Zig-PSP

A project to bring Zig to the Sony PlayStation Portable

Why Zig on the PSP?

In the PSP programming community, many libraries, tools, and other features are written in C or C++, which as we know has its problems with writing clean, reusable, and high quality code. Given that the core objectives of Zig as a language are to allow us to create well-designed and reusable software, Zig seems like a perfect fit for integrating older PSP libraries while striving to develop higher quality software!

Special Thanks

Special thanks is given to the Rust-PSP team whose efforts influenced and helped to get this project off the ground. No harm is intended, and it’s thanks to you Rustaceans that fellow Ziguanas can program for the PSP.

Requirements

• Zig 0.16.0-dev nightly (see build.zig.zon for the exact fingerprint)

No legacy PSPSDK or external C toolchain is required. All build tools (zPRXGen, zSFOTool, zPBPTool) are written in Zig and built automatically.

Getting Started

1. Add pspsdk to your project

zig fetch --save=pspsdk git+https://github.com/zPSP-Dev/Zig-PSP

This adds the dependency to your build.zig.zon automatically.

2. Set up your build.zig

const std = @import("std");
const pspsdk = @import("pspsdk");

pub fn build(b: *std.Build) void {
    const optimize = b.standardOptimizeOption(.{});

    pspsdk.buildPspEboot(b, .{
        .name             = "my_app",
        .root_source_file = b.path("src/main.zig"),
        .title            = "My App Title",
        .optimize         = optimize,
    }, .{});
}

buildPspEboot runs the full pipeline (Zig -> ELF -> PRX -> SFO -> PBP) and installs the output to zig-out/bin/my_app/. Run zig build to produce EBOOT.PBP, app.prx, and app.elf.

Optional PBP asset fields are available on PspEbootOptions: .icon0, .icon1, .pic0, .pic1, .snd0 (all ?std.Build.LazyPath). The output directory defaults to the app name but can be overridden via PspOutputOptions.dir.

Lower-level API for engine/framework integration

If your build system needs to create and configure the executable itself (e.g. to attach engine modules or link additional dependencies), two lower-level functions are available:

• configurePspExecutable(exe) — applies PSP-specific settings (linker script, entry point, relocation emission) and adds the pspsdk module import to an existing executable.
• addEbootSteps(b, exe, options) — runs the ELF -> PRX -> SFO -> PBP pipeline on an existing PSP executable and optionally installs artifacts.

const std = @import("std");
const pspsdk = @import("pspsdk");

pub fn build(b: *std.Build) void {
    const optimize = b.standardOptimizeOption(.{});
    const psp_target = pspsdk.getPspTarget(b);

    const exe = b.addExecutable(.{
        .name = "main",
        .root_module = b.createModule(.{
            .root_source_file = b.path("src/main.zig"),
            .target = psp_target,
            .optimize = optimize,
            .strip = false,
            .imports = &.{
                .{ .name = "engine", .module = engine_mod },
            },
        }),
    });

    // Apply PSP build settings (linker script, entry point, pspsdk import)
    pspsdk.configurePspExecutable(exe);

    // Run the packaging pipeline and install artifacts
    _ = pspsdk.addEbootSteps(b, exe, .{
        .title = "My App",
        .output_dir = "my_app",
    });
}

buildPspEboot is implemented as a thin wrapper around these two functions and remains the recommended API for simple projects.

3. Write your app

Every PSP app needs a module_info comptime call and the panic handler override:

const std = @import("std");
const sdk = @import("pspsdk");

// Required: overrides the default panic handler which pulls in posix symbols.
pub const panic = sdk.extra.debug.panic;

// Required: routes std.debug.print through PSP I/O instead of posix.
pub const std_options_debug_threaded_io: ?*std.Io.Threaded = null;
pub const std_options_debug_io: std.Io = sdk.extra.Io.psp_io;
pub fn std_options_cwd() std.Io.Dir { return .{ .handle = -1 }; }

comptime {
    asm (sdk.extra.module.module_info("My App Name", .{ .mode = .User }, 1, 0));
}

pub fn main(_: std.process.Init) !void {
    sdk.extra.utils.enableHBCB();
    sdk.extra.debug.screenInit();

    sdk.extra.debug.print("Hello from Zig!", .{});
}

API Tiers

The SDK exposes PSP functions through two tiers:

