diff --git a/hw/bsp/brtmm90x/family.mk b/hw/bsp/brtmm90x/family.mk
index 211f97f1b..d47f4820c 100644
--- a/hw/bsp/brtmm90x/family.mk
+++ b/hw/bsp/brtmm90x/family.mk
@@ -1,11 +1,28 @@
-
+# GCC prefix for FT90X compile tools.
 CROSS_COMPILE = ft32-elf-
-DEPS_SUBMODULES += hw/mcu/bridgetek/ft9xx/hardware
 SKIP_NANOLIB = 1
 
-# This is installed at "C:/Program Files(x86)/Bridgetek/FT9xx Toolchain/Toolchain/hardware"
-FT9XX_SDK = $(TOP)/hw/mcu/bridgetek/ft9xx/hardware
+# Set to use FT90X prebuilt libraries.
+FT90X_PREBUILT_LIBS = 1
+ifeq ($(FT90X_PREBUILT_LIBS),1)
+# If the FT90X toolchain is installed on Windows systems then the SDK 
+# include files and prebuilt libraries are at: %FT90X_TOOLCHAIN%/hardware
+FT9XX_SDK = $(FT90X_TOOLCHAIN)/hardware
+else
+# The submodule BRTSG-FOSS/ft90x-sdk contains header files and source
+# code for the Bridgetek SDK. This can be used instead of the prebuilt
+# library.
+DEPS_SUBMODULES += hw/mcu/bridgetek/ft9xx/hardware
+# The SDK can be used to load specific files from the Bridgetek SDK.
+FT9XX_SDK = hw/mcu/bridgetek/ft9xx/hardware/Source
+endif
 
+# Add include files which are within the TinyUSB directory structure.
+INC += \
+	$(TOP)/hw/mcu/bridgetek/ft9xx/hardware/Source/include \
+	$(TOP)/$(BOARD_PATH)
+
+# Add required C Compiler flags for FT90X.
 CFLAGS += \
 	-D__FT900__ \
 	-fvar-tracking \
@@ -16,20 +33,34 @@ CFLAGS += \
 
 # lwip/src/core/raw.c:334:43: error: declaration of 'recv' shadows a global declaration
 CFLAGS += -Wno-error=shadow
-CFLAGS:=$(filter-out -Wcast-function-type,$(CFLAGS))
 
-# All source paths should be relative to the top level.
-LDINC += $(FT9XX_SDK)/lib/Release
-LIBS += -lft900
-LD_FILE = hw/mcu/bridgetek/ft9xx/hardware/scripts/ldscript.ld
+# Add include files outside the TinyUSB structure that are added manually.
+CFLAGS += -I"$(FT9XX_SDK)/include"
+
+# Set Linker flags.
+LD_FILE = hw/mcu/bridgetek/ft9xx/scripts/ldscript.ld
 LDFLAGS += $(addprefix -L,$(LDINC)) \
 	-Xlinker --entry=_start \
 	-Wl,-lc
 
+# Additional Source files for FT90X.
 SRC_C += src/portable/bridgetek/ft9xx/dcd_ft9xx.c 
 
-#SRC_S += hw/mcu/bridgetek/ft9xx/hardware/scripts/crt0.S
+# Linker library.
+ifneq ($(FT90X_PREBUILT_LIBS),1)
+# Optionally add in files from the Bridgetek SDK instead of the prebuilt
+# library. These are the minimum required.
+SRC_C += $(FT9XX_SDK)/src/sys.c
+SRC_C += $(FT9XX_SDK)/src/interrupt.c
+SRC_C += $(FT9XX_SDK)/src/delay.c
+SRC_C += $(FT9XX_SDK)/src/timers.c
+SRC_C += $(FT9XX_SDK)/src/uart_simple.c
+SRC_C += $(FT9XX_SDK)/src/gpio.c
+else
+# Or if using the prebuilt libraries add them.
+LDFLAGS += -L"$(FT9XX_SDK)/lib"
+LIBS += -lft900
+endif
 
-INC += \
-	$(FT9XX_SDK)/include \
-	$(TOP)/$(BOARD_PATH)
+# Not required crt0 file for FT90X. Use compiler built-in file.
+#SRC_S += hw/mcu/bridgetek/ft9xx/scripts/crt0.S
diff --git a/hw/mcu/bridgetek/ft9xx/hardware/scripts/crt0.S b/hw/mcu/bridgetek/ft9xx/scripts/crt0.S
similarity index 100%
rename from hw/mcu/bridgetek/ft9xx/hardware/scripts/crt0.S
rename to hw/mcu/bridgetek/ft9xx/scripts/crt0.S
diff --git a/hw/mcu/bridgetek/ft9xx/hardware/scripts/ldscript.ld b/hw/mcu/bridgetek/ft9xx/scripts/ldscript.ld
similarity index 97%
rename from hw/mcu/bridgetek/ft9xx/hardware/scripts/ldscript.ld
rename to hw/mcu/bridgetek/ft9xx/scripts/ldscript.ld
index d1b4d46cd..987c2b2ba 100644
--- a/hw/mcu/bridgetek/ft9xx/hardware/scripts/ldscript.ld
+++ b/hw/mcu/bridgetek/ft9xx/scripts/ldscript.ld
@@ -9,6 +9,7 @@ MEMORY
 {
   flash     (rx)   : ORIGIN = 0,        LENGTH = __PMSIZE
   ram       (rw!x) : ORIGIN = 0x800000, LENGTH = __RAMSIZE
+  ehci_mmap (rw!x) : ORIGIN = 0x811000, LENGTH = 2K
 }
 SECTIONS
 {
diff --git a/src/portable/bridgetek/ft9xx/dcd_ft9xx.c b/src/portable/bridgetek/ft9xx/dcd_ft9xx.c
index 09ca2904f..3235d0ef1 100644
--- a/src/portable/bridgetek/ft9xx/dcd_ft9xx.c
+++ b/src/portable/bridgetek/ft9xx/dcd_ft9xx.c
@@ -29,20 +29,19 @@
  * in https://brtchip.com/BRTSourceCodeLicenseAgreement
  */
 
+#include <stdint.h>
+#include <ft900.h>
+#include <registers/ft900_registers.h>
+
 #include "board.h"
 #include "bsp/board.h"
 #include "tusb_option.h"
 
 #if TUSB_OPT_DEVICE_ENABLED && \
-  (CFG_TUSB_MCU == OPT_MCU_FT90X || CFG_TUSB_MCU == OPT_MCU_FT93X)
+  (CFG_TUSB_MCU == OPT_MCU_FT90X || CFG_TUSB_MCU == OPT_MCU_FT93X) 
 
 #define USBD_USE_STREAMS
 
-#include <stdint.h>
-#include <errno.h>
-#include <ft900.h>
-#include <registers/ft900_registers.h>
-
 #include "device/dcd.h"
 
 //--------------------------------------------------------------------+