diff --git a/records/tools/armcc.yaml b/records/tools/armcc.yaml
index 6b36c2e58..d22b0d3c6 100644
--- a/records/tools/armcc.yaml
+++ b/records/tools/armcc.yaml
@@ -13,7 +13,7 @@ tool_specific:
                 - -O2
                 - -Ospace
                 - --gnu
-                - --c99
+                - --c11
                 - --asm
                 - --split_sections
                 - --interleave
@@ -37,7 +37,7 @@ tool_specific:
             c_flags:
                 # uvision.uvproj.tmpl specifies:
                 # - O2, space
-                # - C99
+                # - C11
                 # - split sections
                 - --gnu
                 - --asm
diff --git a/records/tools/armclang.yaml b/records/tools/armclang.yaml
index 78e584772..78bd9f14a 100644
--- a/records/tools/armclang.yaml
+++ b/records/tools/armclang.yaml
@@ -18,12 +18,11 @@ tool_specific:
                 - --target=arm-arm-none-eabi
                 - -Oz
                 - -g
-                - --std=c99
+                - --std=c11
                 - -fdata-sections
                 - -ffunction-sections
                 - -fno-builtin
                 - -fshort-enums
-                - -fshort-wchar
                 - -funsigned-char
                 - -masm=auto
                 - -nostdlib
diff --git a/records/tools/gcc_arm.yaml b/records/tools/gcc_arm.yaml
index 3ca532e65..a8cbe20a5 100644
--- a/records/tools/gcc_arm.yaml
+++ b/records/tools/gcc_arm.yaml
@@ -17,8 +17,7 @@ tool_specific:
                 - -Werror
                 - -ffunction-sections
                 - -fdata-sections
-                - -std=gnu99
-                - -fshort-wchar
+                - -std=gnu11
                 - -fno-common
                 - -ffreestanding
                 - -fverbose-asm
diff --git a/records/tools/uvision.uvproj.tmpl b/records/tools/uvision.uvproj.tmpl
index 6fdaf15d6..d0b6c0e83 100644
--- a/records/tools/uvision.uvproj.tmpl
+++ b/records/tools/uvision.uvproj.tmpl
@@ -356,7 +356,7 @@
             <wLevel>0</wLevel>
             <uThumb>0</uThumb>
             <uSurpInc>0</uSurpInc>
-            <uC99>1</uC99>
+            <uC99>2</uC99>
             <useXO>0</useXO>
             <VariousControls>
               <MiscControls></MiscControls>
diff --git a/source/daplink/uchar.h b/source/daplink/uchar.h
new file mode 100644
index 000000000..d1d2ffb72
--- /dev/null
+++ b/source/daplink/uchar.h
@@ -0,0 +1,32 @@
+/** 
+ * @file    uchar.h 
+ * @brief   Compatibility for libcs without uchar.h
+ * 
+ * DAPLink Interface Firmware 
+ * Copyright (c) 2023 Google LLC, All Rights Reserved 
+ * SPDX-License-Identifier: Apache-2.0 
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may 
+ * not use this file except in compliance with the License. 
+ * You may obtain a copy of the License at 
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0 
+ * 
+ * Unless required by applicable law or agreed to in writing, software 
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
+ * See the License for the specific language governing permissions and 
+ * limitations under the License. 
+ */
+
+#ifndef DAPLINK_UCHAR_H
+#define DAPLINK_UCHAR_H
+
+#if __has_include_next(<uchar.h>)
+#include_next <uchar.h>
+#else
+#include <stdint.h>
+typedef uint16_t char16_t;
+#endif
+
+#endif
diff --git a/source/hic_hal/atmel/sam3u2c/usb_config.c b/source/hic_hal/atmel/sam3u2c/usb_config.c
index e78132cd4..4bf71cde0 100644
--- a/source/hic_hal/atmel/sam3u2c/usb_config.c
+++ b/source/hic_hal/atmel/sam3u2c/usb_config.c
@@ -90,16 +90,16 @@
 //     </e>
 //   </h>
 #define USBD_STRDESC_LANGID         0x0409
-#define USBD_STRDESC_MAN            L"Arm"
+#define USBD_STRDESC_MAN            u"Arm"
 #ifndef USB_PROD_STR
-#define USBD_STRDESC_PROD           L"DAPLink CMSIS-DAP"
+#define USBD_STRDESC_PROD           u"DAPLink CMSIS-DAP"
 #else
-#define _TOWIDE(x)                   L ## #x
+#define _TOWIDE(x)                   u ## #x
 #define TOWIDE(x)                   _TOWIDE(x)
 #define USBD_STRDESC_PROD           TOWIDE(USB_PROD_STR)
 #endif
 #define USBD_STRDESC_SER_ENABLE     1
-#define USBD_STRDESC_SER            L"0001A0000000"
+#define USBD_STRDESC_SER            u"0001A0000000"
 
 //   <e0> Class Support
 //     <i> Enables USB Device Class specific Requests
@@ -169,8 +169,8 @@
 #define USBD_HID_HS_ENABLE          1
 #define USBD_HID_HS_WMAXPACKETSIZE  64
 #define USBD_HID_HS_BINTERVAL       1
-#define USBD_HID_STRDESC            L"CMSIS-DAP v1"
-#define USBD_WEBUSB_STRDESC         L"WebUSB: CMSIS-DAP"
+#define USBD_HID_STRDESC            u"CMSIS-DAP v1"
+#define USBD_WEBUSB_STRDESC         u"WebUSB: CMSIS-DAP"
 #define USBD_HID_INREPORT_NUM       1
 #define USBD_HID_OUTREPORT_NUM      1
 #define USBD_HID_INREPORT_MAX_SZ    64
@@ -221,7 +221,7 @@
 #define USBD_MSC_HS_ENABLE          1
 #define USBD_MSC_HS_WMAXPACKETSIZE  512
 #define USBD_MSC_HS_BINTERVAL       0
-#define USBD_MSC_STRDESC            L"USB_MSC"
+#define USBD_MSC_STRDESC            u"USB_MSC"
 // Make sure changes to USBD_MSC_INQUIRY_DATA are coordinated with mbed-ls
 // since this is used to detect DAPLink drives
 #define USBD_MSC_INQUIRY_DATA       "MBED    "         \
@@ -266,9 +266,9 @@
 #define USBD_ADC_BINTERVAL          1
 #define USBD_ADC_HS_ENABLE          0
 #define USBD_ADC_HS_WMAXPACKETSIZE  64
-#define USBD_ADC_CIF_STRDESC        L"USB_ADC"
-#define USBD_ADC_SIF1_STRDESC       L"USB_ADC1"
-#define USBD_ADC_SIF2_STRDESC       L"USB_ADC2"
+#define USBD_ADC_CIF_STRDESC        u"USB_ADC"
+#define USBD_ADC_SIF1_STRDESC       u"USB_ADC1"
+#define USBD_ADC_SIF2_STRDESC       u"USB_ADC2"
 #define USBD_ADC_BSUBFRAMESIZE      2
 #define USBD_ADC_BBITRESOLUTION     16
 #define USBD_ADC_TSAMFREQ           32000
@@ -349,8 +349,8 @@
 #define USBD_CDC_ACM_HS_ENABLE1         1
 #define USBD_CDC_ACM_HS_WMAXPACKETSIZE1 512
 #define USBD_CDC_ACM_HS_BINTERVAL1      1
-#define USBD_CDC_ACM_CIF_STRDESC        L"mbed Serial Port"
-#define USBD_CDC_ACM_DIF_STRDESC        L"mbed Serial Port"
+#define USBD_CDC_ACM_CIF_STRDESC        u"mbed Serial Port"
+#define USBD_CDC_ACM_DIF_STRDESC        u"mbed Serial Port"
 #define USBD_CDC_ACM_SENDBUF_SIZE       USBD_CDC_ACM_HS_WMAXPACKETSIZE1
 #define USBD_CDC_ACM_RECEIVEBUF_SIZE    USBD_CDC_ACM_HS_WMAXPACKETSIZE1
 #if (((USBD_CDC_ACM_HS_ENABLE1) && (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_HS_WMAXPACKETSIZE1)) || (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_WMAXPACKETSIZE1))
@@ -401,7 +401,7 @@
 #define USBD_BULK_WMAXPACKETSIZE     64
 #define USBD_BULK_HS_ENABLE          1
 #define USBD_BULK_HS_WMAXPACKETSIZE  512
-#define USBD_BULK_STRDESC            L"CMSIS-DAP v2"
+#define USBD_BULK_STRDESC            u"CMSIS-DAP v2"
 
