Booting with modified kernel parameters?

[zackw]

Is there a way to do a one-off boot with changes to the kernel's "command line", ideally without opening up the PBP or attaching a serial console?  Like one would do on an x86 with GRUB by editing the menu entry.

I specifically want to interrupt the boot sequence while it's still running out of the initramfs and / isn't mounted, so that I can resize the partition, but I haven't been able to find anything on here talking about the general case.

I'm using the stock Debian install on the eMMC and I don't have a micro-SD card to put another OS instance on, unfortunately.

[Arwen]

In theory, you can edit the U-Boot configuration file for the command line. I don't know the option to do what you are asking, but this is the file you would need to edit on the stock Debian, as well as the line;

Code:

/boot/extlinux/extlinux.conf
append console=ttyS2,1500000n8 rw root=/dev/mmcblk1p2 rootwait rootfstype=ext4 panic=10 init=/sbin/init coherent_pool=1M ethaddr=${ethaddr} eth1addr=${eth1addr} serial=${serial#} cgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory swapaccount=1 zswap.enabled=1 video=HDMI-A-1:1920x1080@60 video=eDP-1:1920x1080@60 loglevel=3 vga=current

One thing. I think the default is to mount "/boot" as R/O, so keep that in mind. I forced it to be R/W so I don't have to worry about it.