fuzzy: simple syscall fuzzing tool

Cargo.lock

@@ -2638,6 +2638,70 @@ dependencies = [
  "yggdrasil-abi",
 ]
 
+[[package]]
+name = "ygg_driver_bsp_arm"
+version = "0.1.0"
+dependencies = [
+ "bytemuck",
+ "device-api",
+ "device-tree",
+ "libk",
+ "libk-mm",
+ "libk-util",
+ "log",
+ "tock-registers",
+ "yggdrasil-abi",
+]
+
+[[package]]
+name = "ygg_driver_bsp_bcm283x"
+version = "0.1.0"
+dependencies = [
+ "bytemuck",
+ "device-api",
+ "device-tree",
+ "futures-util",
+ "kernel-arch-aarch64",
+ "libk",
+ "libk-mm",
+ "libk-util",
+ "log",
+ "tock-registers",
+ "yggdrasil-abi",
+]
+
+[[package]]
+name = "ygg_driver_bsp_jh7110"
+version = "0.1.0"
+dependencies = [
+ "bytemuck",
+ "device-api",
+ "device-tree",
+ "futures-util",
+ "libk",
+ "libk-mm",
+ "libk-util",
+ "log",
+ "tock-registers",
+ "yggdrasil-abi",
+]
+
+[[package]]
+name = "ygg_driver_bsp_riscv"
+version = "0.1.0"
+dependencies = [
+ "bytemuck",
+ "device-api",
+ "device-tree",
+ "kernel-arch-riscv64",
+ "libk",
+ "libk-mm",
+ "libk-util",
+ "log",
+ "tock-registers",
+ "yggdrasil-abi",
+]
+
 [[package]]
 name = "ygg_driver_fat32"
 version = "0.1.0"
@@ -2951,6 +3015,10 @@ dependencies = [
  "yboot-proto",
  "ygg_driver_acpi",
  "ygg_driver_ahci",
+ "ygg_driver_bsp_arm",
+ "ygg_driver_bsp_bcm283x",
+ "ygg_driver_bsp_jh7110",
+ "ygg_driver_bsp_riscv",
  "ygg_driver_fat32",
  "ygg_driver_input",
  "ygg_driver_net_core",

kernel/Cargo.toml

@@ -56,11 +56,16 @@ git-version = "0.3.9"
 aarch64-cpu.workspace = true
 device-tree.workspace = true
 kernel-arch-aarch64.workspace = true
+ygg_driver_bsp_arm.path = "driver/bsp/arm"
+ygg_driver_bsp_bcm283x.path = "driver/bsp/bcm283x"
 
 [target.'cfg(target_arch = "riscv64")'.dependencies]
 device-tree.workspace = true
 kernel-arch-riscv64.workspace = true
+ygg_driver_bsp_arm.path = "driver/bsp/arm"  # PrimeCell components
+ygg_driver_bsp_riscv.path = "driver/bsp/riscv"
 ygg_driver_net_stmmac.path = "driver/net/stmmac"
+ygg_driver_bsp_jh7110.path = "driver/bsp/jh7110"
 
 [target.'cfg(target_arch = "x86_64")'.dependencies]
 yboot-proto.workspace = true
@@ -87,7 +92,11 @@ kernel-arch-aarch64.workspace = true
 kernel-arch-riscv64.workspace = true
 
 ygg_driver_acpi.path = "driver/acpi"
+ygg_driver_bsp_arm.path = "driver/bsp/arm"
+ygg_driver_bsp_riscv.path = "driver/bsp/riscv"
 ygg_driver_net_stmmac.path = "driver/net/stmmac"
+ygg_driver_bsp_bcm283x.path = "driver/bsp/bcm283x"
+ygg_driver_bsp_jh7110.path = "driver/bsp/jh7110"
 
 [features]
 default = ["fb_console"]

kernel/arch/riscv64/src/lib.rs

@@ -44,6 +44,7 @@ pub struct PerCpuData {
 }
 
 pub static CPU_COUNT: AtomicUsize = AtomicUsize::new(1);
+pub static mut BOOT_HART_ID: u64 = 0;
 static IPI_QUEUES: OneTimeInit<Vec<IpiQueue<ArchitectureImpl>>> = OneTimeInit::new();
 static HART_TO_QUEUE: IrqSafeSpinlock<ArchitectureImpl, BTreeMap<u32, usize>> =
     IrqSafeSpinlock::new(BTreeMap::new());
@@ -60,6 +61,11 @@ impl CpuData for PerCpuData {
     }
 }
 
