[SOLVED] /boot/cmdline.txt on RPi3 running aarch64 image

[wolt]

I'm trying to add something to my command line params by editing /boot/cmdline.txt and having no luck. I've searched around and found that /boot/cmdline.txt IS the file to edit here, but I'm suspicious that running a 64 bit image is the culprit, as I've been unable to find any information about editing command line args on a Pi3 running a 64-bit kernel.

There is this thread mentioning a similar issue to mine: viewtopic.php?f=65&t=11793 where the poster for some reason decided to not answer questions to help find out the solution to his problem (grr...). Another person with the same problem and no help: here

/boot/cmdline.txt initially didn't exist, I created it with the following:
$this->bbcode_second_pass_code('', 'cat /proc/cmdline > /boot/cmdline.txt')

My modified /boot/cmdline.txt
$this->bbcode_second_pass_code('', '
console=ttyS1,115200 console=tty0 root=PARTUUID=d2175aeb-02 rw rootwait smsc95xx.macaddr=b8:27:eb:ff:e0:73 usb-storage.quirks=0x0bc2:0xa013:u
')

My /proc/cmdline after booting with the above /boot/cmdline.txt
$this->bbcode_second_pass_code('', '
console=ttyS1,115200 console=tty0 root=PARTUUID=d2175aeb-02 rw rootwait smsc95xx.macaddr=b8:27:eb:ff:e0:73
')

Anybody know how to edit the command line args on a Pi3 running a 64 bit image?

[ufo6000]

rpi3 with aarch64 uses another boot type, uboot.

You need to install the tools with pacman first: uboot-tools

Then you can edit /boot/boot.txt - the file should be existing.
After editing the file you need to "compile" it by running ./mkscr in this folder.

[TheSaint]

As you'll get to edit and compile boot.txt, just to remember to edit the bootargs variable, and add the kernel parameters that you need.

[wolt]

Thanks to you both, that's what was needed.