 
 /* USB Device Calculations ---------------------------------------------------*/
diff --git a/source/hic_hal/freescale/k20dx/usb_config.c b/source/hic_hal/freescale/k20dx/usb_config.c
index 972a0523f..363dff044 100644
--- a/source/hic_hal/freescale/k20dx/usb_config.c
+++ b/source/hic_hal/freescale/k20dx/usb_config.c
@@ -90,16 +90,16 @@
 //     </e>
 //   </h>
 #define USBD_STRDESC_LANGID         0x0409
-#define USBD_STRDESC_MAN            L"Arm"
+#define USBD_STRDESC_MAN            u"Arm"
 #ifndef USB_PROD_STR
-#define USBD_STRDESC_PROD           L"DAPLink CMSIS-DAP"
+#define USBD_STRDESC_PROD           u"DAPLink CMSIS-DAP"
 #else
-#define _TOWIDE(x)                   L ## #x
+#define _TOWIDE(x)                   u ## #x
 #define TOWIDE(x)                   _TOWIDE(x)
 #define USBD_STRDESC_PROD           TOWIDE(USB_PROD_STR)
 #endif
 #define USBD_STRDESC_SER_ENABLE     1
-#define USBD_STRDESC_SER            L"0001A0000000"
+#define USBD_STRDESC_SER            u"0001A0000000"
 
 //   <e0> Class Support
 //     <i> Enables USB Device Class specific Requests
@@ -169,8 +169,8 @@
 #define USBD_HID_HS_ENABLE          0
 #define USBD_HID_HS_WMAXPACKETSIZE  64
 #define USBD_HID_HS_BINTERVAL       6
-#define USBD_HID_STRDESC            L"CMSIS-DAP v1"
-#define USBD_WEBUSB_STRDESC         L"WebUSB: CMSIS-DAP"
+#define USBD_HID_STRDESC            u"CMSIS-DAP v1"
+#define USBD_WEBUSB_STRDESC         u"WebUSB: CMSIS-DAP"
 #define USBD_HID_INREPORT_NUM       1
 #define USBD_HID_OUTREPORT_NUM      1
 #define USBD_HID_INREPORT_MAX_SZ    64
@@ -220,7 +220,7 @@
 #define USBD_MSC_HS_ENABLE          0
 #define USBD_MSC_HS_WMAXPACKETSIZE  512
 #define USBD_MSC_HS_BINTERVAL       0
-#define USBD_MSC_STRDESC            L"USB_MSC"
+#define USBD_MSC_STRDESC            u"USB_MSC"
 // Make sure changes to USBD_MSC_INQUIRY_DATA are coordinated with mbed-ls
 // since this is used to detect DAPLink drives
 #define USBD_MSC_INQUIRY_DATA       "MBED    "         \
@@ -265,9 +265,9 @@
 #define USBD_ADC_BINTERVAL          1
 #define USBD_ADC_HS_ENABLE          0
 #define USBD_ADC_HS_WMAXPACKETSIZE  64
-#define USBD_ADC_CIF_STRDESC        L"USB_ADC"
-#define USBD_ADC_SIF1_STRDESC       L"USB_ADC1"
-#define USBD_ADC_SIF2_STRDESC       L"USB_ADC2"
+#define USBD_ADC_CIF_STRDESC        u"USB_ADC"
+#define USBD_ADC_SIF1_STRDESC       u"USB_ADC1"
+#define USBD_ADC_SIF2_STRDESC       u"USB_ADC2"
 #define USBD_ADC_BSUBFRAMESIZE      2
 #define USBD_ADC_BBITRESOLUTION     16
 #define USBD_ADC_TSAMFREQ           32000
@@ -347,8 +347,8 @@
 #define USBD_CDC_ACM_HS_ENABLE1         0
 #define USBD_CDC_ACM_HS_WMAXPACKETSIZE1 64
 #define USBD_CDC_ACM_HS_BINTERVAL1      0
-#define USBD_CDC_ACM_CIF_STRDESC        L"mbed Serial Port"
-#define USBD_CDC_ACM_DIF_STRDESC        L"mbed Serial Port"
+#define USBD_CDC_ACM_CIF_STRDESC        u"mbed Serial Port"
+#define USBD_CDC_ACM_DIF_STRDESC        u"mbed Serial Port"
 #define USBD_CDC_ACM_SENDBUF_SIZE       64
 #define USBD_CDC_ACM_RECEIVEBUF_SIZE    64
 #if (((USBD_CDC_ACM_HS_ENABLE1) && (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_HS_WMAXPACKETSIZE1)) || (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_WMAXPACKETSIZE1))
@@ -399,7 +399,7 @@
 #define USBD_BULK_WMAXPACKETSIZE     64
 #define USBD_BULK_HS_ENABLE          0
 #define USBD_BULK_HS_WMAXPACKETSIZE  512
-#define USBD_BULK_STRDESC            L"CMSIS-DAP v2"
+#define USBD_BULK_STRDESC            u"CMSIS-DAP v2"
 
 
 /* USB Device Calculations ---------------------------------------------------*/
diff --git a/source/hic_hal/freescale/k26f/usb_config.c b/source/hic_hal/freescale/k26f/usb_config.c
index 9b8dde6c1..faca95c2b 100644
--- a/source/hic_hal/freescale/k26f/usb_config.c
+++ b/source/hic_hal/freescale/k26f/usb_config.c
@@ -99,16 +99,16 @@
 //     </e>
 //   </h>
 #define USBD_STRDESC_LANGID         0x0409
-#define USBD_STRDESC_MAN            L"Arm"
+#define USBD_STRDESC_MAN            u"Arm"
 #ifndef USB_PROD_STR
-#define USBD_STRDESC_PROD           L"DAPLink CMSIS-DAP"
+#define USBD_STRDESC_PROD           u"DAPLink CMSIS-DAP"
 #else
-#define _TOWIDE(x)                   L ## #x
+#define _TOWIDE(x)                   u ## #x
 #define TOWIDE(x)                   _TOWIDE(x)
 #define USBD_STRDESC_PROD           TOWIDE(USB_PROD_STR)
 #endif
 #define USBD_STRDESC_SER_ENABLE     1
-#define USBD_STRDESC_SER            L"0001A0000000"
+#define USBD_STRDESC_SER            u"0001A0000000"
 
 //   <e0> Class Support
 //     <i> Enables USB Device Class specific Requests
@@ -178,8 +178,8 @@
 #define USBD_HID_HS_ENABLE          1
 #define USBD_HID_HS_WMAXPACKETSIZE  64 //| (2<<11)
 #define USBD_HID_HS_BINTERVAL       1
-#define USBD_HID_STRDESC            L"CMSIS-DAP v1"
-#define USBD_WEBUSB_STRDESC         L"WebUSB: CMSIS-DAP"
+#define USBD_HID_STRDESC            u"CMSIS-DAP v1"
+#define USBD_WEBUSB_STRDESC         u"WebUSB: CMSIS-DAP"
 #define USBD_HID_INREPORT_NUM       1
 #define USBD_HID_OUTREPORT_NUM      1
 #define USBD_HID_INREPORT_MAX_SZ    64
@@ -229,7 +229,7 @@
 #define USBD_MSC_HS_ENABLE          1
 #define USBD_MSC_HS_WMAXPACKETSIZE  512
 #define USBD_MSC_HS_BINTERVAL       0
-#define USBD_MSC_STRDESC            L"USB_MSC"
+#define USBD_MSC_STRDESC            u"USB_MSC"
 // Make sure changes to USBD_MSC_INQUIRY_DATA are coordinated with mbed-ls
 // since this is used to detect DAPLink drives
 #define USBD_MSC_INQUIRY_DATA       "MBED    "         \
@@ -274,9 +274,9 @@
 #define USBD_ADC_BINTERVAL          1
 #define USBD_ADC_HS_ENABLE          0
 #define USBD_ADC_HS_WMAXPACKETSIZE  64
-#define USBD_ADC_CIF_STRDESC        L"USB_ADC"
-#define USBD_ADC_SIF1_STRDESC       L"USB_ADC1"
-#define USBD_ADC_SIF2_STRDESC       L"USB_ADC2"
+#define USBD_ADC_CIF_STRDESC        u"USB_ADC"
+#define USBD_ADC_SIF1_STRDESC       u"USB_ADC1"
+#define USBD_ADC_SIF2_STRDESC       u"USB_ADC2"
 #define USBD_ADC_BSUBFRAMESIZE      2
 #define USBD_ADC_BBITRESOLUTION     16
 #define USBD_ADC_TSAMFREQ           32000
@@ -356,8 +356,8 @@
 #define USBD_CDC_ACM_HS_ENABLE1         1
 #define USBD_CDC_ACM_HS_WMAXPACKETSIZE1 512
 #define USBD_CDC_ACM_HS_BINTERVAL1      1
-#define USBD_CDC_ACM_CIF_STRDESC        L"mbed Serial Port"
-#define USBD_CDC_ACM_DIF_STRDESC        L"mbed Serial Port"
+#define USBD_CDC_ACM_CIF_STRDESC        u"mbed Serial Port"
+#define USBD_CDC_ACM_DIF_STRDESC        u"mbed Serial Port"
 #define USBD_CDC_ACM_SENDBUF_SIZE       USBD_CDC_ACM_HS_WMAXPACKETSIZE1
 #define USBD_CDC_ACM_RECEIVEBUF_SIZE    USBD_CDC_ACM_HS_WMAXPACKETSIZE1
 #if (((USBD_CDC_ACM_HS_ENABLE1) && (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_HS_WMAXPACKETSIZE1)) || (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_WMAXPACKETSIZE1))
@@ -408,7 +408,7 @@
 #define USBD_BULK_WMAXPACKETSIZE     64
 #define USBD_BULK_HS_ENABLE          1
 #define USBD_BULK_HS_WMAXPACKETSIZE  512
-#define USBD_BULK_STRDESC            L"CMSIS-DAP v2"
+#define USBD_BULK_STRDESC            u"CMSIS-DAP v2"
 
