x86: Create a new header for EFI

The setup routines are called from zimage but don't really belong in the
zimage header. Add a new EFI header to house these. Add comments so it is
clear what the functions do.

Note that these functions are x86-specific. The zimage business is not
used on other architectures.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

arch/x86/include/asm/efi.h

@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright Google LLC
+ */
+
+#ifndef _ASM_EFI_H_
+#define _ASM_EFI_H_
+
+struct efi_info;
+struct screen_info;
+
+/**
+ * setup_video() - Set up the screen info in the x86 setup
+ *
+ * This is needed so Linux can use the display (when U-Boot is an EFI payload)
+ *
+ * @efi_info: Pointer to place to put the screen info in the x86 setup base
+ */
+void setup_video(struct screen_info *screen_info);
+
+/**
+ * setup_efi_info() - Set up the EFI info needed by Linux to boot
+ *
+ * This writes a suitable signature, table pointers, memory-map pointer, etc.
+ * These are needed for Linux to boot from U-Boot (when U-Boot is an EFI
+ * payload).
+ *
+ * @efi_info: Pointer to place to put the EFI info in the x86 setup base
+ */
+void setup_efi_info(struct efi_info *efi_info);
+
+#endif

arch/x86/include/asm/zimage.h

@@ -72,7 +72,4 @@ int setup_zimage(struct boot_params *setup_base, char *cmd_line, int auto_boot,
  */
 void zimage_dump(struct boot_params *base_ptr);
 
-void setup_video(struct screen_info *screen_info);
-void setup_efi_info(struct efi_info *efi_info);
-
 #endif

arch/x86/lib/zimage.c

@@ -29,6 +29,7 @@
 #include <asm/byteorder.h>
 #include <asm/bootm.h>
 #include <asm/bootparam.h>
+#include <asm/efi.h>
 #include <asm/global_data.h>
 #ifdef CONFIG_SYS_COREBOOT
 #include <asm/arch/timestamp.h>