+/// Returns the ID of the bootstrap HART
+pub fn boot_hart_id() -> u64 {
+    unsafe { BOOT_HART_ID }
+}
+
 #[unsafe(naked)]
 extern "C" fn idle_task(_: usize) -> ! {
     core::arch::naked_asm!("1: nop; j 1b");

kernel/driver/bsp/arm/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "ygg_driver_bsp_arm"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+device-tree.workspace = true
+device-api.workspace = true
+yggdrasil-abi.workspace = true
+libk-mm.workspace = true
+libk-util.workspace = true
+libk.workspace = true
+
+tock-registers.workspace = true
+log.workspace = true
+bytemuck.workspace = true

kernel/driver/bsp/arm/src/lib.rs

@@ -0,0 +1,7 @@
+#![allow(unsafe_op_in_unsafe_fn)]
+#![no_std]
+
+extern crate alloc;
+
+mod pl011;
+mod pl061;

kernel/driver/bsp/arm/src/pl011.rs

@@ -1,5 +1,3 @@
-//! ARM PL011 driver
-use abi::{error::Error, io::TerminalOptions};
 use alloc::sync::Arc;
 use device_api::{
     device::{Device, DeviceInitContext},
@@ -18,6 +16,7 @@ use tock_registers::{
     register_bitfields, register_structs,
     registers::{ReadOnly, ReadWrite, WriteOnly},
 };
+use yggdrasil_abi::{error::Error, io::TerminalOptions};
 
 register_bitfields! {
     u32,

kernel/driver/bsp/arm/src/pl061.rs

@@ -1,6 +1,5 @@
 use core::sync::atomic::{AtomicU64, Ordering};
 
-use abi::error::Error;
 use alloc::{sync::Arc, vec::Vec};
 use device_api::{
     clock::{ClockHandle, ResetHandle},
@@ -26,6 +25,7 @@ use tock_registers::{
     register_structs,
     registers::{ReadOnly, ReadWrite, WriteOnly},
 };
+use yggdrasil_abi::error::Error;
 
 register_structs! {
     #[allow(non_snake_case)]

kernel/driver/bsp/bcm283x/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "ygg_driver_bsp_bcm283x"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+device-tree.workspace = true
+device-api.workspace = true
+yggdrasil-abi.workspace = true
+libk-mm.workspace = true
+libk-util.workspace = true
+libk.workspace = true
+kernel-arch-aarch64.workspace = true
+
+tock-registers.workspace = true
+log.workspace = true
+bytemuck.workspace = true
+futures-util.workspace = true

kernel/driver/bsp/bcm283x/src/aux.rs

@@ -1,6 +1,3 @@
-//! BCM283x AUX peripheral
-use aarch64_cpu::registers::ReadWriteable;
-use abi::error::Error;
 use alloc::sync::Arc;
 use device_api::{
     clock::{ClockController, ClockHandle},
@@ -13,9 +10,11 @@ use device_tree::{
 use libk_mm::{address::PhysicalAddress, device::DeviceMemoryIo};
 use libk_util::{sync::IrqSafeSpinlock, OneTimeInit};
 use tock_registers::{
+    interfaces::ReadWriteable,
     register_bitfields, register_structs,
     registers::{ReadOnly, ReadWrite},
 };
+use yggdrasil_abi::error::Error;
 
 register_bitfields! {
     u32,

kernel/driver/bsp/bcm283x/src/aux_uart.rs

@@ -1,9 +1,3 @@
-//! Broadcom BCM2835 mini-UART driver
-
-use abi::{
-    error::Error,
-    io::{TerminalOptions, TerminalOutputOptions},
-};
 use alloc::sync::Arc;
 use device_api::{
     clock::ClockHandle,
@@ -23,6 +17,10 @@ use tock_registers::{
     register_bitfields, register_structs,
     registers::{ReadOnly, ReadWrite},
 };
+use yggdrasil_abi::{
+    error::Error,
+    io::{TerminalOptions, TerminalOutputOptions},
+};
 
