Here is the meta-intel-edison that builds, tries to stay up to date. Master is based on Yocto Poky Gatesgarth LTS 5.10.yy vanilla kernels. It builds a 32bit kernel (Gatesgarth branch 64bit) with ACPI enabled and corresponding rootfs. Telegram group: https://t.me/IntelEdison Web-site:
Looking at ap-mode-toggle, to allow tethering it needs brctl (from bridge-utils). And bridge-utils needs ethernet bridge support from the kernel.