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authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>2010-01-26 22:14:23 +0100
committerUwe Kleine-König <u.kleine-koenig@pengutronix.de>2010-06-17 11:09:40 +0200
commit4a8d57a54fb21f32ee17e0a61ca54c7a6f8f83da (patch)
treee63465bea306778518c6d8e3b3107d2a8a2975cf /arch/arm/boot
parent88237c25aa4fe0dad177ae11214136ad78bc908f (diff)
ARM: zImage: some comments for __armv3_mpu_cache_on
__armv3_mpu_cache_on seems broken. As there is noone around who knows about these machines just keep the code as is but point out the strange things. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Diffstat (limited to 'arch/arm/boot')
-rw-r--r--arch/arm/boot/compressed/head.S6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index 390aa92ef04d..7b7d95c84641 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -396,12 +396,18 @@ __armv3_mpu_cache_on:
mov r0, #0
mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
+ /*
+ * ?? ARMv3 MMU does not allow reading the control register,
+ * does this really work on ARMv3 MPU?
+ */
mrc p15, 0, r0, c1, c0, 0 @ read control reg
@ .... .... .... WC.M
orr r0, r0, #0x000d @ .... .... .... 11.1
+ /* ?? this overwrites the value constructed above? */
mov r0, #0
mcr p15, 0, r0, c1, c0, 0 @ write control reg
+ /* ?? invalidate for the second time? */
mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
mov pc, lr