2006-05-30 21:34:24

by Deepak Saxena

[permalink] [raw]
Subject: [PATCH] ARM: explicitly disable BTB on ixp2350


We don't enable the BTB on the ixp2350 as that can cause weird
crashes (erratum #42.) However, some bootloaders enable the BTB,
which means that we have to disable the BTB explicitly.

Found thanks to Tom Rini.

Signed-off-by: Lennert Buytenhek <[email protected]>
Signed-off-by: Deepak Saxena <[email protected]>

Index: linux-2.6.17-rc3/arch/arm/mm/proc-xsc3.S
===================================================================
--- linux-2.6.17-rc3.orig/arch/arm/mm/proc-xsc3.S
+++ linux-2.6.17-rc3/arch/arm/mm/proc-xsc3.S
@@ -427,12 +427,13 @@ __xsc3_setup:
#endif
mcr p15, 0, r0, c1, c0, 1 @ set auxiliary control reg
mrc p15, 0, r0, c1, c0, 0 @ get control register
- bic r0, r0, #0x0200 @ .... ..R. .... ....
bic r0, r0, #0x0002 @ .... .... .... ..A.
orr r0, r0, #0x0005 @ .... .... .... .C.M
#if BTB_ENABLE
+ bic r0, r0, #0x0200 @ .... ..R. .... ....
orr r0, r0, #0x3900 @ ..VI Z..S .... ....
#else
+ bic r0, r0, #0x0a00 @ .... Z.R. .... ....
orr r0, r0, #0x3100 @ ..VI ...S .... ....
#endif
#if L2_CACHE_ENABLE


--
Deepak Saxena - [email protected] - http://www.plexity.net

In the end, they will not say, "those were dark times," they will ask
"why were their poets silent?" - Bertold Brecht