Sub-namespaces: sdk.adhoc, sdk.atrac3, sdk.audio, sdk.audiocodec, sdk.ctrl, sdk.display, sdk.dmac, sdk.ge, sdk.gu, sdk.gum, sdk.hprm, sdk.http, sdk.impose, sdk.internal, sdk.io, sdk.jpeg, sdk.kermit, sdk.kernel, sdk.mp3, sdk.mpeg, sdk.net, sdk.openpsid, sdk.power, sdk.reg, sdk.rtc, sdk.ssl, sdk.umd, sdk.usb, sdk.usbcam, sdk.usbstor, sdk.utility, sdk.wlan.

The utility layer lives under sdk.extra: sdk.extra.debug, sdk.extra.module, sdk.extra.utils, sdk.extra.allocator, sdk.extra.vram, sdk.extra.Io, sdk.extra.constants, sdk.extra.net.

Building This Repository

# Build everything (tools + examples) -- default
zig build

# Build only the host tools (zPRXGen, zSFOTool, zPBPTool)
zig build tools

# Build only examples
zig build examples

# Build examples as a standalone sub-project (exercises the package API)
cd examples && zig build

Output lands in zig-out/bin/<name>/ with EBOOT.PBP, app.prx, and app.elf for each example.

Running on PSP

Copy the output to your memory stick:

PSP/GAME/MyAppName/EBOOT.PBP

The application will appear under Game -> Memory Stick in the XMB. Custom firmware (CFW) is required.

Examples

The repository includes the following examples:

std.Io Integration

Zig-PSP implements a PSP-native std.Io vtable, allowing standard library I/O to work transparently on the PSP. This includes std.debug.print, file and directory operations, process CWD, clocks, sleep, random number generation, and TCP/UDP networking — all routed through PSP syscalls (sceIo*, sceRtc*, sceKernelDelayThread, sceNetInet*, etc.).

To enable std.Io in your app, add these declarations:

pub const std_options_debug_threaded_io: ?*std.Io.Threaded = null;
pub const std_options_debug_io: std.Io = sdk.extra.Io.psp_io;

pub fn std_options_cwd() std.Io.Dir {
    return .{ .handle = -1 };
}

The vtable covers all 56 feasible functions (100%) — directory, file, time/random, stderr, process CWD, cancellation, and network support.

Networking

To use WiFi networking, initialize the stack with sdk.extra.net:

try sdk.extra.net.init();
defer sdk.extra.net.deinit();
try sdk.extra.net.connectToApctl(1, 30_000_000); // connect to saved network #1

After initialization, the std.Io network vtable functions (netConnectIp, netRead, netWrite, etc.) and raw sceNetInet* socket calls are both available. std.http.Client works out of the box for plain HTTP requests — see examples/http.zig.

HTTPS / TLS

PSP has no system CA certificate store, so std.http.Client cannot verify server certificates by default. To use HTTPS, embed the required root CA as a DER file and load it into the client’s CA bundle before making requests:

const root_ca_der = @embedFile("root_ca.der");

// ...after WiFi init:
const now = std.Io.Clock.real.now(io);
try http_client.ca_bundle.bytes.appendSlice(gpa, root_ca_der);
try http_client.ca_bundle.parseCert(gpa, 0, now.toSeconds());
http_client.now = now;

TLS crypto requires extra stack space — set pub const psp_stack_size: u32 = 512 * 1024; in your app. See examples/https.zig for a complete working example.

Comparisons To C/C++

Without the weight of the C standard library, Zig produces notably smaller PSP executables. LLVM is an excellent backend, and a simple Hello World in Zig comes in around 10 KB versus ~68 KB for an equivalent C program — roughly an 85% reduction in size.

Documentation

Auto-generated API docs are published at https://zpsp-dev.github.io/Zig-PSP/ and updated on every push to trunk.

PSP system calls are also documented in C. The Zig SDK types and wrappers closely mirror those names and signatures. Binding sources live in src/c/module/ (auto-generated — do not edit by hand) and src/sdk/ (idiomatic Zig wrappers).

Debugging

PSPLink (from the legacy PSPSDK) can be used for USB debugging and psp-gdb access. Zig’s own panic handler (sdk.extra.debug.panic) prints a backtrace to the screen, which is useful without a USB connection.