 register_bitfields! {
     u32,

kernel/driver/bsp/bcm283x/src/gpio.rs

@@ -1,4 +1,3 @@
-use abi::error::Error;
 use alloc::sync::Arc;
 use device_api::{
     device::{Device, DeviceInitContext},
@@ -20,6 +19,7 @@ use tock_registers::{
     register_structs,
     registers::{ReadOnly, ReadWrite, WriteOnly},
 };
+use yggdrasil_abi::error::Error;
 
 const PUPD_NONE: u32 = 0b00;
 

kernel/driver/bsp/bcm283x/src/lib.rs

@@ -0,0 +1,8 @@
+#![no_std]
+
+extern crate alloc;
+
+mod aux;
+mod aux_uart;
+mod gpio;
+mod mbox;

kernel/driver/bsp/bcm283x/src/mbox.rs

@@ -1,8 +1,5 @@
-#![allow(missing_docs)]
-
 use core::{cell::UnsafeCell, mem::MaybeUninit};
 
-use abi::error::Error;
 use alloc::sync::Arc;
 use device_api::device::{Device, DeviceInitContext};
 use device_tree::driver::{device_tree_driver, Node, ProbeContext};
@@ -25,6 +22,7 @@ use tock_registers::{
     register_bitfields, register_structs,
     registers::{ReadOnly, ReadWrite, WriteOnly},
 };
+use yggdrasil_abi::error::Error;
 
 register_bitfields! {
     u32,

kernel/driver/bsp/jh7110/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "ygg_driver_bsp_jh7110"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+device-tree.workspace = true
+device-api.workspace = true
+yggdrasil-abi.workspace = true
+libk-mm.workspace = true
+libk-util.workspace = true
+libk.workspace = true
+
+tock-registers.workspace = true
+log.workspace = true
+bytemuck.workspace = true
+futures-util.workspace = true

kernel/driver/bsp/jh7110/src/clocks.rs

@@ -1,8 +1,5 @@
-//! StarFive JH7110 clock drivers
-
 use core::{marker::PhantomData, ops::Index};
 
-use abi::error::Error;
 use alloc::sync::Arc;
 use device_api::{
     clock::{ClockController, ClockHandle, Hertz, ResetController, ResetHandle},
@@ -17,6 +14,7 @@ use device_tree::{
 };
 use libk_mm::{address::PhysicalAddress, device::DeviceMemoryIoMut};
 use libk_util::sync::IrqSafeSpinlock;
+use yggdrasil_abi::error::Error;
 
 // SYSCRG clocks
 

kernel/driver/bsp/jh7110/src/lib.rs

@@ -0,0 +1,7 @@
+#![allow(unsafe_op_in_unsafe_fn)]
+#![no_std]
+
+extern crate alloc;
+
+mod clocks;
+mod pinctrl;

kernel/driver/bsp/jh7110/src/pinctrl.rs

@@ -1,4 +1,3 @@
-use abi::error::Error;
 use alloc::{sync::Arc, vec::Vec};
 use device_api::{
     clock::{ClockHandle, ResetHandle},
@@ -18,6 +17,7 @@ use device_tree::{
 };
 use libk_mm::{address::PhysicalAddress, device::DeviceMemoryIoMut};
 use libk_util::{bit::BitField, sync::IrqSafeSpinlock, OneTimeInit};
+use yggdrasil_abi::error::Error;
 
 #[derive(Debug)]
 struct PinMuxConfig {

kernel/driver/bsp/riscv/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "ygg_driver_bsp_riscv"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+device-tree.workspace = true
+device-api.workspace = true
+yggdrasil-abi.workspace = true
+libk-mm.workspace = true
+libk-util.workspace = true
+libk.workspace = true
+kernel-arch-riscv64.workspace = true
+
+tock-registers.workspace = true
+log.workspace = true
+bytemuck.workspace = true

kernel/driver/bsp/riscv/src/lib.rs

@@ -0,0 +1,6 @@
+#![allow(unsafe_op_in_unsafe_fn)]
+#![no_std]
+
+extern crate alloc;
+
+mod plic;

