[Xenomai] Limited kernel size for booting ?

[Xenomai] Limited kernel size for booting ?

[Thierry Bultel]

Hi Gilles,

First, I apologize for posting such a question that is sincerely not 
really related to xenomai.
But I am using the kernel from ipipe-gch.git, branch ipipe-3.0-imx6q

The issue I have is that it is not booting when using a really big 
built-in initramfs(about 60 Mo)
It does not seem to reach "start_kernel", there is nomore log after 
Uboot says "Starting kernel"

I have payed attention to address zones, and even tried to use an 
uncompressed kernel
in the uImage container, to skip and discriminate the gzip phase. Same 
result.

I do not have an operational Jtag probe yet, thus I only would like to 
get your opinion on
this. To your mind, is this assumed to work ?

Thanks in advance for any clues on that "out of scope" request.

Cheers
Thierry

Re: [Xenomai] Limited kernel size for booting ?

[Gilles Chanteperdrix]

On 03/19/2013 09:57 AM, Thierry Bultel wrote:

> Hi Gilles,
> 
> First, I apologize for posting such a question that is sincerely not 
> really related to xenomai.
> But I am using the kernel from ipipe-gch.git, branch ipipe-3.0-imx6q
> 
> The issue I have is that it is not booting when using a really big 
> built-in initramfs(about 60 Mo)
> It does not seem to reach "start_kernel", there is nomore log after 
> Uboot says "Starting kernel"
> 
> I have payed attention to address zones, and even tried to use an 
> uncompressed kernel
> in the uImage container, to skip and discriminate the gzip phase. Same 
> result.
> 
> I do not have an operational Jtag probe yet, thus I only would like to 
> get your opinion on
> this. To your mind, is this assumed to work ?


No, the maximum size of initramfs is limited, you need to change the
linker script to put the initramfs at the end of the memory used by the
kernel, a patch exists to do that on the linux arm kernel mailing list
and has been merged in recent kernels.


-- 
                                                                Gilles.

Re: [Xenomai] Limited kernel size for booting ?

[Gilles Chanteperdrix]

On 03/19/2013 11:05 AM, Gilles Chanteperdrix wrote:

> On 03/19/2013 09:57 AM, Thierry Bultel wrote:
> 
>> Hi Gilles,
>>
>> First, I apologize for posting such a question that is sincerely not 
>> really related to xenomai.
>> But I am using the kernel from ipipe-gch.git, branch ipipe-3.0-imx6q
>>
>> The issue I have is that it is not booting when using a really big 
>> built-in initramfs(about 60 Mo)
>> It does not seem to reach "start_kernel", there is nomore log after 
>> Uboot says "Starting kernel"
>>
>> I have payed attention to address zones, and even tried to use an 
>> uncompressed kernel
>> in the uImage container, to skip and discriminate the gzip phase. Same 
>> result.
>>
>> I do not have an operational Jtag probe yet, thus I only would like to 
>> get your opinion on
>> this. To your mind, is this assumed to work ?
> 
> 
> No, the maximum size of initramfs is limited, you need to change the
> linker script to put the initramfs at the end of the memory used by the
> kernel, a patch exists to do that on the linux arm kernel mailing list
> and has been merged in recent kernels.
> 
> 


https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=3835d69a6c7048a28d0aea3cb8403d5e83a0f867

-- 
                                                                Gilles.

Re: [Xenomai] Limited kernel size for booting ?

[Thierry Bultel]

Really many thanks. This works like a charm.

I also add to hack into arch/arm/kernel/sleep.S,
because the "cpu_resume" is located in .data, and it had a 24bits jump 
to cpu_do_resume
that could not be relocated and led to a linker error.
I have simply removed the line, because I am not insterested in cpu 
suspend for my application anyway.

FYI, the freescale rel_imx_3.0.35_12.09.01 tag version of that file is 
closed enough to
the committed patch for being taken as is.

Also, this is not related, but I have been a little confused by failing 
attempts, because I had forgotten the "rootwait" bootarg,
which is mandatory with that kernel.

Cheers
Thierry

Le 19/03/2013 13:06, Gilles Chanteperdrix a écrit :
> On 03/19/2013 11:05 AM, Gilles Chanteperdrix wrote:
>
>> On 03/19/2013 09:57 AM, Thierry Bultel wrote:
>>
>>> Hi Gilles,
>>>
>>> First, I apologize for posting such a question that is sincerely not
>>> really related to xenomai.
>>> But I am using the kernel from ipipe-gch.git, branch ipipe-3.0-imx6q
>>>
>>> The issue I have is that it is not booting when using a really big
>>> built-in initramfs(about 60 Mo)
>>> It does not seem to reach "start_kernel", there is nomore log after
>>> Uboot says "Starting kernel"
>>>
>>> I have payed attention to address zones, and even tried to use an
>>> uncompressed kernel
>>> in the uImage container, to skip and discriminate the gzip phase. Same
>>> result.
>>>
>>> I do not have an operational Jtag probe yet, thus I only would like to
>>> get your opinion on
>>> this. To your mind, is this assumed to work ?
>>
>> No, the maximum size of initramfs is limited, you need to change the
>> linker script to put the initramfs at the end of the memory used by the
>> kernel, a patch exists to do that on the linux arm kernel mailing list
>> and has been merged in recent kernels.
>>
>>
>
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=3835d69a6c7048a28d0aea3cb8403d5e83a0f867
>