v4.19.13 snapshot.
diff --git a/arch/arm/include/debug/imx.S b/arch/arm/include/debug/imx.S
new file mode 100644
index 0000000..92c4476
--- /dev/null
+++ b/arch/arm/include/debug/imx.S
@@ -0,0 +1,50 @@
+/* arch/arm/mach-imx/include/mach/debug-macro.S
+ *
+ * Debugging macro include header
+ *
+ * Copyright (C) 1994-1999 Russell King
+ * Moved from linux/arch/arm/kernel/debug.S by Ben Dooks
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <asm/assembler.h>
+#include "imx-uart.h"
+
+/*
+ * FIXME: This is a copy of IMX_IO_P2V in hardware.h, and needs to
+ * stay sync with that. It's hard to maintain, and should be fixed
+ * globally for multi-platform build to use a fixed virtual address
+ * for low-level debug uart port across platforms.
+ */
+#define IMX_IO_P2V(x) ( \
+ (((x) & 0x80000000) >> 7) | \
+ (0xf4000000 + \
+ (((x) & 0x50000000) >> 6) + \
+ (((x) & 0x0b000000) >> 4) + \
+ (((x) & 0x000fffff))))
+
+#define UART_VADDR IMX_IO_P2V(UART_PADDR)
+
+ .macro addruart, rp, rv, tmp
+ ldr \rp, =UART_PADDR @ physical
+ ldr \rv, =UART_VADDR @ virtual
+ .endm
+
+ .macro senduart,rd,rx
+ ARM_BE8(rev \rd, \rd)
+ str \rd, [\rx, #0x40] @ TXDATA
+ .endm
+
+ .macro waituart,rd,rx
+ .endm
+
+ .macro busyuart,rd,rx
+1002: ldr \rd, [\rx, #0x98] @ SR2
+ ARM_BE8(rev \rd, \rd)
+ tst \rd, #1 << 3 @ TXDC
+ beq 1002b @ wait until transmit done
+ .endm