 
 /* USB Device Calculations ---------------------------------------------------*/
diff --git a/source/hic_hal/freescale/kl26z/usb_config.c b/source/hic_hal/freescale/kl26z/usb_config.c
index 972a0523f..363dff044 100644
--- a/source/hic_hal/freescale/kl26z/usb_config.c
+++ b/source/hic_hal/freescale/kl26z/usb_config.c
@@ -90,16 +90,16 @@
 //     </e>
 //   </h>
 #define USBD_STRDESC_LANGID         0x0409
-#define USBD_STRDESC_MAN            L"Arm"
+#define USBD_STRDESC_MAN            u"Arm"
 #ifndef USB_PROD_STR
-#define USBD_STRDESC_PROD           L"DAPLink CMSIS-DAP"
+#define USBD_STRDESC_PROD           u"DAPLink CMSIS-DAP"
 #else
-#define _TOWIDE(x)                   L ## #x
+#define _TOWIDE(x)                   u ## #x
 #define TOWIDE(x)                   _TOWIDE(x)
 #define USBD_STRDESC_PROD           TOWIDE(USB_PROD_STR)
 #endif
 #define USBD_STRDESC_SER_ENABLE     1
-#define USBD_STRDESC_SER            L"0001A0000000"
+#define USBD_STRDESC_SER            u"0001A0000000"
 
 //   <e0> Class Support
 //     <i> Enables USB Device Class specific Requests
@@ -169,8 +169,8 @@
 #define USBD_HID_HS_ENABLE          0
 #define USBD_HID_HS_WMAXPACKETSIZE  64
 #define USBD_HID_HS_BINTERVAL       6
-#define USBD_HID_STRDESC            L"CMSIS-DAP v1"
-#define USBD_WEBUSB_STRDESC         L"WebUSB: CMSIS-DAP"
+#define USBD_HID_STRDESC            u"CMSIS-DAP v1"
+#define USBD_WEBUSB_STRDESC         u"WebUSB: CMSIS-DAP"
 #define USBD_HID_INREPORT_NUM       1
 #define USBD_HID_OUTREPORT_NUM      1
 #define USBD_HID_INREPORT_MAX_SZ    64
@@ -220,7 +220,7 @@
 #define USBD_MSC_HS_ENABLE          0
 #define USBD_MSC_HS_WMAXPACKETSIZE  512
 #define USBD_MSC_HS_BINTERVAL       0
-#define USBD_MSC_STRDESC            L"USB_MSC"
+#define USBD_MSC_STRDESC            u"USB_MSC"
 // Make sure changes to USBD_MSC_INQUIRY_DATA are coordinated with mbed-ls
 // since this is used to detect DAPLink drives
 #define USBD_MSC_INQUIRY_DATA       "MBED    "         \
@@ -265,9 +265,9 @@
 #define USBD_ADC_BINTERVAL          1
 #define USBD_ADC_HS_ENABLE          0
 #define USBD_ADC_HS_WMAXPACKETSIZE  64
-#define USBD_ADC_CIF_STRDESC        L"USB_ADC"
-#define USBD_ADC_SIF1_STRDESC       L"USB_ADC1"
-#define USBD_ADC_SIF2_STRDESC       L"USB_ADC2"
+#define USBD_ADC_CIF_STRDESC        u"USB_ADC"
+#define USBD_ADC_SIF1_STRDESC       u"USB_ADC1"
+#define USBD_ADC_SIF2_STRDESC       u"USB_ADC2"
 #define USBD_ADC_BSUBFRAMESIZE      2
 #define USBD_ADC_BBITRESOLUTION     16
 #define USBD_ADC_TSAMFREQ           32000
@@ -347,8 +347,8 @@
 #define USBD_CDC_ACM_HS_ENABLE1         0
 #define USBD_CDC_ACM_HS_WMAXPACKETSIZE1 64
 #define USBD_CDC_ACM_HS_BINTERVAL1      0
-#define USBD_CDC_ACM_CIF_STRDESC        L"mbed Serial Port"
-#define USBD_CDC_ACM_DIF_STRDESC        L"mbed Serial Port"
+#define USBD_CDC_ACM_CIF_STRDESC        u"mbed Serial Port"
+#define USBD_CDC_ACM_DIF_STRDESC        u"mbed Serial Port"
 #define USBD_CDC_ACM_SENDBUF_SIZE       64
 #define USBD_CDC_ACM_RECEIVEBUF_SIZE    64
 #if (((USBD_CDC_ACM_HS_ENABLE1) && (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_HS_WMAXPACKETSIZE1)) || (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_WMAXPACKETSIZE1))
@@ -399,7 +399,7 @@
 #define USBD_BULK_WMAXPACKETSIZE     64
 #define USBD_BULK_HS_ENABLE          0
 #define USBD_BULK_HS_WMAXPACKETSIZE  512
-#define USBD_BULK_STRDESC            L"CMSIS-DAP v2"
+#define USBD_BULK_STRDESC            u"CMSIS-DAP v2"
 
 
 /* USB Device Calculations ---------------------------------------------------*/
diff --git a/source/hic_hal/freescale/kl27z/usb_config.c b/source/hic_hal/freescale/kl27z/usb_config.c
index 7bd4a8225..278775b21 100644
--- a/source/hic_hal/freescale/kl27z/usb_config.c
+++ b/source/hic_hal/freescale/kl27z/usb_config.c
@@ -91,16 +91,16 @@
 //     </e>
 //   </h>
 #define USBD_STRDESC_LANGID         0x0409
-#define USBD_STRDESC_MAN            L"Arm"
+#define USBD_STRDESC_MAN            u"Arm"
 #ifndef USB_PROD_STR
-#define USBD_STRDESC_PROD           L"DAPLink CMSIS-DAP"
+#define USBD_STRDESC_PROD           u"DAPLink CMSIS-DAP"
 #else
-#define _TOWIDE(x)                   L ## #x
+#define _TOWIDE(x)                   u ## #x
 #define TOWIDE(x)                   _TOWIDE(x)
 #define USBD_STRDESC_PROD           TOWIDE(USB_PROD_STR)
 #endif
 #define USBD_STRDESC_SER_ENABLE     1
-#define USBD_STRDESC_SER            L"0001A0000000"
+#define USBD_STRDESC_SER            u"0001A0000000"
 
