fix: Switch to space-separated sources.conf format

- Change from colon to space separation to avoid URL parsing issues
- Update sources.conf format: TYPE NAME URL VERSION BUILD_FUNCTION [EXTRA]
- Implement awk-based parsing for reliable field extraction
- Fix firmware package list (remove unavailable linux-firmware-marvell)

initramfs/usr/lib/udev/rules.d/64-btrfs.rules

@@ -0,0 +1,17 @@
+# do not edit this file, it will be overwritten on update
+
+SUBSYSTEM!="block", GOTO="btrfs_end"
+ACTION=="remove", GOTO="btrfs_end"
+ENV{ID_FS_TYPE}!="btrfs", GOTO="btrfs_end"
+ENV{SYSTEMD_READY}=="0", GOTO="btrfs_end"
+
+# let the kernel know about this btrfs filesystem, and check if it is complete
+IMPORT{builtin}="btrfs ready $devnode"
+
+# mark the device as not ready to be used by the system
+ENV{ID_BTRFS_READY}=="0", ENV{SYSTEMD_READY}="0"
+
+# reconsider pending devices in case when multidevice volume awaits
+ENV{ID_BTRFS_READY}=="1", RUN+="/bin/udevadm trigger -s block -p ID_BTRFS_READY=0"
+
+LABEL="btrfs_end"