diff --git a/Makefile b/Makefile
index a2f2c10c..d7a29dc6 100644
--- a/Makefile
+++ b/Makefile
@@ -40,14 +40,13 @@ examples:
 
 test/packed_fs.c: Makefile src/ssi.h test/fuzz.c test/data/a.txt
 	$(CC) $(CFLAGS) test/pack.c -o pack
-	./pack Makefile src/ssi.h test/fuzz.c test/data/a.txt -z 'gzip -c' test/data/range.txt > $@
+	./pack Makefile src/ssi.h test/fuzz.c test/data/a.txt test/data/range.txt > $@
 
 DIR ?= test/data/
 OUT ?= gui.c
-ZIP ?= -z 'gzip -c'
 mkfs:
 	$(CC) $(CFLAGS) test/pack.c -o pack
-	./pack $(ZIP) -s $(DIR) `find $(DIR) -type f` > $(OUT)
+	./pack -s $(DIR) `find $(DIR) -type f` > $(OUT)
 #	find $(DIR) -type f | sed -e s,^$(DIR),,g -e s,^/,,g
 
 # Check that all external (exported) symbols have "mg_" prefix
@@ -70,7 +69,7 @@ unamalgamated: $(HDRS) Makefile test/packed_fs.c
 	$(CC) src/*.c test/packed_fs.c test/unit_test.c $(CFLAGS) $(LDFLAGS) -g -o unit_test
 
 unpacked:
-	$(CC) -I. mongoose.c test/unit_test.c -o unit_test
+	$(CC) -I. mongoose.c test/unit_test.c -o $@
 
 fuzzer: mongoose.c mongoose.h Makefile test/fuzz.c
 	clang++ mongoose.c test/fuzz.c $(WARN) $(INCS) $(TFLAGS) $(EXTRA) -DMG_ENABLE_LINES -DMG_ENABLE_LOG=0 -fsanitize=fuzzer,signed-integer-overflow,address -Wno-deprecated -o $@
@@ -102,10 +101,10 @@ infer:
 	infer run -- cc test/unit_test.c -c -W -Wall -Werror -Isrc -I. -O2 -DMG_ENABLE_MBEDTLS=1 -DMG_ENABLE_LINES -I/usr/local/Cellar/mbedtls/2.23.0/include  -DMG_ENABLE_IPV6=1 -g -o /dev/null
 
 arm: mongoose.h $(SRCS)
-	$(DOCKER) mdashnet/armgcc arm-none-eabi-gcc -mcpu=cortex-m3 -mthumb $(SRCS) test/mongoose_custom.c -Itest -DMG_ARCH=MG_ARCH_CUSTOM $(OPTS) $(WARN) $(INCS) $(DEFS) -o unit_test -nostartfiles --specs nosys.specs -e 0
+	$(DOCKER) mdashnet/armgcc arm-none-eabi-gcc -mcpu=cortex-m3 -mthumb $(SRCS) test/mongoose_custom.c -Itest -DMG_ARCH=MG_ARCH_NEWLIB $(OPTS) $(WARN) $(INCS) $(DEFS) -o unit_test -nostartfiles --specs nosys.specs -e 0
 
 riscv: mongoose.h $(SRCS)
-	$(DOCKER) mdashnet/riscv riscv-none-elf-gcc -march=rv32imc -mabi=ilp32 $(SRCS) test/mongoose_custom.c -Itest -DMG_ARCH=MG_ARCH_CUSTOM $(OPTS) $(WARN) $(INCS) $(DEFS) -o unit_test
+	$(DOCKER) mdashnet/riscv riscv-none-elf-gcc -march=rv32imc -mabi=ilp32 $(SRCS) test/mongoose_custom.c -Itest -DMG_ARCH=MG_ARCH_NEWLIB $(OPTS) $(WARN) $(INCS) $(DEFS) -o unit_test
 
 #vc98: VCFLAGS += -DMG_ENABLE_IPV6=1
 vc98: Makefile mongoose.h $(SRCS)
@@ -154,5 +153,5 @@ mongoose.h: $(HDRS) Makefile
 	(cat src/license.h; echo; echo '#ifndef MONGOOSE_H'; echo '#define MONGOOSE_H'; echo; cat src/version.h ; echo; echo '#ifdef __cplusplus'; echo 'extern "C" {'; echo '#endif'; cat src/arch.h src/arch_*.h src/config.h src/str.h src/log.h src/timer.h src/fs.h src/util.h src/url.h src/iobuf.h src/base64.h src/md5.h src/sha1.h src/event.h src/net.h src/http.h src/ssi.h src/tls.h src/tls_mbed.h src/tls_openssl.h src/ws.h src/sntp.h src/mqtt.h src/dns.h | sed -e 's,#include ".*,,' -e 's,^#pragma once,,'; echo; echo '#ifdef __cplusplus'; echo '}'; echo '#endif'; echo '#endif  // MONGOOSE_H')> $@
 
