diff --git a/hw/mcu/st/cmsis_device_f0 b/hw/mcu/st/cmsis_device_f0
new file mode 160000
index 0000000000..2fc25ee222
--- /dev/null
+++ b/hw/mcu/st/cmsis_device_f0
@@ -0,0 +1 @@
+Subproject commit 2fc25ee22264bc27034358be0bd400b893ef837e
diff --git a/hw/mcu/st/cmsis_device_f3 b/hw/mcu/st/cmsis_device_f3
new file mode 160000
index 0000000000..5e4ee5ed7a
--- /dev/null
+++ b/hw/mcu/st/cmsis_device_f3
@@ -0,0 +1 @@
+Subproject commit 5e4ee5ed7a7b6c85176bb70a9fd3c72d6eb99f1b
diff --git a/hw/mcu/st/cmsis_device_g0 b/hw/mcu/st/cmsis_device_g0
new file mode 160000
index 0000000000..3a23e12244
--- /dev/null
+++ b/hw/mcu/st/cmsis_device_g0
@@ -0,0 +1 @@
+Subproject commit 3a23e1224417f3f2d00300ecd620495e363f2094
diff --git a/lib/FreeRTOS-Kernel b/lib/FreeRTOS-Kernel
new file mode 160000
index 0000000000..cc0e0707c0
--- /dev/null
+++ b/lib/FreeRTOS-Kernel
@@ -0,0 +1 @@
+Subproject commit cc0e0707c0c748713485b870bb980852b210877f
diff --git a/lib/lwip b/lib/lwip
new file mode 160000
index 0000000000..159e31b689
--- /dev/null
+++ b/lib/lwip
@@ -0,0 +1 @@
+Subproject commit 159e31b689577dbf69cf0683bbaffbd71fa5ee10
diff --git a/src/portable/raspberrypi/rp2040/dcd_rp2040.c b/src/portable/raspberrypi/rp2040/dcd_rp2040.c
index af08b549dc..b91dd38d5f 100644
--- a/src/portable/raspberrypi/rp2040/dcd_rp2040.c
+++ b/src/portable/raspberrypi/rp2040/dcd_rp2040.c
@@ -496,6 +496,12 @@ bool dcd_edpt_iso_alloc(uint8_t rhport, uint8_t ep_addr, uint16_t largest_packet
 bool dcd_edpt_iso_activate(uint8_t rhport, tusb_desc_endpoint_t const * ep_desc) {
   (void) rhport;
   const uint8_t ep_addr = ep_desc->bEndpointAddress;
+
+  // init w/o allocate
+  const uint16_t mps = ep_desc->wMaxPacketSize;
+  uint16_t size = (uint16_t)tu_div_ceil(mps, 64) * 64u;
+  hw_endpoint_init(ep_addr, size, TUSB_XFER_ISOCHRONOUS);
+
   // Fill in endpoint control register with buffer offset
   struct hw_endpoint* ep = hw_endpoint_get_by_addr(ep_addr);
   TU_ASSERT(ep->hw_data_buf != NULL); // must be inited and buffer allocated