[Cialug] Kernel?

[Matt Stanton]

The drivers for most things in Android are binary blobs of some sort.  This would be true of the GPU and media codec "drivers" for the SoC and any "peripheral" devices, like the camera, bluetooth chip, wifi chip, and maybe the touchscreen.  There are "kernel drivers" that serve as memory block placeholders for these binary blobs to interact with the hardware, though.

There are also things that the companies don't mind open-sourcing, like the power management and HSIC chips, which might only be used for a single phone before a better chip comes out (or one chip may be cheaper during one production run... or one chip may be taylored to provide power for 1.8V devices and the next SoC goes to 1.2V, etc, etc).  The eMMC driver from Samsung (which I think was used with the SGS3?) is "open source", even though Samsung has no interest in submitting it to mainline for review.

When software meets hardware, I start losing any ability to understand what is going on, so everything I know about this subject was heard (read on IRC) second-hand.

--Matt (N0BOX)

Sent from my ASUS Transformer

-----Original Message-----
From: Scott Yates <Scott at yatesframe.com>
To: Central Iowa Linux Users Group <cialug at cialug.org>
Sent: Wed, 02 Apr 2014 2:16 PM
Subject: Re: [Cialug] Kernel?

That is a good point, though the kernel is really separate from the user
space apps and drivers/modules isn't it?


On Wed, Apr 2, 2014 at 1:28 PM, Matt Stanton <matt at itwannabe.com> wrote:

> I'll take a different viewpoint from the other Linux kernel fans (I am a
> fan, too, though!).  The MAINLINE Linux kernel is remarkably bug-free.  The
> Linux kernel that is found in just about any version of Android running on
> a mobile device is buggy as all hell.  The reason being that Samsung, LG,
> Asus, or whoever bring eMMC chips, USB HSICs, power management ICs, and a
> new collection of CPUs, media codec ICs, and GPUs with every new phone or
> tablet.  They don't bother contributing that code to the Linux mainline, so
> it never gets reviewed, and customers are left to think that (luckily)
> Android is to blame for crashing or hanging for seconds at a time.
>
> That said, Linux is being kinda pushy about not accepting any code that
> doesn't use the device tree model, even if the kernel being used in the end
> product is pre-DT.  I know that some developers at (or possibly just users
> of boards created by)  Hardkernel (a company that uses Samsung's SoCs to
> build little ARM Android/Linux dev boards) have been working to try to get
> the kernels that Samsung provides converted to the DT spec.
>
> So, I have seen a bunch of buggy ARM-oriented Linux kernels, but none of
> them were ever seen by the Linux kernel team.  They were derivative works
> based on the kernel, really.
>
> -- Matt (N0BOX)
>
> Sent from my ASUS Transformer
>
> -----Original Message-----
> From: Brian Wood <woodbrian77 at gmail.com>
> To: cialug at cialug.org
> Sent: Tue, 01 Apr 2014 9:45 PM
> Subject: [Cialug] Kernel?
>
> How would you describe or review the Linux kernel?  I read
> a post today on a C++ newsgroup that described it as buggy.
> The author of the post is a knowledgeable guy in my opinion.
> I haven't found it to be buggy, but I wonder if it is.  Tia.
>
> --
> Brian
> Ebenezer Enterprises
> http://webEbenezer.net
> _______________________________________________
> Cialug mailing list
> Cialug at cialug.org
> http://cialug.org/mailman/listinfo/cialug
> _______________________________________________
> Cialug mailing list
> Cialug at cialug.org
> http://cialug.org/mailman/listinfo/cialug
>
_______________________________________________
Cialug mailing list
Cialug at cialug.org
http://cialug.org/mailman/listinfo/cialug