Author: wmb Date: Wed Nov 14 08:47:41 2012 New Revision: 3426 URL: http://tracker.coreboot.org/trac/openfirmware/changeset/3426
Log: OLPC ARM MMP3 - turn off static branch prediction because it causes erratic results.
Modified: cpu/arm/mmp2/initmmu.fth
Modified: cpu/arm/mmp2/initmmu.fth ============================================================================== --- cpu/arm/mmp2/initmmu.fth Wed Nov 14 08:41:30 2012 (r3425) +++ cpu/arm/mmp2/initmmu.fth Wed Nov 14 08:47:41 2012 (r3426) @@ -87,6 +87,16 @@
mcr p15, 0, r0, cr7, cr5, 6 \ Flush branch target cache
+[ifdef] mmp3 + \ This erratum is not listed in PJ4B-MP.ARMv7-ErrataRev-18.pdf + \ but we found this workaround in the qseven Linux kernel source. + \ It fixes a problem we were seeing with Python (trac #12164) so + \ I am including it in OFW just in case. + mcr p15,1,r0,cr15,cr1,1 \ Workaround for PJ4B Errata 6409 + bic r0,r0,#0x04 \ Disable static branch prediction + mrc p15,1,r0,cr15,cr1,1 +[then] + mrc p15,0,r0,cr1,cr0,0 \ Read control register orr r0,r0,#0x1000 \ ICache on orr r0,r0,#0x0800 \ Branch prediction on