diff --git a/firmware/hackrf_usb/usb_api_board_info.c b/firmware/hackrf_usb/usb_api_board_info.c
index ba2a6ddd..f3d8ab2b 100644
--- a/firmware/hackrf_usb/usb_api_board_info.c
+++ b/firmware/hackrf_usb/usb_api_board_info.c
@@ -56,11 +56,11 @@ usb_request_status_t usb_vendor_request_read_version_string(
 	return USB_REQUEST_STATUS_OK;
 }
 
+static read_partid_serialno_t read_partid_serialno;
 usb_request_status_t usb_vendor_request_read_partid_serialno(
 	usb_endpoint_t* const endpoint, const usb_transfer_stage_t stage)
 {
 	uint8_t length;
-	read_partid_serialno_t read_partid_serialno;
 	iap_cmd_res_t iap_cmd_res;
 
 	if (stage == USB_TRANSFER_STAGE_SETUP) 
@@ -101,4 +101,4 @@ usb_request_status_t usb_vendor_request_reset(
 		usb_transfer_schedule_ack(endpoint->in);
 	}
 	return USB_REQUEST_STATUS_OK;
-}
\ No newline at end of file
+}
diff --git a/firmware/hackrf_usb/usb_api_cpld.c b/firmware/hackrf_usb/usb_api_cpld.c
index e6fa3784..a104cc1d 100644
--- a/firmware/hackrf_usb/usb_api_cpld.c
+++ b/firmware/hackrf_usb/usb_api_cpld.c
@@ -32,6 +32,7 @@
 #include <stddef.h>
 #include <stdint.h>
 #include <stdbool.h>
+#include <string.h>
 
 uint8_t cpld_xsvf_buffer[512];
 volatile bool cpld_wait = false;
@@ -98,7 +99,8 @@ usb_request_status_t usb_vendor_request_cpld_checksum(
 		}
 		
 		length = (uint8_t)sizeof(cpld_crc);
-		usb_transfer_schedule_block(endpoint->in, &cpld_crc, length,
+		memcpy(endpoint->buffer, &cpld_crc, length);
+		usb_transfer_schedule_block(endpoint->in, endpoint->buffer, length,
 					    NULL, NULL);
 		usb_transfer_schedule_ack(endpoint->out);
 	}
diff --git a/firmware/hackrf_usb/usb_api_operacake.c b/firmware/hackrf_usb/usb_api_operacake.c
index 43f14a52..6001a361 100644
--- a/firmware/hackrf_usb/usb_api_operacake.c
+++ b/firmware/hackrf_usb/usb_api_operacake.c
@@ -31,9 +31,8 @@ usb_request_status_t usb_vendor_request_operacake_get_boards(
 	usb_endpoint_t* const endpoint, const usb_transfer_stage_t stage)
 {
 	if (stage == USB_TRANSFER_STAGE_SETUP) {
-		uint8_t addresses[8];
-		operacake_get_boards(addresses);
-		usb_transfer_schedule_block(endpoint->in, addresses, 8, NULL, NULL);
+		operacake_get_boards(endpoint->buffer);
+		usb_transfer_schedule_block(endpoint->in, endpoint->buffer, 8, NULL, NULL);
 		usb_transfer_schedule_ack(endpoint->out);
 	}
 	return USB_REQUEST_STATUS_OK;
diff --git a/firmware/hackrf_usb/usb_api_spiflash.c b/firmware/hackrf_usb/usb_api_spiflash.c
index 9663f676..769fa0bc 100644
--- a/firmware/hackrf_usb/usb_api_spiflash.c
+++ b/firmware/hackrf_usb/usb_api_spiflash.c
@@ -124,10 +124,9 @@ usb_request_status_t usb_vendor_request_read_spiflash(
 usb_request_status_t usb_vendor_request_spiflash_status(
 	usb_endpoint_t* const endpoint, const usb_transfer_stage_t stage)
 {
-	uint8_t data[2];
 	if (stage == USB_TRANSFER_STAGE_SETUP) {
-		w25q80bv_get_full_status(&spi_flash, data);
-		usb_transfer_schedule_block(endpoint->in, &data, 2, NULL, NULL);
+		w25q80bv_get_full_status(&spi_flash, endpoint->buffer);
+		usb_transfer_schedule_block(endpoint->in, &endpoint->buffer, 2, NULL, NULL);
 		return USB_REQUEST_STATUS_OK;
 	} else if (stage == USB_TRANSFER_STAGE_DATA) {
 		usb_transfer_schedule_ack(endpoint->out);
@@ -145,4 +144,4 @@ usb_request_status_t usb_vendor_request_spiflash_clear_status(
 		usb_transfer_schedule_ack(endpoint->in);
 	}
 return USB_REQUEST_STATUS_OK;
-}
\ No newline at end of file
+}