[HN Gopher] If you own an M2 MacBook Air or MacBook Pro there's ...
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If you own an M2 MacBook Air or MacBook Pro there's an update for
your cable
Author : cheeaun
Score : 93 points
Date : 2023-02-16 15:48 UTC (7 hours ago)
(HTM) web link (www.macworld.com)
(TXT) w3m dump (www.macworld.com)
| rollulus wrote:
| What could possibly be the use for any sort of logic in such
| cable be, given that on both ends of it there's already a
| computer as well?
| duskwuff wrote:
| USB PD negotiation.
|
| The MagSafe connector only has three distinct contacts (there
| are five pins, but it's mirrored), so there has to be some
| protocol translation between USB PD and the single control
| signal used in MagSafe.
| tesseract wrote:
| * Translation between USB PD and whatever communication
| protocol runs on the center Magsafe pin (in Magsafe 1 and 2 it
| was Dallas 1-wire)
|
| * Disabling power output when the cable is not connected to a
| computer, so that a metal object touching the spring pins can't
| create a dangerous short circuit
|
| * Driving the LED
| traceroute66 wrote:
| > What could possibly be the use for any sort of logic in such
| cable be, given that on both ends of it there's already a
| computer as well?
|
| Maybe because MacBooks can be charged via both USB-C and
| MagSafe connector it forms part of the safety mechanism against
| frying your motherboard and/or against arcing during
| connection/disconnection. Especially on the higher-end of the
| spectrum (e.g. 16-inch MacBooks with 140W MagSafe).
|
| Sort of like the same way electric car chargers handshake
| before throwing amps down the cable.
| cal85 wrote:
| Just been scratching my head about this. Then I thought, is it
| just so they can detect authentic Apple cables and scold you
| for using an inauthentic one? Because iOS definitely does that.
| Some kind of challenge/response thing that requires a full
| Turing machine maybe.
|
| Another thought was something to do with monitoring current or
| degradation but I cant see why they couldn't do the same things
| from either the computer in the power adaptor or the computer
| in the actual computer.
| Fauntleroy wrote:
| In a few more years, security will simply cease to exist
| entirely.
| adolph wrote:
| _There's no way to directly update the cable, but it should
| update automatically when plugged into your Mac. While you can
| check the firmware of your power adapter by attaching it to your
| Mac and clicking on the Apple logo in the top left corner of the
| menu bar, then About This Mac, System Report, and Power, it's not
| clear how to check the specific firmware version of the cable._
|
| So presumably there is some UART to the cable, and the cable to
| the power adapter. Is it all stuffed in the cable treated as a
| USB device or is there some proprietary control on the laptop
| side to communicate with the cable?
| FateOfNations wrote:
| The only interface the computer normally has to the cable is
| the single control pin on in the middle of the MagSafe
| connector, so they are likely having to do something more
| sophisticated than UART.
|
| (Apple could have had you plug the other end that has the USB-C
| connector into the computer to do the firmware update, but that
| isn't particularly intuitive or user friendly).
| crazygringo wrote:
| Between this and "Help, Bing Won't Stop Declaring Its Love for
| Me", man... HN headlines are making me _laugh_ today.
|
| Keep it up, technological progress! :)
| ripvanwinkle wrote:
| "Everything that can physically accommodate a processor and be
| powered, will eventually have a processor" -
| Anonymous
| adolph wrote:
| Goes like peanut butter with the jelly of Atwood's Law: any
| application that can be written in JavaScript, will eventually
| be written in JavaScript
|
| https://blog.codinghorror.com/the-principle-of-least-power/
| conductr wrote:
| > It's not clear what the firmware fixes or patches
|
| I'm on M2 MB Air, and it seems odd to me that it (seems to) runs
| off battery even when plugged in and fully charged. Mine has been
| plugged in at desk for over a week, every day when I get on it
| says it's "Power Source: Power Adapter" yet it battery charging
| goes "On Hold" and dwindles as if it's running off battery all
| day. For example, it's mid-day for me and I'm at 79% but it's
| never been unplugged.
|
| My last was a MB Air 2013 so maybe this is new behavior that I'm
| just not used to, but it seems strange. If I had to unplug and
| leave, I'd expect to be leaving with 100% charge.
|
| Edit: "Optimized Battery Charging" was turned on as commenter
| mentioned, thanks for the tech support HN!
| robostac wrote:
| If it thinks it's going to be plugged in for a long time (based
| on previous usage) it'll pause the charging around 80% to
| preserve the battery health.
|
| https://support.apple.com/en-us/HT
| EricE wrote:
| One of the many utilities I love that comes with my Set App
| subscription is AlDente Pro. As others have pointed out, it
| allows me to set 80% as the max for my battery and it also will
| change the color of the LED on the magsafe connector to green
| once it gets to 80% and charging stops.
