From nobody Fri Nov 26 15:04:54 2021 X-Original-To: freebsd-hackers@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 42E6018B7F0A for ; Fri, 26 Nov 2021 15:05:04 +0000 (UTC) (envelope-from manu@bidouilliste.com) Received: from mx.blih.net (mail.blih.net [212.83.155.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "mx.blih.net", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4J0yht6b4Kz4vCC for ; Fri, 26 Nov 2021 15:05:02 +0000 (UTC) (envelope-from manu@bidouilliste.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bidouilliste.com; s=mx; t=1637939095; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=NjNEA7Vq+B1brrAZFS5azRCnHlI3DryDjVNY5M4QjDA=; b=NCjyquY73UOWqUKY6kihP9B+QPflhRtucbf4wY91a2HLO0IvRtJEIehNXFKngKBGMGlmFb IbTy4CiLXmG+jKO/Dfo9tOU4uaHcqOQ8qE63tqFTTApILZh9/xUztaPQZ/u3ZgrzbUdlnq i292YbZej4yzA4G9teaxY4Y63A0FV5Q= Received: from skull.home.blih.net (lfbn-idf2-1-1163-183.w90-92.abo.wanadoo.fr [90.92.222.183]) by mx.blih.net (OpenSMTPD) with ESMTPSA id 3013f216 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO) for ; Fri, 26 Nov 2021 15:04:55 +0000 (UTC) Date: Fri, 26 Nov 2021 16:04:54 +0100 From: Emmanuel Vadot To: freebsd-hackers@freebsd.org Subject: Reasons for keeping sc(4) and libvgl ? Message-Id: <20211126160454.3eb827365a02103169ab9adc@bidouilliste.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; amd64-portbld-freebsd14.0) List-Id: Technical discussions relating to FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-hackers List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-hackers@freebsd.org Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 4J0yht6b4Kz4vCC X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=bidouilliste.com header.s=mx header.b=NCjyquY7; dmarc=pass (policy=none) header.from=bidouilliste.com; spf=pass (mx1.freebsd.org: domain of manu@bidouilliste.com designates 212.83.155.74 as permitted sender) smtp.mailfrom=manu@bidouilliste.com X-Spamd-Result: default: False [-2.50 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; R_DKIM_ALLOW(-0.20)[bidouilliste.com:s=mx]; FREEFALL_USER(0.00)[manu]; FROM_HAS_DN(0.00)[]; MV_CASE(0.50)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-hackers@freebsd.org]; TO_DN_NONE(0.00)[]; RCPT_COUNT_ONE(0.00)[1]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; R_SPF_ALLOW(-0.20)[+ip4:212.83.155.74/32]; DKIM_TRACE(0.00)[bidouilliste.com:+]; MID_RHS_MATCH_FROM(0.00)[]; DMARC_POLICY_ALLOW(-0.50)[bidouilliste.com,none]; NEURAL_HAM_SHORT(-1.00)[-1.000]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; SUBJECT_ENDS_QUESTION(1.00)[]; ASN(0.00)[asn:12876, ipnet:212.83.128.0/19, country:FR]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[] X-ThisMailContainsUnwantedMimeParts: N Hello all, I'm currently re-implementing the framebuffer code in linuxkpi for drm-kmod and this made me look at sc(4), vt(4) and friends. So I looked at what sc could do and vt couldn't and vice-versa. What sc(4) can't do : - Work with EFI firmware. - Support UTF-8 - Maybe other things but everything here is EFI-based so let me know. What vt(4) can't do : - You can't get the modes or adapter info with vidcontrol. vidcontrol -i mode is really made for anything vesa based as it iterates on all the modes and display them if present. In the modern world (EFI), we don't have that, EFI GOP doesn't support changing resolution after ExitBootService was called so there is only one "mode". I could possibly hack some patch so vidcontrol -i mode/adapter would work and display the current framebuffer info if people wants (but I honestly doubt that vidcontrol is useful at all in an EFI world). - "Blanking" screen doesn't do what you think it does. For some reason in vt(4) we just write black colors on the screen and ignore the blank mode passed in the ioctl. Now again, blanking/dpms/blah isn't possible with efi_fb but it make sense to fix vt(4) and drm-kmod so it calls the drm module blanking function, I'll work on that next week. - There is no screensaver, again see notes above for dpms but do people still use sc(4) just for the screensaver ?? - Maybe other things, please let me know. For libvgl it probably made sense back in the 90s but does it now ?? Based on my small list I don't see any good reason to keep sc(4) but maybe I've missed something bigger so please let me know. P.S.: I'm really not interested by people saying stuff like "I've always used sc(4), it works for me don't touch it" without some technical argument. Cheers, -- Emmanuel Vadot