[Vm-dev] Cog + Pi + OSProcess

[Eliot Miranda]

Hi David,


> On Jun 16, 2016, at 6:40 PM, David T. Lewis <lewis at mail.msen.com> wrote:
> 
> 
>> On Wed, Jun 08, 2016 at 11:42:57AM -0700, tim Rowledge wrote:
>> 
>> I finally got a moment to look at this - not that I really have much clue
>> about the whole unix process thing - and it appears that something is odd
>> with the compiled code in the plugin.
>> 
>> My test is very simple - run the UnixProcess class>listDirectory example.
>> It exits with a segfault and the forkAndExec??? method as the last thing
>> on the stack.
>> 
>> I build a debug vm (and had some fun with asserts and the ARM fp offset in
>> the process, all fixed now) and??? it doesn???t fail. I???ve tried compiling
>> the plugin with varying levels of optimisation, since we???ve fairly regularly
>> seen problems there, and even at -O0 it fails. So debug -> OK, no-debug -> boom.
>> Nice.
>> 
>> Ideas?
> 
> I just unpacked my new Raspberry Pi (thanks Ben and Tim for the shopping and
> setup advice). Very cool. My only usability complaint is that the TV monitor
> is in the next room, so I am getting a stiff neck trying to look at the monitor
> while I type on my chiclet keyboard here in the kitchen. But it works, and it
> is a real computer.

I recommend you either set up a VNC server on the Pi and VNC in or use X11.  I never attach a monitor to the Pi except during setup.  

> 
> I started by compiling an interpreter VM to run against "trunk level" V3 image
> with OSProcess/CommandShell loaded. What I found so far:
> 
> - The 32-bit VM running 64-bit image does not work, cannot load X11 driver.
> This used to work 6 or 8 years ago on 64 bit x86, so probably some regression
> because I have not been testing on 32-bit host, and Raspbian is 32-bit.
> 
> - After loading OSProcess/CommandShell, I was getting errors, something like
> fork not being able to allocate memory. Sorry, I did not capture the error,
> and it's gone now.
> 
> - I then ran the OSP/CommandShell test suite. This crashed my login session
> and took me to a login prompt. WTF?!? This is supposed to be impossible on
> a Unix system. I'm still provisionally impressed with Raspbian, but ...
> 
> - I logged back in and ran the OSP/CommandShell tests again. Everything looks
> good now, except that tests related to file locking protocol are failing.
> These are rarely used functions and may be linux distro dependent, so I'm
> not worried about these failures.
> 
> - RemoteTask seems to be working also. Nice.
> 
> - Overall, most of the OSProcess functionality seems to be just working, so
> that is a pleasant surprise.
> 
> - I have gotten a few image lockups. I don't think it is related to OSProcess,
> more likely that I am trying to use a "trunk level" V3 image, maybe a bit
> buggy at this point.
> 
> I will try setting up a Cog/Spur build next, and see what that looks like.
> But probably not tonight :-)
> 
> Dave
>