kernel/driver/bsp/riscv/src/plic.rs

@@ -1,6 +1,3 @@
-//! RISC-V PLIC driver
-
-use abi::{error::Error, primitive_enum};
 use alloc::{sync::Arc, vec::Vec};
 use device_api::{
     device::{Device, DeviceInitContext},
@@ -15,6 +12,7 @@ use device_tree::{
     },
     DeviceTreePropertyRead, TProp,
 };
+use kernel_arch_riscv64::boot_hart_id;
 use libk::{arch::Cpu, device::register_external_interrupt_controller};
 use libk_mm::{address::PhysicalAddress, device::DeviceMemoryIo};
 use libk_util::{sync::spin_rwlock::IrqSafeRwLock, OneTimeInit};
@@ -23,8 +21,7 @@ use tock_registers::{
     register_structs,
     registers::{ReadOnly, ReadWrite},
 };
-
-use crate::arch::riscv64::boot::boot_hart_id;
+use yggdrasil_abi::{error::Error, primitive_enum};
 
 const MAX_IRQS: usize = 1024;
 

kernel/libk/src/task/mem.rs

@@ -243,7 +243,7 @@ fn validate_user_align_size(addr: usize, layout: &Layout) -> Result<(), Error> {
         return Err(Error::InvalidArgument);
     }
     if addr + layout.size() > KERNEL_VIRT_OFFSET {
-        todo!();
+        return Err(Error::InvalidArgument);
     }
 
     Ok(())

kernel/src/arch/riscv64/boot/mod.rs

@@ -7,7 +7,7 @@ use core::{
 
 use elf::{abi, relocation::Elf64_Rela};
 use kernel_arch::{Architecture, ArchitectureImpl};
-use kernel_arch_riscv64::{mem, CPU_COUNT};
+use kernel_arch_riscv64::{mem, BOOT_HART_ID, CPU_COUNT};
 use libk::{
     debug,
     fs::{devfs, sysfs},
@@ -28,7 +28,6 @@ const BOOT_STACK_SIZE: usize = 65536;
 
 static mut KERNEL_LOAD_BASE: u64 = 0;
 static mut DTB_ADDRESS: PhysicalAddress = PhysicalAddress::ZERO;
-static mut BOOT_HART_ID: u64 = 0;
 static mut BOOT_STACK: BootStack<BOOT_STACK_SIZE> = BootStack::zeroed();
 
 #[repr(C, align(0x10))]
@@ -58,11 +57,6 @@ unsafe extern "C" fn relocate_kernel(image_base: i64, rela_start: usize, rela_en
     }
 }
 
-/// Returns the ID of the bootstrap HART
-pub fn boot_hart_id() -> u64 {
-    unsafe { BOOT_HART_ID }
-}
-
 unsafe fn long_jump(pc: usize, sp: usize, a0: usize) -> ! {
     core::arch::asm!("mv sp, {sp}; jr {pc}", in("a0") a0, sp = in(reg) sp, pc = in(reg) pc, options(noreturn))
 }

kernel/src/arch/riscv64/smp.rs

@@ -6,7 +6,7 @@ use abi::error::Error;
 use device_api::interrupt::{IpiDeliveryTarget, IpiMessage};
 use device_tree::{DeviceTree, DeviceTreeNodeExt};
 use kernel_arch_riscv64::{
-    mem::auto_lower_address, registers::SIP, sbi, ArchitectureImpl, CPU_COUNT,
+    boot_hart_id, mem::auto_lower_address, registers::SIP, sbi, ArchitectureImpl, CPU_COUNT,
 };
 use libk::arch::Cpu;
 use libk_mm::{
@@ -15,7 +15,7 @@ use libk_mm::{
 };
 use tock_registers::interfaces::ReadWriteable;
 
-use crate::{arch::riscv64::boot::boot_hart_id, panic};
+use crate::panic;
 
 #[allow(missing_docs)]
 pub const SECONDARY_STACK_SIZE: usize = 32768;

kernel/src/device/clock/mod.rs

@@ -1,10 +1,4 @@
 //! Clock controller drivers
 
-#[cfg(any(target_arch = "aarch64", rust_analyzer))]
-pub mod bcm2835_aux;
-
-#[cfg(any(target_arch = "riscv64", rust_analyzer))]
-pub mod jh7110_clocks;
-
 #[cfg(any(target_arch = "aarch64", target_arch = "riscv64", rust_analyzer))]
 pub mod fixed;

kernel/src/device/interrupt/mod.rs

@@ -1,4 +0,0 @@
-//! Interrupt controller drivers
-
-#[cfg(any(target_arch = "riscv64", rust_analyzer))]
-pub mod riscv_plic;

