STRUCT CONSW(9)

✨ NAME ✨

struct consw — the callback squad for consoles 💅 (this is from the struct consw(9) page in the Kernel API Manual, bestie)

🌸 SYNOPSIS 🌸

struct consw {
    struct module *owner;
    const char *(*con_startup)(void);
    void (*con_init)(struct vc_data *vc, bool init);
    void (*con_deinit)(struct vc_data *vc);
    void (*con_clear)(struct vc_data *vc, unsigned int y, unsigned int
x, unsigned int count);
    void (*con_putc)(struct vc_data *vc, u16 ca, unsigned int y,
unsigned int x);
    void (*con_putcs)(struct vc_data *vc, const u16 *s, unsigned int
count, unsigned int ypos, unsigned int xpos);
    void (*con_cursor)(struct vc_data *vc, bool enable);
    bool (*con_scroll)(struct vc_data *vc, unsigned int top, unsigned
int bottom, enum con_scroll dir, unsigned int lines);
    bool (*con_switch)(struct vc_data *vc);
    bool (*con_blank)(struct vc_data *vc, enum vesa_blank_mode blank,
bool mode_switch);
    int (*con_font_set)(struct vc_data *vc, const struct console_font
*font, unsigned int vpitch, unsigned int flags);
    int (*con_font_get)(struct vc_data *vc, struct console_font *font,
unsigned int vpitch);
    int (*con_font_default)(struct vc_data *vc, struct console_font
*font, const char *name);
    int (*con_resize)(struct vc_data *vc, unsigned int width, unsigned
int height, bool from_user);
    void (*con_set_palette)(struct vc_data *vc, const unsigned char
*table);
    void (*con_scrolldelta)(struct vc_data *vc, int lines);
    bool (*con_set_origin)(struct vc_data *vc);
    void (*con_save_screen)(struct vc_data *vc);
    u8 (*con_build_attr)(struct vc_data *vc, u8 color, enum vc_intensity
intensity, bool blink, bool underline, bool reverse, bool italic);
    void (*con_invert_region)(struct vc_data *vc, u16 *p, int count);
 };

🎀 Members 🎀

Okay so this struct is literally just a big bundle of function pointers, and each one is a lil vibe check the console layer does on your driver. Let's go through every single one, no skips, no cap 🔥

• owner — the module we grab references on when this console is in use, iykyk 🫶
• con_startup — sets up the console and returns its name (like VGA, EGA, ...). Name reveal moment ✨
• con_init — initializes the console on vc. The init flag is true for the very first call on this vc — so yes, it's giving "first time? bestie" energy 🎀
• con_deinit — deinitializes the console from vc. It's the goodbye hug 😭
• con_clear — erases count characters at [x, y] on vc. Heads up: count >= 1, always 💅
• con_putc — emits one character with attributes ca to [x, y] on vc. Optional — if you don't have it, con_putcs gets called instead 🦋
• con_putcs — emits count characters with attributes s to [x, y] on vc. The group-chat version of con_putc fr fr 💬
• con_cursor — enables/disables the cursor depending on enable. Blinking or not, that's the question 👀
• con_scroll — moves lines from top to bottom in direction dir, by lines. Returns true if no generic handling should be done. It's invoked by csi_M and by printing to the console. Return-value girlies, this one's for you 🔥
• con_switch — the notifier that a console switch happened; it's supposed to return true if a redraw is needed. Basically "do I need to redo my makeup" 💄
• con_blank — blanks/unblanks the console. The target mode comes in through blank. mode_switch is set if we're changing from/to text/graphics. The hook is supposed to return true if a redraw is needed 👑
• con_font_set — sets console vc's font to font with height vpitch. flags can be KD_FONT_FLAG_DONT_RECALC. (Optional)
• con_font_get — fetches the current font on vc of height vpitch into font. (Optional) 🎀
• con_font_default — sets the default font on vc. name can be NULL or a font name to search for. font can be filled back. (Optional)
• con_resize — resizes the vc console to width x height. from_user is true when this change comes from user space. Glow-up incoming ✨
• con_set_palette — sets the palette of the console vc to table. (Optional) Aesthetic customization, we love to see it 🌈
• con_scrolldelta — the contents of the console should be scrolled by lines. Invoked by the user. (Optional)
• con_set_origin — sets the origin (see vc_data::vc_origin) of the vc. If it's not provided, or it returns false, the origin is set to vc->vc_screenbuf. (Optional) 🧚
• con_save_screen — saves screen content into vc->vc_screenbuf. Called, for example, upon entering graphics. (Optional) Screenshot before the graphics era 💀
• con_build_attr — builds attributes based on color, intensity, and other parameters. The result is used for both normal and erase characters. (Optional) 🍓
• con_invert_region — inverts a region of length count on vc starting at p. (Optional) Uno reverse card 🃏

👑 SEE ALSO 👑

Go read these next, bestie, they're all in the same friend group:

• Kernel file ./include/linux/console.h
• enum cons_flags(9)
• struct nbcon_state(9)
• enum nbcon_prio(9)
• struct nbcon_context(9)
• struct nbcon_write_context(9)
• struct console(9)
• console_srcu_read_flags(9)
• console_srcu_write_flags(9)
• for_each_console_srcu(9)
• for_each_console(9)

Okay that's the whole page, nothing skipped, I promise 🫶 this one lives in ./include/linux and the manual page itself is dated October 2026 — struct consw(9), periodt 💖 stay slaying those callbacks ✨