From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Tue, 07 Jan 2025 16:52:22 +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 1tVBsT-000NII-1O for lore@lore.pengutronix.de; Tue, 07 Jan 2025 16:52:21 +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 1tVBsQ-0007S2-1f for lore@pengutronix.de; Tue, 07 Jan 2025 16:52:21 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=nQPyDiJjTxj5dZMtyTsCsXoOQ7vvTz708FpTZsTGs8M=; b=0bm1J3180gYOerRhsoWozmGl+I iOeM7PO59WTUWc7AB9H6dauSI2dvs9pTD9R8mKAWPhgBqRYkxQBGV5Vbe1QWtq9E+tOY3QKgSZ0rH lesjImtS3/H9ScDSv2+VVCnJZ0Nf06vKHdlc2pVsXcepMEXwyK9sKMAphroPbO6RNswTI5Gpjs3NG +tPCiyMDoTioX1zZgFihWCQpX95mT64Ifj5A7EtuWiwSohaj688yLPKuitIx+J0TtIYCI+O5peQFp AMNgDRbnOgcMbgG52srW/YCvss07pzOMRzDXmxsRacTCDPq1rzF9yJfjFl8LPdPDguSzPi8hy2LBp DOYBZkOQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tVBsC-00000005VlG-1I4T; Tue, 07 Jan 2025 15:52:04 +0000 Received: from zdiv.net ([2001:4b98:dc0:43:f816:3eff:fee4:1d8c]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tVAia-00000005FEd-15Ps for barebox@lists.infradead.org; Tue, 07 Jan 2025 14:38:08 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zdiv.net; s=24; t=1736260669; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=nQPyDiJjTxj5dZMtyTsCsXoOQ7vvTz708FpTZsTGs8M=; b=uMYR96HvESmFP2b7nvC8C9Cd5LwMVW71k0c5SY4o9sbEmLZ/9fXUTwdPIj3O+Pzn1Vq+2L YZ4rDayiRygjbMOlyJg4c2rpPiEMISBLM0JrDl/FNXn/6ZnFOsw8Kjl4bUlaJ2nonMYvUs NBEHSJGJGw/a7ZG95kisclmNNkqnL8iVxHPGnfF8m+BnvYnVfuRKHvkzXcq+UYf+1+dOHj z/mFFV/oI9p8zFvkkbIcsWdz4gKXPXyLEEuU4aGHS2Flp6mJ0jfV7FAAxYtSDNxIHtrmVi 05IGj3B/wy8nxPFVl7ojyVxJ73H8gOdTOw3vCGPJ96vGtoKW4JFFZ+BsGTZEhA== Received: from mini.my.domain ( [2a01:e0a:12:d860:cfea:c4a:f4aa:bbd]) by zdiv.net (OpenSMTPD) with ESMTPSA id 7e73f891 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Tue, 7 Jan 2025 15:37:49 +0100 (CET) From: Jules Maselbas To: barebox@lists.infradead.org Cc: Jules Maselbas Date: Tue, 7 Jan 2025 15:37:40 +0100 Message-ID: <20250107143740.16903-7-jmaselbas@zdiv.net> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250107143740.16903-1-jmaselbas@zdiv.net> References: <20250107143740.16903-1-jmaselbas@zdiv.net> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250107_063804_607778_2B3B5297 X-CRM114-Status: GOOD ( 25.83 ) 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: , 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=-5.4 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: [PATCH v2 6/6] Documentation: sunxi: Add some documentation 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) Add some informations about Allwinner sunxi boardsupport: the general boot process, how to use sunxi-fel tool, and how to create a bootable image disk. Signed-off-by: Jules Maselbas --- Documentation/boards/sunxi.rst | 132 +++++++++++++++++++++++++++++++++ 1 file changed, 132 insertions(+) create mode 100644 Documentation/boards/sunxi.rst diff --git a/Documentation/boards/sunxi.rst b/Documentation/boards/sunxi.rst new file mode 100644 index 0000000000..46832559c9 --- /dev/null +++ b/Documentation/boards/sunxi.rst @@ -0,0 +1,132 @@ +.. + SPDX-License-Identifier: GPL-2.0+ + + Copyright (C) 2022, Jules Maselbas + +Allwinner sunxi +=============== + +Because of size constraints Barebox proper cannot boot directly, the uses +of :doc:`PBL` allows to compress the Barebox image and it's device-tree. +However this is not enough, and two images are acctually needed. The first +image is suffixed *_xload* and it only consist of the PBL with a special +entry point that looks for ``barebox.bin`` the root of a FAT partition. +Only the SD card is currently searched, but this could also be in eMMC. +The second image is your standard Barebox plus PBL image (suffixed ``.pblb``). + +Boot process +------------ + +On power-up Allwinner SoC starts in boot ROM, aka BROM, which will search +for an eGON image: first from the SD card, then from eMMC. If no image is +found then the BROM will enter into FEL mode that can be used for initial +programming and recovery of devices using USB. + +Some board may have a button to enter FEL mode at startup. If not, another +way to enter FEL mode is to not have a valid image eGON image, this can be +achived by erasing existing eGON image headers. + +eGON