1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
|
/// GOP framebuffer driver — renders text via a bitmap font.
use crate::font;
use crate::uefi::{GraphicsOutputProtocol, PIXEL_BGR, PIXEL_RGB};
use core::fmt;
use core::ptr;
/// Framebuffer state captured before ExitBootServices.
pub struct Framebuffer {
base: *mut u8,
#[allow(dead_code)]
width: usize,
height: usize,
pitch: usize, // bytes per scan line
bytes_per_pixel: usize,
bg: u32, // packed BGRA or RGBA background colour
fg: u32, // packed foreground colour
cursor_x: usize,
cursor_y: usize,
rows: usize,
cols: usize,
}
static mut FB: Option<Framebuffer> = None;
/// Initialise the framebuffer from GOP. Call *before* ExitBootServices.
pub fn init(gop: &mut GraphicsOutputProtocol) {
let mode = unsafe { &*gop.mode };
let info = unsafe { &*mode.info };
let base = mode.framebuffer_base as *mut u8;
let width = info.horizontal_resolution as usize;
let height = info.vertical_resolution as usize;
let pitch = info.pixels_per_scan_line as usize * 4; // 32-bit pixel
let bpp = 4;
// Pick colours based on pixel format
let (fg, bg) = match info.pixel_format {
PIXEL_BGR => (0x00_FF_FF_FFu32, 0x00_00_00_00u32), // white fg, black bg
PIXEL_RGB => (0x00_FF_FF_FFu32, 0x00_00_00_00u32),
_ => (0x00_FF_FF_FFu32, 0x00_00_00_00u32),
};
let rows = height / 16;
let cols = width / 8;
let fb = Framebuffer {
base,
width,
height,
pitch,
bytes_per_pixel: bpp,
bg,
fg,
cursor_x: 0,
cursor_y: 0,
rows,
cols,
};
fb.clear();
unsafe {
FB = Some(fb);
}
}
/// Draw a character at the current cursor position and advance.
pub fn put_char(c: char) {
let fb = unsafe {
match FB.as_mut() {
Some(f) => f,
None => return,
}
};
if c == '\x08' {
// Backspace - move cursor back and erase
if fb.cursor_x > 0 {
fb.cursor_x -= 1;
} else if fb.cursor_y > 0 {
fb.cursor_y -= 1;
fb.cursor_x = fb.cols - 1;
} else {
return;
}
// Draw glyph 32 (space) to erase — glyph 0 is NUL, not blank
fb.draw_glyph(32, fb.cursor_x, fb.cursor_y);
return;
}
if c == '\n' {
fb.cursor_x = 0;
fb.cursor_y += 1;
if fb.cursor_y >= fb.rows {
fb.scroll();
}
return;
}
if c == '\r' {
fb.cursor_x = 0;
return;
}
let idx = c as usize;
if idx >= 256 {
// Unmapped character: draw a space
fb.draw_glyph(0, fb.cursor_x, fb.cursor_y);
} else {
fb.draw_glyph(idx, fb.cursor_x, fb.cursor_y);
}
fb.cursor_x += 1;
if fb.cursor_x >= fb.cols {
fb.cursor_x = 0;
fb.cursor_y += 1;
if fb.cursor_y >= fb.rows {
fb.scroll();
}
}
}
/// Write a string to the framebuffer.
pub fn write_str(s: &str) {
for c in s.chars() {
put_char(c);
}
}
/// Clear the entire screen to background colour and reset cursor to (0, 0).
pub fn clear_screen() {
let fb = unsafe {
match FB.as_mut() {
Some(f) => f,
None => return,
}
};
fb.clear();
// Reset cursor back to top-left so the next prompt appears at (0, 0)
fb.cursor_x = 0;
fb.cursor_y = 0;
}
// ---------------------------------------------------------------------------
// Framebuffer implementation
// ---------------------------------------------------------------------------
impl Framebuffer {
fn clear(&self) {
let size = self.pitch * self.height;
// Fill with background colour (32-bit writes)
let mut p = self.base;
let end = unsafe { p.add(size) };
unsafe {
while p < end {
ptr::write_volatile(p as *mut u32, self.bg);
p = p.add(4);
}
}
}
fn scroll(&mut self) {
// Move everything up one row (16 pixels)
let row_bytes = self.pitch * 16;
let total = self.pitch * self.height;
unsafe {
ptr::copy(self.base.add(row_bytes), self.base, total - row_bytes);
// Clear last row
let last_row = self.base.add(total - row_bytes);
for i in 0..(self.pitch * 16 / 4) {
ptr::write_volatile(last_row.add(i * 4) as *mut u32, self.bg);
}
}
self.cursor_y -= 1;
}
fn draw_glyph(&self, glyph_idx: usize, col: usize, row: usize) {
let glyph = font::GLYPH_8X16;
let data = match glyph.get(glyph_idx) {
Some(d) => *d,
None => return,
};
let x = col * 8;
let y = row * 16;
for cy in 0..16 {
let row_bits = data[cy];
for cx in 0..8 {
if row_bits & (0x80 >> cx) != 0 {
// Set foreground pixel
let offset = (y + cy) * self.pitch + (x + cx) * self.bytes_per_pixel;
unsafe {
ptr::write_volatile(self.base.add(offset) as *mut u32, self.fg);
}
} else {
// Set background pixel
let offset = (y + cy) * self.pitch + (x + cx) * self.bytes_per_pixel;
unsafe {
ptr::write_volatile(self.base.add(offset) as *mut u32, self.bg);
}
}
}
}
}
}
// ---------------------------------------------------------------------------
// fmt::Write wrapper
// ---------------------------------------------------------------------------
pub struct GopWriter;
impl fmt::Write for GopWriter {
fn write_str(&mut self, s: &str) -> fmt::Result {
write_str(s);
Ok(())
}
}
/// Write a formatted string to the framebuffer.
#[macro_export]
macro_rules! gop_print {
($($arg:tt)*) => {{
use core::fmt::Write;
let _ = write!(&mut $crate::gop::GopWriter, $($arg)*);
}};
}
#[macro_export]
macro_rules! gop_println {
() => { $crate::gop::write_str("\n"); };
($($arg:tt)*) => {{
$crate::gop_print!($($arg)*);
$crate::gop::write_str("\n");
}};
}
|