|
| I had optimized battery charging enabled but my Mac seemed to
| always charge to 100% - with Al Dente I can force it to do what
| I want.
|
| And recently I found Al Dente pausing charging because the
| battery temp got too warm. So then I went down a rabbit hole
| and found out I could tweak the fans up slightly higher with
| iStat Menus (also part of my Set app sub). There are other
| utilities that will do similar things - those just happen to be
| two I use, especially since I tend to use my MBP plugged in the
| majority of the time.
| crummy wrote:
| Are you using the stock charger? I would see similar behaviour
| on my 2018 MBP when I used a USB-C charger without enough
| power.
| davidbarker wrote:
| It sounds like Optimized Battery Charging may be turned on.
|
| https://support.apple.com/en-us/HT212049
| conductr wrote:
| Yep, solved! Did not know about this setting (kind of buried
| in the Settings UI) - thanks for the tech support!
| [deleted]
| count wrote:
| 80% is the 'ideal storage' condition for the battery. If it's
| always charging to 100%, the battery life is pretty
| dramatically shortened. Apple enabled this new charging manager
| that tries to learn your patterns (if you always unplug in the
| AM and leave with it, it'll learn to charge to 100% before you
| leave, for example). You can also click the battery icon in the
| tray (if you have that turned on) and tell it to charge to 100%
| 'right now', which only takes a minute or two with a full size
| charger.
|
| This is a positive thing for the life of your battery, but if
| you do want to disable it, there's a setting in System Settings
| - click the 'i' in the circle next to Battery Health, and turn
| off 'Optimize Battery Charging' there.
| falcolas wrote:
| Probably see more and more of this as cables continue the trend
| of becoming computers that abstract the communication between the
| two plugs.
| powersnail wrote:
| Given the trend, I've really come to see all electric cables as
| not-yet-evolved computers, the same way every light bulb is a
| low resolution display.
| danpalmer wrote:
| A worrying trend given that most people buy the cheapest cables
| they can from companies who may have questionable motives or
| state backing.
| hooverd wrote:
| I'm more worried about companies forbidding third party
| cables or bricking cables you own. "Sorry, this cable was
| only licensed for 100 charging cycles. Please buy a new one,
| for your safety of course."
| pathartl wrote:
| No reason to forbid cables when you can just remove
| physical ports.
| traceroute66 wrote:
| [flagged]
| pc86 wrote:
| Where in the comment above do they even mention Apple?
| boramalper wrote:
| I don't like their tone but they have a point.
| Historically Apple has been fussier than many other
| companies.
| hooverd wrote:
| If anything, consumer hardware is amazingly fungible,
| compared to the things B2B manufacturers do.
| hooverd wrote:
| I didn't say anything about Apple. I just don't trust
| hardware companies to not DRM everything if they know
| they can get away with it.
| tpxl wrote:
| I have been given a 'you need an official USB-C - 3.5mm
| jack adapter' warning by a non-apple brand. So yeah, this
| is happening.
| closewith wrote:
| I wonder if there's a viable business model in "free" cables
| that inject ads into video streams.
| hooverd wrote:
| Don't give them ideas.
| closewith wrote:
| Maybe the "free" ad-supported cables could have limited
| charging or data transfer speeds, but those features
| could be unlocked by paying a subscription or watching
| more ads.
| Tostino wrote:
| Please, just stop with that thought.
| closewith wrote:
| Maybe we could integrate an IOT M2M eSIM so there's no
| way to block the ad server.
| Tostino wrote:
| You monster...
| noodlesUK wrote:
| I'm really surprised that these cables have updatable firmware.
| Surely that makes the attack surface that much larger?
| Arrath wrote:
| Just waiting for an 'illegal peripheral' exception when I try
| to use a cable condom, if those exist for anything other than
| USB yet.
| exabrial wrote:
| When you have so much money and you don't know how to spend it...
| this is what you get.
| peterkelly wrote:
| Apple's lightning-to-HDMI cable contains an embedded ARM SoC with
| 256MB of memory running the XNU kernel and a daemon that performs
| video decoding.
|
| https://panic.com/blog/the-lightning-digital-av-adapter-surp...
| baq wrote:
| I would like to post something substantial or whatever but how
| can you add anything to that...?
|
| Mind blown.
| [deleted]
| adolph wrote:
| That post is a classic and the first thing I thought of when I
| saw the headline.
| ericboehs wrote:
| Can you brick your cable if you unplug it during the upgrade?
