From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 25 Sep 2007 12:29:35 +1000 From: David Gibson To: Valentine Barshak Subject: Re: [RFC] [PATCH] PowerPC: add more than 4MB kernel image size support to bootwarapper Message-ID: <20070925022935.GI30338@localhost.localdomain> References: <20070924113627.GA30504@ru.mvista.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20070924113627.GA30504@ru.mvista.com> Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Sep 24, 2007 at 03:36:27PM +0400, Valentine Barshak wrote: > Currently zImage is linked at the 4MB base address. > Some platforms (using cuboot, treeboot) need the zImage's > entry point and base address. They place zImage exactly > at the base address it's been linked to. Sometimes 4MB left > at the start of the memory is simply not enough to unpack zImage. > This could happen with initramfs enabled, since the kernel image > packed along with initramfs.cpio could be over 5MB in size. > This patch checks vmlinux image size and links zImage at > the base address that is equal to the unpacked image size > aligned to 4MB boundary. This way zImage base address is 4MB > only if unpacked kernel image size is less then 4MB. Good plan. However.. [snip] > diff -ruN linux-2.6.orig/arch/powerpc/boot/zImage.lds.S linux-2.6/arch/powerpc/boot/zImage.lds.S > --- linux-2.6.orig/arch/powerpc/boot/zImage.lds.S 2007-09-22 00:48:08.000000000 +0400 > +++ linux-2.6/arch/powerpc/boot/zImage.lds.S 2007-09-22 04:03:58.000000000 +0400 > @@ -3,7 +3,7 @@ > EXTERN(_zimage_start) > SECTIONS > { > - . = (4*1024*1024); > + . = ALIGN((_kend - _kstart), (4*1024*1024)); ..I don't see any reason to keep the 4MB granularity. I would just align the address to say a 64k boundary (64k because that's the granularity used in the normal ABI). > _start = .; > .text : > { > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@ozlabs.org > https://ozlabs.org/mailman/listinfo/linuxppc-dev > -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson