From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f48.google.com (mail-wm1-f48.google.com [209.85.128.48]) (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 ED72542BC2A for ; Tue, 4 Aug 2026 20:56:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.48 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785876991; cv=none; b=rr2vMqtFexOsYLPbjEVrREJNNzNQcbYeniIlGnHYgagmWvjGne5upXF3KGNAI1zixqHA6kZPc8Mg/TLhl5zndpHqxur75Xy0gbvJJ817MJrxJLFJTCJctuZwXxhQKhUAZ7rMmKdkrRHeE08v5vLVxJqAOLvFIeaPFH63qvTXS4g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785876991; c=relaxed/simple; bh=yu7fTJEvu/WM6iPEXNZYvP9LNyFeTGKqeWmRli0lQx4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=iDvAshsK3qRppd3/pESLQG6Owcm7qXB8bvTLYEC4OkspdFfhuwmTpQwvC1Ni9UkKD/dxyy+3xfHgKTietalPoNzYK/TSj52JmvdtcIAzNxbKkv+uEFxuPUOVqCT4hzU+oLlTxB5jwyrZwfeXz5poKN2JZZpyt0F1xYGjBqTFW0E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Mo0GdF3Q; arc=none smtp.client-ip=209.85.128.48 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Mo0GdF3Q" Received: by mail-wm1-f48.google.com with SMTP id 5b1f17b1804b1-4921eed3fa2so2098145e9.0 for ; Tue, 04 Aug 2026 13:56:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1785876988; x=1786481788; 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:content-type; bh=SHxdaaypANO4SJdv7vjmn9Syq8V3Ebhk1vARZd9Mr0s=; b=Mo0GdF3QcDQm4YHlRyfbx+lTUWgf6Mv/BK4DFeijlJ6PeSeIi31Yt1F+mT0KjBi4YC tB5oMX0imr0pKiZF8qhRSNGcd4QymbE7OqPrh0UycDm5FP40Jwkoyv0m30w1yTCZ/Y+B 7skLtt45Ap5j3WPY3LqjcsxdbY2k78Nje4RFrdLK89axRUFc4T9Jr3jePGNl1Vn+8KUU UJ/+BVdy7rrqRWpgUFewEMkNX55cb3eN8VRphrDHd92vYjChl3/jdYGJQwJL+kG76Ehf x/lZAicCg06959pEV87iqdit8ut1qps6yXaba5+9h+DOQvTwhbpPaGoqVWBDsXD+vi4B W0Uw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785876988; x=1786481788; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=SHxdaaypANO4SJdv7vjmn9Syq8V3Ebhk1vARZd9Mr0s=; b=oh1L6ZwqKwke00preK/++3tzhz5CFWlHyV7Jvd+ppRy2bSI9g9Z9Nk4buM1JjOX295 PQJVlKluqdwUGn/FqqSAzjUUG6L4Eq6Sif2oLLc902HPXEowlwp62iO3clw0Smu8w/jo UXpshgfzZ7j0/HeV61VY2k7R0zMhmziA0Ev0YMfDVTqOyHE4sqNltg9/CUTV5yHkq1qS mlcgdH086xnTdm2L2FNrnHBsxgle+X4EvvpJX54onRkFXVqaVDuHYzM2lWLTMA0UGMGn wAp8Kd2pokqrz+EdFtktRAjWNp0hJloRB6u58kon5TdtQoeXS6gDDQbBjCJCehep6+P6 f6jw== X-Forwarded-Encrypted: i=1; AHgh+Rr+Ip8YTS8hG6aEvQ++XZGF74VnketoIPRKVdPl5UrLzd5klSjouX4XjkoY6qHHOtuAkR4TLoxfpP61LRk=@vger.kernel.org X-Gm-Message-State: AOJu0YyG4OBAKzYAGEr5ZygitZrSHNB+lS1N5YQW5itDqFOK50X7lmyk JmkGLSv+8KqPJ8byNMx6Y4279eAAxKlWS7MLFbxdni+WFAoa8EKN47Zz X-Gm-Gg: AR+sD11IN63fKxGBs1hkQouHZN7W3EkwwwWkO+LdlRqCejczlG+KhAc+O+ohaXTKPlI lB1RcFJL0YXHl1cmxn7Jfhk7XknmGYAmX/dM70EE8G+p22WhciKRns03r+B9ptcwdqtlnfouZhg IzHhII9ddm/i1sjs2Ui+Oj2LnBCbbOD7io8WZczVmTbJyv/s29Fl7OzJn4vVlX7y/KkM1AeOFvq 0xMlM6WzHO6g1L6xz6iP3SFPq5khczUaeOqUnDb2aKvvcd5GEMa0GViNGnvr//gP3YZcrt6len2 BocVd1NkQv1lC5D3S5w1QMMib90f86JrNcp20d+9Z/kU0ojQzoyBbi8hfQ6jYwK6DU737FU5z13 S3ZVsRFVQLewSdPw8QxbD2Ulecbaa18/1JdBjTN3g/bRxxy0offdnureZpSfZBWahGR3U6zOGfi PEHvz0eWEmnN3BBj0mixiTWieB64IWDXeJZWzEb/2ydAAC+XySkyFN03ybJMD1q+MX5IZIBCWAD 2CUx6K7KBrCy3c= X-Received: by 2002:a05:600c:1d22:b0:495:6338:1453 with SMTP id 5b1f17b1804b1-4994e7cfdcfmr12133965e9.16.1785876988197; Tue, 04 Aug 2026 13:56:28 -0700 (PDT) Received: from ingenieria31.oficinasStQ.local ([79.116.176.33]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4994e4bf820sm12070645e9.0.2026.08.04.13.56.