Developers ValentinBreiz and Vultra have updated the Linux Loader payload to support PS4 4.55. Similarly to the 4.05 release, in general only Phat PS4s and a subset of PS4 Slim are compatible with this release (see details below).

Download & run Linux Loader for PS4 4.55

You can download the payload from the developer’s github here.

To install and run, from the project’s readme:

For now only some PS4 FAT models are supported, see the list here. You need a FAT32 formatted USB drive plugged in on any PS4’s USB port with the following files on the root directory : bzImage and initramfs.cpio.gz. You can download them here. Then you will need to send the payload (PS4-Linux-Loader.bin) to your PS4. For that go to your PS4 web browser, send the payload to your PS4 using netcat or other.. (You can also use my tool: PS4 Payload Sender).

Source: Valentinbreiz