arm: Move CP15 init out of cpu_init_crit()
Some SOCs have do not start up with their 'main' CPU. The first U-Boot
code may then be executed with a CPU which does not have a CP15, or not a
useful one.
Here we split the initialization of CP15 into a separate call, which can
be performed later if required.
Once the main CPU is running, you should call cpu_init_cp15() to perform
this init as early as possible.
Existing ARMv7 boards which define CONFIG_SKIP_LOWLEVEL_INIT should not
need to change, this CP15 init is still skipped in that case. The only
impact for these boards is that the cpu_init_cp15() will be available
even if it is never used on these boards.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
index d23dc9d..b05be6c 100644
--- a/arch/arm/cpu/armv7/start.S
+++ b/arch/arm/cpu/armv7/start.S
@@ -162,6 +162,7 @@
/* the mask ROM code should have PLL and others stable */
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
+ bl cpu_init_cp15
bl cpu_init_crit
#endif
@@ -299,17 +300,16 @@
_board_init_r_ofs:
.word board_init_r - _start
-
-#ifndef CONFIG_SKIP_LOWLEVEL_INIT
/*************************************************************************
*
- * CPU_init_critical registers
+ * cpu_init_cp15
*
- * setup important registers
- * setup memory timing
+ * Setup CP15 registers (cache, MMU, TLBs). The I-cache is turned on unless
+ * CONFIG_SYS_ICACHE_OFF is defined.
*
*************************************************************************/
-cpu_init_crit:
+.globl cpu_init_cp15
+cpu_init_cp15:
/*
* Invalidate L1 I/D
*/
@@ -334,7 +334,19 @@
orr r0, r0, #0x00001000 @ set bit 12 (I) I-cache
#endif
mcr p15, 0, r0, c1, c0, 0
+ mov pc, lr @ back to my caller
+
+#ifndef CONFIG_SKIP_LOWLEVEL_INIT
+/*************************************************************************
+ *
+ * CPU_init_critical registers
+ *
+ * setup important registers
+ * setup memory timing
+ *
+ *************************************************************************/
+cpu_init_crit:
/*
* Jump to board specific initialization...
* The Mask ROM will have already initialized