diff --git a/ports/unix/Makefile b/ports/unix/Makefile
index 2fa1373e73..567b1d5c22 100644
--- a/ports/unix/Makefile
+++ b/ports/unix/Makefile
@@ -1,16 +1,29 @@
--include mpconfigport.mk
+# Select the variant to build for.
+VARIANT ?= standard
+
+# If the build directory is not given, make it reflect the variant name.
+BUILD ?= build-$(VARIANT)
+
+VARIANT_DIR ?= variants/$(VARIANT)
+ifeq ($(wildcard $(VARIANT_DIR)/.),)
+$(error Invalid VARIANT specified: $(VARIANT_DIR))
+endif
+
 include ../../py/mkenv.mk
+-include mpconfigport.mk
+include $(VARIANT_DIR)/mpconfigvariant.mk
 
 # use FROZEN_MANIFEST for new projects, others are legacy
 FROZEN_MANIFEST ?= manifest.py
 FROZEN_DIR =
 FROZEN_MPY_DIR =
 
-# define main target
-PROG = micropython
+# This should be configured by the mpconfigvariant.mk
+PROG ?= micropython
 
 # qstr definitions (must come before including py.mk)
 QSTR_DEFS = qstrdefsport.h
+QSTR_GLOBAL_DEPENDENCIES = $(VARIANT_DIR)/mpconfigvariant.h
 
 # OS name, for simple autoconfig
 UNAME_S := $(shell uname -s)
@@ -27,7 +40,7 @@ INC += -I$(BUILD)
 # compiler settings
 CWARN = -Wall -Werror
 CWARN += -Wpointer-arith -Wuninitialized
-CFLAGS = $(INC) $(CWARN) -std=gnu99 -DUNIX $(CFLAGS_MOD) $(COPT) $(CFLAGS_EXTRA)
+CFLAGS = $(INC) $(CWARN) -std=gnu99 -DUNIX $(CFLAGS_MOD) $(COPT) -I$(VARIANT_DIR) $(CFLAGS_EXTRA)
 
 # Debugging/Optimization
 ifdef DEBUG
@@ -156,7 +169,8 @@ SRC_C = \
 	alloc.c \
 	coverage.c \
 	fatfs_port.c \
-	$(SRC_MOD)
+	$(SRC_MOD) \
+	$(wildcard $(VARIANT_DIR)/*.c)
 
 LIB_SRC_C = $(addprefix lib/,\
 	$(LIB_SRC_C_EXTRA) \
@@ -188,83 +202,42 @@ endif
 
 include $(TOP)/py/mkrules.mk
 
-.PHONY: test
+.PHONY: test test_full
 
 test: $(PROG) $(TOP)/tests/run-tests
 	$(eval DIRNAME=ports/$(notdir $(CURDIR)))
 	cd $(TOP)/tests && MICROPY_MICROPYTHON=../$(DIRNAME)/$(PROG) ./run-tests
 
-# install micropython in /usr/local/bin
-TARGET = micropython
-PREFIX = $(DESTDIR)/usr/local
-BINDIR = $(PREFIX)/bin
+test_full: $(PROG) $(TOP)/tests/run-tests
+	$(eval DIRNAME=ports/$(notdir $(CURDIR)))
+	cd $(TOP)/tests && MICROPY_MICROPYTHON=../$(DIRNAME)/$(PROG) ./run-tests
+	cd $(TOP)/tests && MICROPY_MICROPYTHON=../$(DIRNAME)/$(PROG) ./run-tests -d thread
+	cd $(TOP)/tests && MICROPY_MICROPYTHON=../$(DIRNAME)/$(PROG) ./run-tests --emit native
+	cd $(TOP)/tests && MICROPY_MICROPYTHON=../$(DIRNAME)/$(PROG) ./run-tests --via-mpy -d basics float micropython
+	cd $(TOP)/tests && MICROPY_MICROPYTHON=../$(DIRNAME)/$(PROG) ./run-tests --via-mpy --emit native -d basics float micropython
+	cat $(TOP)/tests/basics/0prelim.py | ./$(PROG) | grep -q 'abc'
 
-install: micropython
-	install -d $(BINDIR)
-	install $(TARGET) $(BINDIR)/$(TARGET)
+test_gcov: test_full
+	gcov -o $(BUILD)/py $(TOP)/py/*.c
+	gcov -o $(BUILD)/extmod $(TOP)/extmod/*.c
 
