bindings: Implement JNI bindings for librvvm

- Add a tiny portable JNI header to build JNI bindings in-tree
- Supports many RVVM API features, but no high-level wrappers yet

src/bindings/jni/lekkit/rvvm/RVVMNative.java

@@ -0,0 +1,106 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+package lekkit.rvvm;
+
+import java.nio.ByteBuffer;
+
+// Regenerate C prototypes: $ javac -h . RvvmJni.java
+
+public class RVVMNative {
+    // Do not crash the JVM if we failed to load native lib
+    public static boolean loaded = false;
+
+    // Manually load librvvm
+    public static boolean loadLib(String path) {
+        if (loaded) return true;
+        try {
+            System.load(path);
+            int abi = get_abi_version();
+            if (abi == 6) {
+                loaded = true;
+            } else {
+                System.out.println("ERROR: Invalid librvvm ABI version: " + Integer.toString(abi));
+            }
+        } catch (Throwable e) {
+            System.out.println("ERROR: Failed to load librvvm: " + e.toString());
+        }
+        return loaded;
+    }
+
+    static {
+        try {
+            System.loadLibrary("rvvm");
+            int abi = get_abi_version();
+            if (abi == 6) {
+                loaded = true;
+            } else {
+                System.out.println("ERROR: Invalid librvvm ABI version: " + Integer.toString(abi));
+            }
+        } catch (Throwable e) {
+            System.out.println("INFO: Failed to load system-wide librvvm: " + e.toString());
+        }
+    }
+
+    public static boolean isLoaded() {
+        return loaded;
+    }
+
+    public static final long DEFAULT_MEMBASE = 0x80000000L;
+
+    public static native int get_abi_version();
+
+    // Common RVVM API functions
+    public static native long       create_machine(long mem_base, long mem_size, int smp, boolean rv64);
+    public static native ByteBuffer get_dma_buf(long machine, long addr, long size);
+    public static native long       get_plic(long machine);
+    public static native void       set_plic(long machine, long plic);
+    public static native long       get_pci_bus(long machine);
+    public static native void       set_pci_bus(long machine, long pci_bus);
+    public static native long       get_i2c_bus(long machine);
+    public static native void       set_i2c_bus(long machine, long i2c_bus);
+    public static native void       set_cmdline(long machine, String cmdline);
+    public static native void       append_cmdline(long machine, String cmdline);
+    public static native long       get_opt(long machine, int opt);
+    public static native void       set_opt(long machine, int opt, long val);
+    public static native boolean    load_bootrom(long machine, String path);
+    public static native boolean    load_kernel(long machine, String path);
+    public static native boolean    load_dtb(long machine, String path);
+    public static native boolean    dump_dtb(long machine, String path);
+    public static native boolean    start_machine(long machine);
+    public static native boolean    pause_machine(long machine);
+    public static native boolean    reset_machine(long machine, boolean reset);
+    public static native boolean    machine_powered(long machine);
+    public static native void       free_machine(long machine);
+    public static native void       detach_mmio(long machine, int handle, boolean cleanup);
+    public static native void       run_eventloop();
+
+    // Devices
+    public static native void clint_init_auto(long machine);
+    public static native long plic_init_auto(long machine);
+    public static native long pci_bus_init_auto(long machine);
+    public static native long i2c_bus_init_auto(long machine);
+    public static native int  ns16550a_init_auto(long machine);
+    public static native int  rtc_goldfish_init_auto(long machine);
+    public static native int  syscon_init_auto(long machine);
+    public static native long rtl8169_init_auto(long machine);
+    public static native long nvme_init_auto(long machine, String image_path, boolean rw);
+    public static native int  mtd_physmap_init_auto(long machine, String image_path, boolean rw);
+    public static native int  framebuffer_init_auto(long machine, ByteBuffer fb, int x, int y, int bpp);
+    public static native long hid_mouse_init_auto(long machine);
+    public static native long hid_keyboard_init_auto(long machine);
+
+    public static native void pci_remove_device(long dev);
+
+    public static native void hid_mouse_place(long mouse, int x, int y);
+    public static native void hid_mouse_move(long mouse, int x, int y);
+    public static native void hid_mouse_press(long mouse, byte btns);
+    public static native void hid_mouse_release(long mouse, byte btns);
+    public static native void hid_mouse_scroll(long mouse, int offset);
+
+    public static native void hid_keyboard_press(long kb, byte key);
+    public static native void hid_keyboard_release(long kb, byte key);
+}