[embedded platform] kernel questions

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Hello,

I'm in for a porting Linux on ARM926EJ-S based System-on-Chip running at
216MHz. Only uCos has been ported on the board so far (not by me).

This is my first experience of Linux porting, so I found a few articles on
the Web to read up. Right now I want to clear a few major questions:

- what kernel version to choose. I understand it depends on system
requirements and hardware specs, and I think 2.6.x branch should be given a
preference, as it supports a lot more hardware then 2.4 and
community provides better support as well :) Question is what version of
2.6.x family to choose, is there a strict criterion to choose ?

- what bootloader can you recommend to choose for porting on the board?
There are U-boot, Redboot and ARMboot as the most common and portable. I
briefly check the Web Links and found that only U-Boot supports ARM9, am I
right?

- I mentioned above about uCos - is it reasonable trying to port uCos device
drivers on to the Linux platform, or drivers should be rewritten from
scratch, as uCos and Linux architectures I guess are
quite different ?

Thanks in advance and looking forward to getting answers to my queries!

With best regards, Roman Mashak.  E-mail: snipped-for-privacy@tusur.ru



Re: [embedded platform] kernel questions
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2.4 is dead. If you need help, or special drivers or new features you are
lost with 2.4.

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For new hardware always start with the most recent kernel. And as long
development is going on, continue to use the next recent kernel if it gets
released.
 
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Don't know uCos. But I guess you will find more examples or (perhaps) ready
to use drivers in the kernel source tree for your hardware. And you will
find many frameworks in the kernel, so the real "drivers" for hardware
access gets smaller and smaller and easier to maintain.

jbe


Re: [embedded platform] kernel questions
Hello, Juergen!
You wrote  on Fri, 15 Aug 2008 17:14:30 +0200:

 ??>> Question is what version of
 ??>> 2.6.x family to choose, is there a strict criterion to choose ?

 JB> For new hardware always start with the most recent kernel. And as long
 JB> development is going on, continue to use the next recent kernel if it
 JB> gets released.

Is it sensible to take vanilla kernel from ftp.kernel.org and start with
this or there're seperate branches with ARM-specific patches, which might be
more reasonable to use?

And one question on toolchains. The chip-maker doesn't provide any
Linux-based toolchain. Does it make sense to spend time (and I'm pretty sure
building crosstools may consume lots of weeks) to prepare our own tools or
to pick out the pre-built one?

Thanks.

With best regards, Roman Mashak.  E-mail: snipped-for-privacy@tusur.ru



Re: [embedded platform] kernel questions
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I'm always working with the vanilla kernel. Don't know if it is the best
way. Sometimes its easier to start with a vanilla kernel, and to add some
patches specific to your hardware. Sometimes its easier to start with
sources the manufacturer provides. It depends on your hardware and
requirements.

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There are various ready-to-use binary ARM toolchains around. So it should be
easy to find one that is working for you.

jbe


Re: [embedded platform] kernel questions
Hello, Juergen!
You wrote  on Sat, 16 Aug 2008 09:37:59 +0200:

[skip]
Thanks for your comments.

 ??>> And one question on toolchains. The chip-maker doesn't provide any
 ??>> Linux-based toolchain. Does it make sense to spend time (and I'm
 ??>> pretty sure building crosstools may consume lots of weeks) to prepare
 ??>> our own tools or to pick out the pre-built one?

 JB> There are various ready-to-use binary ARM toolchains around. So it
 JB> should be easy to find one that is working for you.
I searched, but found only papers describing building crosstools yourself.
Can you recommend any sites offering pre-build toolchains?

With best regards, Roman Mashak.  E-mail: snipped-for-privacy@tusur.ru



Re: [embedded platform] kernel questions
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I simply tried google with "ARM toolchain" and found many toolchains.
For example "http://www.gnuarm.org /" and many other.

jbe


Re: [embedded platform] kernel questions
Hello, Juergen!
You wrote  on Mon, 18 Aug 2008 20:17:08 +0200:

[skip]
 ??>> I searched, but found only papers describing building crosstools
 ??>> yourself. Can you recommend any sites offering pre-build toolchains?

 JB> I simply tried google with "ARM toolchain" and found many toolchains.
 JB> For example "http://www.gnuarm.org /" and many other.
I already went through this link. It seems to provide bare-metal only
toolchains; crosstools provided by codesourcery.com (there is a lite
free-of-charge version) doesn't support arm926ejs. Hence I asked in this
group.

With best regards, Roman Mashak.  E-mail: snipped-for-privacy@tusur.ru



Re: [embedded platform] kernel questions
Hello Roman,

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A simple ARM v4 or ARM v5 core toolchain should help you. You don't need a
specific arm926ejs toolchain.

jbe


Re: kernel questions
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 Please check this link

 http://kerneltrap.org/mailarchive/linux-kernel-newbies/2008/8/18/2972024

 I hope this help,
/roberto

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