From nobody Mon Feb 9 16:02:59 2026 Received: from mail-oa1-f54.google.com (mail-oa1-f54.google.com [209.85.160.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AF8D25223 for ; Tue, 27 Feb 2024 00:36:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.54 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708994200; cv=none; b=Qw/XCOUjm+AngDUtA0GU+lVuRH/AnIuDKAI+kUp0GCJcWxtnNaI+enuLoqAn2oaV5QupfHE3JH4O2vKWFGZnsrDx9awLSzzKN71FPTcj2FMAalG0k8KsL0O3iDWHJjbwQY8Y964NlRE+8XE1+YYkgdZCsWLPWAbT5P4fFnRCcR4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708994200; c=relaxed/simple; bh=pjl4fEaMJkh7DZc3EiKaxaa2HCJZf6Iu0TXjya2kYwU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BxUWu7FeYP6vDW6sy6mhPRI49Lw/t8yARwrTpdQXB5iVr4jyECTMLIc0Lg7Eb7Eciz6w8xeCYFpqlvtobBbTv7cFdIFiNrTYivVL1tD3xSf5l7w8D4h7TQNQcWR1QoND2JGV0KQnd7Ghy/O4WgA+IRwbhpW16Sq+xq5HvcdX5TE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=sifive.com; spf=pass smtp.mailfrom=sifive.com; dkim=pass (2048-bit key) header.d=sifive.com header.i=@sifive.com header.b=LYBBrYFC; arc=none smtp.client-ip=209.85.160.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=sifive.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sifive.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sifive.com header.i=@sifive.com header.b="LYBBrYFC" Received: by mail-oa1-f54.google.com with SMTP id 586e51a60fabf-204235d0913so2574305fac.1 for ; Mon, 26 Feb 2024 16:36:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sifive.com; s=google; t=1708994198; x=1709598998; darn=vger.kernel.org; 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=9IhytZLl3RHTt2r80xPYLkB9iZxHThEoH75QMIzrbQ8=; b=LYBBrYFCBqmHYY4jYJk04eL9VVtk9pCYpc/tRIs4YN+e6YuCQL3ON6on7+aPNyd0qG ZNyL/a7ZuMgzrGZv8qjI97BOCl5/TygDsOCkWlC3p7iE6dWGn8e8dVQGxdza2SH9/0rG sS0nW7M8+SnBglAyMopliXeBZLewRoLzd2KebRVcOADKKh8c/2NbmC9452l+i5HN0gyz T/AstmFQdAZ3IdGwu+Xh7/5VogMqB/3cCJBj6HLP8/QFc65O/lymtuW8nwj2LNa0ISGV gGWPV6tCSFSIZhzr1kPODoeFkus9cgN+qK5cxN1xhqm4P9Q9L2ugI9Rief3ZtsvfDwHm sEbQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1708994198; x=1709598998; 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=9IhytZLl3RHTt2r80xPYLkB9iZxHThEoH75QMIzrbQ8=; b=C9U/DdeBG4DobvcwKbjF1nCYFfARfb4W5ABdLmxcC8dv+qKintIXG9CypJIYhjCfum vA8sSXNR3IaqEt8sT0269heKU6Mg3QRaZp21hlhUOrHPJ5a0sFcfiIOPTlHboG+1m1w5 3i3lU7FL1uJUiFgUbGBtF4YqEB+bQ612m+1C3CmNvYjOdK5acKasdNTP9Q0i5zwC+ecN HtBK7q4JGU03fInWDAGbdGsIdhNcqmMhQOZWCOuLfElbmkDCULb8VzK6DPAi7+3n6lbB 3QSerI9R40TPWkN2fjtE+Xt3QfVEJCOUYCFcDgwJbz3bZt6AcRAqXqBVTSU1ng5RXJXF OmzA== X-Gm-Message-State: AOJu0YwcqACjzKyFFa6ZgI424cnuQXERSsjlpqYbTaBIxGUCKLh1ecr5 C3+yPtvrEs/QJHyHK+V3Xmf34/obh0g7ij7JEwrlZ4VKBIhQbCKwLY8plSyXdRI= X-Google-Smtp-Source: AGHT+IHuBZg/S/3Di/VYl17m/qNJYD118ohwXH+f7ieMrzQ9VNxL/lys1ubJ/2vm2l8Q2yXGwE0xZw== X-Received: by 2002:a05:6871:230f:b0:21f:a4ce:d532 with SMTP id sf15-20020a056871230f00b0021fa4ced532mr9485542oab.31.1708994197885; Mon, 26 Feb 2024 16:36:37 -0800 (PST) Received: from sw06.internal.sifive.com ([4.53.31.132]) by smtp.gmail.com with ESMTPSA id z25-20020a631919000000b005dc85821c80sm4504117pgl.12.2024.02.26.16.36.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Feb 2024 16:36:37 -0800 (PST) From: Samuel Holland To: Palmer Dabbelt , linux-riscv@lists.infradead.org Cc: linux-kernel@vger.kernel.org, Samuel Holland Subject: [PATCH 4/4] riscv: Allow NOMMU kernels to run in S-mode Date: Mon, 26 Feb 2024 16:34:49 -0800 Message-ID: <20240227003630.3634533-5-samuel.holland@sifive.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240227003630.3634533-1-samuel.holland@sifive.com> References: <20240227003630.3634533-1-samuel.holland@sifive.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" For ease of testing, it is convenient to run NOMMU kernels in supervisor mode. The only required change is to offset the kernel load address, since the beginning of RAM is usually reserved for M-mode firmware. Signed-off-by: Samuel Holland Reviewed-by: Conor Dooley --- arch/riscv/Kconfig | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index ef53c00470d6..0dc09b2ac2f6 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -64,7 +64,7 @@ config RISCV select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU select BUILDTIME_TABLE_SORT if MMU - select CLINT_TIMER if !MMU + select CLINT_TIMER if RISCV_M_MODE select CLONE_BACKWARDS select COMMON_CLK select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND @@ -220,8 +220,12 @@ config ARCH_MMAP_RND_COMPAT_BITS_MAX =20 # set if we run in machine mode, cleared if we run in supervisor mode config RISCV_M_MODE - bool - default !MMU + bool "Build a kernel that runs in machine mode" + depends on !MMU + default y + help + Select this option if you want to run the kernel in M-mode, + without the assistance of any other firmware. =20 # set if we are running in S-mode and can use SBI calls config RISCV_SBI @@ -238,8 +242,9 @@ config MMU =20 config PAGE_OFFSET hex - default 0xC0000000 if 32BIT && MMU - default 0x80000000 if !MMU + default 0x80000000 if !MMU && RISCV_M_MODE + default 0x80200000 if !MMU + default 0xc0000000 if 32BIT default 0xff60000000000000 if 64BIT =20 config KASAN_SHADOW_OFFSET --=20 2.43.0