Custom kernel in archlinux live cd

There are no quirks getting a custom kernel in Archlinux live cd. Install the kernel as you install any other package (in chroot).

For example:

pacman -Syu linux-lts

Though, additionally, it is recommended to install the archiso package. Currently, JLIVECD tries to install it automatically which may change in future. Thus, it is suggested to install that package manually:

pacman -Syu archiso

After exiting chroot, let JLiveCD rebuild the initramfs:

*** ##### Init script & Kernel related #####
Rebuild the initramfs if you have 
1. changed init scripts or kernel modules
2. installed new kernel and want to boot that kernel in the live session.

=== Rebuild initramfs (Y/n)? (default 'n'): y

and give the kernel:

=== Enter kernel (n to skip) (default 'linux-lts'):

That's it.