diff --git a/extmod/modhashlib.c b/extmod/modhashlib.c
index ef98a80166..86a1a2987e 100644
--- a/extmod/modhashlib.c
+++ b/extmod/modhashlib.c
@@ -136,6 +136,7 @@ STATIC mp_obj_t hashlib_sha256_make_new(const mp_obj_type_t *type, size_t n_args
 }
 
 STATIC mp_obj_t hashlib_sha256_update(mp_obj_t self_in, mp_obj_t arg) {
+    check_not_unicode(arg);
     mp_obj_hash_t *self = MP_OBJ_TO_PTR(self_in);
     hashlib_ensure_not_final(self);
     mp_buffer_info_t bufinfo;
diff --git a/ports/unix/Makefile b/ports/unix/Makefile
index 3775a3561b..60bc5ae98c 100644
--- a/ports/unix/Makefile
+++ b/ports/unix/Makefile
@@ -200,8 +200,6 @@ SRC_C += \
 	unix_mphal.c \
 	mpthreadport.c \
 	input.c \
-	modtime.c \
-	moduselect.c \
 	alloc.c \
 	fatfs_port.c \
 	supervisor/stub/filesystem.c \
@@ -211,6 +209,10 @@ SRC_C += \
 	$(SRC_MOD) \
 	$(wildcard $(VARIANT_DIR)/*.c)
 
+# CIRCUITPY-CHANGE
+# CircuitPython doesn't use extmod/modtime.c, but ports/unix/extmod.c depends on it.
+SRC_EXTMOD_C += extmod/modtime.c
+
 $(BUILD)/supervisor/shared/translate/translate.o: $(HEADER_BUILD)/qstrdefs.generated.h $(HEADER_BUILD)/compressed_translations.generated.h
 
 SHARED_SRC_C += $(addprefix shared/,\
diff --git a/ports/unix/modos.c b/ports/unix/modos.c
index d0138edc7a..3c7f87f614 100644
--- a/ports/unix/modos.c
+++ b/ports/unix/modos.c
@@ -147,4 +147,4 @@ STATIC mp_obj_t mp_os_errno(size_t n_args, const mp_obj_t *args) {
     errno = mp_obj_get_int(args[0]);
     return mp_const_none;
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_uos_errno_obj, 0, 1, mp_uos_errno);
+STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_os_errno_obj, 0, 1, mp_os_errno);
diff --git a/ports/unix/modtime.c b/ports/unix/modtime.c
index 8eb5b4116a..b6fbae0d1c 100644
--- a/ports/unix/modtime.c
+++ b/ports/unix/modtime.c
@@ -71,7 +71,6 @@ STATIC mp_obj_t mp_time_time_get(void) {
     return mp_obj_new_int((mp_int_t)time(NULL));
     #endif
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(mod_time_time_obj, mod_time_time);
 
 // Note: this is deprecated since CPy3.3, but pystone still uses it.
 STATIC mp_obj_t mod_time_clock(void) {
@@ -125,7 +124,6 @@ STATIC mp_obj_t mp_time_sleep(mp_obj_t arg) {
     #endif
     return mp_const_none;
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_time_sleep_obj, mod_time_sleep);
 
 STATIC mp_obj_t mod_time_gm_local_time(size_t n_args, const mp_obj_t *args, struct tm *(*time_func)(const time_t *timep)) {
     time_t t;
@@ -202,31 +200,8 @@ STATIC mp_obj_t mod_time_mktime(mp_obj_t tuple) {
 }
 MP_DEFINE_CONST_FUN_OBJ_1(mod_time_mktime_obj, mod_time_mktime);
 
-STATIC const mp_rom_map_elem_t mp_module_time_globals_table[] = {
-    { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_time) },
-    { MP_ROM_QSTR(MP_QSTR_clock), MP_ROM_PTR(&mod_time_clock_obj) },
-    { MP_ROM_QSTR(MP_QSTR_sleep), MP_ROM_PTR(&mod_time_sleep_obj) },
-    { MP_ROM_QSTR(MP_QSTR_sleep_ms), MP_ROM_PTR(&mp_time_sleep_ms_obj) },
-    { MP_ROM_QSTR(MP_QSTR_sleep_us), MP_ROM_PTR(&mp_time_sleep_us_obj) },
-    { MP_ROM_QSTR(MP_QSTR_time), MP_ROM_PTR(&mod_time_time_obj) },
-    { MP_ROM_QSTR(MP_QSTR_ticks_ms), MP_ROM_PTR(&mp_time_ticks_ms_obj) },
-    { MP_ROM_QSTR(MP_QSTR_ticks_us), MP_ROM_PTR(&mp_time_ticks_us_obj) },
-    { MP_ROM_QSTR(MP_QSTR_ticks_cpu), MP_ROM_PTR(&mp_time_ticks_cpu_obj) },
-    { MP_ROM_QSTR(MP_QSTR_ticks_add), MP_ROM_PTR(&mp_time_ticks_add_obj) },
-    { MP_ROM_QSTR(MP_QSTR_ticks_diff), MP_ROM_PTR(&mp_time_ticks_diff_obj) },
-    { MP_ROM_QSTR(MP_QSTR_time_ns), MP_ROM_PTR(&mp_time_time_ns_obj) },
-    { MP_ROM_QSTR(MP_QSTR_gmtime), MP_ROM_PTR(&mod_time_gmtime_obj) },
-    { MP_ROM_QSTR(MP_QSTR_localtime), MP_ROM_PTR(&mod_time_localtime_obj) },
+#define MICROPY_PY_TIME_EXTRA_GLOBALS \
+    { MP_ROM_QSTR(MP_QSTR_clock), MP_ROM_PTR(&mod_time_clock_obj) }, \
+    { MP_ROM_QSTR(MP_QSTR_gmtime), MP_ROM_PTR(&mod_time_gmtime_obj) }, \
+    { MP_ROM_QSTR(MP_QSTR_localtime), MP_ROM_PTR(&mod_time_localtime_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_mktime), MP_ROM_PTR(&mod_time_mktime_obj) },
-};
-
-STATIC MP_DEFINE_CONST_DICT(mp_module_time_globals, mp_module_time_globals_table);
-
-const mp_obj_module_t mp_module_time = {
-    .base = { &mp_type_module },
-    .globals = (mp_obj_dict_t *)&mp_module_time_globals,
-};
-
-MP_REGISTER_MODULE(MP_QSTR_time, mp_module_time);
-
-#endif // MICROPY_PY_TIME
diff --git a/ports/unix/mphalport.h b/ports/unix/mphalport.h
index e3c2a8035b..d782741750 100644
--- a/ports/unix/mphalport.h
+++ b/ports/unix/mphalport.h
@@ -31,7 +31,8 @@
 #define CHAR_CTRL_C (3)
 #endif
 
-void mp_hal_set_interrupt_char(char c);
+// CIRCUITPY-CHANGE: mp_hal_set_interrupt_char(int) instead of char
+void mp_hal_set_interrupt_char(int c);
 bool mp_hal_is_interrupted(void);
 
 #define mp_hal_stdio_poll unused // this is not implemented, nor needed
diff --git a/ports/unix/unix_mphal.c b/ports/unix/unix_mphal.c
index 3682575e19..35c8c8b3f7 100644
--- a/ports/unix/unix_mphal.c
+++ b/ports/unix/unix_mphal.c
@@ -72,7 +72,8 @@ STATIC void sighandler(int signum) {
 }
 #endif
 
-void mp_hal_set_interrupt_char(char c) {
+// CIRCUITPY-CHANGE: mp_hal_set_interrupt_char(int) instead of char
+void mp_hal_set_interrupt_char(int c) {
     // configure terminal settings to (not) let ctrl-C through
     if (c == CHAR_CTRL_C) {
         #ifndef _WIN32
diff --git a/ports/unix/variants/coverage/mpconfigvariant.h b/ports/unix/variants/coverage/mpconfigvariant.h
index 1090f2d7e0..67b1f3c803 100644
--- a/ports/unix/variants/coverage/mpconfigvariant.h
+++ b/ports/unix/variants/coverage/mpconfigvariant.h
@@ -46,4 +46,3 @@
 #define MICROPY_PY_CRYPTOLIB          (0)
 #define MICROPY_PY_CRYPTOLIB_CTR      (0)
 #define MICROPY_PY_STRUCT              (0) // uses shared-bindings struct
-#define MICROPY_GC_SPLIT_HEAP          (0)
diff --git a/py/gc.c b/py/gc.c
index 0b528da5b8..ccd6be8f71 100644
--- a/py/gc.c
+++ b/py/gc.c
@@ -338,14 +338,16 @@ STATIC bool gc_try_add_heap(size_t failed_alloc) {
 
 #endif
 
+#if !MICROPY_GC_SPLIT_HEAP
 // CIRCUITPY-CHANGE
-// TODO FOR MERGE: fix this for multiple areas??
+// TODO FOR MERGE: fix this for split heap
 void gc_deinit(void) {
     // Run any finalisers before we stop using the heap.
     gc_sweep_all();
-    MP_STATIC_ASSERT(!MICROPY_GC_SPLIT_HEAP);
+    /// MP_STATIC_ASSERT(!MICROPY_GC_SPLIT_HEAP);
     memset(&MP_STATE_MEM(area), 0, sizeof(MP_STATE_MEM(area)));
 }
+#endif
 
 void gc_lock(void) {
     // This does not need to be atomic or have the GC mutex because:
@@ -958,12 +960,12 @@ void gc_free(void *ptr) {
     mp_state_mem_area_t *area;
     #if MICROPY_GC_SPLIT_HEAP
     area = gc_get_ptr_area(ptr);
+    // assert(area);
+    #else
     // CIRCUITPY-CHANGE: extra checking
     if (MP_STATE_MEM(gc_pool_start) == 0) {
         reset_into_safe_mode(SAFE_MODE_GC_ALLOC_OUTSIDE_VM);
     }
-    // assert(area);
-    #else
     assert(VERIFY_PTR(ptr));
     area = &MP_STATE_MEM(area);
     #endif