header +----------- + +The eGON header structure is described in the file ``include/mach/sunxi/egon.h``. +This is also documented on https://linux-sunxi.org/EGON . + +The eGON header, followed by the actual image, must be located at the fixed +offset of 8192 bytes (8KB) from the start of the disk (sector 16), either +from SD card; or from eMMC. + +.. code-block:: sh + + # copy the "pine64_xload" eGON image into disk sdX + dd if=images/start_pine64_pine64_xload.pblb.egonimg of=/dev/sdX bs=512 seek=16 + +The above will write the entire "pine64_xload" Barebox PBL plus the eGON +header into the disk "/dev/sdX". + +The boot ROM will load, at most, the first 32KB of the image into SRAM, +including the header itself! The eGON header starts with a jump instruction +to jump over the header, this jump instruction needs to be patched accordingly +with the header size. + +.. note:: + + On sunxi platforms the boot ROM loads the entire image **including** + the eGON header. The actual base address will be offset by the eGON header + (currently 96 bytes), this bad because arm instructions used for relocation + expect the base address to be aligned on 4K boundary. + As a workaround, a eGON header is included and linked into the Barebox + PBL image, this dummy header will be filled later by egon_mkimage. + + +Board images are defined in ``images/Makefile.sunxi``, here is an example:: + +.. code-block:: none + + pblb-$(CONFIG_MACH_PINE64_PINE64) += start_pine64_pine64_xload + MAX_PBL_IMAGE_SIZE_start_pine64_pine64_xload = 0x8000 + FILE_barebox-pine64-pine64_xload.img = start_pine64_pine64_xload.pblb.egonimg + image-$(CONFIG_MACH_PINE64_PINE64) += barebox-pine64-pine64_xload.img + + +RMR aarch64 switch +------------------ + +Aarch64 capable SoC (A64/sun50i) boot by default in 32-bit mode. A special header +is added to the start of the PBL image in order to switch to aarch64 mode as soon +as possible. This must be done very early in the boot process since both ISA are +not compatible. The code to switch mode is already assembled (mostly arm 32bit) +and is documented in the header file ``include/mach/sunxi/rmr_switch.h``. + +FEL +--- + +The ``sunxi-fel`` tool is used to interact, through USB, with sunxi devices +in FEL mode. ``sunxi-fel`` is part of the sunxi-tools_. + +.. _sunxi-tools: https://github.com/linux-sunxi/sunxi-tools + +More documentation about FEL_ and how to use the sunxi-fel tool can be +found on https://linux-sunxi.org/FEL/USBBoot . + +.. note:: + + ``sunxi-fel`` has a commands dedicated to boot u-boot images but theses + commands require a valid eGON header, if not more. This can be easily bypassed. + +The ``sunxi-fel`` tool can be used to load any arbitrary image at a given address +and can also request the processor to jump and start executing at any address. +This can be achieved by the following two commands:: + +.. code-block:: sh + + sunxi-fel write-with-progress 0x00018000 images/start_pine64_pinephone.pblb + sunxi-fel exe 0x00018000 + +These two commands allows the use of a different and bigger SRAM than the +default 32KB used by the boot ROM. + +The ``sunxi-fel`` tool might require additional permissions to acces the USB device, +this can be fixed by using a udev rule to add the most appropriated group to the device, +as an exemple adding the device to the dialout group can be done with the following rule:: + + SUBSYSTEMS=="usb", ATTRS{idVendor}=="1f3a", ATTRS{idProduct}=="efe8", GROUP+="dialout" + + +Arm Trusted Firmware (TF-A) +--------------------------- + +Boards using a 64-bit Soc (A64, H5, H6, H616, R329) require the BL31 stage of +the `Arm Trusted Firmware-A`_ firmware. This provides the reference +implementation of secure software for Armv8-A, offering PSCI and SMCCC +services. Allwinner support is fully mainlined. To build bl31.bin:: + +.. code-block:: sh + + git clone https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git + cd trusted-firmware-a + make CROSS_COMPILE=aarch64-linux-gnu- PLAT=sun50i_a64 DEBUG=1 + cp build/sun50i_a64/debug/bl31.bin ${barebox_dir}/firmware/sun50i-a64-bl31.bin + +The target platform (``PLAT=``) for A64 and H5 SoCs is sun50i_a64, for the H6 +sun50i_h6, for the H616 sun50i_h616, and for the R329 sun50i_r329. -- 2.47.1