Those of you who are Linux fans will love to hear that the PS4 and firmware 4.55 is now avaible for linux, heres the news:
Valentinbreiz announced via twitter that he and Vultra have updated the PS4 Linux loader payload for supported systems with firmware 4.55. According to the developer, the supported systems so far are all CUH-11XXX and some CUH-10XXX models, with CUH-1008A confirmed not working.
To get started you need two USB sticks (one is technically sufficient, but it's recommended to use a dedicated one with Linux installed). The first USB stick is used for the initialization process and the second one contains Linux and is ext2 formatted. The first one should be FAT 32 formatted and have bzImage and initramfs.cpio.gz on the root directory. You can get them on the developer's Github page. With that USB stick plugged in on any USB port, the PS4 is booted up. Next step is to start the payload, which is done by launching the PS4 web browser and using netcat to send the PS4-Linux-Loader.bin to the PS4. As another option, the developer suggests using his own PS4 Payload Sender tool.
Now in Rescue Shell, the first USB stick is removed and the second one plugged in. With an external keyboard, you have to find your second USB stick by typing the command fdisk -l. It is identified as /dev/sdc1 etc. Next commands to execute are mount /dev/sdc1 /newroot and exec switch_root /newroot/ /newroot/sbin/init. After that you should be good to go. If you have any questions, please post them in the linked discussion topic below.