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 04 Aug 2026 13:56:27 -0700 (PDT) From: Max Pedraza To: Helge Deller Cc: Geert Uytterhoeven , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Thomas Zimmermann , Maxime Ripard , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Max Pedraza Subject: [PATCH v2 4/6] dt-bindings: display: allow the boot logo in a reserved memory region Date: Wed, 5 Aug 2026 00:56:15 +0200 Message-Id: <20260804225617.264861-5-maximpedraza@gmail.com> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20260804225617.264861-1-maximpedraza@gmail.com> References: <20260804225617.264861-1-maximpedraza@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Carrying the image in the device tree ties it to the device tree, but the image and where it goes on screen are independent axes of variation. One board sold to several customers wants several device trees that differ in the logo; one customer with several products built on that board wants the same logo placed differently on each panel. The second case would otherwise mean duplicating the same image into every device tree. Let the node point at a reserved memory region filled in by the bootloader instead, so one image can be shared by device trees that differ only in placement. The region starts with a small header carrying a magic number and the geometry, so the kernel can tell a logo from an empty or stale region and bounds check everything against the reservation. A phandle to a declared region is used rather than a bare address: the reservation is what makes the memory safe to read and what gives the kernel a size to validate against. The two ways of supplying the image are mutually exclusive. Signed-off-by: Max Pedraza --- .../display/linux,boot-logo-clut224.yaml | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/Documentation/devicetree/bindings/display/linux,boot-logo-clut224.yaml b/Documentation/devicetree/bindings/display/linux,boot-logo-clut224.yaml index a6a206964..7aec0cc2d 100644 --- a/Documentation/devicetree/bindings/display/linux,boot-logo-clut224.yaml +++ b/Documentation/devicetree/bindings/display/linux,boot-logo-clut224.yaml @@ -59,6 +59,23 @@ properties: index into the colour lookup table. The property length must be equal to width multiplied by height. + memory-region: + maxItems: 1 + description: | + Reserved memory region holding the logo, as an alternative to carrying + it in the width, height, clut and data properties. The bootloader is + expected to have placed the image there before starting the kernel. + + This lets one image be shared by several device trees that differ only + in where the logo goes, which is what a family of products built on the + same board but with different panels needs. + + The region starts with a header of four little endian 32 bit words: + the magic number 0x4f474f4c ("LOGO"), the width, the height and the + number of palette entries. The palette follows, as consecutive red, + green and blue bytes per entry, and then one byte per pixel, each an + index into that palette. + logo-position: $ref: /schemas/types.yaml#/definitions/uint32-array description: -- 2.39.5