[Cuis] ChromeOS vs Cog VM

[KenD]

By the way, I got a chance to work with Tim Rowledge at the Nanaimo Camp Smalltalk.

I'm sure Tim would have rather showed me around the Raspberry Pi VM work, but I have been unable to get any Cog VMs to work on either of my ARM Chromebooks.

CogVM works fine on the ATM RasPi system.

It turns out that Chromebooks are very serious about protecting maximally against code hijacking.  They don't allow arbitrary code to be written into memory and executed.

This is very good for safety in an uncertain world, but is also the definition of Just-In-Time code generation.

I expected that Google's V8 JavaScript, which JITs, would show how to do this sanely under ChromeOS so that we could Cog it, but the code base for V8 shows that they only run the bytecodes -- no JIT -- on Chromebooks.


There is hope for the future, but some changes will be required:
See 

"Exploiting and Protecting Dynamic Code Generation"

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjguP_RxJ3JAhXQT4gKHS2VAUYQFggeMAA&url=http%3A%2F%2Fwenke.gtisc.gatech.edu%2Fpapers%2Fsdcg.pdf&usg=AFQjCNF52_QFDuMcP05WvfeHNi2wUK-yHg&sig2=8SzTcWKA7VBubmzdzJmIiA


Google's "Safe Self-Modifying Code" patent: (Patent! Ack!! 8^{)

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=0ahUKEwilmsKlxZ3JAhVRKYgKHfXgDOMQFgg5MAM&url=http%3A%2F%2Fwww.google.com%2Fpatents%2FUS8850574&usg=AFQjCNHTAbYqbvqy80Edcww1YDsgUvoKMQ&sig2=FK01uFZEn778RNmRm7iz4A


Also "Certified Self-Modifying Code"

http://flint.cs.yale.edu/flint/publications/smctr.pdf

More hoops, sigh.

FYI,
-KenD