On Wed, 1 Aug 2007 15:20:22 -0500 "Keith Mund" keith.mund@clearcube.com 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@h ori r3, r3, CFG_IMMRBAR@l stw r3, IMMRBAR(r4)
mtspr MBAR, r3Are 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