Hi alh.
I managed to have it working, in BIOS Legacy mode (MBR), by editing the Syslinux boot-menu, adding "ip=dhcp archiso_http_srv=http://${pxeserver}:16000/eiso/id/<eiso_ID>/" (pay attention to having the last slash after the eiso ID, else it won't find "<eiso>airootfs.sfs").
I didn't try in UEFI/GPT mode up to now, it should consist in adding the equivalent to Grub's config, but what I'm sure, the "${pxeserver}" variable isn't available in Grub, it perhaps have an other name.
I managed to have it working, in BIOS Legacy mode (MBR), by editing the Syslinux boot-menu, adding "ip=dhcp archiso_http_srv=http://${pxeserver}:16000/eiso/id/<eiso_ID>/" (pay attention to having the last slash after the eiso ID, else it won't find "<eiso>airootfs.sfs").
I didn't try in UEFI/GPT mode up to now, it should consist in adding the equivalent to Grub's config, but what I'm sure, the "${pxeserver}" variable isn't available in Grub, it perhaps have an other name.