Microkernel thing OS experiment (Zig ⚡)
pci.express
1const std = @import("std");
2
3pub const Psf2Header = extern struct {
4 magic: u32 = 0x864ab572,
5 version: u32,
6 header_size: u32,
7 flags: u32,
8 numglyph: u32,
9 bytes_per_glyph: u32,
10 height: u32,
11 width: u32,
12
13 pub fn bytesPerLine(self: *const Psf2Header) u32 {
14 return (self.width + 7) / 8;
15 }
16};
17
18pub const Font = struct {
19 const Self = @This();
20 fontdata: []const u8 align(4),
21 pub fn new(fontdata: []const u8) Self {
22 return .{
23 .fontdata = fontdata,
24 };
25 }
26
27 pub fn getHdr(self: *const Self) *const Psf2Header {
28 return @ptrCast(@alignCast(self.fontdata));
29 }
30
31 pub fn getGlyph(self: *const Self, ch: u8) ![]const u8 {
32 const hdr = self.getHdr();
33 const startpos: u64 = @as(u64, hdr.header_size) + @as(u64, ch) * @as(u64, hdr.bytes_per_glyph);
34
35 if (self.fontdata.len < startpos + @as(u64, hdr.bytes_per_glyph)) return error.InvalidCharacter;
36
37 return self.fontdata[startpos..][0..hdr.bytes_per_glyph];
38 }
39};