Add support for Vesa BIOS extensions

For option ROMs we can use these extensions to request a particular video
mode. Add a header file which defines the binary interface.

Signed-off-by: Simon Glass <sjg@chromium.org>

include/vbe.h

+/******************************************************************************
+ * Copyright (c) 2004, 2008 IBM Corporation
+ * Copyright (c) 2009 Pattrick Hueper <phueper@hueper.net>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier:	BSD-2-Clause
+ *
+ * Contributors:
+ *     IBM Corporation - initial implementation
+ *****************************************************************************/
+#ifndef _VBE_H
+#define _VBE_H
+
+/* these structs are for input from and output to OF */
+struct __packed screen_info {
+	u8 display_type;	/* 0=NONE, 1= analog, 2=digital */
+	u16 screen_width;
+	u16 screen_height;
+	/* bytes per line in framebuffer, may be more than screen_width */
+	u16 screen_linebytes;
+	u8 color_depth;	/* color depth in bits per pixel */
+	u32 framebuffer_address;
+	u8 edid_block_zero[128];
+};
+
+struct __packed screen_info_input {
+	u8 signature[4];
+	u16 size_reserved;
+	u8 monitor_number;
+	u16 max_screen_width;
+	u8 color_depth;
+};
+
+/* these structs only store the required a subset of the VBE-defined fields */
+struct __packed vbe_info {
+	char signature[4];
+	u16 version;
+	u8 *oem_string_ptr;
+	u32 capabilities;
+	u16 video_mode_list[256];
+	u16 total_memory;
+};
+
+struct __packed vesa_mode_info {
+	u16 mode_attributes;	/* 00 */
+	u8 win_a_attributes;	/* 02 */
+	u8 win_b_attributes;	/* 03 */
+	u16 win_granularity;	/* 04 */
+	u16 win_size;		/* 06 */
+	u16 win_a_segment;	/* 08 */
+	u16 win_b_segment;	/* 0a */
+	u32 win_func_ptr;	/* 0c */
+	u16 bytes_per_scanline;	/* 10 */
+	u16 x_resolution;	/* 12 */
+	u16 y_resolution;	/* 14 */
+	u8 x_charsize;		/* 16 */
+	u8 y_charsize;		/* 17 */
+	u8 number_of_planes;	/* 18 */
+	u8 bits_per_pixel;	/* 19 */
+	u8 number_of_banks;	/* 20 */
+	u8 memory_model;	/* 21 */
+	u8 bank_size;		/* 22 */
+	u8 number_of_image_pages; /* 23 */
+	u8 reserved_page;
+	u8 red_mask_size;
+	u8 red_mask_pos;
+	u8 green_mask_size;
+	u8 green_mask_pos;
+	u8 blue_mask_size;
+	u8 blue_mask_pos;
+	u8 reserved_mask_size;
+	u8 reserved_mask_pos;
+	u8 direct_color_mode_info;
+	u32 phys_base_ptr;
+	u32 offscreen_mem_offset;
+	u16 offscreen_mem_size;
+	u8 reserved[206];
+};
+
+struct vbe_mode_info {
+	u16 video_mode;
+	bool valid;
+	union {
+		struct vesa_mode_info vesa;
+		u8 mode_info_block[256];
+	};
+};
+
+struct vbe_ddc_info {
+	u8 port_number;	/* i.e. monitor number */
+	u8 edid_transfer_time;
+	u8 ddc_level;
+	u8 edid_block_zero[128];
+};
+
+#define VESA_GET_INFO		0x4f00
+#define VESA_GET_MODE_INFO	0x4f01
+#define VESA_SET_MODE		0x4f02
+
+struct graphic_device;
+int vbe_get_video_info(struct graphic_device *gdev);
+
+#endif