From patchwork Mon Jun 26 14:36:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 13293026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 26EA0EB64D7 for ; Mon, 26 Jun 2023 14:36:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=241po2+nvcNE+XphD1fxKYh8e4cFjiM4VfzaxhwW6zU=; b=u1FgTcY+BYX7GI dV50eV5ByezxByhnvrxz7Uk7MwMvHFz+rReIoCIiZz7s0ZE/B9zYuyLdd1G2r3GNWPUDgclotwOKl UH6SQbZbz8uauFiBu0MzKMiJVCPefHNofYSP+5TbFQUpIzINSX6n0yt6OKzaKC+RPi60st9FBJTNY /YD+C+9aYbn/TxeTkzk8uhInOs2tbfKuJXJAeNxQ3ITXqt5NvNlwf01l9F4VYQWF8aWI56i7mUE8g Ed8dOXx5tn3XM2tvdB/FnnK1gsdkVPBttNTQwkOYVgathG8GMy9sIEGc/FZ0dkZjGTqtsqzSLVT5G 6ZSYh9vYkXZgXagnJL3g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qDnKU-00AP3c-1T; Mon, 26 Jun 2023 14:36:34 +0000 Received: from mail-wm1-x32c.google.com ([2a00:1450:4864:20::32c]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qDnKS-00AP2s-0Y for linux-riscv@lists.infradead.org; Mon, 26 Jun 2023 14:36:33 +0000 Received: by mail-wm1-x32c.google.com with SMTP id 5b1f17b1804b1-3f9b0f139feso47969555e9.3 for ; Mon, 26 Jun 2023 07:36:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20221208.gappssmtp.com; s=20221208; t=1687790189; x=1690382189; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=yyS6js1uEQcGpjrlLFsApXkwWbdmfkq2O19nl/ntD9I=; b=0rRx16vPEz4otpjwTB2+xwwCPkN6laJ920t/o9tdeRTI3/IWz7rHFhmjtl4BtcLvbK 8sd8i1ixF3tILm07mAiNcvuah+F64takI0yNg5lzTCOlWuLa+ihQipMWAUO2Kp7G97oA Kl18TQkv7lLhVwW0P5B06IdBRRNGQMkZCAXjn1QX/rmD9XuGHUQIL4tjK7oqW4c6xyS2 XvOUThw0ASzBjXMK30mELoMgSwN7Os79KpEA2iYAlHD4pXmyBqLFFyOM2aiuoARShzqT tWGzwRLzkTbjzHvkL55xqVOVYZF9H4OdGqOpt8tX1uNXHuhNDjLsqM3YFqXjdOr1B+kV GlJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687790189; x=1690382189; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=yyS6js1uEQcGpjrlLFsApXkwWbdmfkq2O19nl/ntD9I=; b=KJtUs4rgg5JiUtTL/G8woAihcinjktCv9Kgwz/rKTaQEqHhISmwONiUS9GHcrWjCm0 f5wAty7uIr/M7BL1ZtICACWUm5Crf4D79qFhkgrsn6WCcv1jXnCAB/c4QXbLQXaAw8BP pBAIfjo8odZNJdcCJy8I3X96LzWMkTFjFvfzOPsVoWHYD33ZDE7oUcykI5nq6sHDcqXP 1hBfUz7S98063qbG2cxXrJLeoCUQFecfxxyfgMdy075SUOyabu70h7Z3Bbdhftj/lZ44 ENrG6supnwljECu+OPRn9GWk7PuCmwLGFXo6AxTnF0qAryJ6pqCON91oOKVPDzY1tdsI 3vfw== X-Gm-Message-State: AC+VfDyzk0jCtLSv3B57ug0j9mta1RRwUcqQbzlozHNs66XkB0tESP0j bTHczBtXBzLoSkPSvXy4cnkbtw== X-Google-Smtp-Source: ACHHUZ5trI2VVLtdJQUt4Re6CkgIlyCdijkloV8ba7d0Pgi+frLUfcc37GZ0qPHllho9aVsX9sOgmw== X-Received: by 2002:a1c:6a12:0:b0:3fa:934c:8356 with SMTP id f18-20020a1c6a12000000b003fa934c8356mr3011833wmc.10.1687790188830; Mon, 26 Jun 2023 07:36:28 -0700 (PDT) Received: from localhost.localdomain (amontpellier-656-1-456-62.w92-145.abo.wanadoo.fr. [92.145.124.62]) by smtp.gmail.com with ESMTPSA id z10-20020a7bc7ca000000b003f8f8fc3c32sm7934552wmk.31.2023.06.26.07.36.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Jun 2023 07:36:28 -0700 (PDT) From: Alexandre Ghiti To: Jonathan Corbet , Paul Walmsley , Palmer Dabbelt , Albert Ou , =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , Andrew Jones , Conor Dooley , Sunil V L , Song Shuai , linux-doc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Alexandre Ghiti , Atish Patra Subject: [PATCH v4 1/3] Documentation: arm: Add bootargs to the table of added DT parameters Date: Mon, 26 Jun 2023 16:36:24 +0200 Message-Id: <20230626143626.106584-1-alexghiti@rivosinc.com> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230626_073632_207784_E62950C3 X-CRM114-Status: GOOD ( 10.79 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org The bootargs node is also added by the EFI stub in the function update_fdt(), so add it to the table. Signed-off-by: Alexandre Ghiti Reviewed-by: Atish