The leds-gpio module fails to load on WRT54GS v1.1 with this error message in the console:
"leds-gpio: probe of leds-gpio failed with error -16"
This applies both to OpenWRT 15.05.1 and LEDE 17.01.2 as well as the latest Snapshot.
User jmv2009 on #lede-dev experienced exactly the same issue with his WRT54G v2.2
His boardtype is also 0x0708 and GPIO5 is also used by the reset button on his.
The boardflags on his WRT54G v2.2 router is 0x0118
There is one error in that list though, I wrote above:
"That actually matches several WRT54G v2 > v3.1 devices"
Actually the second entry on the list is incorrect. so it should be: "WRT54G v2.2 > v3.1 devices"
You can confirm this because "eou_device_id" is identical on the following entry.
The “SecureEasySetup” WPS button was added in WRT54G v3.0 & WRT54GS v2.0
But looking at the "boardflags" nvram variable this is identical between:
WRT54G v2.2 > 3.1
WRT54GS v1.1 > v2.1
So unfortunately that can not be used to differentiate if the board has a WPS button or not.