[PATCH] bootm: filter out "<NULL>" rootopts to avoid kernel cmdline noise

[Alexander Shiyan]

Hello, Sasha.

This does not work as expected.

barebox at Diasom DS-RK3568-SOM-EVB:/ global.boot.default=mmc1.2
barebox at Diasom DS-RK3568-SOM-EVB:/ boot
ext4 ext40: EXT2 rev 1, inode_size 256, descriptor size 64
Booting entry 'extlinux: linux'
extlinux: Booting extlinux label 'linux'
Adding "root=/dev/mmcblk1p3 <NULL>" to Kernel commandline

Loading ARM aarch64 Linux/EFI image '/mnt/mmc1.2/boot/extlinux/../vmlinuz'
Loaded initrd from GZIP compressed
/mnt/mmc1.2/boot/extlinux/../initrd.img to
0x000000000d390000-0x000000000fb48ca6
Camera IMX662 detected.
commandline: mem=0xef600000 root=/dev/mmcblk1p3 <NULL>
console=ttyS2,1500000n8 ro systemd.unit=setup.target quiet splash
systemd.machine_id=181af2816b4c6b0aef77068e0ccc69ad
Loaded kernel to 0x0a400000, devicetree at 0x000000000fb49000
nv variables modified, saving them

пт, 17 апр. 2026 г. в 11:44, Sascha Hauer <s.hauer at pengutronix.de>:
>
> Hi Alexander,
>
> On Thu, Apr 16, 2026 at 03:55:12PM +0300, Alexander Shiyan wrote:
> > When rootopts is set to the literal string "<NULL>" (e.g., due to a
> > missing or invalid value in cdev_get_linux_root_and_opts), the resulting
> > kernel command line contains "root=/dev/... <NULL>", which is invalid
> > and may cause boot failures or confusion.
> >
> > This patch checks for the "<NULL>" string in rootopts and replaces it
> > with NULL before calling format_root_bootarg(), effectively omitting
> > the erroneous token from the command line.
>
> I would rather avoid setting it to "<NULL>" in the first place.
>
> Does the patch I just sent help or is there another place where this
> happens?
>
> Sascha
>
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