kernel/src/device/mbox/mod.rs

@@ -1,4 +0,0 @@
-//! Mailbox interfaces
-
-#[cfg(any(rust_analyzer, target_arch = "aarch64"))]
-mod bcm2835_mbox;

kernel/src/device/mod.rs

@@ -6,13 +6,12 @@ use libk_util::OneTimeInit;
 pub mod bus;
 pub mod clock;
 pub mod display;
-pub mod gpio;
-pub mod interrupt;
-pub mod mbox;
-pub mod pinctrl;
 pub mod power;
 pub mod serial;
 // pub mod timer;
 
+#[cfg(any(rust_analyzer, not(target_arch = "x86_64")))]
+pub mod gpio;
+
 /// Generic machine description string
 pub static MACHINE_NAME: OneTimeInit<String> = OneTimeInit::new();

kernel/src/device/pinctrl/mod.rs

@@ -1,8 +0,0 @@
-//! GPIO/Pin controller, multiplexer drivers
-
-#[cfg(any(target_arch = "aarch64", rust_analyzer))]
-mod bcm2711_gpio;
-#[cfg(any(target_arch = "riscv64", rust_analyzer))]
-mod jh7110_pinctrl;
-#[cfg(any(target_arch = "aarch64", rust_analyzer))]
-mod pl061;

kernel/src/device/serial/mod.rs

@@ -1,11 +1,5 @@
 //! Serial device interfaces
 
-#[cfg(any(target_arch = "aarch64", rust_analyzer))]
-pub mod bcm2835_aux_uart;
-
-#[cfg(any(target_arch = "aarch64", rust_analyzer))]
-pub mod pl011;
-
 #[cfg(any(target_arch = "riscv64", rust_analyzer))]
 pub mod ns16550a;
 #[cfg(any(target_arch = "riscv64", rust_analyzer))]

kernel/src/main.rs

@@ -74,7 +74,13 @@ extern crate ygg_driver_virtio_net;
 cfg_if::cfg_if! {
     if #[cfg(target_arch = "x86_64")] {
         extern crate ygg_driver_net_igbe;
+    } else if #[cfg(target_arch = "aarch64")] {
+        extern crate ygg_driver_bsp_arm;
+        extern crate ygg_driver_bsp_bcm283x;
     } else if #[cfg(target_arch = "riscv64")] {
+        extern crate ygg_driver_bsp_riscv;
+        extern crate ygg_driver_bsp_jh7110;
+
         extern crate ygg_driver_net_stmmac;
     }
 }

lib/abi/def/process.abi

@@ -47,6 +47,8 @@ struct SpawnOptions<'a> {
     pub environment: &'a [&'a str],
     /// Working directory
     pub directory: Option<&'a str>,
+    /// Root path
+    pub root: Option<&'a str>,
     /// Optional arguments to specify details of the creation
     pub optional: &'a [SpawnOption],
     /// Extra flags controlling the new process behavior

userspace/Cargo.lock

@@ -901,6 +901,12 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "either"
+version = "1.15.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "48c757948c5ede0e46177b7add2e67155f70e33c07fea8284df6576da70b3719"
+
 [[package]]
 name = "elf"
 version = "0.7.4"
@@ -1089,6 +1095,15 @@ dependencies = [
  "slab",
 ]
 
+[[package]]
+name = "fuzzy"
+version = "0.1.0"
+dependencies = [
+ "itertools",
+ "rand",
+ "runtime",
+]
+
 [[package]]
 name = "generic-array"
 version = "0.14.7"
@@ -1410,6 +1425,15 @@ version = "1.70.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7943c866cc5cd64cbc25b2e01621d07fa8eb2a1a23160ee81ce38704e97b8ecf"
 
+[[package]]
+name = "itertools"
+version = "0.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b192c782037fadd9cfa75548310488aabdbf3d2da73885b31bd0abd03351285"
+dependencies = [
+ "either",
+]
+
 [[package]]
 name = "itoa"
 version = "1.0.15"

userspace/Cargo.toml

@@ -17,6 +17,7 @@ members = [
     "netutils",
     "sysutils",
     "tools/crypt",
+    "tools/fuzzy",
     "tools/init",
     "tools/md2txt",
     "tools/ntpc",

userspace/sysutils/Cargo.toml

@@ -41,6 +41,10 @@ path = "src/lib.rs"
 name = "mount"
 path = "src/mount.rs"
 
