Proceeding the OpenOrbis PS4 Toolchain release, developer John Tornblom recently shared a Tiny PS4 Shell small Telnet server PKG alongside a 7.55 Fork from therootlord for those in the PlayStation 4 Scene with a Jailbroken PS4 to send UNIX-like commands to their console for tasks such as decrypting PS4 SELF and SPRX files. 
Download: IV0000-BREW00009_00-TELNETSHELL00000.pkg / tiny-ps4-shell-master.zip / GIT / 7.55 Fork GIT / tiny-ps4-shell payloads.rar (Compiled) via @Coco Jones (not working on 7.55 per Etherion)
Here's more from the README.md, as follows: Tiny PS4 Shell
Tiny-PS4-shell is a small telnet server for the PS4 with a couple of basic UNIX-like commands, e.g., cd, mkdir, stat, etc.
Building
Assuming you have the OpenOrbis PS4 Toolchain installed on you machine, tiny-ps4-shell can be compiled using the following two commands:
You can also compile for POSIX-like systems:
Usage
Install the compiled pkg on a PS4 with homebrew and the kexec syscall enabled, launch the application, and telnet to the PS4 (port 2323). There are a handful of rudimentary commands available, e.g., cd, ls, and mkdir. Type help in a connected telnet shell for more information. Below are a couple of commands I have found useful.
To get a list of running processes:
To obtain root permissions:
To escape the initial jailed sandbox:
To monitor kernel log:
To decrypt SELF and SPRX files:
Limitations
The login session is not attached to a TTY, so you cannot signal for, e.g., SIGINT with Ctrl+C. Furthermore, most of the commands are only partially implemented. If you find some limitation extra annoying, file a github issue and perhaps it will be addressed.
Reporting Bugs
If you encounter problems with tiny-ps4-shell, please file a github issue. If you plan on sending pull requests which affect more than a few lines of code, please file an issue before you start to work on you changes. This will allow us to discuss the solution properly before you commit time and effort.
License
Tiny-ps4-shell is licensed under the GPLv3+.
Download: IV0000-BREW00009_00-TELNETSHELL00000.pkg / tiny-ps4-shell-master.zip / GIT / 7.55 Fork GIT / tiny-ps4-shell payloads.rar (Compiled) via @Coco Jones (not working on 7.55 per Etherion)
Here's more from the README.md, as follows: Tiny PS4 Shell
Tiny-PS4-shell is a small telnet server for the PS4 with a couple of basic UNIX-like commands, e.g., cd, mkdir, stat, etc.
Building
Assuming you have the OpenOrbis PS4 Toolchain installed on you machine, tiny-ps4-shell can be compiled using the following two commands:
Code:
[email protected]:tiny-ps4-shell$ export OO_PS4_TOOLCHAIN=/path/to/open/orbis
[email protected]:tiny-ps4-shell$ make
Code:
[email protected]:tiny-ps4-shell$ make -f Makefile.posix
[email protected]:tiny-ps4-shell$ ./main_term.bin
Install the compiled pkg on a PS4 with homebrew and the kexec syscall enabled, launch the application, and telnet to the PS4 (port 2323). There are a handful of rudimentary commands available, e.g., cd, ls, and mkdir. Type help in a connected telnet shell for more information. Below are a couple of commands I have found useful.
To get a list of running processes:
Code:
/$ ps
PID PPID PGID SID TTY COMMAND
0 0 0 0 - kernel
1 0 1 1 ttyu0 mini-syscore.elf
...
Code:
/$ setuid 0
Code:
/$ jailbreak
Code:
/$ cat /dev/klog
Code:
/$ self2elf /mini-syscore.elf /mnt/usb0/mini-syscore.elf
The login session is not attached to a TTY, so you cannot signal for, e.g., SIGINT with Ctrl+C. Furthermore, most of the commands are only partially implemented. If you find some limitation extra annoying, file a github issue and perhaps it will be addressed.
Reporting Bugs
If you encounter problems with tiny-ps4-shell, please file a github issue. If you plan on sending pull requests which affect more than a few lines of code, please file an issue before you start to work on you changes. This will allow us to discuss the solution properly before you commit time and effort.
License
Tiny-ps4-shell is licensed under the GPLv3+.