arm: imx: basic i.MX8ULP support

Add basic i.MX8ULP support

For the MMU part, Using a simple way the calculate the MMU size to avoid
default heavy calcaulation. And align address and size in the table
settings to 2MB or 4GB as much as possible. So we can reduce the 4K page
allocations in MMU table which will spends much time in create the
page table

Signed-off-by: Ye Li <ye.li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/arch/arm/mach-imx/imx8ulp/lowlevel_init.S b/arch/arm/mach-imx/imx8ulp/lowlevel_init.S
new file mode 100644
index 0000000000..7d81a75639
--- /dev/null
+++ b/arch/arm/mach-imx/imx8ulp/lowlevel_init.S
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2020 NXP
+ */
+
+#include <config.h>
+
+.align 8
+.global rom_pointer
+rom_pointer:
+	.space 256
+
+/*
+ * Routine: save_boot_params (called after reset from start.S)
+ */
+
+.global save_boot_params
+save_boot_params:
+	/* The firmware provided ATAG/FDT address can be found in r2/x0 */
+	adr	x0, rom_pointer
+	stp	x1, x2, [x0], #16
+	stp	x3, x4, [x0], #16
+
+	/* Returns */
+	b	save_boot_params_ret
+
+.global restore_boot_params
+restore_boot_params:
+	adr	x0, rom_pointer
+	ldp	x1, x2, [x0], #16
+	ldp	x3, x4, [x0], #16
+	ret