feat: initial commit

some basic ROMs already boot (ARM946E-S only), working on Armwrestler
and Rockwrestler next so I can ensure CPU compatability for but ARMv5TE
and ARMv4T

src/main.zig

@@ -0,0 +1,77 @@
+const std = @import("std");
+const clap = @import("zig-clap");
+
+const nds9 = @import("core/nds9.zig");
+const nds7 = @import("core/nds7.zig");
+const emu = @import("core/emu.zig");
+
+const IBus = @import("arm32").Bus;
+const IScheduler = @import("arm32").Scheduler;
+const Ui = @import("platform.zig").Ui;
+const SharedIo = @import("core/io.zig").Io;
+
+const Allocator = std.mem.Allocator;
+const ClapResult = clap.Result(clap.Help, &cli_params, clap.parsers.default);
+
+const cli_params = clap.parseParamsComptime(
+    \\-h, --help        Display this help and exit.
+    \\<str>             Path to the NDS ROM
+    \\
+);
+
+pub fn main() !void {
+    const log = std.log.scoped(.main);
+
+    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    defer std.debug.assert(gpa.deinit() == .ok);
+
+    const allocator = gpa.allocator();
+
+    const result = try clap.parse(clap.Help, &cli_params, clap.parsers.default, .{});
+    defer result.deinit();
+
+    const rom_path = try handlePositional(result);
+    log.debug("loading rom from: {s}", .{rom_path});
+
+    const rom_file = try std.fs.cwd().openFile(rom_path, .{});
+    defer rom_file.close();
+
+    // FIXME: Perf win to allocating on the stack instead?
+    const shared_io = try allocator.create(SharedIo);
+    defer allocator.destroy(shared_io);
+    shared_io.* = .{};
+
+    const nds9_group: nds9.Group = blk: {
+        var scheduler = try nds9.Scheduler.init(allocator);
+        var bus = try nds9.Bus.init(allocator, &scheduler, shared_io);
+        var arm946es = nds9.Arm946es.init(IScheduler.init(&scheduler), IBus.init(&bus));
+
+        break :blk .{ .cpu = &arm946es, .bus = &bus, .scheduler = &scheduler };
+    };
+    defer nds9_group.deinit(allocator);
+
+    const nds7_group: nds7.Group = blk: {
+        var scheduler = try nds7.Scheduler.init(allocator);
+        var bus = try nds7.Bus.init(allocator, &scheduler, shared_io);
+        var arm7tdmi = nds7.Arm7tdmi.init(IScheduler.init(&scheduler), IBus.init(&bus));
+
+        break :blk .{ .cpu = &arm7tdmi, .bus = &bus, .scheduler = &scheduler };
+    };
+    defer nds7_group.deinit(allocator);
+
+    const rom_title = try emu.load(allocator, nds7_group, nds9_group, rom_file);
+
+    var ui = try Ui.init(allocator);
+    defer ui.deinit(allocator);
+
+    ui.setTitle(rom_title);
+    try ui.run(nds7_group, nds9_group);
+}
+
+fn handlePositional(result: ClapResult) ![]const u8 {
+    return switch (result.positionals.len) {
+        0 => error.too_few_positional_arguments,
+        1 => result.positionals[0],
+        else => return error.too_many_positional_arguments,
+    };
+}