From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kim Phillips Date: Wed, 1 Aug 2007 19:20:09 -0500 Subject: [U-Boot-Users] MPC83xx - previous patch to set MBAR In-Reply-To: <5EACFDEA24DADE42BF109303D305A8093120A6@MAIL.clearcube.com> References: <20070801133056.GP3972@stusta.de> <5EACFDEA24DADE42BF109303D305A8093120A6@MAIL.clearcube.com> Message-ID: <20070801192009.656fc2e0.kim.phillips@freescale.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Wed, 1 Aug 2007 15:20:22 -0500 "Keith Mund" wrote: > There was a u-boot 1.1.3 patch for start.S posted on the Freescale LTIB posts concerning u-boot should go to the u-boot-users list (cc'd). > site: > http://www.bitshrine.org/gpp/u-boot-1.1.3-mpc83xx-cpu-4.patch > > The end result simply adds a line to set MBAR to match IMMRBAR. > > lis r3, CFG_IMMRBAR at h > ori r3, r3, CFG_IMMRBAR at l > stw r3, IMMRBAR(r4) > + mtspr MBAR, r3 > > Are these patches routinely added to the mainstream u-boot code? > > Is there any reason why this fix is not a good idea? > does setting MBAR really fix anything? MBAR doesn't live up to its name. It's a general-purpose scratch register - the hardware doesn't do anything with it. So, wrt integrity within u-boot itself, I see no point/value in setting it. If some piece of software needs temporary storage, it can set it and use it as it wishes, independent of u-boot. Kim