 //   <e0> Class Support
 //     <i> Enables USB Device Class specific Requests
@@ -170,8 +170,8 @@
 #define USBD_HID_HS_ENABLE          0
 #define USBD_HID_HS_WMAXPACKETSIZE  64
 #define USBD_HID_HS_BINTERVAL       6
-#define USBD_HID_STRDESC            L"CMSIS-DAP v1"
-#define USBD_WEBUSB_STRDESC         L"WebUSB: CMSIS-DAP"
+#define USBD_HID_STRDESC            u"CMSIS-DAP v1"
+#define USBD_WEBUSB_STRDESC         u"WebUSB: CMSIS-DAP"
 #define USBD_HID_INREPORT_NUM       1
 #define USBD_HID_OUTREPORT_NUM      1
 #define USBD_HID_INREPORT_MAX_SZ    64
@@ -221,7 +221,7 @@
 #define USBD_MSC_HS_ENABLE          0
 #define USBD_MSC_HS_WMAXPACKETSIZE  512
 #define USBD_MSC_HS_BINTERVAL       0
-#define USBD_MSC_STRDESC            L"USB_MSC"
+#define USBD_MSC_STRDESC            u"USB_MSC"
 // Make sure changes to USBD_MSC_INQUIRY_DATA are coordinated with mbed-ls
 // since this is used to detect DAPLink drives
 #define USBD_MSC_INQUIRY_DATA       "MBED    "         \
@@ -266,9 +266,9 @@
 #define USBD_ADC_BINTERVAL          1
 #define USBD_ADC_HS_ENABLE          0
 #define USBD_ADC_HS_WMAXPACKETSIZE  64
-#define USBD_ADC_CIF_STRDESC        L"USB_ADC"
-#define USBD_ADC_SIF1_STRDESC       L"USB_ADC1"
-#define USBD_ADC_SIF2_STRDESC       L"USB_ADC2"
+#define USBD_ADC_CIF_STRDESC        u"USB_ADC"
+#define USBD_ADC_SIF1_STRDESC       u"USB_ADC1"
+#define USBD_ADC_SIF2_STRDESC       u"USB_ADC2"
 #define USBD_ADC_BSUBFRAMESIZE      2
 #define USBD_ADC_BBITRESOLUTION     16
 #define USBD_ADC_TSAMFREQ           32000
@@ -348,8 +348,8 @@
 #define USBD_CDC_ACM_HS_ENABLE1         0
 #define USBD_CDC_ACM_HS_WMAXPACKETSIZE1 64
 #define USBD_CDC_ACM_HS_BINTERVAL1      0
-#define USBD_CDC_ACM_CIF_STRDESC        L"mbed Serial Port"
-#define USBD_CDC_ACM_DIF_STRDESC        L"mbed Serial Port"
+#define USBD_CDC_ACM_CIF_STRDESC        u"mbed Serial Port"
+#define USBD_CDC_ACM_DIF_STRDESC        u"mbed Serial Port"
 #define USBD_CDC_ACM_SENDBUF_SIZE       64
 #define USBD_CDC_ACM_RECEIVEBUF_SIZE    64
 #if (((USBD_CDC_ACM_HS_ENABLE1) && (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_HS_WMAXPACKETSIZE1)) || (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_WMAXPACKETSIZE1))
@@ -400,7 +400,7 @@
 #define USBD_BULK_WMAXPACKETSIZE     64
 #define USBD_BULK_HS_ENABLE          0
 #define USBD_BULK_HS_WMAXPACKETSIZE  512
-#define USBD_BULK_STRDESC            L"CMSIS-DAP v2"
+#define USBD_BULK_STRDESC            u"CMSIS-DAP v2"
 
 
 /* USB Device Calculations ---------------------------------------------------*/
diff --git a/source/hic_hal/maxim/max32620/usb_config.c b/source/hic_hal/maxim/max32620/usb_config.c
index 21abdbaf3..2d41eee2b 100644
--- a/source/hic_hal/maxim/max32620/usb_config.c
+++ b/source/hic_hal/maxim/max32620/usb_config.c
@@ -90,16 +90,16 @@
 //     </e>
 //   </h>
 #define USBD_STRDESC_LANGID         0x0409
-#define USBD_STRDESC_MAN            L"Arm"
+#define USBD_STRDESC_MAN            u"Arm"
 #ifndef USB_PROD_STR
-#define USBD_STRDESC_PROD           L"DAPLink CMSIS-DAP"
+#define USBD_STRDESC_PROD           u"DAPLink CMSIS-DAP"
 #else
-#define _TOWIDE(x)                   L ## #x
+#define _TOWIDE(x)                   u ## #x
 #define TOWIDE(x)                   _TOWIDE(x)
 #define USBD_STRDESC_PROD           TOWIDE(USB_PROD_STR)
 #endif
 #define USBD_STRDESC_SER_ENABLE     1
-#define USBD_STRDESC_SER            L"0001A0000000"
+#define USBD_STRDESC_SER            u"0001A0000000"
 
 //   <e0> Class Support
 //     <i> Enables USB Device Class specific Requests
@@ -173,8 +173,8 @@
 #define USBD_HID_HS_ENABLE          0
 #define USBD_HID_HS_WMAXPACKETSIZE  64
 #define USBD_HID_HS_BINTERVAL       6
-#define USBD_HID_STRDESC            L"CMSIS-DAP v1"
-#define USBD_WEBUSB_STRDESC         L"WebUSB: CMSIS-DAP"
+#define USBD_HID_STRDESC            u"CMSIS-DAP v1"
+#define USBD_WEBUSB_STRDESC         u"WebUSB: CMSIS-DAP"
 #define USBD_HID_INREPORT_NUM       1
 #define USBD_HID_OUTREPORT_NUM      1
 #define USBD_HID_INREPORT_MAX_SZ    64
@@ -224,7 +224,7 @@
 #define USBD_MSC_HS_ENABLE          0
 #define USBD_MSC_HS_WMAXPACKETSIZE  512
 #define USBD_MSC_HS_BINTERVAL       0
-#define USBD_MSC_STRDESC            L"USB_MSC"
+#define USBD_MSC_STRDESC            u"USB_MSC"
 #define USBD_MSC_INQUIRY_DATA       "MBED    "         \
                                     "VFS             " \
                                     "0.1"
@@ -267,9 +267,9 @@
 #define USBD_ADC_BINTERVAL          1
 #define USBD_ADC_HS_ENABLE          0
 #define USBD_ADC_HS_WMAXPACKETSIZE  64
-#define USBD_ADC_CIF_STRDESC        L"USB_ADC"
-#define USBD_ADC_SIF1_STRDESC       L"USB_ADC1"
-#define USBD_ADC_SIF2_STRDESC       L"USB_ADC2"
+#define USBD_ADC_CIF_STRDESC        u"USB_ADC"
+#define USBD_ADC_SIF1_STRDESC       u"USB_ADC1"
+#define USBD_ADC_SIF2_STRDESC       u"USB_ADC2"
 #define USBD_ADC_BSUBFRAMESIZE      2
 #define USBD_ADC_BBITRESOLUTION     16
 #define USBD_ADC_TSAMFREQ           32000
@@ -349,8 +349,8 @@
 #define USBD_CDC_ACM_HS_ENABLE1         0
 #define USBD_CDC_ACM_HS_WMAXPACKETSIZE1 64
 #define USBD_CDC_ACM_HS_BINTERVAL1      0
-#define USBD_CDC_ACM_CIF_STRDESC        L"mbed Serial Port"
-#define USBD_CDC_ACM_DIF_STRDESC        L"mbed Serial Port"
+#define USBD_CDC_ACM_CIF_STRDESC        u"mbed Serial Port"
+#define USBD_CDC_ACM_DIF_STRDESC        u"mbed Serial Port"
 #define USBD_CDC_ACM_SENDBUF_SIZE       64
 #define USBD_CDC_ACM_RECEIVEBUF_SIZE    64
 #if (((USBD_CDC_ACM_HS_ENABLE1) && (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_HS_WMAXPACKETSIZE1)) || (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_WMAXPACKETSIZE1))
@@ -402,7 +402,7 @@
 #define USBD_BULK_WMAXPACKETSIZE     64
 #define USBD_BULK_HS_ENABLE          0
 #define USBD_BULK_HS_WMAXPACKETSIZE  512
-#define USBD_BULK_STRDESC            L"CMSIS-DAP v2"
+#define USBD_BULK_STRDESC            u"CMSIS-DAP v2"
 
 
 /* USB Device Calculations ---------------------------------------------------*/
diff --git a/source/hic_hal/maxim/max32625/usb_config.c b/source/hic_hal/maxim/max32625/usb_config.c
index 21abdbaf3..2d41eee2b 100755
--- a/source/hic_hal/maxim/max32625/usb_config.c
+++ b/source/hic_hal/maxim/max32625/usb_config.c
@@ -90,16 +90,16 @@
 //     </e>
 //   </h>
 #define USBD_STRDESC_LANGID         0x0409
-#define USBD_STRDESC_MAN            L"Arm"
+#define USBD_STRDESC_MAN            u"Arm"
 #ifndef USB_PROD_STR
-#define USBD_STRDESC_PROD           L"DAPLink CMSIS-DAP"
+#define USBD_STRDESC_PROD           u"DAPLink CMSIS-DAP"
 #else
-#define _TOWIDE(x)                   L ## #x
+#define _TOWIDE(x)                   u ## #x
 #define TOWIDE(x)                   _TOWIDE(x)
 #define USBD_STRDESC_PROD           TOWIDE(USB_PROD_STR)
 #endif
 #define USBD_STRDESC_SER_ENABLE     1
-#define USBD_STRDESC_SER            L"0001A0000000"
+#define USBD_STRDESC_SER            u"0001A0000000"
 
