[HN Gopher] Building an open-source Wi-Fi Mac layer for the ESP32
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       Building an open-source Wi-Fi Mac layer for the ESP32
        
       Author : pabs3
       Score  : 150 points
       Date   : 2025-03-09 00:32 UTC (21 hours ago)
        
 (HTM) web link (esp32-open-mac.be)
 (TXT) w3m dump (esp32-open-mac.be)
        
       | pabs3 wrote:
       | A list of other open source firmware:
       | 
       | https://wiki.debian.org/Firmware/Open
        
       | iou wrote:
       | Timely post with the vulnerability research this week?
       | https://www.tarlogic.com/news/backdoor-esp32-chip-infect-ot-...
        
         | dugite-code wrote:
         | That was related to Bluetooth. Interesting undocumented low
         | level commands but it's a bit of a stretch to call it a
         | vulnerability IMHO.
         | 
         | But having the whole stack open would just be better in
         | general.
        
           | gibibit wrote:
           | Correct. HN thread
           | https://news.ycombinator.com/item?id=43301369
           | 
           | Not a vulnerability in the way that Tarlogic makes it sound.
           | Disingenuous and misleading article for sure.
        
             | nottorp wrote:
             | A good bunch of "security" articles that make the news look
             | more like scareware to me in the past years.
        
         | luma wrote:
         | This outfit has changed the term "backdoor" to mean "any
         | undocumented feature". The findings reported are absolutely not
         | a backdoor in any conventional usage of the term. One would
         | need to flash their own code to the micro to make use of these
         | features, which is the normal operating mode for any micro
         | device.
         | 
         | This is nothing other than a security research team trying to
         | get some attention by crying wolf.
        
         | mystified5016 wrote:
         | This isn't a backdoor, it's just an undocumented debugger in
         | the HCI stack. You still need a physical UART connection to the
         | device AFAIK. The exact same type of connection you use to
         | program and debug the device normally.
        
       | megamix wrote:
       | I'd like someone to explain this to me as I find this
       | interesting. I have tech background but the OSI model is not
       | something I've interacted with directly.
       | 
       | Some questions I come to think of
       | 
       | 1. Why ESP32 made it closed? 2. What does the MAC layer in the
       | OSI model make it so important to either make this closed/open
       | source ?
       | 
       | From the article: "security auditability", possibility for
       | features not supported, make research into Wi-Fi networks with
       | lots of nodes more affordable.
       | 
       | E.g. ESP32 is proprietary, but it doesn't limit the connection to
       | certain routers, but could it be made to be?
        
         | pvtmert wrote:
         | i'm also not professional networking engineer but overall open
         | core will allow;
         | 
         | better interfacing and integration as a wifi chip on SBCs like
         | raspberry pi, potentially allowing faster rates and lower
         | latencies on SPI or I2c buses
         | 
         | better security and possibly handling further standards than
         | the espressif allows.
         | 
         | for example, you may implement wpa3 or wpa4 (if it comes out at
         | some point) without needing to wait for espressif to implement
         | and release themselves. plus, they may never have the
         | incentives to do so if a newer chip (esp64?) comes out...
        
           | mannyv wrote:
           | One big win might be power savings.
        
         | magnat wrote:
         | 1. They might have used IP cores with license that forbids
         | disclosing any technical details, including firmware
         | implementation.
         | 
         | 2. Manipulating RF registers could cause the device to operate
         | outside of regulatory parameters, perhaps invalidating FCC
         | certification for the whole device. By not disclosing how to
         | use MAC directly, they can claim they did their best to prevent
         | device from misbehaving.
        
           | xattt wrote:
           | There's many devices that can get uncapped (Yaesu handhelds
           | for example) without losing FCC certification.
        
             | Eduard wrote:
             | "uncapped"?
        
           | luma wrote:
           | Item 1 is certainly the case here. Espressif licensed most of
           | their original IP from tensilica, and this is completely
           | normal for building a commercial microcontroller. If you
           | don't have the in-house skill to build a complete WiFi radio
           | stack from the ground up, you simply license the IP core and
           | roll it into your product.
           | 
           | Nice work by the presenters here, it's a good idea and might
           | help the community, but the current state is not the result
           | of Espressif trying to be jerks.
        
           | KennyBlanken wrote:
           | The second item has been trotted out for roughly two decades
           | as an excuse for why router companies block open source
           | firmwares.
           | 
           | In those two decades there's been no evidence the FCC or
           | other regulatory bodies follow that theory, and no evidence
           | that open source firmware causes "misbehavior."
           | 
           | Please stop talking about it like it's an issue. It isn't.
        
             | MadnessASAP wrote:
             | The chaos that surrounded the Flipper Zero clearly
             | indicates that it is an issue.
        
         | rubatuga wrote:
         | OSI MAC =/= WIFI MAC + PHY
        
         | IshKebab wrote:
         | Just in case you didn't know, the OSI model is wrong. The world
         | uses the "TCP/IP model" - there's no "presentation layer" for
         | example.
        
           | brookst wrote:
           | I would argue that the higher layers of OSI become more
           | abstract and blurry, but it's not wrong per se. TLS maps
           | fairly well (not perfectly) to presentation layer.
           | 
           | Then again, OSI works best as a descriptive model rather than
           | prescriptive. Plenty of applications don't follow the model
           | at all. QUIC is largely an optimization by collapsing many
           | functions that OSI models as separate layers into one
           | monolithic thing.
        
         | londons_explore wrote:
         | A huge part of the cost of developing a WiFi chip is in the
         | firmware. WiFi is a complex set of protocols, and is especially
         | tricky to implement in a low ram, low compute, power
         | constrained device.
         | 
         | There is perhaps a 50/50 effort split between firmware and
         | hardware design. Open source the firmware and suddenly an
         | upstart competitor has only half the cost to market, and
         | therefore could undercut you in price.
        
         | numpad0 wrote:
         | It's just local maxima of utility. Not global ideal but
         | pragmatic useful solutions. They could have delayed release for
         | a century or two until a truly fair and open chip could be
         | designed and fabricated, or you can get the chip today and
         | complain about its pathetic proprietary nature along this long
         | journey towards idealist heaven. The latter is way better.
        
         | mannyv wrote:
         | People have been trying to shoehorn the Internet into the OSI
         | model for decades. It's like the OSI supporters have waged a
         | campaign to be relevant...and won.
         | 
         | It's a nice model, but once it gets above the phy layer it
         | becomes sort of bad.
        
       | bastard_op wrote:
       | I was watching the 38c3 talk about this a few months ago, and
       | just laughed seeing the recent news. Guess they have a good
       | reason to be paranoid, hmm.
       | 
       | https://youtu.be/r8IqkUTGjlA
        
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