Hello,
On 2014-09-16 10:09, Heecheol, Yang wrote:
Hello,
I am personally trying to port Tizen on my odroidXU board which has
Exynos 5410 SoC.
Struggling for about 3 months, I concluded that it is almost
impossible now due to several reasons below, and I am considering to
give up porting work.
However, I thought that I’d better to share my experiences before I
really decide to give up. So, I am writing this mail to share what I
have suffered from.
First of all, I want to mention that the stable Linux kernel version
which OdroidXU supports is 3.4. It is the first barrier that makes me
impossible to port.
As you know, Tizen’s security framework is based on underlying SMACK
in kernel. However, kernel 3.4 doesn’t have adequate version of SMACK.
To be specific, when I booted Tizen on that kernel version, booting
failed because systemd failed to access load2 interface in smackfs.
Actually, LOAD2 interface is supported from kernel >= 3.10. When I
realized the fact, I tried to find higher kernel version that supports
Odroid XU.
Fortunately, I found 3.13 and 3.14 kernel version from link below.
https://github.com/hardkernel/linux/tree/odroid-3.13.y-linaro
It was experimental and non-stable version and It was originally
intended to support Ubuntu. Of course, It works well when I booted
this version with Ubuntu.
However, when I tried to boot the kernel with Tizen rootfs, the
booting stopped printing ‘imprecise external abort’. The error is very
similar to the link below.
http://lists.infradead.org/pipermail/linux-arm-kernel/2013-November/214882.html
At first, I thought that the error may be related to the Tizen, not
kernel. However I changed my thought, and implicitly concluded that it
may be related to kernel. But not exactly.
Anyway, whatever the error is related to, it was so hard to debug for me.
This might be the same issue we had with Odroid U3/X2 boards. The secure
firmware, which is used on those boards protects the last 64k of system
memory for its internal use. Make sure that you limited the total amount
of memory to 2GiB-64k instead of passing whole 2GiB (this is done
automatically by the reference v3.4 kernel).
In summary
1.Stable Odroid XU kernel version(3.4) can’t support Tizen due to old
SMACK version.
2.The experimental version of recent kernel version has a bug
difficult to solve.
These are what I experienced and followings are what I think have to
do if I would continue porting work.
1.Backport up-to-date version of SMACK into the stable kernel 3.4 or
2.Solve the problems in kernel 3.13
The third option would be to add support for Exynos 5410/5420 to v3.10
kernel on tizen.org, but this is still quite a lot of work. The good
thing is that Exynos4/5 related stuff in v3.10 kernel on tizen.org is
more or less compatible with the code merged to mainline kernels.
Please also note that Exynos 5410 has different GPU module (SGI PVR)
than other Exynos SoCs (ARM MALI), what will also require changes to
userspace gfx stack.
Yes, they are possible to do but as a premature person, it is very
difficult for me to do alone. I have no debugging hardware tools, not
enough knowledge, and so on. This is the most important reason: I am
premature.
So I want to conclude my mail by saying thanks to many people who
helped in various ways.
In someday, I wish to port Tizen on my board.
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
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