 //   <e0> Class Support
 //     <i> Enables USB Device Class specific Requests
@@ -173,8 +173,8 @@
 #define USBD_HID_HS_ENABLE          0
 #define USBD_HID_HS_WMAXPACKETSIZE  64
 #define USBD_HID_HS_BINTERVAL       6
-#define USBD_HID_STRDESC            L"CMSIS-DAP v1"
-#define USBD_WEBUSB_STRDESC         L"WebUSB: CMSIS-DAP"
+#define USBD_HID_STRDESC            u"CMSIS-DAP v1"
+#define USBD_WEBUSB_STRDESC         u"WebUSB: CMSIS-DAP"
 #define USBD_HID_INREPORT_NUM       1
 #define USBD_HID_OUTREPORT_NUM      1
 #define USBD_HID_INREPORT_MAX_SZ    64
@@ -224,7 +224,7 @@
 #define USBD_MSC_HS_ENABLE          0
 #define USBD_MSC_HS_WMAXPACKETSIZE  512
 #define USBD_MSC_HS_BINTERVAL       0
-#define USBD_MSC_STRDESC            L"USB_MSC"
+#define USBD_MSC_STRDESC            u"USB_MSC"
 #define USBD_MSC_INQUIRY_DATA       "MBED    "         \
                                     "VFS             " \
                                     "0.1"
@@ -267,9 +267,9 @@
 #define USBD_ADC_BINTERVAL          1
 #define USBD_ADC_HS_ENABLE          0
 #define USBD_ADC_HS_WMAXPACKETSIZE  64
-#define USBD_ADC_CIF_STRDESC        L"USB_ADC"
-#define USBD_ADC_SIF1_STRDESC       L"USB_ADC1"
-#define USBD_ADC_SIF2_STRDESC       L"USB_ADC2"
+#define USBD_ADC_CIF_STRDESC        u"USB_ADC"
+#define USBD_ADC_SIF1_STRDESC       u"USB_ADC1"
+#define USBD_ADC_SIF2_STRDESC       u"USB_ADC2"
 #define USBD_ADC_BSUBFRAMESIZE      2
 #define USBD_ADC_BBITRESOLUTION     16
 #define USBD_ADC_TSAMFREQ           32000
@@ -349,8 +349,8 @@
 #define USBD_CDC_ACM_HS_ENABLE1         0
 #define USBD_CDC_ACM_HS_WMAXPACKETSIZE1 64
 #define USBD_CDC_ACM_HS_BINTERVAL1      0
-#define USBD_CDC_ACM_CIF_STRDESC        L"mbed Serial Port"
-#define USBD_CDC_ACM_DIF_STRDESC        L"mbed Serial Port"
+#define USBD_CDC_ACM_CIF_STRDESC        u"mbed Serial Port"
+#define USBD_CDC_ACM_DIF_STRDESC        u"mbed Serial Port"
 #define USBD_CDC_ACM_SENDBUF_SIZE       64
 #define USBD_CDC_ACM_RECEIVEBUF_SIZE    64
 #if (((USBD_CDC_ACM_HS_ENABLE1) && (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_HS_WMAXPACKETSIZE1)) || (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_WMAXPACKETSIZE1))
@@ -402,7 +402,7 @@
 #define USBD_BULK_WMAXPACKETSIZE     64
 #define USBD_BULK_HS_ENABLE          0
 #define USBD_BULK_HS_WMAXPACKETSIZE  512
-#define USBD_BULK_STRDESC            L"CMSIS-DAP v2"
+#define USBD_BULK_STRDESC            u"CMSIS-DAP v2"
 
 
 /* USB Device Calculations ---------------------------------------------------*/
diff --git a/source/hic_hal/nordic/nrf52820/usb_config.c b/source/hic_hal/nordic/nrf52820/usb_config.c
index 1eaae6b77..d0b377081 100644
--- a/source/hic_hal/nordic/nrf52820/usb_config.c
+++ b/source/hic_hal/nordic/nrf52820/usb_config.c
@@ -86,16 +86,16 @@
 //     </e>
 //   </h>
 #define USBD_STRDESC_LANGID         0x0409
-#define USBD_STRDESC_MAN            L"Arm"
+#define USBD_STRDESC_MAN            u"Arm"
 #ifndef USB_PROD_STR
-#define USBD_STRDESC_PROD           L"DAPLink CMSIS-DAP"
+#define USBD_STRDESC_PROD           u"DAPLink CMSIS-DAP"
 #else
-#define _TOWIDE(x)                   L ## #x
+#define _TOWIDE(x)                   u ## #x
 #define TOWIDE(x)                   _TOWIDE(x)
 #define USBD_STRDESC_PROD           TOWIDE(USB_PROD_STR)
 #endif
 #define USBD_STRDESC_SER_ENABLE     1
-#define USBD_STRDESC_SER            L"0001A0000000"
+#define USBD_STRDESC_SER            u"0001A0000000"
 
 //   <e0> Class Support
 //     <i> Enables USB Device Class specific Requests
@@ -164,8 +164,8 @@
 #define USBD_HID_HS_ENABLE          0
 #define USBD_HID_HS_WMAXPACKETSIZE  64
 #define USBD_HID_HS_BINTERVAL       1
-#define USBD_HID_STRDESC            L"CMSIS-DAP v1"
-#define USBD_WEBUSB_STRDESC         L"WebUSB: CMSIS-DAP"
+#define USBD_HID_STRDESC            u"CMSIS-DAP v1"
+#define USBD_WEBUSB_STRDESC         u"WebUSB: CMSIS-DAP"
 #define USBD_HID_INREPORT_NUM       1
 #define USBD_HID_OUTREPORT_NUM      1
 #define USBD_HID_INREPORT_MAX_SZ    64
@@ -215,7 +215,7 @@
 #define USBD_MSC_HS_ENABLE          0
 #define USBD_MSC_HS_WMAXPACKETSIZE  512
 #define USBD_MSC_HS_BINTERVAL       0
-#define USBD_MSC_STRDESC            L"USB_MSC"
+#define USBD_MSC_STRDESC            u"USB_MSC"
 // Make sure changes to USBD_MSC_INQUIRY_DATA are coordinated with mbed-ls
 // since this is used to detect DAPLink drives
 #define USBD_MSC_INQUIRY_DATA       "MBED    "         \
@@ -260,9 +260,9 @@
 #define USBD_ADC_BINTERVAL          1
 #define USBD_ADC_HS_ENABLE          0
 #define USBD_ADC_HS_WMAXPACKETSIZE  64
-#define USBD_ADC_CIF_STRDESC        L"USB_ADC"
-#define USBD_ADC_SIF1_STRDESC       L"USB_ADC1"
-#define USBD_ADC_SIF2_STRDESC       L"USB_ADC2"
+#define USBD_ADC_CIF_STRDESC        u"USB_ADC"
+#define USBD_ADC_SIF1_STRDESC       u"USB_ADC1"
+#define USBD_ADC_SIF2_STRDESC       u"USB_ADC2"
 #define USBD_ADC_BSUBFRAMESIZE      2
 #define USBD_ADC_BBITRESOLUTION     16
 #define USBD_ADC_TSAMFREQ           32000
@@ -342,8 +342,8 @@
 #define USBD_CDC_ACM_HS_ENABLE1         1
 #define USBD_CDC_ACM_HS_WMAXPACKETSIZE1 64
 #define USBD_CDC_ACM_HS_BINTERVAL1      1
-#define USBD_CDC_ACM_CIF_STRDESC        L"mbed Serial Port"
-#define USBD_CDC_ACM_DIF_STRDESC        L"mbed Serial Port"
+#define USBD_CDC_ACM_CIF_STRDESC        u"mbed Serial Port"
+#define USBD_CDC_ACM_DIF_STRDESC        u"mbed Serial Port"
 #define USBD_CDC_ACM_SENDBUF_SIZE       USBD_CDC_ACM_HS_WMAXPACKETSIZE1
 #define USBD_CDC_ACM_RECEIVEBUF_SIZE    USBD_CDC_ACM_HS_WMAXPACKETSIZE1
 #if (((USBD_CDC_ACM_HS_ENABLE1) && (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_HS_WMAXPACKETSIZE1)) || (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_WMAXPACKETSIZE1))
@@ -395,7 +395,7 @@
 #define USBD_BULK_WMAXPACKETSIZE     64
 #define USBD_BULK_HS_ENABLE          0
 #define USBD_BULK_HS_WMAXPACKETSIZE  512
-#define USBD_BULK_STRDESC            L"CMSIS-DAP v2"
+#define USBD_BULK_STRDESC            u"CMSIS-DAP v2"
 
