diff --git a/nx/Makefile b/nx/Makefile
index 2aed2ada..71ccaac2 100644
--- a/nx/Makefile
+++ b/nx/Makefile
@@ -24,7 +24,7 @@ VERSION	:=	$(LIBNX_MAJOR).$(LIBNX_MINOR).$(LIBNX_PATCH)
 #---------------------------------------------------------------------------------
 TARGET		:=	nx
 #BUILD		:=	build
-SOURCES		:=	source/system source/kernel source/services source/devices source/gfx
+SOURCES		:=	source/arm source/system source/kernel source/services source/gfx
 
 DATA		:=	data
 INCLUDES	:=	include
diff --git a/nx/include/switch.h b/nx/include/switch.h
index 8d485618..b1afb9f8 100644
--- a/nx/include/switch.h
+++ b/nx/include/switch.h
@@ -11,14 +11,15 @@ extern "C" {
 #include <switch/types.h>
 #include <switch/result.h>
 #include <switch/svc.h>
+#include <switch/arm.h>
 #include <switch/ipc.h>
-#include <switch/os.h>
 
 #include <switch/kernel/tmem.h>
 #include <switch/kernel/shmem.h>
 #include <switch/kernel/mutex.h>
 #include <switch/kernel/thread.h>
 #include <switch/kernel/virtmem.h>
+#include <switch/kernel/version.h>
 
 #include <switch/services/sm.h>
 #include <switch/services/fs.h>
@@ -30,8 +31,6 @@ extern "C" {
 #include <switch/services/hid.h>
 #include <switch/services/vi.h>
 
-#include <switch/devices/usb_dev.h>
-
 #include <switch/gfx/gfx.h>
 
 #ifdef __cplusplus
diff --git a/nx/include/switch/arm.h b/nx/include/switch/arm.h
new file mode 100644
index 00000000..9a429fef
--- /dev/null
+++ b/nx/include/switch/arm.h
@@ -0,0 +1,7 @@
+static inline void* armGetTls(void) {
+    void* ret;
+    __asm__ ("mrs %x[data], tpidrro_el0" : [data] "=r" (ret));
+    return ret;
+}
+
+void osDCacheFlush(void* addr, size_t size);
diff --git a/nx/include/switch/kernel/version.h b/nx/include/switch/kernel/version.h
new file mode 100644
index 00000000..a9844bc5
--- /dev/null
+++ b/nx/include/switch/kernel/version.h
@@ -0,0 +1,3 @@
+// Copyright 2017 plutoo
+bool kernelAbove200();
+bool kernelAbove300();
diff --git a/nx/include/switch/os.h b/nx/include/switch/os.h
deleted file mode 100644
index 2f6a8cc8..00000000
--- a/nx/include/switch/os.h
+++ /dev/null
@@ -1 +0,0 @@
-void osDCacheFlush(void* addr, size_t size);
diff --git a/nx/include/switch/svc.h b/nx/include/switch/svc.h
index d36f54dc..0206bad9 100644
--- a/nx/include/switch/svc.h
+++ b/nx/include/switch/svc.h
@@ -12,12 +12,6 @@
 /// Pseudo handle for the current thread
 #define CUR_THREAD_HANDLE 0xFFFF8000
 
-static inline void* armGetTls(void) {
-    void* ret;
-    __asm__ ("mrs %x[data], tpidrro_el0" : [data] "=r" (ret));
-    return ret;
-}
-
 typedef struct {
     u64 base_addr;
     u64 size;
diff --git a/nx/source/kernel/cache.s b/nx/source/arm/cache.s
similarity index 85%
rename from nx/source/kernel/cache.s
rename to nx/source/arm/cache.s
index 816b921e..ca029b20 100644
--- a/nx/source/kernel/cache.s
+++ b/nx/source/arm/cache.s
@@ -11,7 +11,7 @@
 	.cfi_endproc
 .endm
 
-CODE_BEGIN osDCacheFlush
+CODE_BEGIN armDCacheFlush
 	add x1, x1, x0
 	mrs x8, CTR_EL0
 	lsr x8, x8, #16
@@ -22,11 +22,11 @@ CODE_BEGIN osDCacheFlush
 	bic x8, x0, x10
 	mov x10, x1
 
