OpenWRT One: hardware RNG?

[nobrowser]

On the OpenWRT One I see that /dev/hwrng exists. But when I installed rng-tools and tried to start rngd I got:

Thu Dec 25 09:48:35 2025 daemon.err rngd[19740]: Initializing available sources
Thu Dec 25 09:48:35 2025 daemon.err rngd[19740]: [hwrng ]: Initialization Failed
Thu Dec 25 09:48:35 2025 daemon.err rngd[19740]: [rndr  ]: No HW SUPPORT
Thu Dec 25 09:48:35 2025 daemon.err rngd[19740]: [rndr  ]: Initialization Failed
Thu Dec 25 09:48:35 2025 daemon.err rngd[19740]: Can't open any entropy source
Thu Dec 25 09:48:35 2025 daemon.err rngd[19740]: Maybe RNG device modules are not loaded

I hasten to add that I did change /etc/config/system as follows:

root@OpenWrt:~# uci set system.@rngd[0].device='/dev/hwrng'
root@OpenWrt:~# uci set system.@rngd[0].enabled=1
root@OpenWrt:~# uci commit
root@OpenWrt:~# service rngd restart

So, does the One actually have a hwrng or not?

--
Ian

[cshoredaniel]

https://one.openwrt.org/hardware/ has schematics and datasheets, which will have the definitive answer to your question.

Q: "Does existence of the /dev/hwrng device node necessarily mean an hardware rng is present?"
A: No. It only means the base module for hardware rngs is loaded or built into the kernel. An actual hardware RNG driver needs to be loaded for a physically present hardware rng for it to do what you are looking for.

[brada4]

Filogic crypto accelerator driver does not include RNG function (does not seem to be implemented in other driver for same hw, thus concluding no hwrng is there)
REF https://man.freebsd.org/cgi/man.cgi?query=safexcel
REF2: https://www.rambus.com/security/protocol-engines/protocol-ip-93/

[olek210]

MT7981 has a separate IP core for RNG. It is available through SMCCC.
REF https://github.com/openwrt/openwrt/commit/9cfbd691e911a40357ab848f8e902551de32738e

[nobrowser]

I see - so I can look forward to rngd working on the One with 25.10 ?