Fortigate Base Operating system?

See below:
https://community.fortinet.com/t5/Support-Forum/What-version-of-linux-is-the-fortios-running/td-p/94568

And below is from one of our 40Fs.

FortiGate-40F # fnsysctl cat /proc/version
Linux version 3.10.15 (root@build) (gcc version 10.3.0 (GCC) ) #2 SMP Tue Jun 6 16:11:35 UTC 2023

Toshi

FortiGate devices actually run on a custom operating system called FortiOS, which is built on top of Linux. It's specifically designed to handle networking and security tasks. So, while it’s not exactly Linux or BSD in the traditional sense, it's based on Linux, which helps it manage all the features that FortiGate offers. If you're curious about how different operating systems like Linux are used in devices like this, it's pretty interesting to explore.

As per my knowledge, before it was based on CentOS, modified and hardened by Fortinet.

Now as downstream CentOS is dead, if I'm not wrong it should be logically based Rocky Linux or similar.

FortiGate is based on a modified Linux kernel, so the displayed information might have slight differences compared to a standard Linux distribution.


https://community.fortinet.com/t5/FortiGate/Technical-Tip-How-to-check-Kernel-version-of-FortiGate/ta-p/323390#:~:text=FortiGate%20is%20based%20on%20a,to%20a%20standard%20Linux%20distribution.