diff --git a/boards/sim/sim/sim/configs/cxxtest/Make.defs b/boards/sim/sim/sim/configs/cxxtest/Make.defs
deleted file mode 100644
index 7959db2203..0000000000
--- a/boards/sim/sim/sim/configs/cxxtest/Make.defs
+++ /dev/null
@@ -1,144 +0,0 @@
-############################################################################
-# boards/sim/sim/sim/configs/cxxtest/Make.defs
-#
-# Licensed to the Apache Software Foundation (ASF) under one or more
-# contributor license agreements.  See the NOTICE file distributed with
-# this work for additional information regarding copyright ownership.  The
-# ASF licenses this file to you 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.
-#
-############################################################################
-
-include $(TOPDIR)/.config
-include $(TOPDIR)/tools/Config.mk
-
-HOSTOS = ${shell uname -o 2>/dev/null || uname -s 2>/dev/null || echo "Other"}
-
-ifeq ($(CONFIG_DEBUG_SYMBOLS),y)
-  ARCHOPTIMIZATION = -g
-endif
-
-ifneq ($(CONFIG_DEBUG_NOOPT),y)
-  ARCHOPTIMIZATION += -O2 -fno-strict-aliasing
-endif
-
-ARCHCPUFLAGS = -fno-builtin
-ifeq ($(CONFIG_CXX_EXCEPTION),y)
-  ARCHCPUFLAGSXX = -fno-builtin
-else
-  ARCHCPUFLAGSXX = -fno-builtin -fno-exceptions -fcheck-new
-endif
-ARCHPICFLAGS = -fpic
-ARCHWARNINGS = -Wall -Wstrict-prototypes -Wshadow -Wundef
-ARCHWARNINGSXX = -Wall -Wshadow -Wundef
-
-# Add -fno-common because macOS "ld -r" doesn't seem to pick objects
-# for common symbols.
-ARCHCPUFLAGS += -fno-common
-ARCHCPUFLAGSXX += -fno-common
-
-ifeq ($(CONFIG_SIM_M32),y)
-  ARCHCPUFLAGS += -m32
-  ARCHCPUFLAGSXX += -m32
-endif
-
-CC = $(CROSSDEV)cc
-CXX = $(CROSSDEV)c++
-CPP = $(CROSSDEV)cc -E
-LD = $(CROSSDEV)ld
-ifeq ($(CONFIG_HOST_MACOS),y)
-STRIP = $(CROSSDEV)strip
-AR = $(TOPDIR)/tools/macar-rcs.sh
-else
-STRIP = $(CROSSDEV)strip --strip-unneeded
-AR = $(CROSSDEV)ar rcs
-endif
-NM = $(CROSSDEV)nm
-OBJCOPY = $(CROSSDEV)objcopy
-OBJDUMP = $(CROSSDEV)objdump
-
-CFLAGS := $(ARCHWARNINGS) $(ARCHOPTIMIZATION) \
-   $(ARCHCPUFLAGS) $(ARCHINCLUDES) $(ARCHDEFINES) $(EXTRAFLAGS) -pipe
-CXXFLAGS := $(ARCHWARNINGSXX) $(ARCHOPTIMIZATION) \
-   $(ARCHCPUFLAGSXX) $(ARCHXXINCLUDES) $(ARCHDEFINES) $(EXTRAFLAGS) -pipe
-CPPFLAGS := $(ARCHINCLUDES) $(ARCHDEFINES) $(EXTRAFLAGS)
-AFLAGS := $(CFLAGS) -D__ASSEMBLY__
-
-# Loadable module definitions
-
-CMODULEFLAGS = $(CFLAGS)
-# -fno-pic to avoid GOT relocations
-CMODULEFLAGS += -fno-pic
-ifeq ($(CONFIG_LIBC_ARCH_ELF_64BIT),y)
-  # For amd64:
-  # It seems macOS/x86_64 loads the program text around 00000001_xxxxxxxx.
-  # The gcc default (-mcmodel=small) would produce out-of-range 32-bit
-  # relocations.
-  # Even on Linux, NuttX modules are loaded into the NuttX heap, which
-  # can be out of range with -mcmodel=small.
-  CMODULEFLAGS += -mcmodel=large
-endif
-# On Linux, we (ab)use the host compiler to compile binaries for NuttX.
-# Explicitly disable features which might be default on the host while
-# not available on NuttX.
-CMODULEFLAGS += -fno-stack-protector
-
-LDMODULEFLAGS = -r -e module_initialize
-ifeq ($(CONFIG_CYGWIN_WINTOOL),y)
-  LDMODULEFLAGS += -T "${shell cygpath -w $(TOPDIR)/libs/libc/modlib/gnu-elf.ld}"
-else
-  LDMODULEFLAGS += -T $(TOPDIR)/libs/libc/modlib/gnu-elf.ld
-endif
-
-# NuttX modules are ELF binaries.
-# Non-ELF platforms like macOS need to use a separate ELF toolchain.
-ifeq ($(CONFIG_HOST_MACOS),y)
-  # eg. brew install x86_64-elf-gcc
-  MODULECC = x86_64-elf-gcc
-  MODULELD = x86_64-elf-ld
-  MODULESTRIP = x86_64-elf-strip --strip-unneeded
-endif
-
-# ELF module definitions
-
-CELFFLAGS = $(CFLAGS)
-CXXELFFLAGS = $(CXXFLAGS)
-# -fno-pic to avoid GOT relocations
-CELFFLAGS += -fno-pic
-CXXELFFLAGS += -fno-pic
-
-LDELFFLAGS = -r -e main
-ifeq ($(CONFIG_CYGWIN_WINTOOL),y)
-  LDELFFLAGS += -T "${shell cygpath -w $(BOARD_DIR)$(DELIM)scripts$(DELIM)gnu-elf.ld}"
-else
-  LDELFFLAGS += -T $(BOARD_DIR)$(DELIM)scripts$(DELIM)gnu-elf.ld
-endif
-
-LDLINKFLAGS = $(ARCHSCRIPT) # Link flags used with $(LD)
-CCLINKFLAGS = $(ARCHSCRIPT) # Link flags used with $(CC)
-LDFLAGS = $(ARCHSCRIPT) # For backward compatibility, same as CCLINKFLAGS
-
-ifeq ($(CONFIG_DEBUG_SYMBOLS),y)
-  CCLINKFLAGS += -g
-endif
-
-ifeq ($(CONFIG_SIM_M32),y)
-  LDLINKFLAGS += -melf_i386
-  CCLINKFLAGS += -m32
-  LDFLAGS += -m32
-  LDMODULEFLAGS += -melf_i386
-  LDELFFLAGS += -melf_i386
-  HOSTLDFLAGS += -m32
-endif
-
-HOSTCFLAGS = $(ARCHWARNINGS) $(ARCHOPTIMIZATION) \
-   $(ARCHCPUFLAGS) $(HOSTINCLUDES) $(ARCHDEFINES) $(EXTRAFLAGS) -pipe