diff --git a/firmware/target/arm/usb-drv-pp502x.c b/firmware/target/arm/usb-drv-pp502x.c
index af7628f992..bf2076f988 100644
--- a/firmware/target/arm/usb-drv-pp502x.c
+++ b/firmware/target/arm/usb-drv-pp502x.c
@@ -302,8 +302,8 @@ struct transfer_descriptor {
     unsigned int reserved;
 } __attribute__ ((packed));
 
-static struct transfer_descriptor _td_array[NUM_ENDPOINTS*2] __attribute((aligned (32)));
-static struct transfer_descriptor* td_array;
+static struct transfer_descriptor td_array[NUM_ENDPOINTS*2]
+    NOCACHEBSS_ATTR;
 
 /* manual: 32.13.1 Endpoint Queue Head (dQH) */
 struct queue_head {
@@ -318,8 +318,9 @@ struct queue_head {
     unsigned int wait;              /* for softwate use, indicates if the transfer is blocking */
 } __attribute__((packed));
 
-static struct queue_head _qh_array[NUM_ENDPOINTS*2] __attribute((aligned (2048)));
-static struct queue_head* qh_array;
+static struct queue_head qh_array[NUM_ENDPOINTS*2]
+    NOCACHEBSS_ATTR __attribute((aligned (2048)));
+
 static struct event_queue transfer_completion_queue[NUM_ENDPOINTS*2];
 
 
@@ -367,10 +368,8 @@ void usb_drv_init(void)
     REG_PORTSC1 |= PORTSCX_PORT_FORCE_FULL_SPEED;
 #endif
 
-    td_array = (struct transfer_descriptor*)UNCACHED_ADDR(&_td_array);
-    qh_array = (struct queue_head*)UNCACHED_ADDR(&_qh_array);
     init_control_queue_heads();
-    memset(td_array, 0, sizeof _td_array);
+    memset(td_array, 0, sizeof td_array);
 
     REG_ENDPOINTLISTADDR = (unsigned int)qh_array;
     REG_DEVICEADDR = 0;
@@ -646,7 +645,7 @@ void usb_drv_cancel_all_transfers(void)
     REG_ENDPTFLUSH = ~0;
     while (REG_ENDPTFLUSH);
 
-    memset(td_array, 0, sizeof _td_array);
+    memset(td_array, 0, sizeof td_array);
     for(i=0;i<NUM_ENDPOINTS*2;i++) {
         if(qh_array[i].wait) {
             qh_array[i].wait=0;
@@ -776,7 +775,7 @@ static void bus_reset(void)
 static void init_control_queue_heads(void)
 {
     int i;
-    memset(qh_array, 0, sizeof _qh_array);
+    memset(qh_array, 0, sizeof qh_array);
 
     /*** control ***/
     qh_array[EP_CONTROL].max_pkt_length = 64 << QH_MAX_PKT_LEN_POS | QH_IOS;
diff --git a/firmware/usbstack/usb_core.c b/firmware/usbstack/usb_core.c
index ae5606f359..ea00948619 100644
--- a/firmware/usbstack/usb_core.c
+++ b/firmware/usbstack/usb_core.c
@@ -121,7 +121,7 @@ static const struct usb_qualifier_descriptor __attribute__((aligned(2)))
     .bNumConfigurations = 1
 };
 
-static struct usb_string_descriptor __attribute__((aligned(2)))
+static const struct usb_string_descriptor __attribute__((aligned(2)))
                                     usb_string_iManufacturer =
 {
     24,
@@ -129,7 +129,7 @@ static struct usb_string_descriptor __attribute__((aligned(2)))
     {'R','o','c','k','b','o','x','.','o','r','g'}
 };
 
-static struct usb_string_descriptor __attribute__((aligned(2)))
+static const struct usb_string_descriptor __attribute__((aligned(2)))
                                     usb_string_iProduct =
 {
     42,
@@ -152,7 +152,7 @@ static struct usb_string_descriptor __attribute__((aligned(2)))
 /* Generic for all targets */
 
 /* this is stringid #0: languages supported */
-static struct usb_string_descriptor __attribute__((aligned(2)))
+static const struct usb_string_descriptor __attribute__((aligned(2)))
                                     lang_descriptor =
 {
     4,
@@ -160,7 +160,7 @@ static struct usb_string_descriptor __attribute__((aligned(2)))
     {0x0409} /* LANGID US English */
 };
 
-static struct usb_string_descriptor __attribute__((aligned(2)))
+static const struct usb_string_descriptor __attribute__((aligned(2)))
                                     usb_string_charging_only =
 {
     28,
@@ -168,7 +168,7 @@ static struct usb_string_descriptor __attribute__((aligned(2)))
     {'C','h','a','r','g','i','n','g',' ','o','n','l','y'}
 };
 
-static struct usb_string_descriptor* usb_strings[] =
+static struct usb_string_descriptor* const usb_strings[] =
 {
    &lang_descriptor,
    &usb_string_iManufacturer,
@@ -244,8 +244,7 @@ static struct usb_class_driver drivers[USB_NUM_DRIVERS] =
 static void usb_core_control_request_handler(struct usb_ctrlrequest* req);
 static int ack_control(struct usb_ctrlrequest* req);
 
-static unsigned char *response_data;
-static unsigned char __response_data[CACHEALIGN_UP(256)] CACHEALIGN_ATTR;
+static unsigned char response_data[256] NOCACHEBSS_ATTR;
 
 static struct usb_transfer_completion_event_data events[NUM_ENDPOINTS];
 
@@ -317,8 +316,6 @@ void usb_core_init(void)
     if (initialized)
         return;
 
-    response_data = (void*)UNCACHED_ADDR(&__response_data);
-
     usb_drv_init();
 
     /* class driver init functions should be safe to call even if the driver