Files
claude-os/src/font8x16.h
AI 993cf05712 feat: graphical framebuffer support for VGA driver
When GRUB is configured with multiboot2, it may provide a graphical
(RGB) framebuffer instead of legacy VGA text mode. This happens on
UTM/QEMU on macOS and other configurations where the bootloader
switches to a pixel-based display.

- Parse multiboot2 framebuffer tag in kernel_main to detect display mode
- Identity-map the framebuffer address (often at 0xFD000000+) after
  paging is enabled, with write-through caching
- Add framebuffer.h describing the boot-time display info
- Embed 8x16 VGA bitmap font (font8x16.h) for pixel-mode rendering
- Rewrite VGA driver to support both text mode and pixel mode:
  - Text mode: unchanged behavior writing to 0xB8000
  - Pixel mode: renders characters using the bitmap font to the
    GRUB-provided framebuffer, with proper VGA color palette mapping
  - Auto-detects mode from fb_info at init time
- Multiboot2 header now requests text mode via framebuffer tag, but
  gracefully falls back to pixel rendering if GRUB provides RGB
- Reverted grub.cfg gfxpayload=text (caused display issues on UTM)

Tested: boots in both text mode and graphical framebuffer mode.
2026-02-23 13:25:42 +00:00

216 lines
10 KiB
C

/**
* @file font8x16.h
* @brief Embedded 8x16 VGA bitmap font for graphical framebuffer rendering.
*
* Each character is 16 bytes: one byte per scanline, MSB is leftmost pixel.
* Covers ASCII 32 (space) through 126 (~). Characters outside this range
* render as a filled block.
*
* This is the standard VGA 8x16 font data, in the public domain.
*/
#ifndef FONT8X16_H
#define FONT8X16_H
#include <stdint.h>
#define FONT_WIDTH 8
#define FONT_HEIGHT 16
#define FONT_FIRST 32
#define FONT_LAST 126
static const uint8_t font8x16_data[][16] = {
/* 32: space */
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},
/* 33: ! */
{0x00,0x00,0x18,0x3C,0x3C,0x3C,0x18,0x18,0x18,0x00,0x18,0x18,0x00,0x00,0x00,0x00},
/* 34: " */
{0x00,0x66,0x66,0x66,0x24,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},
/* 35: # */
{0x00,0x00,0x00,0x6C,0x6C,0xFE,0x6C,0x6C,0x6C,0xFE,0x6C,0x6C,0x00,0x00,0x00,0x00},
/* 36: $ */
{0x18,0x18,0x7C,0xC6,0xC2,0xC0,0x7C,0x06,0x06,0x86,0xC6,0x7C,0x18,0x18,0x00,0x00},
/* 37: % */
{0x00,0x00,0x00,0x00,0xC2,0xC6,0x0C,0x18,0x30,0x60,0xC6,0x86,0x00,0x00,0x00,0x00},
/* 38: & */
{0x00,0x00,0x38,0x6C,0x6C,0x38,0x76,0xDC,0xCC,0xCC,0xCC,0x76,0x00,0x00,0x00,0x00},
/* 39: ' */
{0x00,0x30,0x30,0x30,0x60,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},
/* 40: ( */
{0x00,0x00,0x0C,0x18,0x30,0x30,0x30,0x30,0x30,0x30,0x18,0x0C,0x00,0x00,0x00,0x00},
/* 41: ) */
{0x00,0x00,0x30,0x18,0x0C,0x0C,0x0C,0x0C,0x0C,0x0C,0x18,0x30,0x00,0x00,0x00,0x00},
/* 42: * */