+[[bin]]
+name = "chroot"
+path = "src/chroot.rs"
+
 [[bin]]
 name = "login"
 path = "src/login.rs"

userspace/sysutils/src/chroot.rs

@@ -0,0 +1,23 @@
+use std::process::ExitCode;
+
+fn usage(cmd: &str) {
+    eprintln!("Usage: {cmd} PATH PROGRAM [ARGS...]");
+}
+
+fn main() -> ExitCode {
+    let mut args = std::env::args();
+    let cmd = args.next().unwrap();
+    let Some(path) = args.next() else {
+        usage(&cmd);
+        return ExitCode::FAILURE;
+    };
+    let Some(program) = args.next() else {
+        usage(&cmd);
+        return ExitCode::FAILURE;
+    };
+    let cmd_args = args.collect::<Vec<_>>();
+
+    println!("Run {program:?} at {path:?} with args {cmd_args:?}");
+
+    ExitCode::SUCCESS
+}

userspace/tools/fuzzy/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "fuzzy"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+itertools = "0.14.0"
+rand.workspace = true
+runtime.workspace = true
+
+[lints]
+workspace = true

userspace/tools/fuzzy/src/main.rs

@@ -0,0 +1,164 @@
+#![feature(rustc_private)]
+
+use itertools::Itertools;
+use rand::Rng;
+use runtime::abi::SyscallFunction;
+
+enum Argument {
+    Fd,
+    OptionFd,
+    Path,
+    AccessMode,
+    BytesRef,
+    BytesMut,
+    FileSize,
+    Enum(usize),
+    Number(usize, usize),
+}
+
+struct Definition {
+    name: &'static str,
+    number: usize,
+    args: &'static [Argument],
+}
+
+const fn syscall(
+    func: SyscallFunction,
+    name: &'static str,
+    args: &'static [Argument],
+) -> Definition {
+    Definition {
+        name,
+        number: func as _,
+        args,
+    }
+}
+
+const DEFS: &[Definition] = const {
+    use Argument::*;
+
+    &[
+        // syscall get_random(buffer: &mut [u8]);
+        syscall(SyscallFunction::GetRandom, "get_random", &[BytesMut]),
+        // syscall get_clock(clock: ClockType, out: &mut MaybeUninit<SystemTime>) -> Result<()>;
+        // syscall set_clock(clock: ClockType, value: &SystemTime) -> Result<()>;
+        // syscall mount(opts: &MountOptions<'_>) -> Result<()>;
+        // syscall unmount(opts: &UnmountOptions) -> Result<()>;
+        // syscall load_module(path: &str) -> Result<()>;
+
+        // syscall filesystem_control(fd: Option<RawFd>, option: u32, value: &mut [u8], len: usize) -> Result<usize>;
+        // syscall get_system_info(option: u32, value: &mut [u8]) -> Result<usize>;
+
+        // syscall open(at: Option<RawFd>, path: &str, opts: OpenOptions, mode: FileMode) -> Result<RawFd>;
+        syscall(SyscallFunction::Open, "open", &[OptionFd, Path, AccessMode]),
+        // syscall check_access(at: Option<RawFd>, path: &str, access: AccessMode) -> Result<()>;
+        syscall(
+            SyscallFunction::CheckAccess,
+            "check_access",
+            &[OptionFd, Path, AccessMode],
+        ),
+        // syscall close(fd: RawFd) -> Result<()>;
+        syscall(SyscallFunction::Close, "close", &[Fd]),
+        // syscall write(fd: RawFd, data: &[u8]) -> Result<usize>;
+        syscall(SyscallFunction::Write, "write", &[Fd, BytesRef]),
+        // syscall read(fd: RawFd, data: &mut [u8]) -> Result<usize>;
+        syscall(SyscallFunction::Read, "read", &[Fd, BytesMut]),
+        // syscall seek(fd: RawFd, pos: SeekFrom, output: &mut u64) -> Result<()>; TODO
+        // syscall truncate(fd: RawFd, size: u64) -> Result<()>;
+        syscall(SyscallFunction::Truncate, "truncate", &[Fd, FileSize]),
+        // syscall fsync(fd: RawFd, what: FileSync) -> Result<()>;
+        // syscall(SyscallFunction::Fsync, "fsync", &[Fd, Enum(123)]), TODO not implemented
+        // syscall read_at(fd: RawFd, pos: u64, data: &mut [u8]) -> Result<usize>;
