PoE passthrough on ramips/mt7621/760igs: how to verify the contents of the configuration file in the current -devel image?

[Antonio Muci]

Hi,

the official OpenWRT 24.10.0 image for 
ramips/mt7621/mikrotik_routerboard_760igs has a small but inconvenient 
bug, where the content of /etc/config/system is not aligned with the 
contents of the devicetree, resulting in PoE passthrough not working.

The solution is easy (https://github.com/openwrt/openwrt/issues/17980), 
and I've reported it on the wiki at 
https://openwrt.org/toh/mikrotik/rb760igs#poe, too.

However, meddling around the repos, I was not able to figure out how the 
contents of /etc/config/system is put together by the build scripts.
I also tried to manually mount a development snapshot in a linux machine 
(playing with mtd, loop device and yaffs2), but I was not able to do it.

So I try the direct human-to-human way: could please a developer verify 
that the current contents of /etc/config/system for the target Mikrotik 
Routerboard 760igs (Hex S) is as follows?

```
config gpio_switch 'poe_passthrough'
     option name 'PoE Passthrough'
     option gpio_pin '529'  # <-- 24.10.0 contains '497', which is wrong
```

As I said, all the details are in 
https://github.com/openwrt/openwrt/issues/17980. I'd just like to 
prevent issues in future releases.

Thank you very much!
Antonio