root/arch/x86/xen/vga.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/screen_info.h>
#include <linux/init.h>

#include <asm/setup.h>

#include <xen/interface/xen.h>

#include "xen-ops.h"

void __init xen_init_vga(const struct dom0_vga_console_info *info, size_t size,
                         struct screen_info *screen_info)
{
        /* This is drawn from a dump from vgacon:startup in
         * standard Linux. */
        screen_info->orig_video_mode = 3;
        screen_info->orig_video_isVGA = 1;
        screen_info->orig_video_lines = 25;
        screen_info->orig_video_cols = 80;
        screen_info->orig_video_ega_bx = 3;
        screen_info->orig_video_points = 16;
        screen_info->orig_y = screen_info->orig_video_lines - 1;

        switch (info->video_type) {
        case XEN_VGATYPE_TEXT_MODE_3:
                if (size < offsetof(struct dom0_vga_console_info, u.text_mode_3)
                    + sizeof(info->u.text_mode_3))
                        break;
                screen_info->orig_video_lines = info->u.text_mode_3.rows;
                screen_info->orig_video_cols = info->u.text_mode_3.columns;
                screen_info->orig_x = info->u.text_mode_3.cursor_x;
                screen_info->orig_y = info->u.text_mode_3.cursor_y;
                screen_info->orig_video_points =
                        info->u.text_mode_3.font_height;
                break;

        case XEN_VGATYPE_EFI_LFB:
        case XEN_VGATYPE_VESA_LFB:
                if (size < offsetof(struct dom0_vga_console_info,
                                    u.vesa_lfb.gbl_caps))
                        break;
                screen_info->orig_video_isVGA = VIDEO_TYPE_VLFB;
                screen_info->lfb_width = info->u.vesa_lfb.width;
                screen_info->lfb_height = info->u.vesa_lfb.height;
                screen_info->lfb_depth = info->u.vesa_lfb.bits_per_pixel;
                screen_info->lfb_base = info->u.vesa_lfb.lfb_base;
                screen_info->lfb_size = info->u.vesa_lfb.lfb_size;
                screen_info->lfb_linelength = info->u.vesa_lfb.bytes_per_line;
                screen_info->red_size = info->u.vesa_lfb.red_size;
                screen_info->red_pos = info->u.vesa_lfb.red_pos;
                screen_info->green_size = info->u.vesa_lfb.green_size;
                screen_info->green_pos = info->u.vesa_lfb.green_pos;
                screen_info->blue_size = info->u.vesa_lfb.blue_size;
                screen_info->blue_pos = info->u.vesa_lfb.blue_pos;
                screen_info->rsvd_size = info->u.vesa_lfb.rsvd_size;
                screen_info->rsvd_pos = info->u.vesa_lfb.rsvd_pos;

                if (size >= offsetof(struct dom0_vga_console_info,
                                     u.vesa_lfb.ext_lfb_base)
                    + sizeof(info->u.vesa_lfb.ext_lfb_base)
                    && info->u.vesa_lfb.ext_lfb_base) {
                        screen_info->ext_lfb_base = info->u.vesa_lfb.ext_lfb_base;
                        screen_info->capabilities |= VIDEO_CAPABILITY_64BIT_BASE;
                }

                if (info->video_type == XEN_VGATYPE_EFI_LFB) {
                        screen_info->orig_video_isVGA = VIDEO_TYPE_EFI;
                        break;
                }

                if (size >= offsetof(struct dom0_vga_console_info,
                                     u.vesa_lfb.mode_attrs)
                    + sizeof(info->u.vesa_lfb.mode_attrs))
                        screen_info->vesa_attributes = info->u.vesa_lfb.mode_attrs;
                break;
        }
}