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IOC indicated some discussion on the hacking / remote-access stuff was happening here -- I think I've posted about the stuff before, but I used to work on the HW/SW for anti-theft / ABS / other ECMs for a few of the major Tier 2s -- we're lucky that someone happily blew this poo poo up in public. Our security precautions were all dependent on obscurity -- all sorts of backdoors and lazy system design to enable cost savings were the priority of the day. Now with OTA updates (and silent ones at that, looking at you Tesla), it's terrifying to think about potentially faulty software getting pushed out to your vehicle. Tesla engages with some of the conventional / traditional suppliers back in MI, and a few of those companies have resident engineers at Tesla to support their development efforts. They were pretty aghast at the cavalier attitude where you have managers used to consumer software pushing out brake SW updates to the test fleet that sometimes rendered them entirely inoperable. Complete strangers to safety-critical SW development. At least there's some separation of CAN busses based on function, but we mostly ended up cutting those apart because of bus utilization issues where we didn't have the bandwidth to keep all the modules talking at once. movax fucked around with this message at 04:04 on Jul 25, 2015 |
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Jul 25, 2015 04:01
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kastein posted:LIN bus is another fun one. It is significantly simpler and smaller, all transactions (read and write from anything to the master) are arbitrated by the master node, there is only one master node and up to (iirc) 15 or 31 slave nodes. It's more used for things like wiper motor controllers, seat position controllers, etc that don't need much in the way of smarts. Actually, a perfect example is the wiper motors in a new-gen Focus. There are two of them for the front instead of just one, with none of the traditional linkages. The left wiper motor has a LIN bus interface and the two wiper motors are slaved together via a synch wire that they use to communicate and synchronize their motion. The motors are each smart enough to stop if they see an overload condition, return to home automatically, and wipe speeds and swept angle can be configured at production time. I looked into using them but they're too heavy for our application. LIN and CAN in the traditional German fashion are designed to go together -- take your driver door, the idea is to throw in one CAN module (pricier, more complex) that has local LIN links to other functions in the door (window motors, switches, mirror control, etc.). It looks really pretty in a system level diagram -- you have complex nodes, and then simpler nodes scattered around the vehicle for the low-bandwidth, sensor/actuator stuff that the complex node controls / filters/ processes and sends out to the rest of the bus. LIN's also attractive because with the right transceivers, you can piggy-back on the existing power wiring and have a simple +12V/GND going to a motor, and enjoy LIN communication on that link as well.
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Jul 25, 2015 04:07
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Galler posted:The update filters the various ports. No idea if they actually fixed the ability to run arbitrary commands and code on the head unit (doubt it) or did anything about the V850 chip's (which is accessible from the head unit and talks on the CAN bus) firmware not bring signed or secured in anyway. Huh, wonder which supplier made that -- we were using V850s about 10 years ago for a lot of modules destined for Nissan and Toyota vehicles -- HVAC control, etc. Firmware updates were never signed, but there was a (static) password to get into the CAN bootloader to deploy the updated software.
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Aug 6, 2015 08:04
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Coredump posted:Honestly, such a thing shouldn't be possible. Stability control, abs, etc is all possible without making those systems exposed to another system with internet access. Absolutely correct, but most of the management of groups designing / building this stuff is utterly incompetent. Same problem exists with avionics, but their stakes have always been higher (killing a couple hundred people at once vs. a couple here and there), and they have some pressure from the government (terrorists!  ) to get some poo poo right.
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Aug 6, 2015 20:20
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