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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 20015C3A5A2 for ; Tue, 3 Sep 2019 17:42:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 00FB421883 for ; Tue, 3 Sep 2019 17:42:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728854AbfICRmQ (ORCPT ); Tue, 3 Sep 2019 13:42:16 -0400 Received: from ste-pvt-msa2.bahnhof.se ([213.80.101.71]:54497 "EHLO ste-pvt-msa2.bahnhof.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725782AbfICRmQ (ORCPT ); Tue, 3 Sep 2019 13:42:16 -0400 Received: from localhost (localhost [127.0.0.1]) by ste-pvt-msa2.bahnhof.se (Postfix) with ESMTP id 51E8E3FA5A; Tue, 3 Sep 2019 19:42:14 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at bahnhof.se Received: from ste-pvt-msa2.bahnhof.se ([127.0.0.1]) by localhost (ste-ftg-msa2.bahnhof.se [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 53auHPq8taU7; Tue, 3 Sep 2019 19:42:13 +0200 (CEST) Received: from localhost (h-41-252.A163.priv.bahnhof.se [46.59.41.252]) (Authenticated sender: mb547485) by ste-pvt-msa2.bahnhof.se (Postfix) with ESMTPA id 97DEE3F5F6; Tue, 3 Sep 2019 19:42:13 +0200 (CEST) Date: Tue, 3 Sep 2019 19:42:12 +0200 From: Fredrik Noring To: Jiaxun Yang Cc: linux-mips@vger.kernel.org Subject: Re: [PATCH 094/120] MIPS: PS2: FB: Frame buffer driver for the PlayStation 2 Message-ID: <20190903174212.GA22657@sx9> References: <4927c42fb3401c42c4c5a077f272331ac79d80b1.1567326213.git.noring@nocrew.org> <1003c9cc-c30e-00a7-7494-4f1cb4862e88@flygoat.com> <20190902144007.GA2479@sx9> <2ac424e5-017b-5892-ef38-fe25ec5f38d1@flygoat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <2ac424e5-017b-5892-ef38-fe25ec5f38d1@flygoat.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org > DRM do have fb_helper providing FB console. > > I think refactor your current FB driver with drm gem cma helper won't be > very hard. Thanks! I will update that for v2. > Ahh, the guy runs Linux on that gaming console is really cool! How do > you debug your code? The video screen is used for the earliest stages, even before the kernel is decompressed in arch/mips/boot/compressed/decompress.c. I have a simple patch that sets up the Graphics Synthesizer and uses DMA to render a trivial frame buffer console, displaying zimage at: 00803BE0 00BDDE8C Uncompressing Linux at load address 80010000 Now, booting the kernel... and so on as a video image. This is functionally equivalent to the serial port drivers for prom_putchar() that other MIPS platforms have, and essential to debug early boot and kexec. [ I assume this code will not be accepted, since the approach is rather nontraditional, which is why I didn't include it in the patch set. ] Somewhat later the fbcon driver takes over the video screen console. Then USB is configured with a wifi device, an ssh daemon is started etc. for remote login and scripting. I have QEMU patches for R5900 user mode emulation, that can be used for development and debugging. I mainly use it to compile Gentoo for the PlayStation 2. Fredrik