arm: mvebu: Move internal registers in arch_very_early_init() function
Moving of internal registers from INTREG_BASE_ADDR_REG to SOC_REGS_PHY_BASE
needs to be done very early, prior calling any function which may touch
internal registers, like debug_uart_init().
So do it earlier in arch_very_early_init() instead of arch_cpu_init().
Movement is done in proper U-Boot, not in SPL. SPL may return to bootrom
and bootrom requires internal registers at (old) expected location.
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/arch/arm/mach-mvebu/lowlevel.S b/arch/arm/mach-mvebu/lowlevel.S
new file mode 100644
index 0000000..2491310
--- /dev/null
+++ b/arch/arm/mach-mvebu/lowlevel.S
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#include <config.h>
+#include <linux/linkage.h>
+
+ENTRY(arch_very_early_init)
+#ifdef CONFIG_ARMADA_38X
+ /*
+ * Only with disabled MMU its possible to switch the base
+ * register address on Armada 38x. Without this the SDRAM
+ * located at >= 0x4000.0000 is also not accessible, as its
+ * still locked to cache.
+ */
+ mrc p15, 0, r0, c1, c0, 0
+ bic r0, #1
+ mcr p15, 0, r0, c1, c0, 0
+#endif
+
+ /* Move internal registers from INTREG_BASE_ADDR_REG to SOC_REGS_PHY_BASE */
+ ldr r0, =SOC_REGS_PHY_BASE
+ ldr r1, =INTREG_BASE_ADDR_REG
+ str r0, [r1]
+ add r0, r0, #0xC000
+ mcr p15, 4, r0, c15, c0
+
+ bx lr
+ENDPROC(arch_very_early_init)