arm: Allow skipping of low-level init with I-cache on
At present CONFIG_SKIP_LOWLEVEL_INIT prevents U-Boot from calling
lowlevel_init(). This means that the instruction cache is not enabled and
the board runs very slowly.
What is really needed in many cases is to skip the call to lowlevel_init()
but still perform CP15 init. Add an option to handle this.
Reviewed-by: Heiko Schocher <hs@denx.de>
Tested-on: smartweb, corvus, taurus, axm
Tested-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Joe Hershberger <joe.hershberger@ni.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Andreas Bießmann <andreas@biessmann.org>
diff --git a/arch/arm/cpu/arm1136/start.S b/arch/arm/cpu/arm1136/start.S
index 3ebdfdd..2f8fd6a 100644
--- a/arch/arm/cpu/arm1136/start.S
+++ b/arch/arm/cpu/arm1136/start.S
@@ -82,6 +82,7 @@
orr r0, r0, #0x00001000 @ set bit 12 (I) I-Cache
mcr p15, 0, r0, c1, c0, 0
+#ifndef CONFIG_SKIP_LOWLEVEL_INIT_ONLY
/*
* Jump to board specific initialization... The Mask ROM will have already initialized
* basic memory. Go here to bump up clock rate and handle wake up conditions.
@@ -89,5 +90,6 @@
mov ip, lr /* persevere link reg across call */
bl lowlevel_init /* go setup pll,mux,memory */
mov lr, ip /* restore link */
+#endif
mov pc, lr /* back to my caller */
#endif /* CONFIG_SKIP_LOWLEVEL_INIT */