-osDCacheFlush_L0:
+armDCacheFlush_L0:
 	dc civac, x8
 	add x8, x8, x9
 	cmp x8, x10
-	bcc osDCacheFlush_L0
+	bcc armDCacheFlush_L0
 
 	dsb sy
 	ret
diff --git a/nx/source/devices/usb_dev.c b/nx/source/devices/usb_dev.c
deleted file mode 100644
index 4d9351a2..00000000
--- a/nx/source/devices/usb_dev.c
+++ /dev/null
@@ -1,296 +0,0 @@
-#include <string.h>
-#include <malloc.h>
-#include <switch.h>
-
-//TODO: devoptab support
-
-static bool g_usbDevInitialized = false;
-
-static UsbDsInterface* interface = NULL;
-static UsbDsEndpoint *g_usbDev_endpoint_in = NULL, *g_usbDev_endpoint_out = NULL;
-
-static u8 *g_usbDev_endpoint_in_buffer = NULL, *g_usbDev_endpoint_out_buffer = NULL;
-
-static Result _usbDevInit(void);
-
-static Result _usbDevWrite(const void* buffer, size_t size, size_t *transferredSize);
-
-Result usbDevInitialize(void)
-{
-    if (g_usbDevInitialized) return 0;
-
-    Result ret=0;
-
-    usbDsDeviceInfo deviceinfo = {
-        .idVendor = 0x0403, // "Future Technology Devices International, Ltd"
-        .idProduct = 0x6001, // "FT232 USB-Serial (UART) IC"
-        .bcdDevice = 0x0200,
-        .Manufacturer = "libnx",
-        .Product = "usbDev",
-        .SerialNumber = "1337",
-    };
-
-    ret = usbDsInitialize(USBCOMPLEXID_Default, &deviceinfo);
-
-    if (R_SUCCEEDED(ret)) {
-        //The buffer for PostBufferAsync commands must be 0x1000-byte aligned.
-		g_usbDev_endpoint_in_buffer = memalign(0x1000, 0x1000);
-		if (g_usbDev_endpoint_in_buffer==NULL) ret = MAKERESULT(MODULE_LIBNX, LIBNX_OUTOFMEM);
-
-        if (R_SUCCEEDED(ret)) {
-		    g_usbDev_endpoint_out_buffer = memalign(0x1000, 0x1000);
-		    if (g_usbDev_endpoint_out_buffer==NULL) ret = MAKERESULT(MODULE_LIBNX, LIBNX_OUTOFMEM);
-        }
-
-        if (R_SUCCEEDED(ret)) {
-            memset(g_usbDev_endpoint_in_buffer, 0, 0x1000);
-            memset(g_usbDev_endpoint_out_buffer, 0, 0x1000);
-            ret = _usbDevInit();
-        }
-
-        if (R_FAILED(ret)) {
-            usbDsExit();
-
-            if (g_usbDev_endpoint_in_buffer) {
-                free(g_usbDev_endpoint_in_buffer);
-                g_usbDev_endpoint_in_buffer = NULL;
-            }
-
-            if (g_usbDev_endpoint_out) {
-                free(g_usbDev_endpoint_out_buffer);
-                g_usbDev_endpoint_out_buffer = NULL;
-            }
-        }
-    }
-
-    if (R_SUCCEEDED(ret)) g_usbDevInitialized=true;
-
-    return ret;
-}
-
-void usbDevExit(void)
-{
-    if (!g_usbDevInitialized) return;
-
-    usbDsExit();
-
-    g_usbDevInitialized = false;
-
-    g_usbDev_endpoint_in = NULL;
-    g_usbDev_endpoint_out = NULL;
-
-    if (g_usbDev_endpoint_in_buffer) {
-        free(g_usbDev_endpoint_in_buffer);
-        g_usbDev_endpoint_in_buffer = NULL;
-    }
-
-    if (g_usbDev_endpoint_out) {
-        free(g_usbDev_endpoint_out_buffer);
-        g_usbDev_endpoint_out_buffer = NULL;
-    }
-}
-
-static Result _usbDevInit(void)
-{
-    Result ret=0;
-    size_t transferredSize=0;
-
-    struct usb_interface_descriptor interface_descriptor = {
-        .bLength = USB_DT_INTERFACE_SIZE,
-        .bDescriptorType = USB_DT_INTERFACE,
-        .bInterfaceNumber = USBDS_DEFAULT_InterfaceNumber,
-        .bInterfaceClass = USB_CLASS_VENDOR_SPEC,
-        .bInterfaceSubClass = USB_CLASS_VENDOR_SPEC,
-        .bInterfaceProtocol = USB_CLASS_VENDOR_SPEC,
-    };
-
-    struct usb_endpoint_descriptor endpoint_descriptor_in = {
-        .bLength = USB_DT_ENDPOINT_SIZE,
-        .bDescriptorType = USB_DT_ENDPOINT,
-        .bEndpointAddress = USB_ENDPOINT_IN,
-        .bmAttributes = USB_TRANSFER_TYPE_BULK,
-        .wMaxPacketSize = 0x200,
