[giantrobot]

It only has power level control up to the limits for ISM devices on its operating frequencies. Its license is only valid for antennas with specific gain.

You technically can overwrite its firmware to turn the radio into some general purpose software defined radio transmitter but that's not how the device is licensed and sold.

[jchw]

Wait, though. Doesn't that seem to make this point moot? If they're not responsible for what users do hacking around, then there's not really any need to keep firmware closed source or locked down.

To be fair, I think at least at one point, that is in fact how it worked. I recall having a wrt54g and being able to run it out-of-spec using DD-WRT.

[giantrobot]

> Doesn't that seem to make this point moot? If they're not responsible for what users do hacking around, then there's not really any need to keep firmware closed source or locked down.

To sell the device the manufacturer has to make sure the device follows regulations and normal usage will follow end user regulations. The easier they make it for regulation-violating user modifications the more likely the product is to not get a license for sale of the device.

In something where the radio baseband is a physical circuit layout conformance is easy. Without modifying surface mount parts that circuit will always conform to its license.

For complicated basebands (WiFi etc) with software control having a fixed/closed firmware is the easiest way to get a license and not get it pulled after the fact.

The WRT54G is a fluke because it ended up using Linux/GPL code in the firmware. It was then obliged to release the source because of that. You can buy devices that allow firmware development and modification but not at retail and you can't offer them for sale without an FCC license covering them.

[Pet_Ant]

Okay, but you could release the source code for the firmware, and only accept a signed binary blob. This would still be open source (GPL v2 compliant, but not v3 AFAIK) and auditable, but it still be conforming and certifiable.

[pabs3]

This is what the Intel Sound "open" Firmware does, and it is incredibly annoying.

https://github.com/thesofproject/sof/issues/5814

I don't think that would be GPLv2 compliant either:

https://sfconservancy.org/blog/2021/mar/25/install-gplv2/ https://sfconservancy.org/blog/2021/jul/23/tivoization-and-t...

[giantrobot]

And some manufacturers do just that. Many do not because they're sub-licensing components/code from other companies. Others don't because they want to license their hardware to others and firmware source is a special sauce when the functions of the radio are all in software.

[megous]

You can use channels not allowed in your country. The firmware doesn't prevent that.

[giantrobot]

A device SKU only meant to be sold in ITU region 2 or North America specifically will often have the available bands/channels locked in the firmware despite the capability of the underlying hardware. Same for a SKU meant for other ITU regions or countries. It's far less common to have user selectable region settings for things like WiFi channels. It used to be more common but regional SKUs are just easier for everyone involved.

Even if a device enables you to specify channels not allowed in your country/region doesn't mean you're legally in the clear. "But there's a switch" isn't a defense against an FCC fine. It's unlikely you'll get caught and fined for using channels 12-14 on a Wifi device in the US but if you interfere with something important you're breaking several laws and if caught can potentially face jail time.

[megous]

Allright, so firmware lock is not a requirement then?