66 lines
1.6 KiB
Zig
66 lines
1.6 KiB
Zig
const std = @import("std");
|
|
|
|
const Allocator = std.mem.Allocator;
|
|
const Self = @This();
|
|
|
|
title: [12]u8,
|
|
buf: []u8,
|
|
alloc: Allocator,
|
|
|
|
const log = std.log.scoped(.GamePak);
|
|
|
|
pub fn init(alloc: Allocator, path: []const u8) !Self {
|
|
const file = try std.fs.cwd().openFile(path, .{});
|
|
defer file.close();
|
|
|
|
const len = try file.getEndPos();
|
|
const buf = try file.readToEndAlloc(alloc, len);
|
|
const title = parseTitle(buf);
|
|
|
|
const pak = Self{ .buf = buf, .alloc = alloc, .title = title };
|
|
pak.parseHeader();
|
|
|
|
return pak;
|
|
}
|
|
|
|
fn parseHeader(self: *const Self) void {
|
|
const title = parseTitle(self.buf);
|
|
const code = self.buf[0xAC..0xB0];
|
|
const maker = self.buf[0xB0..0xB2];
|
|
const version = self.buf[0xBC];
|
|
|
|
log.info("Title: {s}", .{title});
|
|
if (version != 0) log.info("Version: {}", .{version});
|
|
log.info("Game Code: {s}", .{code});
|
|
if (lookupMaker(maker)) |c| log.info("Maker Code: {s}", .{c}) else log.info("Maker: {s}", .{maker});
|
|
}
|
|
|
|
fn parseTitle(buf: []u8) [12]u8 {
|
|
return buf[0xA0..0xAC].*;
|
|
}
|
|
|
|
fn lookupMaker(slice: *const [2]u8) ?[]const u8 {
|
|
const num = @as(u16, slice[1]) << 8 | @as(u16, slice[0]);
|
|
|
|
return switch (num) {
|
|
0x3130 => "Nintendo",
|
|
else => null,
|
|
};
|
|
}
|
|
|
|
pub fn deinit(self: Self) void {
|
|
self.alloc.free(self.buf);
|
|
}
|
|
|
|
pub fn get32(self: *const Self, idx: usize) u32 {
|
|
return (@as(u32, self.get16(idx + 2)) << 16) | @as(u32, self.get16(idx));
|
|
}
|
|
|
|
pub fn get16(self: *const Self, idx: usize) u16 {
|
|
return (@as(u16, self.buf[idx + 1]) << 8) | @as(u16, self.buf[idx]);
|
|
}
|
|
|
|
pub fn get8(self: *const Self, idx: usize) u8 {
|
|
return self.buf[idx];
|
|
}
|