Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/powerpc/boot/main.c b/arch/powerpc/boot/main.c
index 78aaf4f..a9d2091 100644
--- a/arch/powerpc/boot/main.c
+++ b/arch/powerpc/boot/main.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (C) Paul Mackerras 1997.
  *
  * Updates for PPC64 by Todd Inglett, Dave Engebretsen & Peter Bergner.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
  */
 #include <stdarg.h>
 #include <stddef.h>
@@ -150,6 +146,46 @@
 	return (struct addr_range){(void *)initrd_addr, initrd_size};
 }
 
+#ifdef __powerpc64__
+static void prep_esm_blob(struct addr_range vmlinux, void *chosen)
+{
+	unsigned long esm_blob_addr, esm_blob_size;
+
+	/* Do we have an ESM (Enter Secure Mode) blob? */
+	if (_esm_blob_end <= _esm_blob_start)
+		return;
+
+	printf("Attached ESM blob at 0x%p-0x%p\n\r",
+	       _esm_blob_start, _esm_blob_end);
+	esm_blob_addr = (unsigned long)_esm_blob_start;
+	esm_blob_size = _esm_blob_end - _esm_blob_start;
+
+	/*
+	 * If the ESM blob is too low it will be clobbered when the
+	 * kernel relocates to its final location.  In this case,
+	 * allocate a safer place and move it.
+	 */
+	if (esm_blob_addr < vmlinux.size) {
+		void *old_addr = (void *)esm_blob_addr;
+
+		printf("Allocating 0x%lx bytes for esm_blob ...\n\r",
+		       esm_blob_size);
+		esm_blob_addr = (unsigned long)malloc(esm_blob_size);
+		if (!esm_blob_addr)
+			fatal("Can't allocate memory for ESM blob !\n\r");
+		printf("Relocating ESM blob 0x%lx <- 0x%p (0x%lx bytes)\n\r",
+		       esm_blob_addr, old_addr, esm_blob_size);
+		memmove((void *)esm_blob_addr, old_addr, esm_blob_size);
+	}
+
+	/* Tell the kernel ESM blob address via device tree. */
+	setprop_val(chosen, "linux,esm-blob-start", (u32)(esm_blob_addr));
+	setprop_val(chosen, "linux,esm-blob-end", (u32)(esm_blob_addr + esm_blob_size));
+}
+#else
+static inline void prep_esm_blob(struct addr_range vmlinux, void *chosen) { }
+#endif
+
 /* A buffer that may be edited by tools operating on a zImage binary so as to
  * edit the command line passed to vmlinux (by setting /chosen/bootargs).
  * The buffer is put in it's own section so that tools may locate it easier.
@@ -218,6 +254,7 @@
 	vmlinux = prep_kernel();
 	initrd = prep_initrd(vmlinux, chosen,
 			     loader_info.initrd_addr, loader_info.initrd_size);
+	prep_esm_blob(vmlinux, chosen);
 	prep_cmdline(chosen);
 
 	printf("Finalizing device tree...");