We use livecd-rootfs to build the 24.04 build.
Kernel used is https://git.codelinaro.org/clo/le/canonical-kernel/ubuntu/source/linux-qcom/noble/-/tree/canonical/master-next?ref_type=heads.
This Canonical/Qualcomm 24.04 (Noble) Ubuntu kernel with a bunch of cherry-picks from non-mainline Qualcomm fork.
See this docs page for everything:
https://developer.particle.io/tachyon/software/ubuntu_24_04/ubuntu-24.04-status