[Buildroot] Kernel build process

[Buildroot] Kernel build process

[Paul Jones]

Hi all,

 

Just some comments about the new kernel cleanup code. If a kernel config is
not supplied, the default action is to stop with a rather cryptic error.
This doesn't seem like a good idea to me, especially when the previous
behaviour was to just create a default .config and continue. I can see a lot
of beginners getting caught out with that one.

 

What I would like to suggest is this:

1)      Change the default Kernel Configuration to "Using a custom config
file" (is currently set to use a defconfig)

2)      Leave "Configuration file path" blank as default

3)      Add code to ignore copying config file if "Configuration file path"
is still blank and just continue compiling the kernel with the default
options.

 

That way it should be obvious to any beginners what the options do, and if
they are not set (ie left as default) the build will still be able to
continue.

 

 

Thoughts?

 

 

Paul.

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[Buildroot] Kernel build process

[Thomas Petazzoni]

Hello,

On Wed, 30 Jun 2010 21:03:22 +1000
"Paul Jones" <paul@pauljones.id.au> wrote:

> Just some comments about the new kernel cleanup code. If a kernel
> config is not supplied, the default action is to stop with a rather
> cryptic error.

Hum true.

> This doesn't seem like a good idea to me, especially when the
> previous behaviour was to just create a default .config and continue.
> I can see a lot of beginners getting caught out with that one.
> 
> What I would like to suggest is this:
> 
> 1)      Change the default Kernel Configuration to "Using a custom
> config file" (is currently set to use a defconfig)

Ok, why not.

> 2)      Leave "Configuration file path" blank as default

Yes.

> 
> 3)      Add code to ignore copying config file if "Configuration file
> path" is still blank and just continue compiling the kernel with the
> default options.
> 
> That way it should be obvious to any beginners what the options do,
> and if they are not set (ie left as default) the build will still be
> able to continue.

I'm not sure about this last part, though. What kind of "default
options" will the kernel select ? Just a random set of options for the
architecture selected ? Yes for x86 this will do something more or less
sensible, but for other embedded architectures such as ARM, there's no
such thing as a "default set of options that makes sense".

So I'd prefer to detect the fact that the configuration file path
option has been left empty, and abort the build by showing an explicit
and clear error message about this.

Same could be done for the defconfig option.

What do you think ?

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] Kernel build process

[Thiago A. Corrêa]

Hi,

    Also, there is one thing I'm missing: Copy kernel to root filesystem.

    In my target, uboot loads the kernel from /boot. The changes to
the kernel build removed that option. Could we have it back? or should
I run a script after the build to copy it and do any other misc
adjustments?

Kind Regards,
    Thiago A. Correa

[Buildroot] Kernel build process

[Paul Jones]

> -----Original Message-----
> From: buildroot-bounces at busybox.net [mailto:buildroot-
> bounces at busybox.net] On Behalf Of Thomas Petazzoni
> Sent: Thursday, 1 July 2010 2:58 AM
> To: buildroot at busybox.net
> Subject: Re: [Buildroot] Kernel build process
> 
> >
> > 3)      Add code to ignore copying config file if "Configuration file
> > path" is still blank and just continue compiling the kernel with the
> > default options.
> >
> > That way it should be obvious to any beginners what the options do,
> > and if they are not set (ie left as default) the build will still be
> > able to continue.
> 
> I'm not sure about this last part, though. What kind of "default options"
will
> the kernel select ? Just a random set of options for the architecture
selected
> ? Yes for x86 this will do something more or less sensible, but for other
> embedded architectures such as ARM, there's no such thing as a "default
set
> of options that makes sense".
> 
> So I'd prefer to detect the fact that the configuration file path option
has
> been left empty, and abort the build by showing an explicit and clear
error
> message about this.
> 
> Same could be done for the defconfig option.
> 
> What do you think ?

Good point. I guess if we tell the user to run "make linux26-menuconfig"
that would be just as good.



Paul.

[Buildroot] Kernel build process

[Thomas Petazzoni]

On Thu, 1 Jul 2010 08:22:55 +1000
"Paul Jones" <paul@pauljones.id.au> wrote:

> Good point. I guess if we tell the user to run "make
> linux26-menuconfig" that would be just as good.

Or to give a configuration file or defconfig name. The problem with
"make linux26-menuconfig" is that the configuration of the kernel will
be stored in output/build/linux-..../.config, and being part of the
output/ directory, it will be removed if the user doesn't save it
elsewhere.

Regards,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] Kernel build process

[Paul Jones]

> -----Original Message-----
> From: buildroot-bounces at busybox.net [mailto:buildroot-
> bounces at busybox.net] On Behalf Of Thomas Petazzoni
> Sent: Thursday, 1 July 2010 4:45 PM
> To: buildroot at busybox.net
> Subject: Re: [Buildroot] Kernel build process
> 
> On Thu, 1 Jul 2010 08:22:55 +1000
> "Paul Jones" <paul@pauljones.id.au> wrote:
> 
> > Good point. I guess if we tell the user to run "make
> > linux26-menuconfig" that would be just as good.
> 
> Or to give a configuration file or defconfig name. The problem with "make
> linux26-menuconfig" is that the configuration of the kernel will be stored
in
> output/build/linux-..../.config, and being part of the output/ directory,
it will
> be removed if the user doesn't save it elsewhere.

Why not have buildroot copy it back? I find it a pain having to remember to
copy my .config before I rm -Rf the output dir.
Also would a new user know how to create a .config? 



Paul.