feat: add RTL-SDR, R820t drivers, radio APIs, and sdr demo tool

kernel/src/Api/Sdr.hpp

@@ -0,0 +1,55 @@
+/*
+    * Sdr.hpp
+    * Software-defined radio receive syscalls.
+    * SYS_SDR_COUNT / INFO / OPEN / CLOSE / START / STOP / READ / SETPARAM / GETPARAM
+    * Thin syscall layer over the generic SDR subsystem (Drivers::Radio::Sdr).
+    * Copyright (c) 2026 Daniel Hammer
+*/
+
+#pragma once
+#include <cstdint>
+#include <Drivers/Radio/Sdr.hpp>
+
+#include "Syscall.hpp"
+
+namespace montauk::abi {
+
+    static int64_t Sys_SdrCount() {
+        return (int64_t)Drivers::Radio::Sdr::Count();
+    }
+
+    static int64_t Sys_SdrInfo(int index, SdrDeviceInfo* out) {
+        if (!out) return -1;
+        return Drivers::Radio::Sdr::GetInfo(index, out) ? 0 : -1;
+    }
+
+    static int64_t Sys_SdrOpen(int index) {
+        return (int64_t)Drivers::Radio::Sdr::Open(index);
+    }
+
+    static int64_t Sys_SdrClose(int handle) {
+        return (int64_t)Drivers::Radio::Sdr::Close(handle);
+    }
+
+    static int64_t Sys_SdrStart(int handle) {
+        return (int64_t)Drivers::Radio::Sdr::Start(handle);
+    }
+
+    static int64_t Sys_SdrStop(int handle) {
+        return (int64_t)Drivers::Radio::Sdr::Stop(handle);
+    }
+
+    static int64_t Sys_SdrRead(int handle, uint8_t* buf, uint32_t len) {
+        if (!buf) return -1;
+        return (int64_t)Drivers::Radio::Sdr::Read(handle, buf, len);
+    }
+
+    static int64_t Sys_SdrSetParam(int handle, int param, uint64_t value) {
+        return (int64_t)Drivers::Radio::Sdr::SetParam(handle, param, value);
+    }
+
+    static int64_t Sys_SdrGetParam(int handle, int param) {
+        return (int64_t)Drivers::Radio::Sdr::GetParam(handle, param);
+    }
+
+}