/**
 * @file framebuffer.h
 * @brief Framebuffer information from the bootloader.
 *
 * Stores the display mode and framebuffer address provided by GRUB
 * via the multiboot2 framebuffer tag. The VGA driver uses this to
 * decide between text-mode writes (0xB8000) and pixel rendering.
 */

#ifndef FRAMEBUFFER_H
#define FRAMEBUFFER_H

#include <stdint.h>

/** Framebuffer types (matches multiboot2 definitions). */
#define FB_TYPE_INDEXED  0
#define FB_TYPE_RGB      1
#define FB_TYPE_EGA_TEXT 2

/**
 * Framebuffer information structure.
 * Populated during boot from the multiboot2 framebuffer tag.
 */
typedef struct {
    uint32_t addr;         /**< Physical address of the framebuffer. */
    uint32_t pitch;        /**< Bytes per scanline. */
    uint32_t width;        /**< Width in pixels (or columns for text). */
    uint32_t height;       /**< Height in pixels (or rows for text). */
    uint8_t  bpp;          /**< Bits per pixel. */
    uint8_t  type;         /**< FB_TYPE_RGB, FB_TYPE_EGA_TEXT, etc. */

    /* RGB field positions (only valid when type == FB_TYPE_RGB). */
    uint8_t  red_pos;
    uint8_t  red_size;
    uint8_t  green_pos;
    uint8_t  green_size;
    uint8_t  blue_pos;
    uint8_t  blue_size;
} framebuffer_info_t;

/** Global framebuffer info, filled by kernel_main. */
extern framebuffer_info_t fb_info;

#endif /* FRAMEBUFFER_H */