Patra Reviewed-by: Song Shuai --- Documentation/arm/uefi.rst | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/Documentation/arm/uefi.rst b/Documentation/arm/uefi.rst index baebe688a006..2b7ad9bd7cd2 100644 --- a/Documentation/arm/uefi.rst +++ b/Documentation/arm/uefi.rst @@ -50,7 +50,7 @@ The stub populates the FDT /chosen node with (and the kernel scans for) the following parameters: ========================== ====== =========================================== -Name Size Description +Name Type Description ========================== ====== =========================================== linux,uefi-system-table 64-bit Physical address of the UEFI System Table. @@ -67,4 +67,6 @@ linux,uefi-mmap-desc-ver 32-bit Version of the mmap descriptor format. kaslr-seed 64-bit Entropy used to randomize the kernel image base address location. + +bootargs String Kernel command line ========================== ====== =========================================== From patchwork Mon Jun 26 14:36:25 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 13293027 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C72B3EB64D7 for ; Mon, 26 Jun 2023 14:37:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=4LOhp0HdF0MbxP8s43NEglDzpDNb+k8RulfHpJ6m4Hs=; b=Hb7mpX3NPl1XCC IQvA/Agd/BNUd953MVQg0q2/dKDQhALIz9cvpQVB+zAjpoWlkSjorL7Jyq5j/Lkoivqeaw7+yRJ57 mvwkA4mKE1e+JROpastMUFB6woXcaMBBSj9baySK3L/j4eivFewe9MNodpQzcAooVyLDFsadTG7qv zKZiDUFHy7NeJ43YA4ibRiUhKqlNvxRK8x26vBBskCyPtE6+QGJxBi1Ozh1IyW5pYUMoGAnoOAoXZ taP4LjHqkF2j27xGliocKsALONgLChnswfqWbcrOpm97aODBD/nXsnFIXtf0/3RteLktELhgXR1oX 8JFoppmJQO6vF3rlaV6g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qDnLV-00APGV-0T; Mon, 26 Jun 2023 14:37:37 +0000 Received: from mail-wm1-x330.google.com ([2a00:1450:4864:20::330]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qDnLS-00APF9-0C for linux-riscv@lists.infradead.org; Mon, 26 Jun 2023 14:37:35 +0000 Received: by mail-wm1-x330.google.com with SMTP id 5b1f17b1804b1-3fa94ea1caaso10414285e9.1 for ; Mon, 26 Jun 2023 07:37:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20221208.gappssmtp.com; s=20221208; t=1687790250; x=1690382250; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=APwyby8MHvPbj/+Q6ciqlRQJlAXkF02ht9f+NF2/vFw=; b=Ir2iuPX8hmCzw5Dr2c2Ieq3P+FbgV42idzrp6d6izkqVncdI9GZE5wXWXzvzGXYvck ZTWJD8SmXM9WqXzzJHcEQuKKotDzx9jIW5kJTmrjbF76sxe7mkKRWbcrYe+rcw2v8pR7 JPmXrlhXYqC/zT3Gti1lvi5JLGIy8P9y5xdn9MhdHpLFkSP6EQm8zuJ06o7bO7RtfeVK y2s8CwW0yJd8zPojSP9pIrShpXmiIEqHVnWKAD3VtXTGknvWD8XK4kAhykK+cCZbQdXD 4iy1Z0raLGnKyg3KFiDmVNx5SfjyRvfh+Lqm1Zb8rm9SgDcfCDEff/Etw5Q1Rj3724Dc bl+g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687790250; x=1690382250; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=APwyby8MHvPbj/+Q6ciqlRQJlAXkF02ht9f+NF2/vFw=; b=mBxZNbnh+DgRA3KFPO0tqrG3wPRAJfktduLi46qeCkE7OWaxUXGwVAmdSAQOAZNIOw BpnReF9BTnD/VcT7Jce2jev4+oMuWDFZeZw+HaHNO7EWy8Pu1PAVE+1bfpt22UTOqqRA VrWVUTz/xFLiYzG1bEpe+y2W+Fvn/16yDEAW3ccZs0RZ3zD4QBBYlYwB2OEQwF49+Khw OwuqZNpPm45noIveN5I13nvLguZtd76ZRlqIKDi+LcgInaYJwqnSInc/ny/amPCo4p+H 5GBlSKY0h3vhGZ3sl/BzurMp+iX94lYkh7IoNnTdmX+9JKQxTWCkFE23ivjWXewhq1Sc l3kQ== X-Gm-Message-State: AC+VfDx9vAGpaOA8sB3ihL37vFyqq3tv4qqGt/8d+lj6R3kkPkZlRrwI kJYKU8KNM15/Nzk8jZvaK4J64Q== X-Google-Smtp-Source: ACHHUZ7MTJHhMSOxVcEeACVc+5Tm1tJpwUzaMvPeaUfU3sJDGhsGKgWI4dZkQ+8JAD5yex4Hc5U+HQ== X-Received: by 2002:a05:600c:4e92:b0:3fa:7515:902e with SMTP id f18-20020a05600c4e9200b003fa7515902emr11783937wmq.16.1687790250097; Mon, 26 Jun 2023 07:37:30 -0700 (PDT) Received: from localhost.localdomain (amontpellier-656-1-456-62.w92-145.abo.wanadoo.fr. [92.145.124.62]) by smtp.gmail.com with ESMTPSA id a25-20020a5d4579000000b003048477729asm7566182wrc.81.2023.06.26.07.37.