 
 /* USB Device Calculations ---------------------------------------------------*/
diff --git a/source/hic_hal/nuvoton/m48ssidae/usb_config.c b/source/hic_hal/nuvoton/m48ssidae/usb_config.c
index 79ae70d77..37e10312c 100644
--- a/source/hic_hal/nuvoton/m48ssidae/usb_config.c
+++ b/source/hic_hal/nuvoton/m48ssidae/usb_config.c
@@ -90,16 +90,16 @@
 //     </e>
 //   </h>
 #define USBD_STRDESC_LANGID         0x0409
-#define USBD_STRDESC_MAN            L"Arm"
+#define USBD_STRDESC_MAN            u"Arm"
 #ifndef USB_PROD_STR
-#define USBD_STRDESC_PROD           L"DAPLink CMSIS-DAP"
+#define USBD_STRDESC_PROD           u"DAPLink CMSIS-DAP"
 #else
-#define _TOWIDE(x)                   L ## #x
+#define _TOWIDE(x)                   u ## #x
 #define TOWIDE(x)                   _TOWIDE(x)
 #define USBD_STRDESC_PROD           TOWIDE(USB_PROD_STR)
 #endif
 #define USBD_STRDESC_SER_ENABLE     1
-#define USBD_STRDESC_SER            L"0001A0000000"
+#define USBD_STRDESC_SER            u"0001A0000000"
 
 //   <e0> Class Support
 //     <i> Enables USB Device Class specific Requests
@@ -173,8 +173,8 @@
 #define USBD_HID_HS_ENABLE          1
 #define USBD_HID_HS_WMAXPACKETSIZE  64
 #define USBD_HID_HS_BINTERVAL       4
-#define USBD_HID_STRDESC            L"CMSIS-DAP v1"
-#define USBD_WEBUSB_STRDESC         L"WebUSB: CMSIS-DAP"
+#define USBD_HID_STRDESC            u"CMSIS-DAP v1"
+#define USBD_WEBUSB_STRDESC         u"WebUSB: CMSIS-DAP"
 #define USBD_HID_INREPORT_NUM       1
 #define USBD_HID_OUTREPORT_NUM      1
 #define USBD_HID_INREPORT_MAX_SZ    64
@@ -224,7 +224,7 @@
 #define USBD_MSC_HS_ENABLE          1
 #define USBD_MSC_HS_WMAXPACKETSIZE  512
 #define USBD_MSC_HS_BINTERVAL       0
-#define USBD_MSC_STRDESC            L"USB_MSC"
+#define USBD_MSC_STRDESC            u"USB_MSC"
 // Make sure changes to USBD_MSC_INQUIRY_DATA are coordinated with mbed-ls
 // since this is used to detect DAPLink drives
 #define USBD_MSC_INQUIRY_DATA       "MBED    "         \
@@ -269,9 +269,9 @@
 #define USBD_ADC_BINTERVAL          1
 #define USBD_ADC_HS_ENABLE          0
 #define USBD_ADC_HS_WMAXPACKETSIZE  64
-#define USBD_ADC_CIF_STRDESC        L"USB_ADC"
-#define USBD_ADC_SIF1_STRDESC       L"USB_ADC1"
-#define USBD_ADC_SIF2_STRDESC       L"USB_ADC2"
+#define USBD_ADC_CIF_STRDESC        u"USB_ADC"
+#define USBD_ADC_SIF1_STRDESC       u"USB_ADC1"
+#define USBD_ADC_SIF2_STRDESC       u"USB_ADC2"
 #define USBD_ADC_BSUBFRAMESIZE      2
 #define USBD_ADC_BBITRESOLUTION     16
 #define USBD_ADC_TSAMFREQ           32000
@@ -351,8 +351,8 @@
 #define USBD_CDC_ACM_HS_ENABLE1         1
 #define USBD_CDC_ACM_HS_WMAXPACKETSIZE1 512
 #define USBD_CDC_ACM_HS_BINTERVAL1      0
-#define USBD_CDC_ACM_CIF_STRDESC        L"mbed Serial Port"
-#define USBD_CDC_ACM_DIF_STRDESC        L"mbed Serial Port"
+#define USBD_CDC_ACM_CIF_STRDESC        u"mbed Serial Port"
+#define USBD_CDC_ACM_DIF_STRDESC        u"mbed Serial Port"
 #define USBD_CDC_ACM_SENDBUF_SIZE       512
 #define USBD_CDC_ACM_RECEIVEBUF_SIZE    512
 #if (((USBD_CDC_ACM_HS_ENABLE1) && (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_HS_WMAXPACKETSIZE1)) || (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_WMAXPACKETSIZE1))
@@ -404,7 +404,7 @@
 #define USBD_BULK_WMAXPACKETSIZE     64
 #define USBD_BULK_HS_ENABLE          0
 #define USBD_BULK_HS_WMAXPACKETSIZE  512
-#define USBD_BULK_STRDESC            L"CMSIS-DAP v2"
+#define USBD_BULK_STRDESC            u"CMSIS-DAP v2"
 
 
 /* USB Device Calculations ---------------------------------------------------*/
diff --git a/source/hic_hal/nxp/lpc11u35/usb_config.c b/source/hic_hal/nxp/lpc11u35/usb_config.c
index 56a3ef7de..e957857bd 100644
--- a/source/hic_hal/nxp/lpc11u35/usb_config.c
+++ b/source/hic_hal/nxp/lpc11u35/usb_config.c
@@ -90,16 +90,16 @@
 //     </e>
 //   </h>
 #define USBD_STRDESC_LANGID         0x0409
-#define USBD_STRDESC_MAN            L"Arm"
+#define USBD_STRDESC_MAN            u"Arm"
 #ifndef USB_PROD_STR
-#define USBD_STRDESC_PROD           L"DAPLink CMSIS-DAP"
+#define USBD_STRDESC_PROD           u"DAPLink CMSIS-DAP"
 #else
-#define _TOWIDE(x)                   L ## #x
+#define _TOWIDE(x)                   u ## #x
 #define TOWIDE(x)                   _TOWIDE(x)
 #define USBD_STRDESC_PROD           TOWIDE(USB_PROD_STR)
 #endif
 #define USBD_STRDESC_SER_ENABLE     1
-#define USBD_STRDESC_SER            L"0001A0000000"
+#define USBD_STRDESC_SER            u"0001A0000000"
 
 //   <e0> Class Support
 //     <i> Enables USB Device Class specific Requests
@@ -174,8 +174,8 @@
 #define USBD_HID_HS_ENABLE          0
 #define USBD_HID_HS_WMAXPACKETSIZE  64
 #define USBD_HID_HS_BINTERVAL       6
-#define USBD_HID_STRDESC            L"CMSIS-DAP v1"
-#define USBD_WEBUSB_STRDESC         L"WebUSB: CMSIS-DAP"
+#define USBD_HID_STRDESC            u"CMSIS-DAP v1"
+#define USBD_WEBUSB_STRDESC         u"WebUSB: CMSIS-DAP"
 #define USBD_HID_INREPORT_NUM       1
 #define USBD_HID_OUTREPORT_NUM      1
 #define USBD_HID_INREPORT_MAX_SZ    64
@@ -225,7 +225,7 @@
 #define USBD_MSC_HS_ENABLE          0
 #define USBD_MSC_HS_WMAXPACKETSIZE  512
 #define USBD_MSC_HS_BINTERVAL       0
-#define USBD_MSC_STRDESC            L"USB_MSC"
+#define USBD_MSC_STRDESC            u"USB_MSC"
 // Make sure changes to USBD_MSC_INQUIRY_DATA are coordinated with mbed-ls
 // since this is used to detect DAPLink drives
 #define USBD_MSC_INQUIRY_DATA       "MBED    "         \
@@ -270,9 +270,9 @@
 #define USBD_ADC_BINTERVAL          1
 #define USBD_ADC_HS_ENABLE          0
 #define USBD_ADC_HS_WMAXPACKETSIZE  64
-#define USBD_ADC_CIF_STRDESC        L"USB_ADC"
-#define USBD_ADC_SIF1_STRDESC       L"USB_ADC1"
-#define USBD_ADC_SIF2_STRDESC       L"USB_ADC2"
+#define USBD_ADC_CIF_STRDESC        u"USB_ADC"
+#define USBD_ADC_SIF1_STRDESC       u"USB_ADC1"
+#define USBD_ADC_SIF2_STRDESC       u"USB_ADC2"
 #define USBD_ADC_BSUBFRAMESIZE      2
 #define USBD_ADC_BBITRESOLUTION     16
 #define USBD_ADC_TSAMFREQ           32000
@@ -352,8 +352,8 @@
 #define USBD_CDC_ACM_HS_ENABLE1         0
 #define USBD_CDC_ACM_HS_WMAXPACKETSIZE1 64
 #define USBD_CDC_ACM_HS_BINTERVAL1      0
-#define USBD_CDC_ACM_CIF_STRDESC        L"mbed Serial Port"
-#define USBD_CDC_ACM_DIF_STRDESC        L"mbed Serial Port"
+#define USBD_CDC_ACM_CIF_STRDESC        u"mbed Serial Port"
+#define USBD_CDC_ACM_DIF_STRDESC        u"mbed Serial Port"
 #define USBD_CDC_ACM_SENDBUF_SIZE       64
 #define USBD_CDC_ACM_RECEIVEBUF_SIZE    64
 #if (((USBD_CDC_ACM_HS_ENABLE1) && (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_HS_WMAXPACKETSIZE1)) || (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_WMAXPACKETSIZE1))
@@ -405,7 +405,7 @@
 #define USBD_BULK_WMAXPACKETSIZE     64
 #define USBD_BULK_HS_ENABLE          0
 #define USBD_BULK_HS_WMAXPACKETSIZE  512
-#define USBD_BULK_STRDESC            L"CMSIS-DAP v2"
+#define USBD_BULK_STRDESC            u"CMSIS-DAP v2"
 