-    };
-
-    struct usb_endpoint_descriptor endpoint_descriptor_out = {
-        .bLength = USB_DT_ENDPOINT_SIZE,
-        .bDescriptorType = USB_DT_ENDPOINT,
-        .bEndpointAddress = USB_ENDPOINT_OUT,
-        .bmAttributes = USB_TRANSFER_TYPE_BULK,
-        .wMaxPacketSize = 0x200,
-    };
-
-    //Setup interface.
-    ret = usbDsGetDsInterface(&interface, &interface_descriptor, "usb");
-    if (R_FAILED(ret)) return ret;
-
-    //Setup endpoints.
-    ret = usbDsInterface_GetDsEndpoint(interface, &g_usbDev_endpoint_in, &endpoint_descriptor_in);//device->host
-    if (R_FAILED(ret)) return ret;
-
-    ret = usbDsInterface_GetDsEndpoint(interface, &g_usbDev_endpoint_out, &endpoint_descriptor_out);//host->device
-    if (R_FAILED(ret)) return ret;
-
-    ret = usbDsInterface_EnableInterface(interface);
-    if (R_FAILED(ret)) return ret;
-
-    //Host-side serial handling breaks with binary data without this.
-    ret = _usbDevWrite("\n", 1, &transferredSize);
-    if (R_SUCCEEDED(ret) && transferredSize!=1) ret = MAKERESULT(MODULE_LIBNX, LIBNX_IOERROR);
-
-    return ret;
-}
-
-static Result _usbDevRead(void* buffer, size_t size, size_t *transferredSize)
-{
-    Result ret=0;
-    u32 urbId=0;
-    u8 *bufptr = (u8*)buffer;
-    s32 tmpindex=0;
-    u32 chunksize=0;
-    u32 tmp_transferredSize = 0;
-    size_t total_transferredSize=0;
-    usbDsReportData reportdata;
-
-    //Makes sure endpoints are ready for data-transfer / wait for init if needed.
-    ret = usbDsWaitReady();
-    if (R_FAILED(ret)) return ret;
-
-    while(size)
-    {
-        chunksize = 0x1000;
-        if (size<chunksize) chunksize = size;
-
-        //Start a host->device transfer.
-        ret = usbDsEndpoint_PostBufferAsync(g_usbDev_endpoint_out, g_usbDev_endpoint_out_buffer, chunksize, &urbId);
-        if (R_FAILED(ret)) return ret;
-
-        //Wait for the transfer to finish.
-        svcWaitSynchronization(&tmpindex, &g_usbDev_endpoint_out->CompletionEvent, 1, U64_MAX);
-        svcClearEvent(g_usbDev_endpoint_out->CompletionEvent);
-
-        ret = usbDsEndpoint_GetReportData(g_usbDev_endpoint_out, &reportdata);
-        if (R_FAILED(ret)) return ret;
-
-        ret = usbDsParseReportData(&reportdata, urbId, NULL, &tmp_transferredSize);
-        if (R_FAILED(ret)) return ret;
-
-        if (tmp_transferredSize > chunksize) tmp_transferredSize = chunksize;
-        total_transferredSize+= (size_t)tmp_transferredSize;
-
-        memcpy(bufptr, g_usbDev_endpoint_out_buffer, chunksize);
-        bufptr+= chunksize;
-        size-= chunksize;
-
-        if(tmp_transferredSize < chunksize)break;
-    }
-
-    if (transferredSize) *transferredSize = total_transferredSize;
-
-    return ret;
-}
-
-static Result _usbDevWrite(const void* buffer, size_t size, size_t *transferredSize)
-{
-    Result ret=0;
-    u32 urbId=0;
-    u32 chunksize=0;
-    u32 bufpos=0;
-    u32 transfer_size=0;
-    u32 total_chunks=0;
-    u32 last_chunksize=0;
-    u8 *bufptr = (u8*)buffer;
-    s32 tmpindex=0;
-    u32 tmp_transferredSize = 0;
-    u32 partial_transfer=0;
-    size_t total_transferredSize=0;
-    usbDsReportData reportdata;
-
-    //Makes sure endpoints are ready for data-transfer / wait for init if needed.
-    ret = usbDsWaitReady();
-    if (R_FAILED(ret)) return ret;
-
-    while(size)
-    {
-        memset(g_usbDev_endpoint_in_buffer, 0, 0x1000);
-        transfer_size = 0;
-        total_chunks = 0;
-
-        for(bufpos=0; bufpos<0x1000; bufpos+=0x200)
-        {
-            chunksize = 0x200;
-            if(size<chunksize)chunksize = size+2;
-            last_chunksize = chunksize;
-
