[Arm-netbook] Side-Topic: Liberating PocketCHIP

[Pablo Rath]

On Fri, Jul 28, 2017 at 11:08:16AM -0400, doark at mail.com wrote:
> On Tue, 11 Jul 2017 12:10:21 +0200
> Pablo Rath <pablo at parobalth.org> wrote:
> > On Fri, Jul 07, 2017 at 06:19:29PM -0400, David Niklas wrote:
> > > On Thu, 6 Jul 2017 13:21:56 +0200
> > > 
> > > Actually, my PC has a kernel fault   

...

> > > (It's a long story of ntc's evil
> > > doing),   
> > 
> > Why do you believe that ntc is evil?
> 
> When you boot a normal Linux computer you are presented with a plymouth
> boot screen and can hit escape to exit and see the boot messages.
> I pocketchip's case you are presented (serendipity), with a boot screen
> that somehow references a file listed in /home/chip (I forget the
> exact name, it starts with a period), that invokes feh on pocketchip's
> logo boot screen from which there is no escape. If you uninstall plymouth
> and delete the file that invokes feh in /home/chip you are just presented
> with a black screen.
> Once pocketchip finishes booting you cannot use Alt-F[0-9][0-9] to switch
> tty's, nor can you use Ctrl-Alt-F[0-9][0-9], so if the boot fails for any
> reason you are stuck with never being able to fix or diagnose it (though
> you might get the last few messages of some error, which you might have
> read in full if the screen was not black).
> I asked in to forums about how to solve this and it's been weeks without
> any answer (I only ever got one, and that user told me not to side load
> software (which I explained that I never did or even thought of)).

I still don't get why you believe that ntc is evil. In my opinion they
are not evil just because the configured PocketChip like you described.
Boot messages are small and scroll fast anyway so they would probably
don't help you much.

...

> > > I've found two faults that cannot be traced without a postmortem and
> > > I'm really sick of accidentally causing this thing to manifest said
> > > problems and then loosing all the work that I did in between my
> > > backup periods.  
> > 
> > How can you be sure it is a kernel bug and not another problem?
> 
> Can't, that's why I'm in this predicament. All I know is the last few
> messages that say that the kernel is not syncing with the rootfs (and I
> have not touched the partition table, or init, or those scripts and files
> (like fstab), which would alter the mounting process).
> 
> > Can you
> > give us some details. Did you ask on ntc's user forum or did you file a
> > bug report 
> 2. Asked on the forum (I was a bit exasperated at the time since FLOSS
> software is no good to me if I can't debug it).

I know it sucks to have an obscure computer problem you can not
immediately solve but you should not put the blame on FLOSS. It can be a
bug, a wrong config, something you did...

> Here are the post (hmm, seems that email notification of new replies is
> not working:
> https://bbs.nextthing.co/t/pocketchip-boots-to-black-screen/14643
> https://bbs.nextthing.co/t/kernel-panic-not-syncing/17525
> 

User "zwack" gave you good advice to use UART-serial connection.
Basically you connect your PocketChip with another computer and can read
boot messages there. You will even be able to interact with U-Boot
before booting.

...

> > > I'm in need of a way to boot PC without flashing the NAND I there a
> > > way to do this? So far my search results have been unsuccessful.  
> > 
> > 1. Well, you can take your Chip out of the housing and install the
> > distro of you choice on a USB-stick and use it as a regular Chip.
> 
> I thought chip could not boot via usb?

It is possible altough currently a bit quirky. Have you read my previous email on this list and the linked thread on debian-arm mailing list?

> 
> > 2. Can you get PocketChip into fel-mode without taking it out of the
> > enclosure? Ntc's documentation claims it is not possible but there is a
> > forum thread about a reboot option into fel-mode. I have no PoketChip
> > and leave it up to you to research the answers to this questions.
> 
> I think I could but then what? I know repetitively little about FEL mode
> (though I'm willing to learn).
> 

Please read my previous email on this list.
Basically you put PocketChip into fel-mode and connect it with another
computer. You can then use a "special" version of U-Boot via fel and
boot an OS on USB or Debian Installer on USB. 

> > Another point is if the distro of you choice on a USB-stick will support
> > PocketChips hardware (e.g. Keyboard, LCD-Screen) out of the box. Do you
> > have a serial-to-usb-cable to interact with PocketChip?
> 
> I don't think so. But it's confusing when people write things like that
> because USB stands for Universal *Serial* Bus (so USB is a serial
> cable and no conversion is needed!).
> 
I meant a USB TTL Serial cable (USB to serial converter
cables) providing a connection between USB and serial UART
interfaces. You should get one as it seems necessary to debug your
problems. 

kind regards
Pablo