From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C57F5C433E6 for ; Fri, 19 Feb 2021 17:27:01 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4713364E86 for ; Fri, 19 Feb 2021 17:27:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4713364E86 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bugs.launchpad.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:53114 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lD9YS-0005S8-AY for qemu-devel@archiver.kernel.org; Fri, 19 Feb 2021 12:27:00 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:45212) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lD9XC-0004Ap-Dc for qemu-devel@nongnu.org; Fri, 19 Feb 2021 12:25:43 -0500 Received: from indium.canonical.com ([91.189.90.7]:41450) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lD9X9-0001UA-Tz for qemu-devel@nongnu.org; Fri, 19 Feb 2021 12:25:42 -0500 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.86_2 #2 (Debian)) id 1lD9X8-0000jf-5s for ; Fri, 19 Feb 2021 17:25:38 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id 295BC2E80FC for ; Fri, 19 Feb 2021 17:25:38 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Fri, 19 Feb 2021 17:18:32 -0000 From: Peter Maydell <1914535@bugs.launchpad.net> To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=New; importance=Undecided; assignee=None; X-Launchpad-Bug-Tags: arm X-Launchpad-Bug-Information-Type: Public X-Launchpad-Bug-Private: no X-Launchpad-Bug-Security-Vulnerability: no X-Launchpad-Bug-Commenters: avevad pmaydell X-Launchpad-Bug-Reporter: Vadim Averin (avevad) X-Launchpad-Bug-Modifier: Peter Maydell (pmaydell) References: <161241593716.24579.2543593740941156934.malonedeb@wampee.canonical.com> Message-Id: <161375511284.10946.9838968545913659339.malone@chaenomeles.canonical.com> Subject: [Bug 1914535] Re: PL110 8-bit mode is not emulated correctly X-Launchpad-Message-Rationale: Subscriber (QEMU) @qemu-devel-ml X-Launchpad-Message-For: qemu-devel-ml Precedence: bulk X-Generated-By: Launchpad (canonical.com); Revision="bbfee60eef9f7fd8d30b24b3f53e75656e4d5fb0"; Instance="production" X-Launchpad-Hash: 697e90d3c71d7957e5c273d32de0ef2144c7e9ab Received-SPF: none client-ip=91.189.90.7; envelope-from=bounces@canonical.com; helo=indium.canonical.com X-Spam_score_int: -65 X-Spam_score: -6.6 X-Spam_bar: ------ X-Spam_report: (-6.6 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Bug 1914535 <1914535@bugs.launchpad.net> Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Anyway, on first investigation I'm not sure what QEMU's pl11x model is doin= g wrong. The 8-bit mode is a palette-based setup, where the guest must prog= ram in the RGB values it wants to use into the palatte registers as RGB555 = data: https://developer.arm.com/documentation/ddi0293/c/programmer-s-model/regis= ter-descriptions/256x16-bit-color-palette-registers?lang=3Den and if you add some debug printing to QEMU you can see the guest writing in = a variety of definitely-not-shades-of-grey values to the palette, so it's n= ot surprising that it comes back as not-grey. I think https://elixir.bootlin.com/linux/latest/source/drivers/video/fbdev/amba-clc= d.c#L343 is where the driver is writing to the palette and it definitely thinks the = display is pseudocolor, not greyscale. -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1914535 Title: PL110 8-bit mode is not emulated correctly Status in QEMU: New Bug description: When the emulated pl110/pl111 is switched programmatically to 8-bit color depth mode, the display is drawn green and blue, but the real PL110 displays grayscale in 8-bit mode. The bug appears in qemu-system-arm version 3.1.0 (Debian 1:3.1+dfsg-8+deb10u8) and qemu-system-arm version 5.2.50 (v5.2.0-1579-g99ae0cd90d). To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1914535/+subscriptions