 clean:
-	rm -rf $(PROG) *.o *.dSYM unit_test* valgrind_unit_test* ut fuzzer *.gcov *.gcno *.gcda *.obj *.exe *.ilk *.pdb slow-unit* _CL_* infer-out data.txt crash-* test/packed_fs.c pack
+	rm -rf $(PROG) *.o *.dSYM unit_test* valgrind_unit_test* ut fuzzer *.gcov *.gcno *.gcda *.obj *.exe *.ilk *.pdb slow-unit* _CL_* infer-out data.txt crash-* test/packed_fs.c pack unpacked
 	@for X in $(EXAMPLES); do test -f $$X/Makefile && $(MAKE) -C $$X clean; done
diff --git a/mongoose.h b/mongoose.h
index d275bd3a..cc895b8d 100644
--- a/mongoose.h
+++ b/mongoose.h
@@ -37,6 +37,7 @@ extern "C" {
 #define MG_ARCH_AZURERTOS 7
 #define MG_ARCH_RTX_LWIP 8
 #define MG_ARCH_ZEPHYR 9
+#define MG_ARCH_NEWLIB 10
 
 #if !defined(MG_ARCH)
 #if defined(__unix__) || defined(__APPLE__)
@@ -79,6 +80,7 @@ extern "C" {
 
 
 
+
 #if MG_ARCH == MG_ARCH_AZURERTOS
 
 #include <stdarg.h>
@@ -292,6 +294,29 @@ struct timeval {
 #endif  // MG_ARCH == MG_ARCH_FREERTOS_TCP
 
 
+#if MG_ARCH == MG_ARCH_NEWLIB
+#define _POSIX_TIMERS
+
+#include <ctype.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+
+#define MG_PATH_MAX 100
+#define MG_ENABLE_SOCKET 0
+#define MG_ENABLE_DIRLIST 0
+
+#endif
+
+
 #if MG_ARCH == MG_ARCH_RTX_LWIP
 
 #include <ctype.h>
@@ -884,6 +909,7 @@ struct mg_mgr {
   uint16_t mqtt_id;             // MQTT IDs for pub/sub
   void *active_dns_requests;    // DNS requests in progress
   struct mg_timer *timers;      // Active timers
+  void *priv;                   // Used by the experimental stack
 #if MG_ARCH == MG_ARCH_FREERTOS_TCP
   SocketSet_t ss;  // NOTE(lsm): referenced from socket struct
 #endif
diff --git a/src/arch.h b/src/arch.h
index 7204cfa9..3541a52b 100644
--- a/src/arch.h
+++ b/src/arch.h
@@ -10,6 +10,7 @@
 #define MG_ARCH_AZURERTOS 7
 #define MG_ARCH_RTX_LWIP 8
 #define MG_ARCH_ZEPHYR 9
+#define MG_ARCH_NEWLIB 10
 
 #if !defined(MG_ARCH)
 #if defined(__unix__) || defined(__APPLE__)
@@ -47,6 +48,7 @@
 #include "arch_esp8266.h"
 #include "arch_freertos_lwip.h"
 #include "arch_freertos_tcp.h"
+#include "arch_newlib.h"
 #include "arch_unix.h"
 #include "arch_win32.h"
 #include "arch_zephyr.h"
diff --git a/test/mongoose_custom.h b/src/arch_newlib.h
similarity index 90%
rename from test/mongoose_custom.h
rename to src/arch_newlib.h
index dbd41b10..bb0281b9 100644
--- a/test/mongoose_custom.h
+++ b/src/arch_newlib.h
@@ -1,6 +1,6 @@
-// Required by the test ARM build
 #pragma once
 
+#if MG_ARCH == MG_ARCH_NEWLIB
 #define _POSIX_TIMERS
 
 #include <ctype.h>
@@ -19,3 +19,5 @@
 #define MG_PATH_MAX 100
 #define MG_ENABLE_SOCKET 0
 #define MG_ENABLE_DIRLIST 0
+
+#endif
diff --git a/src/net.h b/src/net.h
index e1b46964..e47bdfb0 100644
--- a/src/net.h
+++ b/src/net.h
@@ -29,6 +29,7 @@ struct mg_mgr {
   uint16_t mqtt_id;             // MQTT IDs for pub/sub
   void *active_dns_requests;    // DNS requests in progress
   struct mg_timer *timers;      // Active timers
+  void *priv;                   // Used by the experimental stack
 #if MG_ARCH == MG_ARCH_FREERTOS_TCP
   SocketSet_t ss;  // NOTE(lsm): referenced from socket struct
 #endif
diff --git a/test/pack.c b/test/pack.c
index 312e7f37..1850bf06 100644
--- a/test/pack.c
+++ b/test/pack.c
@@ -24,21 +24,12 @@
 #include <string.h>
 #include <sys/stat.h>
 