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Jun 2023 07:37:29 -0700 (PDT) From: Alexandre Ghiti To: Jonathan Corbet , Paul Walmsley , Palmer Dabbelt , Albert Ou , =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , Andrew Jones , Conor Dooley , Sunil V L , Song Shuai , linux-doc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Alexandre Ghiti , Palmer Dabbelt , Atish Patra Subject: [PATCH v4 2/3] Documentation: riscv: Add early boot document Date: Mon, 26 Jun 2023 16:36:25 +0200 Message-Id: <20230626143626.106584-2-alexghiti@rivosinc.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230626143626.106584-1-alexghiti@rivosinc.com> References: <20230626143626.106584-1-alexghiti@rivosinc.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230626_073734_103553_06192A0A X-CRM114-Status: GOOD ( 33.24 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org This document describes the constraints and requirements of the early boot process in a RISC-V kernel. Signed-off-by: Alexandre Ghiti Reviewed-by: Björn Töpel Reviewed-by: Conor Dooley Reviewed-by: Sunil V L Reviewed-by: Andrew Jones Reviewed-by: Palmer Dabbelt Reviewed-by: Atish Patra Reviewed-by: Song Shuai Acked-by: Palmer Dabbelt Acked-by: Palmer Dabbelt --- Documentation/riscv/boot-image-header.rst | 3 - Documentation/riscv/boot.rst | 169 ++++++++++++++++++++++ Documentation/riscv/index.rst | 1 + 3 files changed, 170 insertions(+), 3 deletions(-) create mode 100644 Documentation/riscv/boot.rst diff --git a/Documentation/riscv/boot-image-header.rst b/Documentation/riscv/boot-image-header.rst index d7752533865f..a4a45310c4c4 100644 --- a/Documentation/riscv/boot-image-header.rst +++ b/Documentation/riscv/boot-image-header.rst @@ -7,9 +7,6 @@ Boot image header in RISC-V Linux This document only describes the boot image header details for RISC-V Linux. -TODO: - Write a complete booting guide. - The following 64-byte header is present in decompressed Linux kernel image:: u32 code0; /* Executable code */ diff --git a/Documentation/riscv/boot.rst b/Documentation/riscv/boot.rst new file mode 100644 index 000000000000..f890ac442c91 --- /dev/null +++ b/Documentation/riscv/boot.rst @@ -0,0 +1,169 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=============================================== +RISC-V Kernel Boot Requirements and Constraints +=============================================== + +:Author: Alexandre Ghiti +:Date: 23 May 2023 + +This document describes what the RISC-V kernel expects from bootloaders and +firmware, but also the constraints that any developer must have in mind when +touching the early boot process. For the purposes of this document, the +``early boot process`` refers to any code that runs before the final virtual +mapping is set up. + +Pre-kernel Requirements and Constraints +======================================= + +The RISC-V kernel expects the following of bootloaders and platform firmware: + +Register state +-------------- + +The RISC-V kernel expects: + + * ``$a0`` to contain the hartid of the current core. + * ``$a1`` to contain the address of the devicetree in memory. + +CSR state +--------- + +The RISC-V kernel expects: + + * ``$satp = 0``: the MMU, if present, must be disabled. + +Reserved memory for resident firmware +------------------------------------- + +The RISC-V kernel must not map any resident memory, or memory protected with +PMPs, in the direct mapping, so the firmware must correctly mark those regions +as per the devicetree specification and/or the UEFI specification. + +Kernel