From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (from majordomo@localhost) by oss.sgi.com (8.11.2/8.11.3) id f73LaVB28922 for linux-mips-outgoing; Fri, 3 Aug 2001 14:36:31 -0700 Received: from www.transvirtual.com (root@www.transvirtual.com [206.14.214.140]) by oss.sgi.com (8.11.2/8.11.3) with SMTP id f73LaUV28915 for ; Fri, 3 Aug 2001 14:36:30 -0700 Received: from www.transvirtual.com (jsimmons@localhost [127.0.0.1]) by localhost (8.12.0.Beta7/8.12.0.Beta7/Debian 8.12.0.Beta7-1) with ESMTP id f73LaHE1027609; Fri, 3 Aug 2001 14:36:17 -0700 Received: from localhost (jsimmons@localhost) by www.transvirtual.com (8.12.0.Beta7/8.12.0.Beta7/Debian 8.12.0.Beta7-1) with ESMTP id f73LaGOX027602; Fri, 3 Aug 2001 14:36:16 -0700 X-Authentication-Warning: www.transvirtual.com: jsimmons owned process doing -bs Date: Fri, 3 Aug 2001 14:36:16 -0700 (PDT) From: James Simmons To: "John D. Davis" cc: SGI MIPS list , Debian MIPS list Subject: Re: printk In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mips@oss.sgi.com Precedence: bulk > Does anyone know off hand, the earlies point that I can use printk? Very early. Right after IRQs are setup and started. If no hardware is present that can print the messages out the messages are queued in the log buffer and once a device registers itself as a console it will flush that buffer, thus printing everything. How soon can a register a device as a console. Well that depends on when linux initializes the hardware. > I added some printk statements to driver/char/console.c and the > resulting kernel hangs with only the logo showing and no text. Printk calls the functons in console.c which in turn calls printk which in turn and so on. So you get this recursive loop that goes on forever. So be careful. Also never call printk in interrupt handler. Printk turns off IRQs when printing. This will be fixed in 2.5.X.