PXE boot from a Raspberry Pi

I am trying to rescue an old laptop with no working cdrom and no usb-boot-support by setting up a tftp server to boot Linux Mint 20 from a Raspberry Pi running archlinux arm.

What i have so far:

• A dhcp-server through NetworkManagers dnsmasq-feature.
• A directory /srv/tftp owned by user/group 'dnsmasq' and 644-Privileges
• A copy of https://mirrors.edge.kernel.org/pub/...ux-6.03.tar.gz from wich i extracted pxelinux.0 to /srv/tftp
• A linuxmint-20-xfce-64Bit.iso mounted on /srv/tftp/image
• A dropin-file for dnsmasq '30-tftp.conf'
  Code:enable-tftp
  tftp-root=/srv/tftp
  tftp-boot=/srv/tftp/pxelinux.0
• and a file /srv/tftp/pxelinux.cfg/default that contains:
  Code:MENU LABEL mint
  LINUX image/casper/vmlinuz
  INITRD image/casper/initrd.lz
  APPEND file=mint/preseed/linuxmint.seed boot=casper acpi=off fetch=tftp://10.0.0.1/image/casper/filesystem.squashfs quiet splash --

So far i get a DHCP Lease and a Timeout when trying to boot (The Boot-Screen says "PXE-E32: TFTP open timeout")
I mostly followed thisToturial allthough i tried to keep it a bit simpler regarding the boot-menu and its features. I feel like i am not totally wrong with the steps above but something is missing for sure. Can someobe please give an opinion?