From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Pitre Subject: Re: [RFC PATCH 0/3] ARM: uncompress.h multi-platform enablement Date: Thu, 27 Sep 2012 23:53:33 -0400 (EDT) Message-ID: References: <1348613212-21897-1-git-send-email-swarren@wwwdotorg.org> <201209261417.18883.arnd@arndb.de> <506315A6.3090300@am.sony.com> <201209261449.48468.arnd@arndb.de> <20120926151023.GC30938@n2100.arm.linux.org.uk> <50632096.7080208@wwwdotorg.org> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: In-reply-to: <50632096.7080208-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Stephen Warren Cc: Russell King - ARM Linux , Stephen Warren , Arnd Bergmann , Rob Herring , Olof Johansson , Tim Bird , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On Wed, 26 Sep 2012, Stephen Warren wrote: > In the Tegra case, by omitting uncompress.h, we lose more than just the > "Decompressing Linux..." message; uncompress.h contains code to parse > extract the platform's debug UART ID from data set up by the boot ROM > (since we have 5 UARTs), and pass this on to debug-macro.S. Let me tell you that this is totally evil. OMAP and Davinci are doing the same abuse. > Without uncompress.h running, debug-macro.S would either have to > hard-code a single UART ID (and different boards uses different UARTs, > which would make running a single kernel image across all Tegra > devices with earlyprintk enabled impossible) *or* we'd have to port > the UART ID extraction code to debug-macro.S too, Please do the later. That's the only sane solution. > which I don't fancy very much since that's assembly whereas > uncompress.h is C. Well, that's too bad. Time to sharpen your assembly skills. ;-) Nicolas From mboxrd@z Thu Jan 1 00:00:00 1970 From: nico@fluxnic.net (Nicolas Pitre) Date: Thu, 27 Sep 2012 23:53:33 -0400 (EDT) Subject: [RFC PATCH 0/3] ARM: uncompress.h multi-platform enablement In-Reply-To: <50632096.7080208@wwwdotorg.org> References: <1348613212-21897-1-git-send-email-swarren@wwwdotorg.org> <201209261417.18883.arnd@arndb.de> <506315A6.3090300@am.sony.com> <201209261449.48468.arnd@arndb.de> <20120926151023.GC30938@n2100.arm.linux.org.uk> <50632096.7080208@wwwdotorg.org> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, 26 Sep 2012, Stephen Warren wrote: > In the Tegra case, by omitting uncompress.h, we lose more than just the > "Decompressing Linux..." message; uncompress.h contains code to parse > extract the platform's debug UART ID from data set up by the boot ROM > (since we have 5 UARTs), and pass this on to debug-macro.S. Let me tell you that this is totally evil. OMAP and Davinci are doing the same abuse. > Without uncompress.h running, debug-macro.S would either have to > hard-code a single UART ID (and different boards uses different UARTs, > which would make running a single kernel image across all Tegra > devices with earlyprintk enabled impossible) *or* we'd have to port > the UART ID extraction code to debug-macro.S too, Please do the later. That's the only sane solution. > which I don't fancy very much since that's assembly whereas > uncompress.h is C. Well, that's too bad. Time to sharpen your assembly skills. ;-) Nicolas