feat: unify system status codes

programs/include/Api/Syscall.hpp

@@ -7,6 +7,7 @@
 #pragma once
 #include <cstdint>
 #include <cstddef>
+#include <montauk/statuscodes.h>
 
 namespace montauk::abi {
 
@@ -312,6 +313,9 @@ namespace montauk::abi {
     static_assert((CAP_ADMIN_SESSION & CAP_COMPOSITOR) == 0,
                   "a session must not delegate the compositor's authority; "
                   "login grants it to the desktop directly");
+    // Capability denial for the Wi-Fi and USB syscalls only, which keep their
+    // own WIFI_ERR_* / USB_ERR_* spaces; everything else returns
+    // CapabilityDenied from StatusCodes.
     static constexpr int SYS_ERR_PERMISSION = -13;
 
     // A process holds two independent sets: what it may use (effective) and

programs/include/libc/montauk.h

@@ -219,6 +219,27 @@ extern "C" {
 #define MTK_SYS_CONSENT_REPLY      193
 /* @SYSCALLS-END */
 
+/* Syscall status codes (montauk/statuscodes.h for C++). */
+/* @STATUS-BEGIN
+   Generated from Common/StatusCodes.hpp by scripts/montauk-syscalls.py.
+   Do not edit by hand; run 'make gen-syscalls' to refresh. */
+#define MTK_STATUS_SUCCESS                (0)
+#define MTK_STATUS_GENERIC_FAILURE        (-1)
+#define MTK_STATUS_PERMISSION_DENIED      (-2)
+#define MTK_STATUS_CAPABILITY_DENIED      (-3)
+#define MTK_STATUS_SYSTEM_INTEGRITY_ERROR (-4)
+#define MTK_STATUS_BAD_POINTER            (-5)
+#define MTK_STATUS_INVALID_ARGUMENT       (-6)
+#define MTK_STATUS_UNSUPPORTED_OP         (-7)
+#define MTK_STATUS_NO_DEVICE              (-8)
+#define MTK_STATUS_IO_FAILURE             (-9)
+#define MTK_STATUS_BAD_INVOCATION         (-10)
+#define MTK_STATUS_NO_SUCH_PATH           (-11)
+#define MTK_STATUS_BUSY                   (-12)
+#define MTK_STATUS_BUFFER_TOO_SMALL       (-13)
+#define MTK_STATUS_OUT_OF_MEMORY          (-14)
+/* @STATUS-END */
+
 #define MTK_SOCK_TCP 1
 #define MTK_SOCK_UDP 2
 #define MTK_IPC_SIGNAL_READABLE    (1u << 0)

programs/include/montauk/statuscodes.h

@@ -0,0 +1,35 @@
+/*
+    * statuscodes.h
+    * MontaukOS status codes
+    * Copyright (c) 2026 Daniel Hammer
+*/
+
+#pragma once
+
+// Userspace mirror of kernel/src/Common/StatusCodes.hpp. Also usable from C
+// (the libc includes it), where the enumerators are unqualified.
+#ifdef __cplusplus
+namespace montauk {
+#endif
+
+enum StatusCodes {
+    Success = 0,
+    GenericFailure = -1,
+    PermissionDenied = -2,
+    CapabilityDenied = -3,
+    SystemIntegrityError = -4,
+    BadPointer = -5,
+    InvalidArgument = -6,
+    UnsupportedOp = -7,
+    NoDevice = -8,
+    IoFailure = -9,
+    BadInvocation = -10,
+    NoSuchPath = -11,
+    Busy = -12,
+    BufferTooSmall = -13,
+    OutOfMemory = -14
+};
+
+#ifdef __cplusplus
+}
+#endif

programs/include/montauk/syscall.h

@@ -6,6 +6,7 @@
 
 #pragma once
 #include <Api/Syscall.hpp>
+#include <montauk/statuscodes.h>
 
 namespace montauk {