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Maciej Krzyżanowski 2024-08-22 23:57:22 +02:00 committed by Maciej Krzyżanowski
commit 5437091707
6 changed files with 183 additions and 0 deletions

2
.gitignore vendored Normal file
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zig-out/
.zig-cache/

36
build.zig Normal file
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const std = @import("std");
pub fn build(b: *std.Build) void {
var disabled_features = std.Target.Cpu.Feature.Set.empty;
var enabled_features = std.Target.Cpu.Feature.Set.empty;
disabled_features.addFeature(@intFromEnum(std.Target.x86.Feature.mmx));
disabled_features.addFeature(@intFromEnum(std.Target.x86.Feature.sse));
disabled_features.addFeature(@intFromEnum(std.Target.x86.Feature.sse2));
disabled_features.addFeature(@intFromEnum(std.Target.x86.Feature.avx));
disabled_features.addFeature(@intFromEnum(std.Target.x86.Feature.avx2));
enabled_features.addFeature(@intFromEnum(std.Target.x86.Feature.soft_float));
const target_query = std.Target.Query{
.cpu_arch = std.Target.Cpu.Arch.x86,
.os_tag = std.Target.Os.Tag.freestanding,
.abi = std.Target.Abi.none,
.cpu_features_sub = disabled_features,
.cpu_features_add = enabled_features,
};
const optimize = b.standardOptimizeOption(.{});
const kernel = b.addExecutable(.{
.name = "kernel.elf",
.root_source_file = b.path("src/main.zig"),
.target = b.resolveTargetQuery(target_query),
.optimize = optimize,
.code_model = .kernel,
});
kernel.setLinkerScript(b.path("src/linker.ld"));
b.installArtifact(kernel);
const kernel_step = b.step("kernel", "Build the kernel");
kernel_step.dependOn(&kernel.step);
}

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src/console.zig Normal file
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const fmt = @import("std").fmt;
const Writer = @import("std").io.Writer;
const VGA_WIDTH = 80;
const VGA_HEIGHT = 25;
const VGA_SIZE = VGA_WIDTH * VGA_HEIGHT;
pub const ConsoleColors = enum(u8) {
Black = 0,
Blue = 1,
Green = 2,
Cyan = 3,
Red = 4,
Magenta = 5,
Brown = 6,
LightGray = 7,
DarkGray = 8,
LightBlue = 9,
LightGreen = 10,
LightCyan = 11,
LightRed = 12,
LightMagenta = 13,
LightBrown = 14,
White = 15,
};
var row: usize = 0;
var column: usize = 0;
var color = vgaEntryColor(ConsoleColors.LightGray, ConsoleColors.Black);
var buffer = @as([*]volatile u16, @ptrFromInt(0xB8000));
fn vgaEntryColor(fg: ConsoleColors, bg: ConsoleColors) u8 {
return @intFromEnum(fg) | (@intFromEnum(bg) << 4);
}
fn vgaEntry(uc: u8, new_color: u8) u16 {
const c: u16 = new_color;
return uc | (c << 8);
}
pub fn initialize() void {
clear();
}
pub fn setColor(new_color: u8) void {
color = new_color;
}
pub fn clear() void {
@memset(buffer[0..VGA_SIZE], vgaEntry(' ', color));
}
pub fn putCharAt(c: u8, new_color: u8, x: usize, y: usize) void {
const index = y * VGA_WIDTH + x;
buffer[index] = vgaEntry(c, new_color);
}
pub fn putChar(c: u8) void {
putCharAt(c, color, column, row);
column += 1;
if (column == VGA_WIDTH) {
column = 0;
row += 1;
if (row == VGA_HEIGHT)
row = 0;
}
}
pub fn puts(data: []const u8) void {
for (data) |c|
putChar(c);
}
pub const writer = Writer(void, error{}, callback){ .context = {} };
fn callback(_: void, string: []const u8) error{}!usize {
puts(string);
return string.len;
}
pub fn printf(comptime format: []const u8, args: anytype) void {
fmt.format(writer, format, args) catch unreachable;
}

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src/grub.cfg Normal file
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menuentry "Zig Bare Bones" {
multiboot /boot/kernel.elf
}

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src/linker.ld Normal file
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ENTRY(_start)
SECTIONS {
. = 1M;
.multiboot {
KEEP(*(.multiboot))
}
.text : ALIGN(4K) {
*(.text)
}
.rodata : ALIGN(4K) {
*(.rodata)
}
.data : ALIGN(4K) {
*(.data)
}
.bss : ALIGN(4K) {
*(COMMON)
*(.bss)
}
}

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src/main.zig Normal file
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const console = @import("console.zig");
const ALIGN = 1 << 0;
const MEMINFO = 1 << 1;
const MAGIC = 0x1BADB002;
const FLAGS = ALIGN | MEMINFO;
const MultibootHeader = packed struct {
magic: i32 = MAGIC,
flags: i32,
checksum: i32,
};
export var multiboot align(4) linksection(".multiboot") = MultibootHeader{
.flags = FLAGS,
.checksum = -(MAGIC + FLAGS),
};
export var stack_bytes: [16 * 1024]u8 align(16) linksection(".bss") = undefined;
const stack_bytes_slice = stack_bytes[0..];
export fn _start() callconv(.Naked) noreturn {
@call(.auto, kmain, .{});
//kmain();
while (true) {}
}
fn kmain() void {
console.initialize();
console.puts("Hello world!");
}