Implement setsys(Get/Set)DeviceNickname.

Thanks to @shchmue & @thog for tips on the send/recv buffers!

nx/include/switch/services/set.h

@@ -175,3 +175,15 @@ Result setsysBindFatalDirtyFlagEvent(Event *out);
  * @param flags_1 Pointer to populate with second 64 flags.
  */
 Result setsysGetFatalDirtyFlags(u64 *flags_0, u64 *flags_1);
+
+/**
+ * @brief Gets the system's nickname.
+ * @param buffer Pointer to output the nickname to. (The buffer size needs to be at least 0x80 bytes)
+ */
+Result setsysGetDeviceNickname(char* buffer);
+
+/**
+ * @brief Sets the system's nickname.
+ * @param buffer Pointer to read the nickname from.
+ */
+Result setsysSetDeviceNickname(char* buffer);

nx/source/services/set.c

@@ -686,3 +686,69 @@ Result setsysGetFatalDirtyFlags(u64 *flags_0, u64 *flags_1) {
 
     return rc;
 }
+
+Result setsysGetDeviceNickname(char* buffer) {
+    IpcCommand c;
+    ipcInitialize(&c);
+
+    ipcAddRecvBuffer(&c, buffer, 0x80, BufferType_Normal);
+ 
+    struct {
+        u64 magic;
+        u64 cmd_id;
+    } *raw;
+
+    raw = ipcPrepareHeader(&c, sizeof(*raw));
+
+    raw->magic = SFCI_MAGIC;
+    raw->cmd_id = 77;
+    
+    Result rc = serviceIpcDispatch(&g_setsysSrv);
+
+    if (R_SUCCEEDED(rc)) {
+        IpcParsedCommand r;
+        ipcParse(&r);
+
+        struct {
+            u64 magic;
+            u64 result;
+        } *resp = r.Raw;
+
+        rc = resp->result;
+    }
+
+    return rc;
+}
+
+Result setsysSetDeviceNickname(char* buffer) {
+    IpcCommand c;
+    ipcInitialize(&c);
+
+    ipcAddSendBuffer(&c, buffer, 0x80, BufferType_Normal);
+
+    struct {
+        u64 magic;
+        u64 cmd_id;
+    } *raw;
+
+    raw = ipcPrepareHeader(&c, sizeof(*raw));
+
+    raw->magic = SFCI_MAGIC;
+    raw->cmd_id = 78;
+
+    Result rc = serviceIpcDispatch(&g_setsysSrv);
+
+    if (R_SUCCEEDED(rc)) {
+        IpcParsedCommand r;
+        ipcParse(&r);
+
+        struct {
+            u64 magic;
+            u64 result;
+        } *resp = r.Raw;
+
+        rc = resp->result;
+    }
+
+    return rc;
+}