Merge 4.16

Change-Id: I11db70a8e25a6656c5ec640a703e7b06d5a3672e

payloads/libpayload/arch/x86/boot_media.c

@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+
+#include <arch/virtual.h>
+#include <boot_device.h>
+#include <commonlib/bsd/cb_err.h>
+#include <stddef.h>
+#include <string.h>
+#include <sysinfo.h>
+
+__attribute__((weak)) ssize_t boot_device_read(void *buf, size_t offset, size_t size)
+{
+	/* Memory-mapping usually only works for the top 16MB. */
+	if (!lib_sysinfo.boot_media_size || lib_sysinfo.boot_media_size - offset > 16 * MiB)
+		return CB_ERR_ARG;
+	const void *const ptr = phys_to_virt(0 - lib_sysinfo.boot_media_size + offset);
+	memcpy(buf, ptr, size);
+	return size;
+}