-            g_usbDev_endpoint_in_buffer[bufpos+0] = 0x11;//2-byte header then the actual data.
-            g_usbDev_endpoint_in_buffer[bufpos+1] = 0x1;
-            memcpy(&g_usbDev_endpoint_in_buffer[bufpos+2], bufptr, chunksize-2);
-
-            size-= chunksize-2;
-            bufptr+= chunksize-2;
-            transfer_size+= chunksize;
-            total_chunks++;
-
-            if(size==0)break;
-        }
-
-        //Start a device->host transfer.
-        ret = usbDsEndpoint_PostBufferAsync(g_usbDev_endpoint_in, g_usbDev_endpoint_in_buffer, transfer_size, &urbId);
-        if(R_FAILED(ret))return ret;
-
-        //Wait for the transfer to finish.
-        svcWaitSynchronization(&tmpindex, &g_usbDev_endpoint_in->CompletionEvent, 1, U64_MAX);
-        svcClearEvent(g_usbDev_endpoint_in->CompletionEvent);
-
-        ret = usbDsEndpoint_GetReportData(g_usbDev_endpoint_in, &reportdata);
-        if (R_FAILED(ret)) return ret;
-
-        ret = usbDsParseReportData(&reportdata, urbId, NULL, &tmp_transferredSize);
-        if (R_FAILED(ret)) return ret;
-
-        if (tmp_transferredSize > transfer_size) tmp_transferredSize = transfer_size;
-
-        partial_transfer = 0;
-        for(bufpos=0; bufpos<transfer_size; bufpos+=0x200)
-        {
-            if(tmp_transferredSize < bufpos+2) {
-                partial_transfer = 1;
-                break;
-            }
-
-            chunksize = 0x200;
-            if(total_chunks==1)chunksize = last_chunksize;
-            total_chunks--;
-
-            if (tmp_transferredSize < bufpos+chunksize) {
-                total_transferredSize+= tmp_transferredSize - bufpos - 2;
-                partial_transfer = 1;
-                break;
-            }
-
-            total_transferredSize+= chunksize-2;
-        }
-        if (partial_transfer) break;
-    }
-
-    if (transferredSize) *transferredSize = total_transferredSize;
-
-    return ret;
-}
-
-size_t usbDevRead(void* buffer, size_t size)
-{
-    size_t transferredSize=0;
-    Result ret = _usbDevRead(buffer, size, &transferredSize);
-    if (R_FAILED(ret)) fatalSimple(ret);
-    return transferredSize;
-}
-
-size_t usbDevWrite(const void* buffer, size_t size)
-{
-    size_t transferredSize=0;
-    Result ret = _usbDevWrite(buffer, size, &transferredSize);
-    if (R_FAILED(ret)) fatalSimple(ret);
-    return transferredSize;
-}
-
diff --git a/nx/source/kernel/version.c b/nx/source/kernel/version.c
new file mode 100644
index 00000000..1af9b4a8
--- /dev/null
+++ b/nx/source/kernel/version.c
@@ -0,0 +1,12 @@
+// Copyright 2017 plutoo
+#include <switch.h>
+
+bool kernelAbove200() {
+    u64 tmp;
+    return svcGetInfo(&tmp, 12, INVALID_HANDLE, 0) != 0xF001;
+}
+
+bool kernelAbove300() {
+    u64 tmp;
+    return svcGetInfo(&tmp, 18, INVALID_HANDLE, 0) != 0xF001;
+}
diff --git a/nx/source/services/usb.c b/nx/source/services/usb.c
index 82c30f1c..f4e1b62c 100644
--- a/nx/source/services/usb.c
+++ b/nx/source/services/usb.c
@@ -28,8 +28,11 @@ Result usbDsInitialize(usbComplexId complexId, const usbDsDeviceInfo* deviceinfo
 
     if (R_SUCCEEDED(rc))rc = _usbDsBindDevice(complexId);
     if (R_SUCCEEDED(rc))rc = _usbDsBindClientProcess(CUR_PROCESS_HANDLE);
-    if (R_SUCCEEDED(rc))rc = _usbDsGetEvent(g_usbDsServiceSession, &g_usbDsStateChangeEvent, 3);//GetStateChangeEvent
-    if (R_SUCCEEDED(rc))rc = _usbDsSetVidPidBcd(deviceinfo);
+    if (R_SUCCEEDED(rc))rc = _usbDsGetEvent(g_usbDsServiceSession, &g_usbDsStateChangeEvent, 3);// GetStateChangeEvent
+
+    if (R_SUCCEEDED(rc) && kernelAbove200()) {
+        rc = _usbDsSetVidPidBcd(deviceinfo);
+    }
 
     if (R_FAILED(rc)) {
         if(g_usbDsStateChangeEvent) {