From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [RFC PATCH v1 12/40] metag: Build infrastructure Date: Tue, 20 Nov 2012 15:43:15 +0000 Message-ID: <201211201543.15837.arnd@arndb.de> References: <1351700061-7203-1-git-send-email-james.hogan@imgtec.com> <201211091446.28068.arnd@arndb.de> <50AB9C76.1010107@imgtec.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Return-path: Received: from moutng.kundenserver.de ([212.227.17.9]:61796 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751856Ab2KTPnT (ORCPT ); Tue, 20 Nov 2012 10:43:19 -0500 In-Reply-To: <50AB9C76.1010107@imgtec.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: James Hogan Cc: linux-arch@vger.kernel.org On Tuesday 20 November 2012, James Hogan wrote: > On 09/11/12 14:46, Arnd Bergmann wrote: > > On Wednesday 31 October 2012, James Hogan wrote: > >> + > >> +define archhelp > >> + echo '* vmlinux.bin - Binary kernel image (arch/$(ARCH)/boot/vmlinux.bin)' > >> + @echo ' uImage - Alias to bootable U-Boot image' > >> + @echo ' uImage.bin - Kernel-only image for U-Boot (bin)' > >> + @echo ' uImage.gz - Kernel-only image for U-Boot (gzip)' > >> + @echo ' uImage.bz2 - Kernel-only image for U-Boot (bzip2)' > >> + @echo ' uImage.lzma - Kernel-only image for U-Boot (lzma)' > >> + @echo ' uImage.xz - Kernel-only image for U-Boot (xz)' > >> + @echo ' uImage.lzo - Kernel-only image for U-Boot (lzo)' > >> +endef > > > > The uImage format is causing some trouble on ARM because it requires knowing > > the load address at boot time, so we try to move people towards using just > > zImage files there. You might want to consider the same. > > Could you point me at some info about this problem? I'm not clear why > needing to know the load address at boot is a problem, or how zImage > helps. Does this presume that the bootloader starts the kernel with the > MMU bypassed? A lot of architectures don't have a fixed location for the start of physical RAM, so the arguments to u-boot mkimage are configuration dependent. If you want to build a kernel that runs on multiple systems with a conflicting requirements, you can't put the load address into a u-boot header. > > It's probably not necessary to have both lzma and xz formats since they > > are the same algorithm with different headers afaik. > > This was copied from arch/sh/boot/Makefile if I remember right. Is > either of them preferred? xz is the one that most people use today. Arnd