{0x00,0x00,0x00,0x00,0x00,0x66,0x3C,0xFF,0x3C,0x66,0x00,0x00,0x00,0x00,0x00,0x00},
/* 43: + */
{0x00,0x00,0x00,0x00,0x00,0x18,0x18,0x7E,0x18,0x18,0x00,0x00,0x00,0x00,0x00,0x00},
/* 44: , */
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x18,0x18,0x18,0x30,0x00,0x00,0x00},
/* 45: - */
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFE,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},
/* 46: . */
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x18,0x18,0x00,0x00,0x00,0x00},
/* 47: / */
{0x00,0x00,0x00,0x00,0x02,0x06,0x0C,0x18,0x30,0x60,0xC0,0x80,0x00,0x00,0x00,0x00},
/* 48: 0 */
{0x00,0x00,0x3C,0x66,0xC3,0xC3,0xDB,0xDB,0xC3,0xC3,0x66,0x3C,0x00,0x00,0x00,0x00},
/* 49: 1 */
{0x00,0x00,0x18,0x38,0x78,0x18,0x18,0x18,0x18,0x18,0x18,0x7E,0x00,0x00,0x00,0x00},
/* 50: 2 */
{0x00,0x00,0x7C,0xC6,0x06,0x0C,0x18,0x30,0x60,0xC0,0xC6,0xFE,0x00,0x00,0x00,0x00},
/* 51: 3 */
{0x00,0x00,0x7C,0xC6,0x06,0x06,0x3C,0x06,0x06,0x06,0xC6,0x7C,0x00,0x00,0x00,0x00},
/* 52: 4 */
{0x00,0x00,0x0C,0x1C,0x3C,0x6C,0xCC,0xFE,0x0C,0x0C,0x0C,0x1E,0x00,0x00,0x00,0x00},
/* 53: 5 */
{0x00,0x00,0xFE,0xC0,0xC0,0xC0,0xFC,0x06,0x06,0x06,0xC6,0x7C,0x00,0x00,0x00,0x00},
/* 54: 6 */
{0x00,0x00,0x38,0x60,0xC0,0xC0,0xFC,0xC6,0xC6,0xC6,0xC6,0x7C,0x00,0x00,0x00,0x00},
/* 55: 7 */
{0x00,0x00,0xFE,0xC6,0x06,0x06,0x0C,0x18,0x30,0x30,0x30,0x30,0x00,0x00,0x00,0x00},
/* 56: 8 */
{0x00,0x00,0x7C,0xC6,0xC6,0xC6,0x7C,0xC6,0xC6,0xC6,0xC6,0x7C,0x00,0x00,0x00,0x00},
/* 57: 9 */
{0x00,0x00,0x7C,0xC6,0xC6,0xC6,0x7E,0x06,0x06,0x06,0x0C,0x78,0x00,0x00,0x00,0x00},
/* 58: : */
{0x00,0x00,0x00,0x00,0x18,0x18,0x00,0x00,0x00,0x18,0x18,0x00,0x00,0x00,0x00,0x00},
/* 59: ; */
{0x00,0x00,0x00,0x00,0x18,0x18,0x00,0x00,0x00,0x18,0x18,0x30,0x00,0x00,0x00,0x00},
/* 60: < */
{0x00,0x00,0x00,0x06,0x0C,0x18,0x30,0x60,0x30,0x18,0x0C,0x06,0x00,0x00,0x00,0x00},
/* 61: = */
{0x00,0x00,0x00,0x00,0x00,0x7E,0x00,0x00,0x7E,0x00,0x00,0x00,0x00,0x00,0x00,0x00},
/* 62: > */
{0x00,0x00,0x00,0x60,0x30,0x18,0x0C,0x06,0x0C,0x18,0x30,0x60,0x00,0x00,0x00,0x00},
/* 63: ? */
{0x00,0x00,0x7C,0xC6,0xC6,0x0C,0x18,0x18,0x18,0x00,0x18,0x18,0x00,0x00,0x00,0x00},
/* 64: @ */
{0x00,0x00,0x00,0x7C,0xC6,0xC6,0xDE,0xDE,0xDE,0xDC,0xC0,0x7C,0x00,0x00,0x00,0x00},
/* 65: A */
{0x00,0x00,0x10,0x38,0x6C,0xC6,0xC6,0xFE,0xC6,0xC6,0xC6,0xC6,0x00,0x00,0x00,0x00},
/* 66: B */
{0x00,0x00,0xFC,0x66,0x66,0x66,0x7C,0x66,0x66,0x66,0x66,0xFC,0x00,0x00,0x00,0x00},
/* 67: C */
{0x00,0x00,0x3C,0x66,0xC2,0xC0,0xC0,0xC0,0xC0,0xC2,0x66,0x3C,0x00,0x00,0x00,0x00},
/* 68: D */
{0x00,0x00,0xF8,0x6C,0x66,0x66,0x66,0x66,0x66,0x66,0x6C,0xF8,0x00,0x00,0x00,0x00},
/* 69: E */
{0x00,0x00,0xFE,0x66,0x62,0x68,0x78,0x68,0x60,0x62,0x66,0xFE,0x00,0x00,0x00,0x00},
/* 70: F */
{0x00,0x00,0xFE,0x66,0x62,0x68,0x78,0x68,0x60,0x60,0x60,0xF0,0x00,0x00,0x00,0x00},