 
 /* USB Device Calculations ---------------------------------------------------*/
diff --git a/source/hic_hal/nxp/lpc4322/usb_config.c b/source/hic_hal/nxp/lpc4322/usb_config.c
index 9b8dde6c1..faca95c2b 100644
--- a/source/hic_hal/nxp/lpc4322/usb_config.c
+++ b/source/hic_hal/nxp/lpc4322/usb_config.c
@@ -99,16 +99,16 @@
 //     </e>
 //   </h>
 #define USBD_STRDESC_LANGID         0x0409
-#define USBD_STRDESC_MAN            L"Arm"
+#define USBD_STRDESC_MAN            u"Arm"
 #ifndef USB_PROD_STR
-#define USBD_STRDESC_PROD           L"DAPLink CMSIS-DAP"
+#define USBD_STRDESC_PROD           u"DAPLink CMSIS-DAP"
 #else
-#define _TOWIDE(x)                   L ## #x
+#define _TOWIDE(x)                   u ## #x
 #define TOWIDE(x)                   _TOWIDE(x)
 #define USBD_STRDESC_PROD           TOWIDE(USB_PROD_STR)
 #endif
 #define USBD_STRDESC_SER_ENABLE     1
-#define USBD_STRDESC_SER            L"0001A0000000"
+#define USBD_STRDESC_SER            u"0001A0000000"
 
 //   <e0> Class Support
 //     <i> Enables USB Device Class specific Requests
@@ -178,8 +178,8 @@
 #define USBD_HID_HS_ENABLE          1
 #define USBD_HID_HS_WMAXPACKETSIZE  64 //| (2<<11)
 #define USBD_HID_HS_BINTERVAL       1
-#define USBD_HID_STRDESC            L"CMSIS-DAP v1"
-#define USBD_WEBUSB_STRDESC         L"WebUSB: CMSIS-DAP"
+#define USBD_HID_STRDESC            u"CMSIS-DAP v1"
+#define USBD_WEBUSB_STRDESC         u"WebUSB: CMSIS-DAP"
 #define USBD_HID_INREPORT_NUM       1
 #define USBD_HID_OUTREPORT_NUM      1
 #define USBD_HID_INREPORT_MAX_SZ    64
@@ -229,7 +229,7 @@
 #define USBD_MSC_HS_ENABLE          1
 #define USBD_MSC_HS_WMAXPACKETSIZE  512
 #define USBD_MSC_HS_BINTERVAL       0
-#define USBD_MSC_STRDESC            L"USB_MSC"
+#define USBD_MSC_STRDESC            u"USB_MSC"
 // Make sure changes to USBD_MSC_INQUIRY_DATA are coordinated with mbed-ls
 // since this is used to detect DAPLink drives
 #define USBD_MSC_INQUIRY_DATA       "MBED    "         \
@@ -274,9 +274,9 @@
 #define USBD_ADC_BINTERVAL          1
 #define USBD_ADC_HS_ENABLE          0
 #define USBD_ADC_HS_WMAXPACKETSIZE  64
-#define USBD_ADC_CIF_STRDESC        L"USB_ADC"
-#define USBD_ADC_SIF1_STRDESC       L"USB_ADC1"
-#define USBD_ADC_SIF2_STRDESC       L"USB_ADC2"
+#define USBD_ADC_CIF_STRDESC        u"USB_ADC"
+#define USBD_ADC_SIF1_STRDESC       u"USB_ADC1"
+#define USBD_ADC_SIF2_STRDESC       u"USB_ADC2"
 #define USBD_ADC_BSUBFRAMESIZE      2
 #define USBD_ADC_BBITRESOLUTION     16
 #define USBD_ADC_TSAMFREQ           32000
@@ -356,8 +356,8 @@
 #define USBD_CDC_ACM_HS_ENABLE1         1
 #define USBD_CDC_ACM_HS_WMAXPACKETSIZE1 512
 #define USBD_CDC_ACM_HS_BINTERVAL1      1
-#define USBD_CDC_ACM_CIF_STRDESC        L"mbed Serial Port"
-#define USBD_CDC_ACM_DIF_STRDESC        L"mbed Serial Port"
+#define USBD_CDC_ACM_CIF_STRDESC        u"mbed Serial Port"
+#define USBD_CDC_ACM_DIF_STRDESC        u"mbed Serial Port"
 #define USBD_CDC_ACM_SENDBUF_SIZE       USBD_CDC_ACM_HS_WMAXPACKETSIZE1
 #define USBD_CDC_ACM_RECEIVEBUF_SIZE    USBD_CDC_ACM_HS_WMAXPACKETSIZE1
 #if (((USBD_CDC_ACM_HS_ENABLE1) && (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_HS_WMAXPACKETSIZE1)) || (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_WMAXPACKETSIZE1))
@@ -408,7 +408,7 @@
 #define USBD_BULK_WMAXPACKETSIZE     64
 #define USBD_BULK_HS_ENABLE          1
 #define USBD_BULK_HS_WMAXPACKETSIZE  512
-#define USBD_BULK_STRDESC            L"CMSIS-DAP v2"
+#define USBD_BULK_STRDESC            u"CMSIS-DAP v2"
 
 
 /* USB Device Calculations ---------------------------------------------------*/
diff --git a/source/hic_hal/nxp/lpc55xx/usb_config.c b/source/hic_hal/nxp/lpc55xx/usb_config.c
index f816f800c..c8d481b79 100644
--- a/source/hic_hal/nxp/lpc55xx/usb_config.c
+++ b/source/hic_hal/nxp/lpc55xx/usb_config.c
@@ -95,16 +95,16 @@
 //     </e>
 //   </h>
 #define USBD_STRDESC_LANGID         0x0409
-#define USBD_STRDESC_MAN            L"Arm"
+#define USBD_STRDESC_MAN            u"Arm"
 #ifndef USB_PROD_STR
-#define USBD_STRDESC_PROD           L"DAPLink CMSIS-DAP"
+#define USBD_STRDESC_PROD           u"DAPLink CMSIS-DAP"
 #else
-#define _TOWIDE(x)                   L ## #x
+#define _TOWIDE(x)                   u ## #x
 #define TOWIDE(x)                   _TOWIDE(x)
 #define USBD_STRDESC_PROD           TOWIDE(USB_PROD_STR)
 #endif
 #define USBD_STRDESC_SER_ENABLE     1
-#define USBD_STRDESC_SER            L"0001A0000000"
+#define USBD_STRDESC_SER            u"0001A0000000"
 
