Re: [PATCH 2/3] Kbuild: Implement CONFIG_UIMAGE_KERNEL_NOLOAD

Jean-Christophe PLAGNIOL-VILLARD
2012-03-07T18:48:57Z

On 11:40 Wed 07 Mar , Stephen Warren wrote:
> On 03/07/2012 11:08 AM, Jean-Christophe PLAGNIOL-VILLARD wrote:
> > On 17:30 Tue 06 Mar , Stephen Warren wrote:
> >> This allows the user to use U-Boot's mkimage's -T kernel_noload option
> >> if their arch Kconfig allows it, and they desire.
> >>
> >> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
> >> ---
> >> The next patch enables this new CONFIG_ALLOW_ option for ARM. I assume
> >> that some other architectures will also be able to enable it, but I'm
> >> not familiar enough with any to know which.
> > I'm going to repeat. I don't think any impromevent here.
> >
> > with no specific kernel load address the uImage for is useless/
>
> No, the whole point of this type of kernel image is that it doesn't need
> a specific load address; the kernel zImage can run from anywhere in RAM
> (provided AUTO_ZRELADDR is enabled, subject to some slight
> restrictions), and hence the uImage doesn't need to be loaded to or
> moved to any particular location.
>
> The scripts that U-Boot runs determine where the image gets loaded into
> memory.
so instead of spending time on the uImage add simply the support the zImage to
U-Boot as this AUTO_ZRELADDR have 0 advantage compare to the zImage

>
> > And this no the job of the kernel to build a boot loader specific boot image
> > format.
>
> Not everyone agrees with this.
so if a new boot loader apear or a new format the kernel will have to support
it. No
>
> > And the uImage format here is called the legacy format where now U-Boot
> > support a new format based on DT format.
> >
> > Will you plan to add it too?
>
> No. The last time I heard anyone talk about that, it sounded like the
> adoption was basically zero, so it seems pointless. Personally, I find
> creating that kind of image more complex, and don't see any benefits in
> that format either.
>
> > no sorry I don't think it's the right way to go.
> >
> > On X86 we boot zImage simply. The new uImage option to do not specify the load
> > address add nothing more than just boot a zImage for kernel point of view.
>
> U-Boot does not currently have the ability to boot zImage on ARM.
so add it and drop the uImage format
>
> > Further more on server the vendor will use grub mostly (even on ARM) and will
> > expect to boot a zImage.
>
> But that is irrelevant for the people who are using U-Boot not grub.
execpt the zIamge is the common boot format for all the server and PC and
other boot loader

Best Regards,
J.