location +--------------- + +The RISC-V kernel expects to be placed at a PMD boundary (2MB aligned for rv64 +and 4MB aligned for rv32). Note that the EFI stub will physically relocate the +kernel if that's not the case. + +Hardware description +-------------------- + +The firmware can pass either a devicetree or ACPI tables to the RISC-V kernel. + +The devicetree is either passed directly to the kernel from the previous stage +using the ``$a1`` register, or when booting with UEFI, it can be passed using the +EFI configuration table. + +The ACPI tables are passed to the kernel using the EFI configuration table. In +this case, a tiny devicetree is still created by the EFI stub. Please refer to +"EFI stub and devicetree" section below for details about this devicetree. + +Kernel entrance +--------------- + +On SMP systems, there are 2 methods to enter the kernel: + +- ``RISCV_BOOT_SPINWAIT``: the firmware releases all harts in the kernel, one hart + wins a lottery and executes the early boot code while the other harts are + parked waiting for the initialization to finish. This method is mostly used to + support older firmwares without SBI HSM extension and M-mode RISC-V kernel. +- ``Ordered booting``: the firmware releases only one hart that will execute the + initialization phase and then will start all other harts using the SBI HSM + extension. The ordered booting method is the preferred booting method for + booting the RISC-V kernel because it can support cpu hotplug and kexec. + +UEFI +---- + +UEFI memory map +~~~~~~~~~~~~~~~ + +When booting with UEFI, the RISC-V kernel will use only the EFI memory map to +populate the system memory. + +The UEFI firmware must parse the subnodes of the ``/reserved-memory`` devicetree +node and abide by the devicetree specification to convert the attributes of +those subnodes (``no-map`` and ``reusable``) into their correct EFI equivalent +(refer to section "3.5.4 /reserved-memory and UEFI" of the devicetree +specification v0.4-rc1). + +RISCV_EFI_BOOT_PROTOCOL +~~~~~~~~~~~~~~~~~~~~~~~ + +When booting with UEFI, the EFI stub requires the boot hartid in order to pass +it to the RISC-V kernel in ``$a1``. The EFI stub retrieves the boot hartid using +one of the following methods: + +- ``RISCV_EFI_BOOT_PROTOCOL`` (**preferred**). +- ``boot-hartid`` devicetree subnode (**deprecated**). + +Any new firmware must implement ``RISCV_EFI_BOOT_PROTOCOL`` as the devicetree +based approach is deprecated now. + +Early Boot Requirements and Constraints +======================================= + +The RISC-V kernel's early boot process operates under the following constraints: + +EFI stub and devicetree +----------------------- + +When booting with UEFI, the devicetree is supplemented (or created) by the EFI +stub with the same parameters as arm64 which are described at the paragraph +"UEFI kernel support on ARM" in Documentation/arm/uefi.rst. + +Virtual mapping installation +---------------------------- + +The installation of the virtual mapping is done in 2 steps in the RISC-V kernel: + +1. ``setup_vm()`` installs a temporary kernel mapping in ``early_pg_dir`` which + allows discovery of the system memory. Only the kernel text/data are mapped + at this point. When establishing this mapping, no allocation can be done + (since the system memory is not known yet), so ``early_pg_dir`` page table is + statically allocated (using only one table for each level). + +2. ``setup_vm_final()`` creates the final kernel mapping in ``swapper_pg_dir`` + and takes advantage of the discovered system memory to create the linear + mapping. When establishing