[Arm-netbook] Side-Topic: Liberating PocketCHIP

[Pablo]

On Wed, May 10, 2017 at 05:05:20PM +0200, mike.valk at gmail.com wrote:
> 2017-05-10 16:38 GMT+02:00 Luke Kenneth Casson Leighton <lkcl at lkcl.net>:
> 
> > On Wed, May 10, 2017 at 3:23 PM, Pablo <pablo at parobalth.org> wrote:
> >
> > > With any non-Chip-kernel you will lose NAND support.
> > > So you can either:
> > > a)patch your libre kernel
> > > or
> > > b) ignore NAND and use flash memory via usb port.
> > >
> > > For b) you will need mainline U-Boot because NextThings U-Boot fork
> > > supports NAND but not booting via usb.
> >
> >  this sounds weird / not quite right. the R8 (aka A13, aka the A10)
> > should be able to use the same sunxi 3.4.104+ kernel source as i've
> > been using for the A20, which has the (sunxi, libre) NAND driver in
> > it.  afaik they didn't change the NAND hardware from the A10/A20 to
> > the A13 to the R8 so this should be a non-issue.
> >
> >  also from what i gather there's been mainline support for the
> > (completely different, MTD-compatible) NAND driver for quite some
> > time, so again, should be a non-issue.
> >
Ah, interesting. Thank you for the correction and additional input.
I would be glad to be wrong here as it makes things so much easier.
My knowledge is quite vague in this area and comes mainly from
NextThings user forum. For example consider the following threads:
https://bbs.nextthing.co/t/is-it-possible-to-boot-from-a-usb-flash-drive/3090/15
https://bbs.nextthing.co/t/can-i-run-multiple-os-on-boot/11196/5
https://bbs.nextthing.co/t/why-c-h-i-p-has-its-own-kernel-fork/1603
https://bbs.nextthing.co/t/install-kernel-via-apt-get/2467/7
https://bbs.nextthing.co/t/ntc-improving-nand-on-linux/10526

It is quite hard to distinguish between facts, guesses and outdated
information. A well maintained wiki would help to complement the user
forum... *sigh*

> >  perhaps someone could ask on #linux-sunxi and/or their mailing list
> > for confirmation of the facts?
Sounds like a good idea. I can't do it because I lack the technical
details to ask the proper questions.
> 
> Wiki says "work in progress"
> 
> http://linux-sunxi.org/Mainlining_Effort
> http://linux-sunxi.org/NAND (Fun facts on supported NAND)
> http://linux-sunxi.org/MTD_Driver
> 
> https://groups.google.com/forum/#!searchin/linux-sunxi/mtd%7Csort:relevance
> 
> Boris has commit access so it's probably all there since 4.7
> 
> His work and derivatives did touch a lot of NAND/MTD drivers though.
> 
> Someone needs to crawl the linux kernel commits though or ask directly.

Thank you for the links and details. It is a lot of new information for
me. I am going to have a closer look in
the next couple of days. 
Maybe I will run some tests on my Chip. 

Pablo