+        syscall(
+            SyscallFunction::ReadAt,
+            "read_at",
+            &[Fd, FileSize, BytesMut],
+        ),
+        // syscall write_at(fd: RawFd, pos: u64, data: &[u8]) -> Result<usize>;
+        syscall(
+            SyscallFunction::WriteAt,
+            "write_at",
+            &[Fd, FileSize, BytesRef],
+        ),
+        // syscall get_file_option(fd: RawFd, option: u32, data: &mut [u8]) -> Result<usize>;
+        syscall(
+            SyscallFunction::GetFileOption,
+            "get_file_option",
+            &[Fd, Number(usize::MIN, usize::MAX), BytesMut],
+        ),
+        // syscall set_file_option(fd: RawFd, option: u32, data: &[u8]) -> Result<()>;
+        syscall(
+            SyscallFunction::SetFileOption,
+            "set_file_option",
+            &[Fd, Number(usize::MIN, usize::MAX), BytesRef],
+        ),
+    ]
+};
+
+fn generate_argument_variants(arg: &Argument) -> Vec<Vec<usize>> {
+    match arg {
+        Argument::Path | Argument::BytesRef => {
+            vec![vec![0, 0], vec![0, 123], vec![0xFFFFFF8012345678, 123]]
+        }
+        Argument::BytesMut => {
+            vec![
+                vec![0, 0],
+                vec![0, 123],
+                vec![0xFFFFFF8012345678, 123],
+                vec!["abcdef".as_ptr().addr(), 123],
+            ]
+        }
+        Argument::OptionFd | Argument::Fd => {
+            vec![vec![1234], vec![usize::MAX]]
+        }
+        Argument::AccessMode => {
+            vec![vec![0], vec![usize::MAX]]
+        }
+        Argument::FileSize => {
+            vec![vec![usize::MAX]]
+        }
+        &Argument::Enum(lower_bound) => {
+            vec![vec![lower_bound + 1], vec![usize::MAX]]
+        }
+        &Argument::Number(a, b) => (0..100)
+            .map(|_| rand::thread_rng().gen_range(a..b))
+            .map(|a| vec![a])
+            .collect(),
+    }
+}
+
+fn fuzz(def: &Definition) {
+    let argument_variants = def
+        .args
+        .iter()
+        .map(generate_argument_variants)
+        .multi_cartesian_product()
+        .map(|combo| combo.into_iter().flatten());
+
+    for variant in argument_variants {
+        let variant = variant.collect::<Vec<_>>();
+        println!("{}: {:x?}", def.name, variant);
+        let result = unsafe {
+            match variant.len() {
+                1 => runtime::rt::syscall!(def.number, variant[0]),
+                2 => runtime::rt::syscall!(def.number, variant[0], variant[1]),
+                3 => runtime::rt::syscall!(def.number, variant[0], variant[1], variant[2]),
+                4 => runtime::rt::syscall!(
+                    def.number, variant[0], variant[1], variant[2], variant[3]
+                ),
+                5 => runtime::rt::syscall!(
+                    def.number, variant[0], variant[1], variant[2], variant[3], variant[4]
+                ),
+                _ => unimplemented!(),
+            }
+        };
+
+        println!("  -> {:#x} ({})", result, result as isize);
+    }
+}
+
+fn main() {
+    for def in DEFS {
+        fuzz(def);
+    }
+}

xtask/src/build/userspace.rs

@@ -31,6 +31,7 @@ const PROGRAMS: &[(&str, &str)] = &[
     // sysutils
     ("echo", "bin/echo"),
     ("mount", "sbin/mount"),
+    ("chroot", "sbin/chroot"),
     ("login", "sbin/login"),
     ("strace", "bin/strace"),
     ("ls", "bin/ls"),
@@ -80,6 +81,7 @@ const PROGRAMS: &[(&str, &str)] = &[
     // crypt
     ("crypt", "bin/crypt"),
     ("dyn-loader", "libexec/dyn-loader"),
+    ("fuzzy", "sbin/fuzzy"),
     // TODO: proper process for C program builds
 ];