[U-Boot] Support of device-tree for PowerPC platform: Query

[Prabhakar Kushwaha]

> -----Original Message-----
> From: York Sun
> Sent: Thursday, June 28, 2018 9:07 PM
> To: Prabhakar Kushwaha <prabhakar.kushwaha at nxp.com>; Simon Glass
> <sjg at chromium.org>
> Cc: u-boot at lists.denx.de; Poonam Aggrwal <poonam.aggrwal at nxp.com>;
> Jagdish Gediya <jagdish.gediya at nxp.com>
> Subject: Re: Support of device-tree for PowerPC platform: Query
> 
> On 06/27/2018 11:30 PM, Prabhakar Kushwaha wrote:
> 
> <snip>
> 
> >> Thanks for the direction.
> >>
> >> We will be following approach "a" with updated flash map.
> >> We will allocate 1MB for uboot in flash. Out which 64K for DTB and
> >> 960KB for u-boot for future increase.
> >>
> >> We will also update location of env and fman ucode for NXP platforms.
> >>
> >
> >
> > Other thought,
> >  use CONFIG_OF_SEPARATE but **don't** concatenate dtb with u-boot.
> In
> > this case user has to program u-boot and dtb separately at different
> > location. It will also have minimal impact on PowerPC platforms
> >
> > Just wondering if this approach has any disadvantages in longer run.
> > What if user forget to program dtb and restart system??
> >
> 
> If we cannot combine DT with U-Boot image, we may have to live with two
> separated images. We may have to shift the ENV sectors to make DT right
> above U-Boot for convenience. If U-Boot can boot up and show a message of
> missing DT, it is acceptable to me.
> 

Putting DT in place of Env require lots of modification. 
I want to use existing QorIQ platform's memory map. 

Here 1 MB flash memory is reserved for Linux DTB.  Just wanted to split into 2 parts (Linux, uboot) with both size 512KB. 
This 1 MB location is far from u-boot, env, fman ucode. 

--pk