Am 17. Dezember 2021 11:19:42 GMT+05:00 schrieb "Sahil Malhotra (OSS)" <[email protected]>: >Hi Michael/Andrey > >Gentle reminder for comment on this patch series. > >Regards, >Sahil Malhotra > >> -----Original Message----- >> From: Sahil Malhotra (OSS) <[email protected]> >> Sent: Friday, December 10, 2021 12:03 PM >> To: ZHIZHIKIN Andrey <[email protected]>; Sahil >> Malhotra (OSS) <[email protected]>; Michael Walle >> <[email protected]> >> Cc: Clément Faure <[email protected]>; Gaurav Jain >> <[email protected]>; Pankaj Gupta <[email protected]>; Priyanka >> Jain <[email protected]>; [email protected]; Varun Sethi >> <[email protected]>; Ye Li <[email protected]> >> Subject: RE: [PATCH 1/2] fsl-layerscape: add dtb overlay feature >> >> Hi Andrey, >> >> > -----Original Message----- >> > From: ZHIZHIKIN Andrey <[email protected]> >> > Sent: Wednesday, December 8, 2021 3:43 PM >> > To: Sahil Malhotra (OSS) <[email protected]>; Michael Walle >> > <[email protected]> >> > Cc: Clément Faure <[email protected]>; Gaurav Jain >> > <[email protected]>; Pankaj Gupta <[email protected]>; >> Priyanka >> > Jain <[email protected]>; [email protected]; Varun Sethi >> > <[email protected]>; Ye Li <[email protected]> >> > Subject: RE: [PATCH 1/2] fsl-layerscape: add dtb overlay feature >> > >> > Hello Sahil, >> > >> > > -----Original Message----- >> > > From: Sahil Malhotra (OSS) <[email protected]> >> > > Sent: Wednesday, December 8, 2021 7:12 AM >> > > To: Michael Walle <[email protected]>; Sahil Malhotra (OSS) >> > > <[email protected]> >> > > Cc: Clément Faure <[email protected]>; Gaurav Jain >> > > <[email protected]>; Pankaj Gupta <[email protected]>; >> > Priyanka >> > > Jain <[email protected]>; u- [email protected]; Varun Sethi >> > > <[email protected]>; Ye Li <[email protected]>; ZHIZHIKIN Andrey >> > > <[email protected]> >> > > Subject: RE: [PATCH 1/2] fsl-layerscape: add dtb overlay feature >> > > >> > > >> > > Hi Michael, >> > > >> > > -----Original Message----- >> > > From: Michael Walle <[email protected]> >> > > Sent: Monday, November 29, 2021 11:17 PM >> > > To: Sahil Malhotra (OSS) <[email protected]> >> > > Cc: Clément Faure <[email protected]>; Gaurav Jain >> > > <[email protected]>; Pankaj Gupta <[email protected]>; >> > Priyanka >> > > Jain <[email protected]>; u- [email protected]; Varun Sethi >> > > <[email protected]>; Ye Li <[email protected]>; ZHIZHIKIN Andrey >> > > <[email protected]> >> > > 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- >> > [email protected] >> >> Regards, >> Sahil Malhotra >> >> >> >
hey sahil, I'm on vacation until the end of this week. will comment beginning of next week. -michael