| simlevesque wrote:
| That's what I was about to ask. It says that the cable should
| update itself transparently, but there can always be a chance
| of corruption. Maybe the cable keeps the old FW and only boots
| the new one if it is signed.
| prewett wrote:
| Presumably there is space for two copies of the firmware, and
| once the new one decompresses and checksums correctly you
| update the firmware-start pointer.
| mecsred wrote:
| Any reasonable manufacturer will rotate firmware images and
| have the bootloader fall back to the most recent validated
| image. Though I imagine this could happen if this practice
| becomes common enough that you get it on some 5$ gas station
| charging cable kinda thing.
| avian wrote:
| A reasonable manufacturer looks at its bottom line and
| doesn't waste his engineering hours and BOM costs (double the
| flash memory!) on silly features like that. Either that or
| there are many unreasonable manufacturers out there.
| tesseract wrote:
| Cost (reputational as well as CSR hours and the actual
| replacement units) of a bunch of warranty claims for
| bricked units is a factor too.
|
| In practice pretty much every embedded device I've worked
| on that has supported in-field firmware updates has had
| either double buffering and/or a recovery mode to limit the
| possibility of bricking.
|
| For the products where every last penny really needs to get
| squeezed out of the BOM (toys, low-end appliances, ...) the
| ability to do in-field firmware upgrades itself is IME
| often one of the first things to go.
| 15155 wrote:
| "Double the flash memory" !!
|
| - How much do you think the NOR flash costs inside this
| cable?
|
| - How big do you think the firmware actually is?
|
| - 16MB Winbond NOR flash is like $0.70 with no price breaks
| (for me, I am not Apple making 1 million units) - there's
| no way they need 1MB for two slots, much less 16MB.
|
| - These cables retail for $49.
|
| Two firmware boot slots is standard practice because it is
| essentially free to provide in any higher-end consumer
| electronic device: especially one that is explicitly
| designed to be unplugged easily.
|
| How many support claims are saved on this $49 cable because
| mid-update bricking does not occur?
| readams wrote:
| Sounds like the firmware is actually stored in RAM and loaded
| when you plug in the cable.
| tenebrisalietum wrote:
| Really that shouldn't be called firmware (the actual firmware
| would be the fixed code that receives second-stage code from
| the host), but "software" doesn't fit that either. Maybe
| "controllerware" or something like that.
| nagisa wrote:
| This is how CPU/GPU microcode is loaded too, though... Is
| that not firmware?
| tenebrisalietum wrote:
| What I always understood firmware to be is: a ROM that
| gives a CPU something to do when power is applied, as RAM
| is blank on power on and things like storage devices
| can't just put stuff in RAM without being directed by the
| CPU (which doesn't have code to do that at power on
| unless provided by a ROM).
|
| Depending on the scope of the device (from multipurpose
| PC down to single-purpose things like microwaves, gas
| pumps, hard drives, LCD controllers) the firmware may
| just allow an operating system to be loaded or actually
| be all the code the appliance needs for its CPU.
|
| If the CPU is embedded in a peripheral, then:
|
| - it has to have some small ROM that does nothing but
| wait for an image to come in from a bus (USB, etc.) and
| then execute. The sound chip in Nintendo's Super NES is
| an example, on power on/reset it has a 64 byte boot ROM
| that does nothing but wait for data to come in from the
| main 65816 CPU and then runs that code when received.
|
| - the host has to have some way of externally programming
| the peripheral's RAM directly and resetting the
| peripheral's CPU but not the peripheral's RAM. I suppose
| JTAG could be used for this.
|
| My opinion: CPU microcode isn't firmware - CPU microcode
| sets the configuration of internal connections/parameters
| in the CPU. It's kind of like a settings file. But: I
| think recent microcodes do actually include code (see
| Xucode) but that code is meant to be the behavior of
| advanced instructions and not designed to be something
| that tells the CPU what to do from the moment it's
| powered on.
| [deleted]
| reportingsjr wrote:
| There are plenty of things that have firmware, but run it
| out of RAM. FPGAs do this, and some microcontrollers.
| Dialog, now Renasas, has microcontrollers that run their
| firmware out of RAM.
|
| Commonly there is a hardware peripheral that pulls the
| firmware from a couple of places (could be an onboard
| ROM, could be jtag, or other) and loads it in to RAM.
| brenouchoa wrote:
| I was having problems charging with my magsafe cable and for the
| last month was using the usb-c port to charge. Today i took if of
| the drawer and it is magically working again. I am using the beta
| mac os 13.2 so it may have solved my problem.
| brenouchoa wrote:
| I spoke too soon. My cable is still blinking orange after i
| plug it in. I will try to reboot.
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(page generated 2023-02-16 23:03 UTC)