[Buildroot] [Bug 6392] New: Extended ARM uImage kernel options

[Buildroot] [Bug 6392] New: Extended ARM uImage kernel options

[bugzilla at busybox.net]

https://bugs.busybox.net/show_bug.cgi?id=6392

           Summary: Extended ARM uImage kernel options
           Product: buildroot
           Version: 2013.05
          Platform: Other
        OS/Version: Linux
            Status: NEW
          Severity: minor
          Priority: P5
         Component: Other
        AssignedTo: unassigned at buildroot.uclibc.org
        ReportedBy: philipp.rahns at meinberg.de
                CC: buildroot at uclibc.org
   Estimated Hours: 0.0


In same cases, and especially for self hosted Linux kernels and ARM projects,
you need additional kernel compiling options. This is what the patch does
including making life easier to use the "native" kernel config used in its
source tree.

-- 
Configure bugmail: https://bugs.busybox.net/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.

[Buildroot] [Bug 6392] Extended ARM uImage kernel options

[bugzilla at busybox.net]

https://bugs.busybox.net/show_bug.cgi?id=6392

Philipp Rahns <philipp.rahns@meinberg.de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at buildroot.uclibc |philipp.rahns at meinberg.de
                   |.org                        |

--- Comment #1 from Philipp Rahns <philipp.rahns@meinberg.de> 2013-07-17 06:36:19 UTC ---
Created attachment 4994
  --> https://bugs.busybox.net/attachment.cgi?id=4994
ARM uImage kernel compilation patches

-- 
Configure bugmail: https://bugs.busybox.net/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.

[Buildroot] [Bug 6392] Extended ARM uImage kernel options

[bugzilla at busybox.net]

https://bugs.busybox.net/show_bug.cgi?id=6392

--- Comment #2 from Thomas Petazzoni <thomas.petazzoni@free-electrons.com> 2013-07-17 07:39:43 UTC ---
Thanks for this contribution.

Can you give examples of usage of BR2_LINUX_KERNEL_MAKE_FLAGS ? Why would it be
limited to ARM and uImage ?

Also, I don't quite understand BR2_LINUX_KERNEL_NATIVE_CONFIG. When you unpack
a kernel tarball or a Git tree, there's normally no .config in the kernel tree,
and it has to be created, either starting from a defconfig, or using one of the
menuconfig/nconfig/gconfig/xconfig configuration interfaces.

Could you expand a bit on the use cases? Thanks!

-- 
Configure bugmail: https://bugs.busybox.net/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.

[Buildroot] [Bug 6392] Extended ARM uImage kernel options

[bugzilla at busybox.net]

https://bugs.busybox.net/show_bug.cgi?id=6392

--- Comment #3 from Philipp Rahns <philipp.rahns@meinberg.de> 2013-07-17 08:01:49 UTC ---
(In reply to comment #2)
> Thanks for this contribution.
> 
> Can you give examples of usage of BR2_LINUX_KERNEL_MAKE_FLAGS ? Why would it be
> limited to ARM and uImage ?
> 
> Also, I don't quite understand BR2_LINUX_KERNEL_NATIVE_CONFIG. When you unpack
> a kernel tarball or a Git tree, there's normally no .config in the kernel tree,
> and it has to be created, either starting from a defconfig, or using one of the
> menuconfig/nconfig/gconfig/xconfig configuration interfaces.
> 
> Could you expand a bit on the use cases? Thanks!

Hi Thomas,

I agree on the first one that it is not neccessarily limited to the ARM
section.
Could be used at any time when compiling a kernel in general.

Concerning native config:
When you have a look at the Zedboard or the Raspberry Pi there are already
modified kernel sources fitting to the board.
In some cases this is not enough for the requirements of oneself and you start
tweaking it. This is the point where you start "branching" the project and
saving ( mostly likely ) the config related to your changes. Of course, you
host this branch on a server and to make life easier for other developers you
provide an out of the box solution. I know I could easily use
"$(LINUX_DIR)/.config" as config file path but I though it was worth a single
option.

-- 
Configure bugmail: https://bugs.busybox.net/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.

[Buildroot] [Bug 6392] Extended ARM uImage kernel options

[bugzilla at busybox.net]

https://bugs.busybox.net/show_bug.cgi?id=6392

Thomas Petazzoni <thomas.petazzoni@free-electrons.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |WONTFIX

--- Comment #4 from Thomas Petazzoni <thomas.petazzoni@free-electrons.com> 2013-10-30 22:28:55 UTC ---
The contributor, Philipp Rahns, proposed the addition of a
BR2_LINUX_KERNEL_MAKE_FLAGS configuration option, to add custom make flags when
building the kernel. However, Philipp hasn't given details on the specific use
case for this, so it's hard to understand why we would want to add that.

The second proposal of Philipp is to add BR2_LINUX_KERNEL_NATIVE_CONFIG, which
tells the Buildroot kernel building logic to use the .config file present
within the kernel tarball as the configuration file. However, this is not a
standard practice, and if people want to store a kernel configuration within
the kernel tree, they should rather store it into arch/<ARCH>/configs/, as a
minimal defconfig. This is the standard practice and is already supported by
Buildroot.

Due to those two reasons, I am not convinced the patch is actually needed. Of
course Philipp, if you disagree, feel free to reopen the bug and provide
additional details about those use cases. It is still possible to convince us!
:-)

-- 
Configure bugmail: https://bugs.busybox.net/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.