Edit /isolinux/menu.cfg to remove system bell on main menu for USB drive?

[sam_devil]

Hello,
I would like to create a custom image of Kali specifically to remove the annoying system bell on the boot menu that someone thought was a bright idea for some unknown reason. I know the file I need to edit is /isolinux/menu.cfg and to remove the "^G"; however, I run into several issues. Modifying the iso directly results in a non-bootable USB drive. If I burn the image to a USB drive and attempt to edit the file, it seems to be in a read-only filesystem that I am unable to mount with read-write permissions. I am also unable to locate the isolinux folder in other operating systems. Finally, taking a look at the custom Kali builder scripts, it does not include the menu.cfg file. Is there any way we can get rid of this beep without removing the laptop speakers?
Thanks!

[scorpius]

Burn a regular ISO to a USB drive via dd. Then use a hexeditor to replace all occurrences of mate<^G> with mate<SPACE>.

So if you use the hexeditor that comes with Kali, just start it with hexeditor -d /dev/sdb, for example. Then for the search term you type "mate" followed by CTRL-V then CTRL-G. And then just replace the 07 at the end of the string menu with 20.

Or if you prefer all hex, replace 6d656e7507 with 6d656e7520. I found 2 occurrences on my iso.

Update: Here's an easy way to do it from the command line.
perl -p -i -e 's;\x6d\x65\x6e\x75\x07;\x6d\x65\x6e\x75\x20;g' your-kali.iso

[brunoaduarte]

Burn a regular ISO to a USB drive via dd. Then use a hexeditor to replace all occurrences of mate<^G> with mate<SPACE>.

So if you use the hexeditor that comes with Kali, just start it with hexeditor -d /dev/sdb, for example. Then for the search term you type "mate" followed by CTRL-V then CTRL-G. And then just replace the 07 at the end of the string menu with 20.

Or if you prefer all hex, replace 6d656e7507 with 6d656e7520. I found 2 occurrences on my iso.

Update: Here's an easy way to do it from the command line.
perl -p -i -e 's;\x6d\x65\x6e\x75\x07;\x6d\x65\x6e\x75\x20;g' your-kali.iso

Thanks scorpius,

I've used HexWorkshop in windows to replace the hex sequences on a Kali USB image and it worked, beep is now disabled. Thanks !