 //   <e0> Class Support
 //     <i> Enables USB Device Class specific Requests
@@ -174,8 +174,8 @@
 #define USBD_HID_HS_ENABLE          1
 #define USBD_HID_HS_WMAXPACKETSIZE  64 //| (2<<11)
 #define USBD_HID_HS_BINTERVAL       1
-#define USBD_HID_STRDESC            L"CMSIS-DAP v1"
-#define USBD_WEBUSB_STRDESC         L"WebUSB: CMSIS-DAP"
+#define USBD_HID_STRDESC            u"CMSIS-DAP v1"
+#define USBD_WEBUSB_STRDESC         u"WebUSB: CMSIS-DAP"
 #define USBD_HID_INREPORT_NUM       1
 #define USBD_HID_OUTREPORT_NUM      1
 #define USBD_HID_INREPORT_MAX_SZ    64
@@ -225,7 +225,7 @@
 #define USBD_MSC_HS_ENABLE          1
 #define USBD_MSC_HS_WMAXPACKETSIZE  512
 #define USBD_MSC_HS_BINTERVAL       0
-#define USBD_MSC_STRDESC            L"USB_MSC"
+#define USBD_MSC_STRDESC            u"USB_MSC"
 // Make sure changes to USBD_MSC_INQUIRY_DATA are coordinated with mbed-ls
 // since this is used to detect DAPLink drives
 #define USBD_MSC_INQUIRY_DATA       "MBED    "         \
@@ -270,9 +270,9 @@
 #define USBD_ADC_BINTERVAL          1
 #define USBD_ADC_HS_ENABLE          0
 #define USBD_ADC_HS_WMAXPACKETSIZE  64
-#define USBD_ADC_CIF_STRDESC        L"USB_ADC"
-#define USBD_ADC_SIF1_STRDESC       L"USB_ADC1"
-#define USBD_ADC_SIF2_STRDESC       L"USB_ADC2"
+#define USBD_ADC_CIF_STRDESC        u"USB_ADC"
+#define USBD_ADC_SIF1_STRDESC       u"USB_ADC1"
+#define USBD_ADC_SIF2_STRDESC       u"USB_ADC2"
 #define USBD_ADC_BSUBFRAMESIZE      2
 #define USBD_ADC_BBITRESOLUTION     16
 #define USBD_ADC_TSAMFREQ           32000
@@ -352,8 +352,8 @@
 #define USBD_CDC_ACM_HS_ENABLE1         1
 #define USBD_CDC_ACM_HS_WMAXPACKETSIZE1 512
 #define USBD_CDC_ACM_HS_BINTERVAL1      1
-#define USBD_CDC_ACM_CIF_STRDESC        L"mbed Serial Port"
-#define USBD_CDC_ACM_DIF_STRDESC        L"mbed Serial Port"
+#define USBD_CDC_ACM_CIF_STRDESC        u"mbed Serial Port"
+#define USBD_CDC_ACM_DIF_STRDESC        u"mbed Serial Port"
 #define USBD_CDC_ACM_SENDBUF_SIZE       USBD_CDC_ACM_HS_WMAXPACKETSIZE1
 #define USBD_CDC_ACM_RECEIVEBUF_SIZE    USBD_CDC_ACM_HS_WMAXPACKETSIZE1
 #if (((USBD_CDC_ACM_HS_ENABLE1) && (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_HS_WMAXPACKETSIZE1)) || (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_WMAXPACKETSIZE1))
@@ -404,7 +404,7 @@
 #define USBD_BULK_WMAXPACKETSIZE     64
 #define USBD_BULK_HS_ENABLE          1
 #define USBD_BULK_HS_WMAXPACKETSIZE  512
-#define USBD_BULK_STRDESC            L"CMSIS-DAP v2"
+#define USBD_BULK_STRDESC            u"CMSIS-DAP v2"
 
 
 /* USB Device Calculations ---------------------------------------------------*/
diff --git a/source/hic_hal/stm32/stm32f103xb/usb_config.c b/source/hic_hal/stm32/stm32f103xb/usb_config.c
index 354b57ae0..139b79fd9 100644
--- a/source/hic_hal/stm32/stm32f103xb/usb_config.c
+++ b/source/hic_hal/stm32/stm32f103xb/usb_config.c
@@ -90,16 +90,16 @@
 //     </e>
 //   </h>
 #define USBD_STRDESC_LANGID         0x0409
-#define USBD_STRDESC_MAN            L"Arm"
+#define USBD_STRDESC_MAN            u"Arm"
 #ifndef USB_PROD_STR
-#define USBD_STRDESC_PROD           L"DAPLink CMSIS-DAP"
+#define USBD_STRDESC_PROD           u"DAPLink CMSIS-DAP"
 #else
-#define _TOWIDE(x)                   L ## #x
+#define _TOWIDE(x)                   u ## #x
 #define TOWIDE(x)                   _TOWIDE(x)
 #define USBD_STRDESC_PROD           TOWIDE(USB_PROD_STR)
 #endif
 #define USBD_STRDESC_SER_ENABLE     1
-#define USBD_STRDESC_SER            L"0001A0000000"
+#define USBD_STRDESC_SER            u"0001A0000000"
 
 //   <e0> Class Support
 //     <i> Enables USB Device Class specific Requests
@@ -173,8 +173,8 @@
 #define USBD_HID_HS_ENABLE          0
 #define USBD_HID_HS_WMAXPACKETSIZE  64
 #define USBD_HID_HS_BINTERVAL       6
-#define USBD_HID_STRDESC            L"CMSIS-DAP v1"
-#define USBD_WEBUSB_STRDESC         L"WebUSB: CMSIS-DAP"
+#define USBD_HID_STRDESC            u"CMSIS-DAP v1"
+#define USBD_WEBUSB_STRDESC         u"WebUSB: CMSIS-DAP"
 #define USBD_HID_INREPORT_NUM       1
 #define USBD_HID_OUTREPORT_NUM      1
 #define USBD_HID_INREPORT_MAX_SZ    64
@@ -224,7 +224,7 @@
 #define USBD_MSC_HS_ENABLE          0
 #define USBD_MSC_HS_WMAXPACKETSIZE  512
 #define USBD_MSC_HS_BINTERVAL       0
-#define USBD_MSC_STRDESC            L"USB_MSC"
+#define USBD_MSC_STRDESC            u"USB_MSC"
 // Make sure changes to USBD_MSC_INQUIRY_DATA are coordinated with mbed-ls
 // since this is used to detect DAPLink drives
 #define USBD_MSC_INQUIRY_DATA       "MBED    "         \
@@ -269,9 +269,9 @@
 #define USBD_ADC_BINTERVAL          1
 #define USBD_ADC_HS_ENABLE          0
 #define USBD_ADC_HS_WMAXPACKETSIZE  64
-#define USBD_ADC_CIF_STRDESC        L"USB_ADC"
-#define USBD_ADC_SIF1_STRDESC       L"USB_ADC1"
-#define USBD_ADC_SIF2_STRDESC       L"USB_ADC2"
+#define USBD_ADC_CIF_STRDESC        u"USB_ADC"
+#define USBD_ADC_SIF1_STRDESC       u"USB_ADC1"
+#define USBD_ADC_SIF2_STRDESC       u"USB_ADC2"
 #define USBD_ADC_BSUBFRAMESIZE      2
 #define USBD_ADC_BBITRESOLUTION     16
 #define USBD_ADC_TSAMFREQ           32000
@@ -351,8 +351,8 @@
 #define USBD_CDC_ACM_HS_ENABLE1         0
 #define USBD_CDC_ACM_HS_WMAXPACKETSIZE1 16
 #define USBD_CDC_ACM_HS_BINTERVAL1      0
-#define USBD_CDC_ACM_CIF_STRDESC        L"mbed Serial Port"
-#define USBD_CDC_ACM_DIF_STRDESC        L"mbed Serial Port"
+#define USBD_CDC_ACM_CIF_STRDESC        u"mbed Serial Port"
+#define USBD_CDC_ACM_DIF_STRDESC        u"mbed Serial Port"
 #define USBD_CDC_ACM_SENDBUF_SIZE       64
 #define USBD_CDC_ACM_RECEIVEBUF_SIZE    64
 #if (((USBD_CDC_ACM_HS_ENABLE1) && (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_HS_WMAXPACKETSIZE1)) || (USBD_CDC_ACM_SENDBUF_SIZE    < USBD_CDC_ACM_WMAXPACKETSIZE1))
@@ -404,7 +404,7 @@
 #define USBD_BULK_WMAXPACKETSIZE     64
 #define USBD_BULK_HS_ENABLE          0
 #define USBD_BULK_HS_WMAXPACKETSIZE  512
-#define USBD_BULK_STRDESC            L"CMSIS-DAP v2"
+#define USBD_BULK_STRDESC            u"CMSIS-DAP v2"
 
 
 /* USB Device Calculations ---------------------------------------------------*/
diff --git a/source/usb/usb_lib.c b/source/usb/usb_lib.c
index fef24c524..42052c29e 100644
--- a/source/usb/usb_lib.c
+++ b/source/usb/usb_lib.c
@@ -20,6 +20,7 @@
  */
 
 #include <string.h>
+#include <uchar.h>
 #include "rl_usb.h"
 #include "usb.h"
 #include "settings.h"
@@ -2343,15 +2344,12 @@ U8 USBD_ConfigDescriptor_HS[200] = { 0 };
 
 #endif
 
-// Verify that wchar_t is UTF-16.
-COMPILER_ASSERT(sizeof(wchar_t) == 2);
-
 /* USB Device Create String Descriptor */
 #define USBD_STR_DEF(n)                 \
   struct {                              \
     U8  len;                            \
     U8  type;                           \
-    wchar_t str[sizeof(USBD_##n)/2-1];      \
+    char16_t str[sizeof(USBD_##n)/2-1];      \
   } desc##n
 
 #define USBD_STR_VAL(n)                  \