this mapping, the kernel can allocate memory but + cannot access it directly (since the direct mapping is not present yet), so + it uses temporary mappings in the fixmap region to be able to access the + newly allocated page table levels. + +For ``virt_to_phys()`` and ``phys_to_virt()`` to be able to correctly convert +direct mapping addresses to physical addresses, they need to know the start of +the DRAM. This happens after step 1, right before step 2 installs the direct +mapping (see ``setup_bootmem()`` function in arch/riscv/mm/init.c). Any usage of +those macros before the final virtual mapping is installed must be carefully +examined. + +Devicetree mapping via fixmap +----------------------------- + +As the ``reserved_mem`` array is initialized with virtual addresses established +by ``setup_vm()``, and used with the mapping established by +``setup_vm_final()``, the RISC-V kernel uses the fixmap region to map the +devicetree. This ensures that the devicetree remains accessible by both virtual +mappings. + +Pre-MMU execution +----------------- + +A few pieces of code need to run before even the first virtual mapping is +established. These are the installation of the first virtual mapping itself, +patching of early alternatives and the early parsing of the kernel command line. +That code must be very carefully compiled as: + +- ``-fno-pie``: This is needed for relocatable kernels which use ``-fPIE``, + since otherwise, any access to a global symbol would go through the GOT which + is only relocated virtually. +- ``-mcmodel=medany``: Any access to a global symbol must be PC-relative to + avoid any relocations to happen before the MMU is setup. +- *all* instrumentation must also be disabled (that includes KASAN, ftrace and + others). + +As using a symbol from a different compilation unit requires this unit to be +compiled with those flags, we advise, as much as possible, not to use external +symbols. diff --git a/Documentation/riscv/index.rst b/Documentation/riscv/index.rst index 175a91db0200..1f66062def6d 100644 --- a/Documentation/riscv/index.rst +++ b/Documentation/riscv/index.rst @@ -5,6 +5,7 @@ RISC-V architecture .. toctree:: :maxdepth: 1 + boot boot-image-header vm-layout hwprobe From patchwork Mon Jun 26 14:36:26 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 13293028 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4077DEB64DA for ; Mon, 26 Jun 2023 14:38:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=W0JY3rH/7vfIEQJvkxNRp1pHZLLmQKNHaIUsGugpmyk=; b=NziyXTFQBOBJYl arY8K1XDd+b3YgJnqraiqdY/szOIbJIohxyfQk91s4BcNg5O04hxAAIpmihkt378xMEebuCTop9xy rinzWTPRiXBUHuUVlLltToQYK+HAypiQBtZl2d33oDZbW8A3x3kqc25Tat7wyOzg1QXQLsdefhsPL l/2CWlRFkjAZPIcIUAW++v7Jnu6drPkAyCvn1QDzuLAhX2M41JXVIETSHh0+hFZ7Tpm37Aa/qNCFW pmaELiup4nm277ELQYZSndUpONDpll7njOsOOBVrgqroT3WDQtX5/qBwmST2kbJOjkD77Cne7Q+FL fALr8t1TxFhsAzurQXCA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qDnMR-00APPd-0h; Mon, 26 Jun 2023 14:38:35 +0000 Received: from mail-wm1-x330.google.com ([2a00:1450:4864:20::330]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qDnMO-00APOp-14 for linux-riscv@lists.infradead.org; Mon, 26 Jun 2023 14:38:33 +0000 Received: by mail-wm1-x330.google.com with SMTP id 5b1f17b1804b1-3fa96fd79feso12429685e9.2 for ; Mon, 26 Jun 2023 07:38:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20221208.gappssmtp.com; s=20221208; t=1687790311; x=1690382311; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=/pQzPxsmpV8ILmUDokZDt4x2j1OZGQdakvLzX04+Ejg=; b=uex3RA9qERfNnTukZWjHbvUoE92GRFB/vSd/56SJYlEKAAJOF2wGlzoyFo3yf4A7FF 8ZBC9aYsVrrNL+HjSWxsFPpv7zb5e08DTroI6Woc8a03XoBhet2OAK6/2JlRryOIeOd3 