/* 71: G */
{0x00,0x00,0x3C,0x66,0xC2,0xC0,0xC0,0xDE,0xC6,0xC6,0x66,0x3A,0x00,0x00,0x00,0x00},
/* 72: H */
{0x00,0x00,0xC6,0xC6,0xC6,0xC6,0xFE,0xC6,0xC6,0xC6,0xC6,0xC6,0x00,0x00,0x00,0x00},
/* 73: I */
{0x00,0x00,0x3C,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x3C,0x00,0x00,0x00,0x00},
/* 74: J */
{0x00,0x00,0x1E,0x0C,0x0C,0x0C,0x0C,0x0C,0xCC,0xCC,0xCC,0x78,0x00,0x00,0x00,0x00},
/* 75: K */
{0x00,0x00,0xE6,0x66,0x66,0x6C,0x78,0x78,0x6C,0x66,0x66,0xE6,0x00,0x00,0x00,0x00},
/* 76: L */
{0x00,0x00,0xF0,0x60,0x60,0x60,0x60,0x60,0x60,0x62,0x66,0xFE,0x00,0x00,0x00,0x00},
/* 77: M */
{0x00,0x00,0xC6,0xEE,0xFE,0xFE,0xD6,0xC6,0xC6,0xC6,0xC6,0xC6,0x00,0x00,0x00,0x00},
/* 78: N */
{0x00,0x00,0xC6,0xE6,0xF6,0xFE,0xDE,0xCE,0xC6,0xC6,0xC6,0xC6,0x00,0x00,0x00,0x00},
/* 79: O */
{0x00,0x00,0x7C,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0x7C,0x00,0x00,0x00,0x00},
/* 80: P */
{0x00,0x00,0xFC,0x66,0x66,0x66,0x7C,0x60,0x60,0x60,0x60,0xF0,0x00,0x00,0x00,0x00},
/* 81: Q */
{0x00,0x00,0x7C,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xD6,0xDE,0x7C,0x0C,0x0E,0x00,0x00},
/* 82: R */
{0x00,0x00,0xFC,0x66,0x66,0x66,0x7C,0x6C,0x66,0x66,0x66,0xE6,0x00,0x00,0x00,0x00},
/* 83: S */
{0x00,0x00,0x7C,0xC6,0xC6,0x60,0x38,0x0C,0x06,0xC6,0xC6,0x7C,0x00,0x00,0x00,0x00},
/* 84: T */
{0x00,0x00,0xFF,0xDB,0x99,0x18,0x18,0x18,0x18,0x18,0x18,0x3C,0x00,0x00,0x00,0x00},
/* 85: U */
{0x00,0x00,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0x7C,0x00,0x00,0x00,0x00},
/* 86: V */
{0x00,0x00,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0x6C,0x38,0x10,0x00,0x00,0x00,0x00},
/* 87: W */
{0x00,0x00,0xC6,0xC6,0xC6,0xC6,0xD6,0xD6,0xD6,0xFE,0xEE,0x6C,0x00,0x00,0x00,0x00},
/* 88: X */
{0x00,0x00,0xC6,0xC6,0x6C,0x7C,0x38,0x38,0x7C,0x6C,0xC6,0xC6,0x00,0x00,0x00,0x00},
/* 89: Y */
{0x00,0x00,0xC3,0xC3,0x66,0x3C,0x18,0x18,0x18,0x18,0x18,0x3C,0x00,0x00,0x00,0x00},
/* 90: Z */
{0x00,0x00,0xFE,0xC6,0x86,0x0C,0x18,0x30,0x60,0xC2,0xC6,0xFE,0x00,0x00,0x00,0x00},
/* 91: [ */
{0x00,0x00,0x3C,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x3C,0x00,0x00,0x00,0x00},
/* 92: \ */
{0x00,0x00,0x00,0x80,0xC0,0xE0,0x70,0x38,0x1C,0x0E,0x06,0x02,0x00,0x00,0x00,0x00},
/* 93: ] */
{0x00,0x00,0x3C,0x0C,0x0C,0x0C,0x0C,0x0C,0x0C,0x0C,0x0C,0x3C,0x00,0x00,0x00,0x00},
/* 94: ^ */
{0x10,0x38,0x6C,0xC6,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},
/* 95: _ */
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFF,0x00,0x00},
/* 96: ` */
{0x30,0x30,0x18,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},
/* 97: a */
{0x00,0x00,0x00,0x00,0x00,0x78,0x0C,0x7C,0xCC,0xCC,0xCC,0x76,0x00,0x00,0x00,0x00},
/* 98: b */
{0x00,0x00,0xE0,0x60,0x60,0x78,0x6C,0x66,0x66,0x66,0x66,0x7C,0x00,0x00,0x00,0x00},
