs, 0, UBI, boot)
> >  #else
> >  #define BOOT_TARGET_DEVICE_UBIFS(func)
> >  #endif
> 
> 
> 
>