[U-Boot] [PATCH v2 1/3] image: Make image_get_fdt work like image_get_{ram_disk, kernel}

Marek Vasut
2011-11-05T22:06:47Z

> Dear Simon Glass,
>
> In message
<CAPnjgZ0bbhvZ1VPwY=0y9YZJdf+EOBgyKKVPFuAkBqy2z4L3HA@mail.gmail.com> you wrote:
> > Just a quick Q. What is the ultimate intent here? Should we be aiming
> > to have U-Boot copy and decompress the data into RAM ready for Linux?
>
> Yes.
>
> Rigth from the beginning of PPCBoot / U-Boot we designed it that
> U-Boot would do all needed steps to verify, load and uncompress an
> image. It make no sense to attach the uncompression and loading code
> to each and every image, and to download it and store it again and
> again and again. This works really well for example on Power, only
> ARM is one of the examples where the PTB never bothered to acquaint
> themself with ideas that went beyond the capabilities of Blob or
> similar boot loaders.

Right, there's no negotiation between linux and uboot on this topic. I think
this is going on for ages now.

>
> > In theory this should be slightly faster since U-Boot already has the
> > data in its cache. I think zImage now supports having an FDT inside
> > but what is the advantage of zImage over a uImage with compressed
> > portions?
>
> There is none. Also, there is no advantage in attaching the DT blob
> to the Linux image/. This is only of use to braindead boot loaders.
>
> Best regards,
>
> Wolfgang Denk