From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Mon, 09 Feb 2026 21:51:26 +0100 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1vpYEA-00Akdu-2Z for lore@lore.pengutronix.de; Mon, 09 Feb 2026 21:51:26 +0100 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1vpYE9-00021G-LW for lore@pengutronix.de; Mon, 09 Feb 2026 21:51:26 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To: Content-Type:MIME-Version:References:Message-ID:Subject:To:From:Date:Reply-To :Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=KbzGwtIr2xsme8qPIT4mHA2KhsOT5IoERPHTqBJD7L8=; b=gBn2BDLeXEv2FMIjbmMwnDo6rF 8lp5T0q8bfFWgr9T/XcxFKLRjptPnKQdZ8C+13uD9xKis/JWCqSE/AQJk60i9U2tDHvGaGJMMcp+h 8LdtYqsgfOhrx1lUtGQqK/sfjhW+fsC+GGbn3ZM8dgOk4jGbTpfMOTL5BTnmFrVPrkveNr7rz8B/f NwJYajk0jHh6TtfC49gWIWSH/vxmqUiFF/p4jiMcEBCrH9VU+gpdBCjxZS9XdO6edwxGkRPYNzb3U 2XB85ePc42uD7XXHtcVzoW2MmxWeMi4+fNPZ1HXihzJ3x+737TfJUSKSXNuUvxzcyCJatZGTuyroU piN5ffJA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vpYDf-0000000G0b7-1mfo; Mon, 09 Feb 2026 20:50:55 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vpYDa-0000000G0aW-0iuv for barebox@lists.infradead.org; Mon, 09 Feb 2026 20:50:51 +0000 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1vpYDX-0001we-HN; Mon, 09 Feb 2026 21:50:47 +0100 Received: from pty.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::c5]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1vpYDY-00514j-05; Mon, 09 Feb 2026 21:50:47 +0100 Received: from mfe by pty.whiteo.stw.pengutronix.de with local (Exim 4.96) (envelope-from ) id 1vpYDX-008A8C-0r; Mon, 09 Feb 2026 21:50:47 +0100 Date: Mon, 9 Feb 2026 21:50:47 +0100 From: Marco Felsch To: Ahmad Fatoum Message-ID: <20260209205047.7nite5dc5n2erpa7@pengutronix.de> References: <20260204-v2025-09-0-topic-optee-of-handling-v2-0-da075e6818e0@pengutronix.de> <20260204-v2025-09-0-topic-optee-of-handling-v2-6-da075e6818e0@pengutronix.de> <20260206100243.dah3jz6r6pzebexe@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260209_125050_216229_1447E5F2 X-CRM114-Status: GOOD ( 37.48 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: BAREBOX Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-3.8 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH v2 06/15] ARM: i.MX: scratch: add FDT support X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) On 26-02-06, Ahmad Fatoum wrote: > Hi, > > On 2/6/26 11:02 AM, Marco Felsch wrote: > >> On 2/4/26 9:01 PM, Marco Felsch wrote: > >>> Add support to store a FDT within the scratch area. The user needs to > >>> query the location and size via imx_scratch_get_fdt() which can be used > >>> afterwards to write the actual FDT into it. > >>> > >>> Signed-off-by: Marco Felsch > > >>> +config SCRATCH_FDT_SIZE > >>> + hex > >>> + default 0x0 > >>> + prompt "Scratch FDT size" > >>> + help > >>> + The size of the scratch area used as destination to load and optional > >>> + decompress the barebox builtin DTB into it. Can be 0x0 if early FDT > >>> + support is not requied. > >>> + > >>> + If specified, SCRATCH_FDT_SIZE <= SCRATCH_SIZE must be ensured. > >>> + > >>> + This option should match the OP-TEE's CFG_DTB_MAX_SIZE configuration > >>> + if used by OP-TEE. > >> > >> AFAIU, this is a workaround because OP-TEE doesn't accept outside > >> information about how big the DTB buffer is, just its base address. > > > > This is correct for the bl_params case. In case of transfer-lists the > > size could be detected by OP-TEE OS. > > > >> In that case, this should go to security/Kconfig and be named something > >> like PBL_OPTEE_DTB_MAX_SIZE. There's no need to ask every user that > >> configures barebox about this. > > > > This would bind the FDT support to OP-TEE but the FDT could be used by > > other boot binaries as well.In the speak of ARM, it could be used by > > the TF-A. In the speak of RISC-V, it could be used by opensbi. Therefore > > I made it generic. > > > > I wanted to avoid multiple Kconfig options to configure the scatch space > > for: > > - OP-TEE FDT > > - OpenSBI FDT > > - TF-A FDT > > > > I'm currently unsure if dropping the OP-TEE note from the help message > > helps. But I have no hard feelings about PBL_OPTEE_DTB_MAX_SIZE either. > > How about: > > struct imx_scratch_space { > union { > u8 __b[CONFIG_SCRATCH_SIZE]; > struct { > u32 bootrom_log[128]; > u32 reserved[128]; > struct optee_header optee_hdr; > u8 fdt[] __aligned(8); This would require, that the 'fdt' element is always the last element. We could add a comment, but it's rather fragile IMHO. > }; > }; > }; > static_assert(sizeof(struct imx_scratch_space) > - offsetof(struct imx_scratch_space, fdt) > <= PBL_OPTEE_DTB_MAX_SIZE); This would introduce a very strict dependency for CONFIG_SCRATCH_SIZE to the not always visible PBL_OPTEE_DTB_MAX_SIZE. As you said: > >> In that case, this should go to security/Kconfig and be named something > >> like PBL_OPTEE_DTB_MAX_SIZE. There's no need to ask every user that > >> configures barebox about this. Therefore I would like to use your name suggestion PBL_OPTEE_DTB_MAX_SIZE but keep it loose like RK does. > The benefits I see: > - Just one argument to tune (CONFIG_SCRATCH_SIZE) like we already use > for Rockchip Rockchip is using two Kconfig switch too (ARCH_ROCKCHIP_ATF_FDT_SIZE). > - We still have a dedicated option that can be kept in-sync with the > exact option value in OP-TEE to find problems at compile-time > - Only those who actually use OP-TEE will be asked about > PBL_OPTEE_DTB_MAX_SIZE Good points! > Would this work for you? Please see above. Regards, Marco > > Cheers, > Ahmad > > > > > > Regards, > > Marco > > > > > >> > >> > >> Cheers, > >> Ahmad > >> > >> -- > >> Pengutronix e.K. | | > >> Steuerwalder Str. 21 | http://www.pengutronix.de/ | > >> 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > >> Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | > >> > >> > > > > -- > Pengutronix e.K. | | > Steuerwalder Str. 21 | http://www.pengutronix.de/ | > 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | > > -- #gernperDu #CallMeByMyFirstName Pengutronix e.K. | | Steuerwalder Str. 21 | https://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-9 |