/* 99: c */
{0x00,0x00,0x00,0x00,0x00,0x7C,0xC6,0xC0,0xC0,0xC0,0xC6,0x7C,0x00,0x00,0x00,0x00},
/* 100: d */
{0x00,0x00,0x1C,0x0C,0x0C,0x3C,0x6C,0xCC,0xCC,0xCC,0xCC,0x76,0x00,0x00,0x00,0x00},
/* 101: e */
{0x00,0x00,0x00,0x00,0x00,0x7C,0xC6,0xFE,0xC0,0xC0,0xC6,0x7C,0x00,0x00,0x00,0x00},
/* 102: f */
{0x00,0x00,0x1C,0x36,0x32,0x30,0x78,0x30,0x30,0x30,0x30,0x78,0x00,0x00,0x00,0x00},
/* 103: g */
{0x00,0x00,0x00,0x00,0x00,0x76,0xCC,0xCC,0xCC,0xCC,0x7C,0x0C,0xCC,0x78,0x00,0x00},
/* 104: h */
{0x00,0x00,0xE0,0x60,0x60,0x6C,0x76,0x66,0x66,0x66,0x66,0xE6,0x00,0x00,0x00,0x00},
/* 105: i */
{0x00,0x00,0x18,0x18,0x00,0x38,0x18,0x18,0x18,0x18,0x18,0x3C,0x00,0x00,0x00,0x00},
/* 106: j */
{0x00,0x00,0x06,0x06,0x00,0x0E,0x06,0x06,0x06,0x06,0x06,0x06,0x66,0x3C,0x00,0x00},
/* 107: k */
{0x00,0x00,0xE0,0x60,0x60,0x66,0x6C,0x78,0x78,0x6C,0x66,0xE6,0x00,0x00,0x00,0x00},
/* 108: l */
{0x00,0x00,0x38,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x3C,0x00,0x00,0x00,0x00},
/* 109: m */
{0x00,0x00,0x00,0x00,0x00,0xE6,0xFF,0xDB,0xDB,0xDB,0xDB,0xDB,0x00,0x00,0x00,0x00},
/* 110: n */
{0x00,0x00,0x00,0x00,0x00,0xDC,0x66,0x66,0x66,0x66,0x66,0x66,0x00,0x00,0x00,0x00},
/* 111: o */
{0x00,0x00,0x00,0x00,0x00,0x7C,0xC6,0xC6,0xC6,0xC6,0xC6,0x7C,0x00,0x00,0x00,0x00},
/* 112: p */
{0x00,0x00,0x00,0x00,0x00,0xDC,0x66,0x66,0x66,0x66,0x7C,0x60,0x60,0xF0,0x00,0x00},
/* 113: q */
{0x00,0x00,0x00,0x00,0x00,0x76,0xCC,0xCC,0xCC,0xCC,0x7C,0x0C,0x0C,0x1E,0x00,0x00},
/* 114: r */
{0x00,0x00,0x00,0x00,0x00,0xDC,0x76,0x66,0x60,0x60,0x60,0xF0,0x00,0x00,0x00,0x00},
/* 115: s */
{0x00,0x00,0x00,0x00,0x00,0x7C,0xC6,0x60,0x38,0x0C,0xC6,0x7C,0x00,0x00,0x00,0x00},
/* 116: t */
{0x00,0x00,0x10,0x30,0x30,0xFC,0x30,0x30,0x30,0x30,0x36,0x1C,0x00,0x00,0x00,0x00},
/* 117: u */
{0x00,0x00,0x00,0x00,0x00,0xCC,0xCC,0xCC,0xCC,0xCC,0xCC,0x76,0x00,0x00,0x00,0x00},
/* 118: v */
{0x00,0x00,0x00,0x00,0x00,0xC3,0xC3,0xC3,0xC3,0x66,0x3C,0x18,0x00,0x00,0x00,0x00},
/* 119: w */
{0x00,0x00,0x00,0x00,0x00,0xC6,0xC6,0xC6,0xD6,0xD6,0xFE,0x6C,0x00,0x00,0x00,0x00},
/* 120: x */
{0x00,0x00,0x00,0x00,0x00,0xC6,0x6C,0x38,0x38,0x38,0x6C,0xC6,0x00,0x00,0x00,0x00},
/* 121: y */
{0x00,0x00,0x00,0x00,0x00,0xC6,0xC6,0xC6,0xC6,0xC6,0x7E,0x06,0x0C,0xF8,0x00,0x00},
/* 122: z */
{0x00,0x00,0x00,0x00,0x00,0xFE,0xCC,0x18,0x30,0x60,0xC6,0xFE,0x00,0x00,0x00,0x00},
/* 123: { */
{0x00,0x00,0x0E,0x18,0x18,0x18,0x70,0x18,0x18,0x18,0x18,0x0E,0x00,0x00,0x00,0x00},
/* 124: | */
{0x00,0x00,0x18,0x18,0x18,0x18,0x00,0x18,0x18,0x18,0x18,0x18,0x00,0x00,0x00,0x00},
/* 125: } */
{0x00,0x00,0x70,0x18,0x18,0x18,0x0E,0x18,0x18,0x18,0x18,0x70,0x00,0x00,0x00,0x00},
/* 126: ~ */
{0x00,0x00,0x76,0xDC,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},
};
#endif /* FONT8X16_H */