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

[Zhiqiang Hou]

+ Rod and Chenhui

> -----Original Message-----
> From: Zhiqiang Hou
> Sent: 2016年1月25日 11:16
> To: 'Scott Wood' <oss at buserror.net>; york sun <york.sun at nxp.com>; Bhupesh
> Sharma <bhupesh.sharma at nxp.com>; Zhiqiang Hou
> <Zhiqiang.Hou at freescale.com>; u-boot at lists.denx.de;
> albert.u.boot at aribaud.net; Mingkai.hu at freescale.com; Stuart Yoder
> <stuart.yoder at nxp.com>; leoli at freescale.com; prabhakar at freescale.com;
> bhupesh.sharma at freescale.com
> Subject: RE: [PATCHv2 2/3] ARMv8/layerscape: Add FSL PPA support
> 
> Hi Rod and Chenhui,
> 
> Can you help to answer the questions about PSCI and PPA?
> 
> > -----Original Message-----
> > From: Scott Wood [mailto:oss at buserror.net]
> > Sent: 2016年1月23日 4:22
> > To: york sun <york.sun at nxp.com>; Bhupesh Sharma
> > <bhupesh.sharma at nxp.com>; Zhiqiang Hou <Zhiqiang.Hou at freescale.com>;
> > u-boot at lists.denx.de; albert.u.boot at aribaud.net;
> > Mingkai.hu at freescale.com; Stuart Yoder <stuart.yoder at nxp.com>;
> > leoli at freescale.com; prabhakar at freescale.com;
> > bhupesh.sharma at freescale.com; Zhiqiang Hou <zhiqiang.hou at nxp.com>
> > Subject: Re: [PATCHv2 2/3] ARMv8/layerscape: Add FSL PPA support
> >
> > On Fri, 2016-01-22 at 20:18 +0000, york sun wrote:
> > > On 01/22/2016 12:14 PM, 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 at 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 at 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.
> > > > The cpu.enable_method needs to be changed from spin-table to psci as well.
> > > >
> > > > See
> > > > http://lxr.free-electrons.com/source/Documentation/devicetree/bind
> > > > in
> > > > gs
> > > > /arm/psci.txt for details.
> > > >
> > >
> > > Bhupesh,
> > >
> > > Before PPA is fully adopted, u-boot has to detect the existence of
> > > PPA and decide to use PSCI or spin table, right? So the device tree
> > > node should also be fixed accordingly.
> >
> > How would U-Boot know what version of PSCI the loaded PPA supports?
> > Is or could there be any metadata on the PPA image to convey such information?
> >
> 
> Thanks,
> Zhiqiang