You need 1 Gb free space disk. Same source is used for all DMS modules. As example, for Debian Bullseye, you can take:
wget https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/linux-5.10.tar.xz
Then uncompress it to the source directory:
sudo tar -xf linux-5.10.tar.xz -C /usr/src