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Former Tesla Firmware Engineer Discusses the System

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Re: Former Tesla Firmware Engineer Discusses the System

#101

Post by Sir_Cmpwn »

andrewmcwatters wrote: post #36
ddevault wrote: post #11

I used to work at SpaceX on the team that did a piece of software called "WarpDrive". It was a massive monolithic ASP.NET application, with large swaths done with ASP.NET WebForms and a slow frontier of ASP.NET MVC gradually growing when I was working there. This application was responsible for practically everything that ran the factory: inventory, supply chain management, cost analysis, etc. Elon is a big Windows f…

> massive monolithic ASP.NET application It's like calling grass green, m8.

Monolithic in design, massive in size

Re: Former Tesla Firmware Engineer Discusses the System

#102

Post by js2 »

BugsJustFindMe wrote: post #74
8_hours_ago wrote: post #52

Earlier quoted context omitted.

> the rockets fly with a heavily customized Linux install My jaw hit the floor the first time I heard this. Why Linux instead of an RTOS?? Apparently Tesla's autopilot also runs Linux, which seems like a huge accident waiting to happen (pun intended).

As a person who used to write navigation and control software for autonomous vehicles who occasionally gets downvoted for telling people that you really don't need a fancy RTOS for this stuff, you really don't need a fancy RTOS for this stuff. Linux is a very common platform for highly responsive robotic systems. I promise that their pid control isn't an Electron app.

Also, an RTOS is susceptible to priority inversion[0] so it’s not necessarily a panacea.

0. which infamously occurred on the Mars Pathfinder. https://www.rapitasystems.com/blog/what-really-happened-to-t...

Re: Former Tesla Firmware Engineer Discusses the System

#103

Post by mlaretallack »

mlaretallack wrote: post #99
BugsJustFindMe wrote: post #74

Earlier quoted context omitted.

As a person who used to write navigation and control software for autonomous vehicles who occasionally gets downvoted for telling people that you really don't need a fancy RTOS for this stuff, you really don't need a fancy RTOS for this stuff. Linux is a very common platform for highly responsive robotic systems. I promise that their pid control isn't an Electron app.

Agree completely. Hard real time is possible with Linux, we use it for sub millisecond control of Traffic Lights. The only issue we ever hit is proving that the code running is the stuff we expected to run.

But I have to add we have a real embedded cortex checking everything, just in case ......

Re: Former Tesla Firmware Engineer Discusses the System

#104

Post by Globz »

floatboth wrote: post #90
mikeash wrote: post #80

Earlier quoted context omitted.

I don't understand how that could happen. MCU reboots, ???, brake system segfaults? What goes in the middle?

Probably everything has access to everything on the CAN bus. IIRC car manufactures are irresponsibly lazy and never properly air-gap infotainment from critical stuff.

There's a firewall between the CAN bus so it cannot be affected at all by the MCU.

Re: Former Tesla Firmware Engineer Discusses the System

#105

Post by jrockway »

karpodiem wrote: post #55
stingraycharles wrote: post #19

Earlier quoted context omitted.

I think this is a naive perspective. I've heard many similar stories from friends that work in the German automotive industry, and I think you would be surprised how many payment systems are tied together (e.g. (insecure) FTP servers to sync daily payments). Every organization has these types of things internally. As an engineer, I don't like it, but it's a fact of life.

Banks can reverse transactions if they want to. Tesla's cavalier attitude towards manufacturing has yielded a 14% first pass through rate on the Model 3 line (which is abysmal and may bankrupt the company along with declining M3 demand) vs. the industry standard of ~80% FPT rate. Source - https://www.businessinsider.com/tesla-hit-model-3-target-by-... We're at the point in the Tesla story similar to that of 2008 wher…

I don't think the rework rate is a big deal for the customer. Ultimately manufacturing is about increasing the yield rate so that costs are lowered, because rework is expensive. But if you can make money with lots of manual rework on every product, it's no big deal. Something to improve next quarter.

I have so many electronic devices, from cheap to expensive, that have some passive component manually bodged on somewhere. They work fine. It just means that paying someone to rework 1000 boards was cheaper than throwing the boards away and spinning up Revision B immediately. It's not a big deal. Waste is worse than a product that is imperfect immediately off the assembly line.

Re: Former Tesla Firmware Engineer Discusses the System

#106

Post by smsm42 »

DCoder wrote: post #44
compostable wrote: post #37

Earlier quoted context omitted.

>> butter clenching Excuse me, I am a native English speaker and I do not understand this reference

When autocorrect meets "buttock-clenching", I'd guess.

That's how I read it. I had to go back and re-read it to see it says "butter" actually. I guess I've successfully installed anti-autocorrect in my brain.

Re: Former Tesla Firmware Engineer Discusses the System

#107

Post by lowry »

eequah9L wrote: post #88
lowry wrote: post #25

Earlier quoted context omitted.

It is common knowledge that Toyota uncontrolled acceleration bug was completely imaginary, see for example http://revisionisthistory.com/episodes/08-blame-game

Check out this, and the linked court transcripts linked therein: http://www.safetyresearch.net/blog/articles/toyota-unintende... The security researchers who were expert witnesses in the Toyota case and that analyzed Toyota's source code testified in court that they managed to reproduce the unintended acceleration with a real car on a dynamometer.

Is it what people call fake news nowadays?

I once had a project with a major lobbying organisation with links throughout the automotive industry. The one that published regular reports on real vs declared emissions discrepancies long before the VW scandal.

They were unanimous when asked about the unintended acceleration bug. It was a case of mass hysteria.

Re: Former Tesla Firmware Engineer Discusses the System

#108

Post by nightski »

mandeepj wrote: post #29
ddevault wrote: post #11

I used to work at SpaceX on the team that did a piece of software called "WarpDrive". It was a massive monolithic ASP.NET application, with large swaths done with ASP.NET WebForms and a slow frontier of ASP.NET MVC gradually growing when I was working there. This application was responsible for practically everything that ran the factory: inventory, supply chain management, cost analysis, etc. Elon is a big Windows f…

> This application was responsible for practically everything that ran the factory: inventory, supply chain management, cost analysis, etc. They could have bought something off the shelf. Not sure what was the value in building everything from scratch

What like SAP? And then spend 10s of millions in customizing it for their needs and dealing with an arcane, unintuitive interface? I've seen this over and over again.

Re: Former Tesla Firmware Engineer Discusses the System

#109

Post by crististm »

kevan wrote: post #59
8_hours_ago wrote: post #52

Earlier quoted context omitted.

> the rockets fly with a heavily customized Linux install My jaw hit the floor the first time I heard this. Why Linux instead of an RTOS?? Apparently Tesla's autopilot also runs Linux, which seems like a huge accident waiting to happen (pun intended).

I'm not familiar with this space but I'm pretty sure there are hard realtime kernels for linux. I'd hope they're using one.

Technically there used to be (still is?) such a thing as realtime Linux but not _for_ Linux (which you probably meant the userland?).

Regardless. There are many and far better alternatives to Linux for real time applications.

Re: Former Tesla Firmware Engineer Discusses the System

#110

Post by jtmcmc »

1123581321 wrote: post #82
java_script wrote: post #18

Earlier quoted context omitted.

I hope this means HN finds the gazillion-page thread mocking HN there.

I think a lot of HN readers over a certain age have spent time on SA. It’s easy to code switch and I wouldn’t have trouble mocking my own comments there in the house style.

exactly - i wonder if my old account is still active... probably best to stay out of SA while at work though...
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