From mboxrd@z Thu Jan 1 00:00:00 1970 From: Scott Wood Date: Fri, 22 Jan 2016 14:32:08 -0600 Subject: [U-Boot] [PATCHv2 2/3] ARMv8/layerscape: Add FSL PPA support In-Reply-To: References: <1453369489-14131-1-git-send-email-Zhiqiang.Hou@freescale.com> <1453369489-14131-2-git-send-email-Zhiqiang.Hou@freescale.com> <1453493357.19133.93.camel@buserror.net> <1453494092.27129.4.camel@buserror.net> Message-ID: <1453494728.27129.9.camel@buserror.net> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Fri, 2016-01-22 at 20:27 +0000, Bhupesh Sharma wrote: > > > -----Original Message----- > > From: Scott Wood [mailto:oss at buserror.net] > > Sent: Saturday, January 23, 2016 1:52 AM > > To: york sun; Bhupesh Sharma; 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 20:18 +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 > > > > > > > > > > > > > > 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 > > > > > > > --- > > > > > > > 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/bindin > > > > 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. > > A static CONFIG_ flag is used for enabling the PPA support currently in > QorIQ-LS u-boot code. > > > > > 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? > > PSCI specifications support the PSCI_VERSION API which is implemented by PPA > and it returns the PSCI_VERSION > supported by PPA. That does not answer the question unless we can assume that PPA always implements PSCI >= 0.2. And maybe there are other services worth advertising in the device tree? Some sort of metadata would be nice. -Scott