From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Fri, 06 Feb 2026 11:03:18 +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 1voIgI-009RgP-2W for lore@lore.pengutronix.de; Fri, 06 Feb 2026 11:03:18 +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 1voIgH-0007aP-JK for lore@pengutronix.de; Fri, 06 Feb 2026 11:03:18 +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=CaYWuMwytWl+sVQIjNFijMm99gv4PU2UefDfscjs2+w=; b=N4C9Mx+TQ6Gaw2N3jJIXswwTJl uzJ+zL0fvNDPNYYbFVL3gPD753ZKAL2/BkL5tCpow/HzG2sr3gvKczKXkqAFqU3vd4DBY+QkLK1dQ ubdfQ0lu0arrowfTZRgmpKLO7rHdbrdQVZEK7k6IgKfsL5t3P5LpgJlqUQs06408rnHM+knfX3k1D mNfvqfRd4luFYSbGoPuM9/g4jkel1fRGBUW9ORqtsrgaAPDvxlkWJUH3zM42FVkcDaMj+pwoHWTYg LiKEQrRaMN62C3ngyt4lUnIAc5I2qFDsCKvJjf2Tu/eJtFXAz29maV7HVZD9jBjqfMoWHAV/RSJCq 4S1z8P/A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1voIfo-0000000B8U5-3NBf; Fri, 06 Feb 2026 10:02:48 +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 1voIfm-0000000B8Tk-0D3W for barebox@lists.infradead.org; Fri, 06 Feb 2026 10:02:47 +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 1voIfk-0007St-9P; Fri, 06 Feb 2026 11:02:44 +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 1voIfk-004Nob-2V; Fri, 06 Feb 2026 11:02:44 +0100 Received: from mfe by pty.whiteo.stw.pengutronix.de with local (Exim 4.96) (envelope-from ) id 1voIfk-002JnR-00; Fri, 06 Feb 2026 11:02:44 +0100 Date: Fri, 6 Feb 2026 11:02:43 +0100 From: Marco Felsch To: Ahmad Fatoum Message-ID: <20260206100243.dah3jz6r6pzebexe@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> 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-20260206_020246_096724_9B44E581 X-CRM114-Status: GOOD ( 36.34 ) 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=-3.9 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: > > > 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 > > --- > > arch/arm/mach-imx/scratch.c | 24 ++++++++++++++++++++++++ > > common/Kconfig | 14 ++++++++++++++ > > include/mach/imx/scratch.h | 2 ++ > > 3 files changed, 40 insertions(+) > > > > diff --git a/arch/arm/mach-imx/scratch.c b/arch/arm/mach-imx/scratch.c > > index e4e2d25969f061c9fcdfd7c3d87701b715eb2805..da138445dfb352f2f3497be77004aefc7d46f188 100644 > > --- a/arch/arm/mach-imx/scratch.c > > +++ b/arch/arm/mach-imx/scratch.c > > @@ -16,7 +16,10 @@ struct imx_scratch_space { > > u32 bootrom_log[128]; > > u32 reserved[128]; /* reserve for bootrom log */ > > struct optee_header optee_hdr; > > + /* FDT needs an 8 byte alignment */ > > + u8 fdt[CONFIG_SCRATCH_FDT_SIZE] __aligned(8); > > }; > > +static_assert(sizeof(struct imx_scratch_space) <= CONFIG_SCRATCH_SIZE); > > > > static struct imx_scratch_space *scratch; > > > > @@ -92,3 +95,24 @@ const struct optee_header *imx_scratch_get_optee_hdr(void) > > > > return &scratch->optee_hdr; > > } > > + > > +u8 *imx_scratch_get_fdt(unsigned int *fdt_sz) > > +{ > > + unsigned int sz; > > + > > + if (!scratch) { > > + if (IN_PBL) > > + return ERR_PTR(-EINVAL); > > + else > > + scratch = (void *)arm_mem_scratch_get(); > > + } > > + > > + sz = sizeof(scratch->fdt); > > + if (sz == 0) > > + return NULL; > > + > > + if (fdt_sz) > > + *fdt_sz = sz; > > + > > + return scratch->fdt; > > +} > > diff --git a/common/Kconfig b/common/Kconfig > > index 50c26695b2b56a943edfd00a7e0cb1067ad269a9..265652900a5632177d36efa84d590be6db2e7015 100644 > > --- a/common/Kconfig > > +++ b/common/Kconfig > > @@ -304,6 +304,20 @@ config SCRATCH_SIZE > > default 0x8000 > > prompt "Scratch size" > > > > +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. 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 | > > -- #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 |