Hi Michael/Andrey Gentle reminder for comment on this patch series.
Regards, Sahil Malhotra > -----Original Message----- > From: Sahil Malhotra (OSS) <sahil.malho...@oss.nxp.com> > Sent: Friday, December 10, 2021 12:03 PM > To: ZHIZHIKIN Andrey <andrey.zhizhi...@leica-geosystems.com>; Sahil > Malhotra (OSS) <sahil.malho...@oss.nxp.com>; Michael Walle > <mich...@walle.cc> > Cc: Clément Faure <clement.fa...@nxp.com>; Gaurav Jain > <gaurav.j...@nxp.com>; Pankaj Gupta <pankaj.gu...@nxp.com>; Priyanka > Jain <priyanka.j...@nxp.com>; u-boot@lists.denx.de; Varun Sethi > <v.se...@nxp.com>; Ye Li <ye...@nxp.com> > Subject: RE: [PATCH 1/2] fsl-layerscape: add dtb overlay feature > > Hi Andrey, > > > -----Original Message----- > > From: ZHIZHIKIN Andrey <andrey.zhizhi...@leica-geosystems.com> > > Sent: Wednesday, December 8, 2021 3:43 PM > > To: Sahil Malhotra (OSS) <sahil.malho...@oss.nxp.com>; Michael Walle > > <mich...@walle.cc> > > Cc: Clément Faure <clement.fa...@nxp.com>; Gaurav Jain > > <gaurav.j...@nxp.com>; Pankaj Gupta <pankaj.gu...@nxp.com>; > Priyanka > > Jain <priyanka.j...@nxp.com>; u-boot@lists.denx.de; Varun Sethi > > <v.se...@nxp.com>; Ye Li <ye...@nxp.com> > > Subject: RE: [PATCH 1/2] fsl-layerscape: add dtb overlay feature > > > > Hello Sahil, > > > > > -----Original Message----- > > > From: Sahil Malhotra (OSS) <sahil.malho...@oss.nxp.com> > > > Sent: Wednesday, December 8, 2021 7:12 AM > > > To: Michael Walle <mich...@walle.cc>; Sahil Malhotra (OSS) > > > <sahil.malho...@oss.nxp.com> > > > Cc: Clément Faure <clement.fa...@nxp.com>; Gaurav Jain > > > <gaurav.j...@nxp.com>; Pankaj Gupta <pankaj.gu...@nxp.com>; > > Priyanka > > > Jain <priyanka.j...@nxp.com>; u- b...@lists.denx.de; Varun Sethi > > > <v.se...@nxp.com>; Ye Li <ye...@nxp.com>; ZHIZHIKIN Andrey > > > <andrey.zhizhi...@leica-geosystems.com> > > > Subject: RE: [PATCH 1/2] fsl-layerscape: add dtb overlay feature > > > > > > > > > Hi Michael, > > > > > > -----Original Message----- > > > From: Michael Walle <mich...@walle.cc> > > > Sent: Monday, November 29, 2021 11:17 PM > > > To: Sahil Malhotra (OSS) <sahil.malho...@oss.nxp.com> > > > Cc: Clément Faure <clement.fa...@nxp.com>; Gaurav Jain > > > <gaurav.j...@nxp.com>; Pankaj Gupta <pankaj.gu...@nxp.com>; > > Priyanka > > > Jain <priyanka.j...@nxp.com>; u- b...@lists.denx.de; Varun Sethi > > > <v.se...@nxp.com>; Ye Li <ye...@nxp.com>; ZHIZHIKIN Andrey > > > <andrey.zhizhi...@leica-geosystems.com> > > > Subject: Re: [PATCH 1/2] fsl-layerscape: add dtb overlay feature > > > > > > Hi Sahil, > > > > > > Am 2021-11-29 12:55, schrieb Sahil Malhotra (OSS): > > > > Am 2021-11-17 19:11, schrieb Sahil Malhotra (OSS): > > > >>> Could you please add some description what this is doing and for > > > >>> what this is intended? To have a "DTB overlay feature", it is > > > >>> enough to just enable CONFIG_OF_LIBFDT_OVERLAY. > > > >> I will add some description, and yes for DTB overlay feature, it > > > >> is enough to enable CONFIG_OF_LIBFDT_OVERLAY but we need to do > > > >> this step before booting the kernel that's why also have to > > > >> enable CONFIG_OF_SYSTEM_SETUP. > > > > > > > >> Ok. What will the overlay do? Could you give an example? > > > > This overlay will be disabling the crypto nodes which will be used > > > > by optee in secure world, so that linux should not use it. > > > > > > > > > > > >>> Apparently you're adding an overlay passed by optee. Doesn't > > > >>> this have to be applied to u-boot's control dtb too? > > > >> Yes, we will be applying the overlay passed by optee, yes it will > > > >> be applied to dtb which will be passed to uboot for kernel booting. > > > > > > > >> If I read this patch correctly, you're modifying the DT before > > > >> you jump to linux. But I was asking whether you also have to > > > >> modify the DT which is used by u-boot. Eg. if you disable some > > > >> kind of crypto nodes (because optee will use them in secure > > > >> world), this also have to communicated to u-boot, not only linux, no? > > > > Yes, I got your point now, and is very valid, but as of now for > > > > u-boot we are just using the first available node for > > > > communicating with CAAM leaving other job rings as it is. > > > > So we need not to apply overlay to DTB used by uboot. > > > > > > > But we should do the correct thing, so that u-boot and linux > > > > doesn't see a > > > different version of the device tree. > > > > > > > Also what do you mean with "the first available node"? > > > > There is already a new CAAM driver for u-boot pending, see > > > > https://lore.kernel.org/u-boot/20211115070014.17586-1-gaurav.jain@ > > > > nx > > > > p.com/ > > > > > > Very first CAAM Job Ring is always used by u-boot, OP-TEE does not > > > use this job ring. Same job ring can be used by Linux once it boots up. > > > > Just for clarification: by saying "Very first CAAM Job Ring" do you > > actually mean JR0? > Yes, Very first CAAM Job Ring means JR0 for Layerscape. > > > > > If the BootROM logic with respect to JR reservation for LS family does > > not differ from i.MX8M family (which I assume does not), then why > > can't the logic be implemented in the same way proposed by Gaurav [1] > here as well? > BootROM logic with respect to JR reservation is different for both Layerscape > and i.MX8M family. > On Layerscape Platforms we don't have HAB, so we don’t need to reserve > JR0. > > > > > DT nodes can be statically disabled if we know that they are held by > > HAB and are not released to NS World. > > > > OP-TEE does set the status itself via dt_enable_secure_status(), which > > should present the properly configured FDT when U-Boot takes over. > Yes, OP-TEE set the status by dt_enable_secure_status() in DTB overlay > which gets merged with DTB provided for Linux bootup and then Linux boots > with merged DTB. > But u-boot uses the DTB embedded in its image. How can we modify that > DTB or merge DTB overlay passed by OP-TEE with uboot DTB ? > > > > > This is however valid only if OP-TEE implementation for LS matches to > > one from i.MX8M family. > > > > If it OP-TEE does differ, then I suggest this should be rather > > addressed there before U-Boot, since OP-TEE have all facilities in > > place to reserve JR nodes as they are needed. > OP-TEE reserves the JR node needed by it, but it needs to tell that to Normal > World entities and that is being done using DTB overlay for now. > > > > > > > > > Regards, > > > Sahil Malhotra > > > > -- andrey > > Link: [1]: https://lore.kernel.org/u-boot/20211207074129.10955-9- > > gaurav.j...@nxp.com > > Regards, > Sahil Malhotra > > >