-# uninstall micropython
-uninstall:
-	-rm $(BINDIR)/$(TARGET)
-
-# build synthetically fast interpreter for benchmarking
+# Maintain historical targets from pre-variant configurations.
 fast:
-	$(MAKE) COPT="-O2 -DNDEBUG -fno-crossjumping" CFLAGS_EXTRA='-DMP_CONFIGFILE="<mpconfigport_fast.h>"' BUILD=build-fast PROG=micropython_fast FROZEN_MANIFEST=
+	$(MAKE) VARIANT=fast
 
-# build a minimal interpreter
 minimal:
-	$(MAKE) COPT="-Os -DNDEBUG" CFLAGS_EXTRA='-DMP_CONFIGFILE="<mpconfigport_minimal.h>"' \
-	    BUILD=build-minimal PROG=micropython_minimal FROZEN_MANIFEST= \
-	    MICROPY_PY_BTREE=0 MICROPY_PY_FFI=0 MICROPY_PY_SOCKET=0 MICROPY_PY_THREAD=0 \
-	    MICROPY_PY_TERMIOS=0 MICROPY_PY_USSL=0 \
-	    MICROPY_USE_READLINE=0
+	$(MAKE) VARIANT=minimal
 
-# build interpreter with nan-boxing as object model
 nanbox:
-	$(MAKE) \
-	CFLAGS_EXTRA='-DMP_CONFIGFILE="<mpconfigport_nanbox.h>"' \
-	BUILD=build-nanbox \
-	PROG=micropython_nanbox \
-	MICROPY_FORCE_32BIT=1
+	$(MAKE) VARIANT=nanbox
 
 freedos:
-	$(MAKE) \
-	CC=i586-pc-msdosdjgpp-gcc \
-	STRIP=i586-pc-msdosdjgpp-strip \
-	SIZE=i586-pc-msdosdjgpp-size \
-	CFLAGS_EXTRA='-DMP_CONFIGFILE="<mpconfigport_freedos.h>" -DMICROPY_NLR_SETJMP -Dtgamma=gamma -DMICROPY_EMIT_X86=0 -DMICROPY_NO_ALLOCA=1 -DMICROPY_PY_USELECT_POSIX=0' \
-	BUILD=build-freedos \
-	PROG=micropython_freedos \
-	MICROPY_PY_SOCKET=0 \
-	MICROPY_PY_FFI=0 \
-	MICROPY_PY_JNI=0 \
-	MICROPY_PY_BTREE=0 \
-	MICROPY_PY_THREAD=0 \
-	MICROPY_PY_USSL=0
+	$(MAKE) VARIANT=freedos
 
-# build an interpreter for coverage testing and do the testing
 coverage:
-	$(MAKE) \
-	    COPT="-O0" CFLAGS_EXTRA='$(CFLAGS_EXTRA) -DMP_CONFIGFILE="<mpconfigport_coverage.h>" \
-	    -fprofile-arcs -ftest-coverage \
-	    -Wdouble-promotion -Wformat -Wmissing-declarations -Wmissing-prototypes -Wsign-compare \
-	    -Wold-style-definition -Wpointer-arith -Wshadow -Wuninitialized -Wunused-parameter \
-	    -DMICROPY_UNIX_COVERAGE' \
-	    LDFLAGS_EXTRA='-fprofile-arcs -ftest-coverage' \
-	    MICROPY_VFS_FAT=1 MICROPY_VFS_LFS1=1 MICROPY_VFS_LFS2=1 \
-	    FROZEN_MANIFEST=manifest_coverage.py \
-	    BUILD=build-coverage PROG=micropython_coverage
-
-coverage_test: coverage
-	$(eval DIRNAME=ports/$(notdir $(CURDIR)))
-	cd $(TOP)/tests && MICROPY_MICROPYTHON=../$(DIRNAME)/micropython_coverage ./run-tests
-	cd $(TOP)/tests && MICROPY_MICROPYTHON=../$(DIRNAME)/micropython_coverage ./run-tests -d thread
-	cd $(TOP)/tests && MICROPY_MICROPYTHON=../$(DIRNAME)/micropython_coverage ./run-tests --emit native
-	cd $(TOP)/tests && MICROPY_MICROPYTHON=../$(DIRNAME)/micropython_coverage ./run-tests --via-mpy -d basics float micropython
-	cd $(TOP)/tests && MICROPY_MICROPYTHON=../$(DIRNAME)/micropython_coverage ./run-tests --via-mpy --emit native -d basics float micropython
-	cat $(TOP)/tests/basics/0prelim.py | ./micropython_coverage | grep -q 'abc'
-	gcov -o build-coverage/py $(TOP)/py/*.c
-	gcov -o build-coverage/extmod $(TOP)/extmod/*.c
+	$(MAKE) VARIANT=coverage
+coverage_test:
+	$(MAKE) VARIANT=coverage test_gcov
 
 # Value of configure's --host= option (required for cross-compilation).
 # Deduce it from CROSS_COMPILE by default, but can be overridden.
diff --git a/ports/unix/mpconfigport.h b/ports/unix/mpconfigport.h
index d633726a16..f435c3ff3c 100644
--- a/ports/unix/mpconfigport.h
+++ b/ports/unix/mpconfigport.h
@@ -24,7 +24,15 @@
  * THE SOFTWARE.
  */
 
-// options to control how MicroPython is built
+// Options to control how MicroPython is built for this port,
+// overriding defaults in py/mpconfig.h.
+
+// Variant-specific definitions.
+#include "mpconfigvariant.h"
+
+// The minimal variant's config covers everything.
+// If we're building the minimal variant, ignore the rest of this file.
+#ifndef MICROPY_UNIX_MINIMAL
 
 #define MICROPY_ALLOC_PATH_MAX      (PATH_MAX)
 #define MICROPY_PERSISTENT_CODE_LOAD (1)
@@ -64,7 +72,9 @@
 #define MICROPY_ENABLE_SOURCE_LINE  (1)
 #define MICROPY_FLOAT_IMPL          (MICROPY_FLOAT_IMPL_DOUBLE)
 #define MICROPY_LONGINT_IMPL        (MICROPY_LONGINT_IMPL_MPZ)
+#ifndef MICROPY_STREAMS_NON_BLOCK
 #define MICROPY_STREAMS_NON_BLOCK   (1)
+#endif
 #define MICROPY_STREAMS_POSIX_API   (1)
 #define MICROPY_OPT_COMPUTED_GOTO   (1)
 #ifndef MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE
@@ -97,11 +107,13 @@
 #define MICROPY_PERSISTENT_CODE_SAVE (1)
 #define MICROPY_COMP_CONST (0)
 #endif
+#ifndef MICROPY_PY_SYS_PLATFORM
 #if defined(__APPLE__) && defined(__MACH__)
     #define MICROPY_PY_SYS_PLATFORM  "darwin"
 #else
     #define MICROPY_PY_SYS_PLATFORM  "linux"
 #endif
+#endif
 #define MICROPY_PY_SYS_MAXSIZE      (1)
 #define MICROPY_PY_SYS_STDFILES     (1)
 #define MICROPY_PY_SYS_EXC_INFO     (1)
@@ -331,3 +343,5 @@ void mp_unix_mark_exec(void);
 // For debugging purposes, make printf() available to any source file.
 #include <stdio.h>
 #endif
+
+#endif // MICROPY_UNIX_MINIMAL
diff --git a/ports/unix/mpconfigport_coverage.h b/ports/unix/variants/coverage/mpconfigvariant.h
similarity index 94%
rename from ports/unix/mpconfigport_coverage.h
rename to ports/unix/variants/coverage/mpconfigvariant.h
index 8a0bf3be48..f383a83700 100644
--- a/ports/unix/mpconfigport_coverage.h
+++ b/ports/unix/variants/coverage/mpconfigvariant.h
@@ -24,14 +24,12 @@
  * THE SOFTWARE.
  */
 
-// Default unix config while intended to be comprehensive, may still not enable
-// all the features, this config should enable more (testable) options.
+// This config enables almost all possible features such that it can be used
+// for coverage testing.
 
 #define MICROPY_VFS                    (1)
 #define MICROPY_PY_UOS_VFS             (1)
 
-#include <mpconfigport.h>
-
 #define MICROPY_OPT_MATH_FACTORIAL     (1)
 #define MICROPY_FLOAT_HIGH_QUALITY_HASH (1)
 #define MICROPY_ENABLE_SCHEDULER       (1)
diff --git a/ports/unix/variants/coverage/mpconfigvariant.mk b/ports/unix/variants/coverage/mpconfigvariant.mk
new file mode 100644
index 0000000000..e55b22eb92
--- /dev/null
+++ b/ports/unix/variants/coverage/mpconfigvariant.mk
@@ -0,0 +1,17 @@
+PROG ?= micropython_coverage
+
+COPT = -O0
+
+CFLAGS_EXTRA += \
+	-fprofile-arcs -ftest-coverage \
+	-Wdouble-promotion -Wformat -Wmissing-declarations -Wmissing-prototypes -Wsign-compare \
+	-Wold-style-definition -Wpointer-arith -Wshadow -Wuninitialized -Wunused-parameter \
+	-DMICROPY_UNIX_COVERAGE
+
+LDFLAGS_EXTRA += -fprofile-arcs -ftest-coverage
+
+FROZEN_MANIFEST = manifest_coverage.py
+
+MICROPY_VFS_FAT = 1
+MICROPY_VFS_LFS1 = 1
+MICROPY_VFS_LFS2 = 1
diff --git a/ports/unix/mpconfigport_fast.h b/ports/unix/variants/fast/mpconfigvariant.h
similarity index 97%
rename from ports/unix/mpconfigport_fast.h
rename to ports/unix/variants/fast/mpconfigvariant.h
index 193567a294..6d73275fde 100644
--- a/ports/unix/mpconfigport_fast.h
+++ b/ports/unix/variants/fast/mpconfigvariant.h
@@ -28,8 +28,9 @@
 // synthetic benchmarking, at the expense of features supported and memory
 // usage. This config is not intended to be used in production.
 
-#include <mpconfigport.h>
 #define MICROPY_PY___FILE__ (0)
 // 91 is a magic number proposed by @dpgeorge, which make pystone run ~ at tie
 // with CPython 3.4.
 #define MICROPY_MODULE_DICT_SIZE (91)
+
+#include "variants/DEV/mpconfigvariant.h"
diff --git a/ports/unix/variants/fast/mpconfigvariant.mk b/ports/unix/variants/fast/mpconfigvariant.mk
new file mode 100644
index 0000000000..60c1d525d3
--- /dev/null
+++ b/ports/unix/variants/fast/mpconfigvariant.mk
@@ -0,0 +1,7 @@
+# build synthetically fast interpreter for benchmarking
+
+COPT = "-O2 -DNDEBUG -fno-crossjumping"
+
+PROG = micropython_fast
+
+FROZEN_MANIFEST =
diff --git a/ports/unix/mpconfigport_freedos.h b/ports/unix/variants/freedos/mpconfigvariant.h
similarity index 94%
rename from ports/unix/mpconfigport_freedos.h
rename to ports/unix/variants/freedos/mpconfigvariant.h
index 09c85ab1e3..338b34492d 100644
--- a/ports/unix/mpconfigport_freedos.h
+++ b/ports/unix/variants/freedos/mpconfigvariant.h
@@ -26,15 +26,15 @@
 
 // options to control how MicroPython is built
 
-#include <mpconfigport.h>
+#define MICROPY_PY_USELECT_POSIX (0)
 
-#undef MICROPY_STREAMS_NON_BLOCK
 #define MICROPY_STREAMS_NON_BLOCK (0)
 
-#undef MICROPY_PY_SYS_PLATFORM
 #define MICROPY_PY_SYS_PLATFORM "freedos"
 
 // djgpp dirent struct does not have d_ino field
 #undef _DIRENT_HAVE_D_INO
 
 #define MICROPY_USE_INTERNAL_ERRNO  (1)
+
+#include "variants/DEV/mpconfigvariant.h"
diff --git a/ports/unix/variants/freedos/mpconfigvariant.mk b/ports/unix/variants/freedos/mpconfigvariant.mk
new file mode 100644
index 0000000000..f1d0ac21b0
--- /dev/null
+++ b/ports/unix/variants/freedos/mpconfigvariant.mk
@@ -0,0 +1,20 @@
+CC = i586-pc-msdosdjgpp-gcc
+
+STRIP = i586-pc-msdosdjgpp-strip
+
+SIZE = i586-pc-msdosdjgpp-size
+
+CFLAGS_EXTRA = \
+	-DMICROPY_NLR_SETJMP \
+	-Dtgamma=gamma \
+	-DMICROPY_EMIT_X86=0 \
+	-DMICROPY_NO_ALLOCA=1 \
+
+PROG = micropython_freedos
+
+MICROPY_PY_SOCKET = 0
+MICROPY_PY_FFI = 0
+MICROPY_PY_JNI = 0
+MICROPY_PY_BTREE = 0
+MICROPY_PY_THREAD = 0
+MICROPY_PY_USSL = 0
diff --git a/ports/unix/mpconfigport_minimal.h b/ports/unix/variants/minimal/mpconfigvariant.h
similarity index 98%
rename from ports/unix/mpconfigport_minimal.h
rename to ports/unix/variants/minimal/mpconfigvariant.h
index c49819e742..e961ff4b24 100644
--- a/ports/unix/mpconfigport_minimal.h
+++ b/ports/unix/variants/minimal/mpconfigvariant.h
@@ -26,6 +26,9 @@
 
 // options to control how MicroPython is built
 
+// Prevent the rest of the default mpconfigport.h being used.
+#define MICROPY_UNIX_MINIMAL (1)
+
 #define MICROPY_ALLOC_QSTR_CHUNK_INIT (64)
 #define MICROPY_ALLOC_PARSE_RULE_INIT (8)
 #define MICROPY_ALLOC_PARSE_RULE_INC  (8)
diff --git a/ports/unix/variants/minimal/mpconfigvariant.mk b/ports/unix/variants/minimal/mpconfigvariant.mk
new file mode 100644
index 0000000000..19f8ad64a3
--- /dev/null
+++ b/ports/unix/variants/minimal/mpconfigvariant.mk
@@ -0,0 +1,14 @@
+# build a minimal interpreter
+COPT = -Os -DNDEBUG
+
+PROG = micropython_minimal
+
+FROZEN_MANIFEST =
+
+MICROPY_PY_BTREE = 0
+MICROPY_PY_FFI = 0
+MICROPY_PY_SOCKET = 0
+MICROPY_PY_THREAD = 0
+MICROPY_PY_TERMIOS = 0
+MICROPY_PY_USSL = 0
+MICROPY_USE_READLINE = 0
diff --git a/ports/unix/mpconfigport_nanbox.h b/ports/unix/variants/nanbox/mpconfigvariant.h
similarity index 90%
rename from ports/unix/mpconfigport_nanbox.h
rename to ports/unix/variants/nanbox/mpconfigvariant.h
index 7da2cf7b80..f827158fb7 100644
--- a/ports/unix/mpconfigport_nanbox.h
+++ b/ports/unix/variants/nanbox/mpconfigvariant.h
@@ -24,6 +24,10 @@
  * THE SOFTWARE.
  */
 
+// This config is mostly used to ensure that the nan-boxing object model
+// continues to build (i.e. catches usage of mp_obj_t that don't work with
+// this representation).
+
 // select nan-boxing object model
 #define MICROPY_OBJ_REPR (MICROPY_OBJ_REPR_D)
 
@@ -39,5 +43,3 @@ typedef int64_t mp_int_t;
 typedef uint64_t mp_uint_t;
 #define UINT_FMT "%llu"
 #define INT_FMT "%lld"
-
-#include <mpconfigport.h>
diff --git a/ports/unix/variants/nanbox/mpconfigvariant.mk b/ports/unix/variants/nanbox/mpconfigvariant.mk
new file mode 100644
index 0000000000..b7b485b512
--- /dev/null
+++ b/ports/unix/variants/nanbox/mpconfigvariant.mk
@@ -0,0 +1,4 @@
+# build interpreter with nan-boxing as object model (object repr D)
+PROG = micropython_nanbox
+
+MICROPY_FORCE_32BIT = 1
diff --git a/ports/unix/variants/standard/mpconfigvariant.h b/ports/unix/variants/standard/mpconfigvariant.h
new file mode 100644
index 0000000000..79b8fe2a3b
--- /dev/null
+++ b/ports/unix/variants/standard/mpconfigvariant.h
@@ -0,0 +1,26 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
diff --git a/ports/unix/variants/standard/mpconfigvariant.mk b/ports/unix/variants/standard/mpconfigvariant.mk
new file mode 100644
index 0000000000..28fad7be77
--- /dev/null
+++ b/ports/unix/variants/standard/mpconfigvariant.mk
@@ -0,0 +1,16 @@
+# This is the default variant when you `make` the Unix port.
+
+PROG ?= micropython
+
+# install micropython in /usr/local/bin
+TARGET = micropython
+PREFIX = $(DESTDIR)/usr/local
+BINDIR = $(PREFIX)/bin
+
+install: micropython
+	install -d $(BINDIR)
+	install $(TARGET) $(BINDIR)/$(TARGET)
+
+# uninstall micropython
+uninstall:
+	-rm $(BINDIR)/$(TARGET)