diff --git a/.gitmodules b/.gitmodules
index 6681d35..ebe7b44 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -67,3 +67,6 @@
 [submodule "deps/pythondata-cpu-vexriscv_smp"]
 	path = deps/pythondata-cpu-vexriscv_smp
 	url = https://github.com/litex-hub/pythondata-cpu-vexriscv_smp.git
+[submodule "firmware/deps/tinyusb-sys-rs"]
+	path = firmware/deps/tinyusb-sys-rs
+	url = git@github.com:schnommus/tinyusb-sys-rs.git
diff --git a/firmware/deps/tinyusb-sys-rs b/firmware/deps/tinyusb-sys-rs
new file mode 160000
index 0000000..6f877c3
--- /dev/null
+++ b/firmware/deps/tinyusb-sys-rs
@@ -0,0 +1 @@
+Subproject commit 6f877c356f19728fd55ef3adc48c614275d7ec22
diff --git a/firmware/litex-fw/src/main.rs b/firmware/litex-fw/src/main.rs
index 18b1973..b570e13 100644
--- a/firmware/litex-fw/src/main.rs
+++ b/firmware/litex-fw/src/main.rs
@@ -17,7 +17,7 @@ use critical_section::Mutex;
 use irq::{handler, scope, scoped_interrupts};
 use litex_interrupt::return_as_is;
 
-use tinyusb_sys::tusb_init;
+use tinyusb_sys::{tusb_init, dcd_int_handler, tud_task};
 
 use ssd1322 as oled;
 
@@ -304,6 +304,21 @@ fn oled_init(timer: &mut Timer, oled_spi: pac::OLED_SPI)
     disp
 }
 
+#[no_mangle]
+pub extern "C" fn tud_dfu_get_timeout_cb(alt: u8, state: u8) -> u32 {
+    // TODO
+    0u32
+}
+
+#[no_mangle]
+pub extern "C" fn tud_dfu_download_cb(alt: u8, block_num: u16, data: *const u8, length: u16)  {
+    // TODO
+}
+
+#[no_mangle]
+pub extern "C" fn tud_dfu_manifest_cb(alt: u8)  {
+    // TODO
+}
 
 #[entry]
 fn main() -> ! {
@@ -336,6 +351,8 @@ fn main() -> ! {
 
     unsafe {
         tusb_init();
+        dcd_int_handler(0);
+        tud_task();
     }
 
     handler!(dma_router0 = || dma_router0_handler(&dma_router, &oscope));