On the same subject can someone recommend a book or any other resource to learn about virtual machine internals? My goal is to try to build a toy clone of VirtualBox/VMWare.
So far I have found one -- Virtual Machines by James E. Smith and Ravi Nair.
[1] https://www.amazon.com/Hardware-Software-Virtualization-Synt...
Another book on Libvirt will be handy since it is the de facto API for most virtualization including VMs and containers[1].
[1]https://www.amazon.com/Foundations-Libvirt-Development-Maint...
It's a really great fun way to learn the key concepts.
https://www.morganclaypool.com/doi/abs/10.2200/S00754ED1V01Y...
Bringing Virtualization to the x86 Architecture with the Original VMware Workstation (2012)
https://m.youtube.com/playlist?list=PLSkhUfcCXvqHsOy2VUxuoAf...
What I've found difficult is the step beyond that. NES and GameBoy are typical steps, however, I've been very frustrated by the confusing documentation of the GameBoy. There are 3/4 references, but one of them has significant mistakes, while another is incomplete. On the other hand, the Pan Docs should be complete and accurate.
I'm not sure if there is an easy middle ground, that, at the same time, is also well documented.
The Atary 2600 is architecturally simpler but less documented, and also requires very accurate timings. I've read somebody suggesting systems like Channel F, Astrocade and Odyssey2, but I'm not sure they're well documented.
I've personally lost my interest once I've found that building an emulator was essentially fighting specifications rather than actually building something.
thou I wouldn’t buy a Toyota that exploded every 400,000 trips world wide Or bank with a bank that lost all my money every 400,000 transactions world wide
Here's a quick, high level, run-down:
https://jalopnik.com/heres-everything-boeing-did-to-fix-the-...
"In practice, the MCAS system accepted readings from only a single angle of attack (AOA) sensor. In the event of a bad sensor reading, the MCAS initiated repeated nose-down inputs. The cockpit alarm for AOA disagreement was also an expensive upcharge.
So Boeing made some changes to the MAX and the MCAS system. The MCAS system now has a maximum limit of one nose-down input during a single event of high angle of attack. The limit doesn’t reset if the pilots activate the electric trim switches. Further, an AOA sensor monitor was added to make sure MCAS doesn’t use AOA input if sensors disagree with each other by more than 5.5 degrees. The Flight Control Computer itself also no longer relies on a single sensor. Another important change is with the AOA DISAGREE alert. Previously, this alert was part of an optional AOA Gauge offered by Boeing. Now the AOA DISAGREE alert is always enabled, regardless of whether the airline has the option or not. All these changes are in the FAA summary."
More detail in a Nytimes article of the flaws:
https://www.nytimes.com/interactive/2019/03/29/business/boei...
Making safety critical software is a totally different world than what is seen on HN. The culture needed is safety culture and it is all about doing boring code, following strict coding rules, doing tons of documentation and analysis prior coding and a doing tons of review of tests. I don't think it will arouse interest here.
However, this is probably not about the airplane part of Airbus. Like Boeing, Airbus also have huge defense and space divisions.