From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 37D4167B6A for ; Fri, 14 Jul 2006 05:43:13 +1000 (EST) Subject: Re: Maple platform - adding graphics to IBM PIBS firmware From: Benjamin Herrenschmidt To: jf simon In-Reply-To: <44B4D2A4.7090204@yahoo.fr> References: <20060710214158.1d8dcf2c@vitb.ru.mvista.com> <1152567817.1576.114.camel@localhost.localdomain> <44B3A772.3000101@yahoo.fr> <1152658938.6346.76.camel@localhost.localdomain> <44B4D2A4.7090204@yahoo.fr> Content-Type: text/plain Date: Fri, 14 Jul 2006 05:43:06 +1000 Message-Id: <1152819786.23037.12.camel@localhost.localdomain> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > I was (naively) thinking that if I could access the legacy VGA register > set, I could set the graphic card to text mode and use the graphic > screen as a alphanumeric console, until linux soft boots the graphic > card . Do you think this is doable? I haven't been able to locate that > VGA register set yet. The legacy VGA operations also require the card to be fully initialized by the BIOS. In addition to that, there is an issue with using VGA text mode on machines using the CPC925 bridge as it doesn't have a legacy memory window: It doesn't have a facility to generate PCI or HT memory cycles in the low addresses required for VGA. You can still hack-around in a somewhat card-specific way using the main memory apperture and doing your onw interleaving of characters and attributes but it's dodgy. In any case, you still need the card to be initialized. Ben.