[U-Boot] [PATCH] OMAP3: set L1NEON bit in aux control register

Mans Rullgard mans at mansr.com
Sat Nov 15 00:01:35 CET 2008


This is required to work around ARM erratum 621766, affecting
Cortex-A8 r1p0-3:

  When a sequence of Neon load instructions is intermixed with several
  branches, some of which are mispredicted, it is possible for the
  processor to deadlock due to Neon loads on the speculative path not
  being properly flushed from the Neon load queue.

Signed-off-by: Mans Rullgard <mans at mansr.com>
---
 cpu/arm_cortexa8/omap3/board.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/cpu/arm_cortexa8/omap3/board.c b/cpu/arm_cortexa8/omap3/board.c
index 90809a6..7c2a7ea 100644
--- a/cpu/arm_cortexa8/omap3/board.c
+++ b/cpu/arm_cortexa8/omap3/board.c
@@ -139,6 +139,8 @@ void setup_auxcr()
 	__asm__ __volatile__("mrc p15, 0, r0, c1, c0, 1");
 	/* Enabling ASA */
 	__asm__ __volatile__("orr r0, r0, #0x10");
+	/* Enable L1NEON */
+	__asm__ __volatile__("orr r0, r0, #1<<5");
 	/* SMI instruction to call ROM Code API */
 	__asm__ __volatile__(".word 0xE1600070");
 	__asm__ __volatile__("mov r0, %0":"=r"(i));
-- 
1.6.0.3



More information about the U-Boot mailing list