I8zI/yrigzMZuoa1Zlpi1pg/KbAe/zkTjZCzFYbA5MTv+E2k183GmHQwYbZH4d/8RKxM JYnOoOnOBhieWlLKxAQoXKiQiFFGGXVm8UL/CZsOzQLSSYXhOmr5G1NMtpRzsMCWp490 AMw2oa2keFry57qcMCFzDn0xN53dGJAe57lsQnHdwyA3ycjoFgAKQdN2+0C18QPEehNu cxHg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687790311; x=1690382311; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=/pQzPxsmpV8ILmUDokZDt4x2j1OZGQdakvLzX04+Ejg=; b=BmjUpMrE/UVtE8bjm3sTBv67brkodLrJGZ/kbzXk3iYq9aPYaHHtkRLxwSpVi3jW5D p7t9OEoSWj8dzCZ43Ev5RUedQF9ceOYQsP38fkuhNysrUMWnJeFJv8bmYpSnpK+dPnC+ 1dvW07qjKAA8W0yAL5R3k23R7aOzWn0nUIhX4fNDBvghv0beKvt+JuL6dSQO7ul1xLz8 teXu+Hkhq48M/vnMrJGupDAd6UaPTAEnMf4DvGg+EXemUnrNDsLqb1dY3nReE5LKmkjO QYS3tryhygvpCclBPlmEQwOV+DDArwo0SS2Ym8srOJjvbH/Um47tx38S8OXQrD+RMhnM 3Jgg== X-Gm-Message-State: AC+VfDzR8x8VwFqG6Yd0R2n2gK51jeuVx+MXN9L6kKTHJLCM6+qFLA8k kz+cVf1R0hk6xJL/pZLMXk129w== X-Google-Smtp-Source: ACHHUZ7/qbfak7GDtutZM70XhoxLKa1hwP1sqmQFIrzcjpha6OqsXY/O69sqJLYVDFnJ+mapPWzwAQ== X-Received: by 2002:a7b:cd97:0:b0:3f9:a6f3:f23c with SMTP id y23-20020a7bcd97000000b003f9a6f3f23cmr18047670wmj.36.1687790311012; Mon, 26 Jun 2023 07:38:31 -0700 (PDT) Received: from localhost.localdomain (amontpellier-656-1-456-62.w92-145.abo.wanadoo.fr. [92.145.124.62]) by smtp.gmail.com with ESMTPSA id v2-20020a5d6782000000b00313f5babb18sm1644944wru.9.2023.06.26.07.38.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Jun 2023 07:38:30 -0700 (PDT) From: Alexandre Ghiti To: Jonathan Corbet , Paul Walmsley , Palmer Dabbelt , Albert Ou , =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , Andrew Jones , Conor Dooley , Sunil V L , Song Shuai , linux-doc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Alexandre Ghiti , Atish Patra , Palmer Dabbelt Subject: [PATCH v4 3/3] Documentation: riscv: Update boot image header since EFI stub is supported Date: Mon, 26 Jun 2023 16:36:26 +0200 Message-Id: <20230626143626.106584-3-alexghiti@rivosinc.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230626143626.106584-1-alexghiti@rivosinc.com> References: <20230626143626.106584-1-alexghiti@rivosinc.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230626_073832_369213_903EC4CC X-CRM114-Status: GOOD ( 14.31 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org The EFI stub is supported on RISC-V so update the documentation that explains how the boot image header was reused to support it. Signed-off-by: Alexandre Ghiti Reviewed-by: Atish Patra Reviewed-by: Palmer Dabbelt Acked-by: Palmer Dabbelt Acked-by: Palmer Dabbelt --- Documentation/riscv/boot-image-header.rst | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/Documentation/riscv/boot-image-header.rst b/Documentation/riscv/boot-image-header.rst index a4a45310c4c4..df2ffc173e80 100644 --- a/Documentation/riscv/boot-image-header.rst +++ b/Documentation/riscv/boot-image-header.rst @@ -28,11 +28,11 @@ header in future. Notes ===== -- This header can also be reused to support EFI stub for RISC-V in future. EFI - specification needs PE/COFF image header in the beginning of the kernel image - in order to load it as an EFI application. In order to support EFI stub, - code0 should be replaced with "MZ" magic string and res3(at offset 0x3c) should - point to the rest of the PE/COFF header. +- This header is also reused to support EFI stub for RISC-V. EFI specification + needs PE/COFF image header in the beginning of the kernel image in order to + load it as an EFI application. In order to support EFI stub, code0 is replaced + with "MZ" magic string and res3(at offset 0x3c) points to the rest of the + PE/COFF header. - version field indicate header version number