About running old kernels with Yoctoo 1.2 or 1.3

About running old kernels with Yoctoo 1.2 or 1.3

[Diego Santa Cruz]

Hi there,

We are starting the development of a product based on TI DM814x SoC and
considering using Yocto to base our development on.

Unfortunately, TI does has only included support for this SoC on a derivative
of the 2.6.37 kernel and has not pushed the SoC specifics upstream to
mainline, so we are stuck to use that kernel as we cannot engage in porting
all the support to a newer kernel at this time.

I am new to Yocto, but as far as I got from the documentation versions 1.2
and 1.3 use a 3.4 kernel as the supported kernel. Would Yocto work with a
2.6.37 kernel or are new features that have been introduced in newer kernel
version required to run Yocto 1.2 or 1.3?

Sincerely,

Diego

--
Diego Santa Cruz, PhD
Technology Architect
_________________________________
SpinetiX S.A.
Rue des Terreaux 17
1003, Lausanne, Switzerland
T +41 21 341 15 50
F +41 21 311 19 56
diego.santacruz@spinetix.com
http://www.spinetix.com
http://www.youtube.com/SpinetiXTeam
_________________________________

Re: About running old kernels with Yoctoo 1.2 or 1.3

[Bruce Ashfield]

On 13-04-24 06:46 AM, Diego Santa Cruz wrote:
> Hi there,
>
> We are starting the development of a product based on TI DM814x SoC and
> considering using Yocto to base our development on.
>
> Unfortunately, TI does has only included support for this SoC on a derivative
> of the 2.6.37 kernel and has not pushed the SoC specifics upstream to
> mainline, so we are stuck to use that kernel as we cannot engage in porting
> all the support to a newer kernel at this time.
>
> I am new to Yocto, but as far as I got from the documentation versions 1.2
> and 1.3 use a 3.4 kernel as the supported kernel. Would Yocto work with a
> 2.6.37 kernel or are new features that have been introduced in newer kernel
> version required to run Yocto 1.2 or 1.3?

Each Yocto release uses a sliding set of kernel's that have had at least
some level of testing with the associated userspace of the release.

  1.4 is: 3.2, 3.4 and 3.8
  1.3 was: 3.4, 3.2 and 3.0
  1.2 was: 3.2, 3.0 and 2.6.37

But obviously, the linux kernel has a very stable userspace ABI, so there
shouldn't be any big compatibility issues with other kernel versions.
It's just that we don't know for sure.

It is true that each of these releases with have a linux-libc-headers
that is newer than the 2.6.x kernel you are talking about, which could
expose syscalls or other interfaces to userspace that aren't supported
in your kernel, but this typically degrades gracefully and the issue
detected when you try your applications.

Cheers,

Bruce



>
> Sincerely,
>
> Diego
>
> --
> Diego Santa Cruz, PhD
> Technology Architect
> _________________________________
> SpinetiX S.A.
> Rue des Terreaux 17
> 1003, Lausanne, Switzerland
> T +41 21 341 15 50
> F +41 21 311 19 56
> diego.santacruz@spinetix.com
> http://www.spinetix.com
> http://www.youtube.com/SpinetiXTeam
> _________________________________
>
>
>
> _______________________________________________
> yocto mailing list
> yocto@yoctoproject.org
> https://lists.yoctoproject.org/listinfo/yocto
>

Re: About running old kernels with Yoctoo 1.2 or 1.3

[Paul Eggleton]

On Wednesday 24 April 2013 08:53:31 Bruce Ashfield wrote:
> On 13-04-24 06:46 AM, Diego Santa Cruz wrote:
> > We are starting the development of a product based on TI DM814x SoC and
> > considering using Yocto to base our development on.
> > 
> > Unfortunately, TI does has only included support for this SoC on a
> > derivative of the 2.6.37 kernel and has not pushed the SoC specifics
> > upstream to mainline, so we are stuck to use that kernel as we cannot
> > engage in porting all the support to a newer kernel at this time.
> > 
> > I am new to Yocto, but as far as I got from the documentation versions 1.2
> > and 1.3 use a 3.4 kernel as the supported kernel. Would Yocto work with a
> > 2.6.37 kernel or are new features that have been introduced in newer
> > kernel
> > version required to run Yocto 1.2 or 1.3?
> 
> Each Yocto release uses a sliding set of kernel's that have had at least
> some level of testing with the associated userspace of the release.
> 
>   1.4 is: 3.2, 3.4 and 3.8
>   1.3 was: 3.4, 3.2 and 3.0
>   1.2 was: 3.2, 3.0 and 2.6.37
> 
> But obviously, the linux kernel has a very stable userspace ABI, so there
> shouldn't be any big compatibility issues with other kernel versions.
> It's just that we don't know for sure.
> 
> It is true that each of these releases with have a linux-libc-headers
> that is newer than the 2.6.x kernel you are talking about, which could
> expose syscalls or other interfaces to userspace that aren't supported
> in your kernel, but this typically degrades gracefully and the issue
> detected when you try your applications.

The usual problematic components are those that rely heavily upon the kernel 
e.g. udev and systemd. For such components you may find you need to downgrade 
or avoid them altogether; most of userspace should work just fine with an older 
kernel though.

Cheers,
Paul

-- 

Paul Eggleton
Intel Open Source Technology Centre

Re: About running old kernels with Yoctoo 1.2 or 1.3

[Diego Santa Cruz]

> -----Original Message-----
> From: Paul Eggleton [mailto:paul.eggleton@linux.intel.com]
> Sent: 24 April 2013 15:36
> To: Diego Santa Cruz
> Cc: yocto@yoctoproject.org; Bruce Ashfield
> Subject: Re: [yocto] About running old kernels with Yoctoo 1.2 or 1.3
> 
> On Wednesday 24 April 2013 08:53:31 Bruce Ashfield wrote:
> >
> > Each Yocto release uses a sliding set of kernel's that have had at least
> > some level of testing with the associated userspace of the release.
> >
> >   1.4 is: 3.2, 3.4 and 3.8
> >   1.3 was: 3.4, 3.2 and 3.0
> >   1.2 was: 3.2, 3.0 and 2.6.37
> >
> > But obviously, the linux kernel has a very stable userspace ABI, so there
> > shouldn't be any big compatibility issues with other kernel versions.
> > It's just that we don't know for sure.
> >
> > It is true that each of these releases with have a linux-libc-headers
> > that is newer than the 2.6.x kernel you are talking about, which could
> > expose syscalls or other interfaces to userspace that aren't supported
> > in your kernel, but this typically degrades gracefully and the issue
> > detected when you try your applications.
> 
> The usual problematic components are those that rely heavily upon the
kernel
> e.g. udev and systemd. For such components you may find you need to
downgrade
> or avoid them altogether; most of userspace should work just fine with an
> older
> kernel though.

Many thanks for the valuable input. Is the traditional init system still
supported, or is Yocto using systemd exclusively?

Best,

Diego

--
Diego Santa Cruz, PhD
Technology Architect
_________________________________
SpinetiX S.A.
Rue des Terreaux 17
1003, Lausanne, Switzerland
T +41 21 341 15 50
F +41 21 311 19 56
diego.santacruz@spinetix.com
http://www.spinetix.com
http://www.youtube.com/SpinetiXTeam
_________________________________

Re: About running old kernels with Yoctoo 1.2 or 1.3

[Burton, Ross]

Hi Diego,

On 25 April 2013 13:27, Diego Santa Cruz <Diego.SantaCruz@spinetix.com> wrote:
> Many thanks for the valuable input. Is the traditional init system still
> supported, or is Yocto using systemd exclusively?

With 1.4 (about to be released), systemd is an option but the default
init is still sysvinit.

Ross