[U-Boot] [PATCHv2 2/3] ARMv8/layerscape: Add FSL PPA support

[Scott Wood <oss@buserror.net>]

On Fri, 2016-01-22 at 20:14 +0000, Bhupesh Sharma wrote:
> 
> > -----Original Message-----
> > From: Scott Wood [mailto:oss at buserror.net]
> > Sent: Saturday, January 23, 2016 1:39 AM
> > To: york sun; Zhiqiang Hou; u-boot at lists.denx.de;
> > albert.u.boot at aribaud.net; Mingkai.hu at freescale.com; Stuart Yoder;
> > leoli at freescale.com; prabhakar at freescale.com;
> > bhupesh.sharma at freescale.com; Zhiqiang Hou
> > Subject: Re: [PATCHv2 2/3] ARMv8/layerscape: Add FSL PPA support
> > 
> > On Fri, 2016-01-22 at 20:05 +0000, york sun wrote:
> > > On 01/21/2016 01:53 AM, Zhiqiang Hou wrote:
> > > > From: Hou Zhiqiang <Zhiqiang.Hou@freescale.com>
> > > > 
> > > > The FSL Primary Protected Application (PPA) is a software component
> > > > loaded during boot which runs in TrustZone and remains resident
> > > > after boot.
> > > > 
> > > > Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@freescale.com>
> > > > ---
> > > > Tested on LS1043A RDB board
> > > > 
> > > 
> > > I presume PSCI is implemented in PPA. How does the SMP boot flow
> > > change with PPA? U-boot has to remain functional in the absence of PPA,
> > right?
> > > 
> > > Would it be possible to write a readme for PPA?
> > 
> > Also, how does the devicetree get updated to indicate the presence of
> > PSCI?
> > 
> 
> One needs to add PSCI node in the DTS for the same, claiming support for
> PSCI specification.

So then we need a different dts based on whether PPA is loaded?  No thanks.

> The cpu.enable_method needs to be changed from spin-table to psci as well.

Right, that's part of updating the devicetree to indicate the presence of
PSCI.

> See http://lxr.free-electrons.com/source/Documentation/devicetree/bindings/a
> rm/psci.txt for details.

I'm familiar with the binding.

-Scott