Re: Compiling kernel-3.4.xxx with gcc-9.x. Need some help.

From: Fawad Lateef <fawadlateef@gmail.com>
To: Greg KH <greg@kroah.com>
Cc: kernelnewbies <kernelnewbies@kernelnewbies.org>,
	linux-kernel@vger.kernel.org
Subject: Re: Compiling kernel-3.4.xxx with gcc-9.x. Need some help.
Date: Mon, 29 Mar 2021 21:20:32 +0200	[thread overview]
Message-ID: <CAGgoGu76FOJd74oVgnu5Sa3GKaHHyLTH+=hP+mLGzS+79Z26fA@mail.gmail.com> (raw)
In-Reply-To: <YGFeQUuAaKgeaqCA@kroah.com>

Hi Greg,

On Mon, 29 Mar 2021 at 06:57, Greg KH <greg@kroah.com> wrote:
>
> On Sun, Mar 28, 2021 at 10:20:50PM +0200, Fawad Lateef wrote:
> > Hi
> >
> > I am using an Olimex A20 SOM with NAND and due to some binary blob for
> > NAND driver, I am stuck with the sunxi kernel 3.4.xxx version. (Repo
> > here: https://github.com/linux-sunxi/linux-sunxi)
>
> Please work with the vendor that is forcing you to use this obsolete and
> insecure kernel version.  You are paying for that support, and they are
> the only ones that can support you.
>

The problem is vendor Olimex now have eMMC based SOM which is
supported by mainline kernel _but_ they still selling NAND SOM and
only supporting 3.4 kernel (as this is the only latest version from
sunxi with NAND support, after that sunxi is now moved away from NAND
too).

> > I am currently using buildroot-2016 and gcc-5.5 for building the
> > kernel and every other package needed.
> >
> > Now the requirement is to move to the latest version of gcc-9.x, so
> > that we can have glibc++ provided by the gcc-9.1 toolchain.
> >
> > Main problem for moving to later versions of buildroot is the kernel
> > 3.4 which we couldn't to work with gcc-6 a few years ago _but_ now the
> > gcc-9.1 requirement is mandatory so now have to look into compiling
> > linux-3.4 with gcc-9.1 or above.
> >
> > Now I need some help.
> >
> > -- Is it realistic to expect 3.4 kernel compiling and boot
> > successfully with gcc-9.1?
>
> No.  It took a lot of work and effort just to get the 4.4.y kernel to
> work with that gcc version.
>

Ok, thanks for the information. Any pointers on what to look at if I
had to go this route for 3.4 kernel?

> Again, please work with the company that you are already paying for
> support from, they can do this for you.
>

From Olimex they say it's an open hardware platform, so I really can't
expect them to do anything for it.
(https://www.olimex.com/Products/SOM/A20/A20-SOM/   NAND version)

Thanks and regards,

Fawad Lateef

> good luck!
>
> greg k-h