From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jerry Van Baren Date: Wed, 06 Aug 2008 15:41:47 -0400 Subject: [U-Boot-Users] [PATCH][FOR 1.3.4] 85xx: Don't move interrupt vector to low memory In-Reply-To: <20080806193205.GA3975@ld0162-tx32.am.freescale.net> References: <41F2F68F-34F5-4D3B-8AA1-294589B48033@kernel.crashing.org> <20080806144251.0D80C24885@gemini.denx.de> <20080806193205.GA3975@ld0162-tx32.am.freescale.net> Message-ID: <4899FE7B.80508@ge.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Scott Wood wrote: > On Wed, Aug 06, 2008 at 04:42:51PM +0200, Wolfgang Denk wrote: >> In message <41F2F68F-34F5-4D3B-8AA1-294589B48033@kernel.crashing.org> you wrote: >>>> Oops? This is expected and normal behaviour. Did anybody complain >>>> about this? > > It's hit me before when I foolishly try to load something at address > zero -- why do we put u-boot at the end of RAM, and put up with the > relocation weirdness, if not to allow loading things at zero? > >>> Real, any reason why? I understand on classic PPC this might be the >>> case but I see no reason for it to be so on book-e parts. >> Well, one reason might be to have identical code for all PPC systems ? > > It's already 85xx-specific code. > >>> Any they are. I'm just removing a second relocation that is a hold >>> over from how 6xx PPC exception vectors work. >> Not only 6xx. Actually all PPC. > > No, not all PPC. Book-E exceptions are different. > > -Scott One nice thing about not relocating the exception vectors to 0 is that it would allow us to recover from a failed bootm all the way up to the jump to linux (or whomever) rather than having to reset the board to recover from a failure late in the bootm sequence. Unfortunately, it would be Book-E specific and probably not worth coding Yet Another Special Case in the already overcomplex bootm code. Best regards, gvb