98 lines
3.2 KiB
C
98 lines
3.2 KiB
C
/*
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StarForth — Steady-State Virtual Machine Runtime
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Copyright (c) 2023–2025 Robert A. James
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All rights reserved.
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Licensed under the StarForth License, Version 1.0.
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*/
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/**
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* framebuffer.h — UEFI GOP framebuffer driver interface
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*
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* Pixel format: BGRX32 (PixelBlueGreenRedReserved8BitPerColor),
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* the dominant format for QEMU virt GOP. RGBX32 is also supported.
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*
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* Color values throughout this API are packed as 0x00RRGGBB.
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*/
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#ifndef STARKERNEL_FRAMEBUFFER_H
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#define STARKERNEL_FRAMEBUFFER_H
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#include <stdint.h>
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#include "uefi.h"
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/* Pixel format of the GOP framebuffer */
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typedef enum {
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FB_PIXEL_BGRX32 = 0, /* PixelBlueGreenRedReserved8BitPerColor (default) */
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FB_PIXEL_RGBX32 = 1, /* PixelRedGreenBlueReserved8BitPerColor */
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} FbPixelFormat;
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/* Pack / unpack 24-bit 0x00RRGGBB color */
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#define FB_RGB(r, g, b) \
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(((uint32_t)(r) << 16) | ((uint32_t)(g) << 8) | (uint32_t)(b))
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#define FB_R(c) (((uint32_t)(c) >> 16) & 0xFFu)
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#define FB_G(c) (((uint32_t)(c) >> 8) & 0xFFu)
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#define FB_B(c) ( (uint32_t)(c) & 0xFFu)
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/* Standard ANSI 16-color palette (indices 0–15) */
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extern const uint32_t FB_ANSI_PALETTE[16] __attribute__((visibility("hidden")));
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/* -----------------------------------------------------------------------
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* Lifecycle
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* --------------------------------------------------------------------- */
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/**
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* Initialize the framebuffer from UEFI bootloader GOP data.
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* Must be called before any other fb_* function.
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* fmt: pixel layout reported by GOP (default FB_PIXEL_BGRX32).
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*/
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void fb_init(const FramebufferInfo *info, FbPixelFormat fmt);
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/** Returns 1 if the framebuffer has been successfully initialized. */
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int fb_is_available(void);
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/* -----------------------------------------------------------------------
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* Geometry queries
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* --------------------------------------------------------------------- */
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uint32_t fb_width(void);
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uint32_t fb_height(void);
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/** Effective character cell width/height in pixels (8/16 × scale factor). */
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uint32_t fb_cell_w(void);
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uint32_t fb_cell_h(void);
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/* -----------------------------------------------------------------------
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* Pixel-level primitives
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* --------------------------------------------------------------------- */
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/** Write a single pixel. Out-of-bounds writes are silently ignored. */
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void fb_put_pixel(uint32_t x, uint32_t y, uint32_t rgb);
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/** Fill a rectangle with a solid color. */
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void fb_fill_rect(uint32_t x, uint32_t y, uint32_t w, uint32_t h,
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uint32_t rgb);
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/* -----------------------------------------------------------------------
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* Glyph rendering (8 × 16 font cells)
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* --------------------------------------------------------------------- */
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/**
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* Draw one 8×16 character glyph at pixel position (px, py).
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* fg / bg are packed 0x00RRGGBB colors.
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*/
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void fb_draw_glyph(uint32_t px, uint32_t py, uint8_t ch,
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uint32_t fg, uint32_t bg);
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/* -----------------------------------------------------------------------
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* Scrolling
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* --------------------------------------------------------------------- */
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/**
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* Scroll the framebuffer up by `char_rows` character rows (each 16 px).
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* The vacated rows at the bottom are filled with bg.
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*/
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void fb_scroll_rows(uint32_t char_rows, uint32_t bg);
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#endif /* STARKERNEL_FRAMEBUFFER_H */
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