-#if defined(_WIN32)
-#undef popen
-#undef pclose
-#undef snprintf
-#define snprintf _snprintf
-#define popen(a, b) _popen((a), (b))
-#define pclose(a) _pclose(a)
-#endif
-
 static const char *code =
-    "const char *mg_unpack(const char *path, size_t *size, time_t *mtime);\n"
     "const char *mg_unlist(size_t no);\n"
     "const char *mg_unlist(size_t no) {\n"
     "  return packed_files[no].name;\n"
     "}\n"
+    "const char *mg_unpack(const char *path, size_t *size, time_t *mtime);\n"
     "const char *mg_unpack(const char *name, size_t *size, time_t *mtime) {\n"
     "  const struct packed_file *p;\n"
     "  for (p = packed_files; p->name != NULL; p++) {\n"
@@ -52,7 +43,7 @@ static const char *code =
 
 int main(int argc, char *argv[]) {
   int i, j, ch;
-  const char *zip_cmd = NULL, *strip_prefix = "";
+  const char *strip_prefix = "";
 
   printf("%s", "#include <stddef.h>\n");
   printf("%s", "#include <string.h>\n");
@@ -60,27 +51,16 @@ int main(int argc, char *argv[]) {
   printf("%s", "\n");
 
   for (i = 1; i < argc; i++) {
-    if (strcmp(argv[i], "-z") == 0 && i + 1 < argc) {
-      zip_cmd = argv[++i];
-    } else if (strcmp(argv[i], "-s") == 0) {
+    if (strcmp(argv[i], "-s") == 0) {
       strip_prefix = argv[++i];
     } else if (strcmp(argv[i], "-h") == 0 || strcmp(argv[i], "--help") == 0) {
-      fprintf(stderr, "Usage: %s [-z ZIP_CMD] [-s STRIP_PREFIX] files...\n",
-              argv[0]);
+      fprintf(stderr, "Usage: %s[-s STRIP_PREFIX] files...\n", argv[0]);
       exit(EXIT_FAILURE);
     } else {
-      char ascii[12], cmd[2048];
-      FILE *fp;
-
-      if (zip_cmd == NULL) {
-        fp = fopen(argv[i], "rb");
-      } else {
-        snprintf(cmd, sizeof(cmd), "%s %s", zip_cmd, argv[i]);
-        fp = popen(cmd, "r");
-      }
+      char ascii[12];
+      FILE *fp = fopen(argv[i], "rb");
       if (fp == NULL) {
-        fprintf(stderr, "Cannot open [%s]: %s\n", zip_cmd ? cmd : argv[i],
-                strerror(errno));
+        fprintf(stderr, "Cannot open [%s]: %s\n", argv[i], strerror(errno));
         exit(EXIT_FAILURE);
       }
 
@@ -97,8 +77,7 @@ int main(int argc, char *argv[]) {
       // as nul-terminated strings.
       // printf(" 0 // %.*s\n", (int) sizeof(ascii), ascii);
       printf(" 0 // %.*s\n};\n", j, ascii);
-      if (zip_cmd == NULL) fclose(fp);
-      if (zip_cmd != NULL) pclose(fp);
+      fclose(fp);
     }
   }
 
@@ -107,7 +86,6 @@ int main(int argc, char *argv[]) {
   printf("%s", "  const unsigned char *data;\n");
   printf("%s", "  size_t size;\n");
   printf("%s", "  time_t mtime;\n");
-  printf("%s", "  int zipped;\n");
   printf("%s", "} packed_files[] = {\n");
 
   for (i = 1; i < argc; i++) {
@@ -120,10 +98,9 @@ int main(int argc, char *argv[]) {
     }
     stat(argv[i], &st);
     if (strncmp(name, strip_prefix, n) == 0) name += n;
-    printf("  {\"/%s\", v%d, sizeof(v%d), %lu, %d},\n", name, i, i, st.st_mtime,
-           zip_cmd == NULL ? 0 : 1);
+    printf("  {\"/%s\", v%d, sizeof(v%d), %lu},\n", name, i, i, st.st_mtime);
   }
-  printf("%s", "  {NULL, NULL, 0, 0, 0}\n");
+  printf("%s", "  {NULL, NULL, 0, 0}\n");
   printf("%s", "};\n\n");
   printf("%s", code);
 
diff --git a/test/unit_test.c b/test/unit_test.c
index 9a7e0bdb..83874918 100644
--- a/test/unit_test.c
+++ b/test/unit_test.c
@@ -1680,18 +1680,20 @@ static void eh7(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
     sopts.fs = &mg_fs_packed;
     mg_http_serve_dir(c, hm, &sopts);
   }
-  (void) ev_data, (void) fn_data;
+  (void) fn_data;
 }
 
 static void test_packed(void) {
   struct mg_mgr mgr;
   const char *url = "http://127.0.0.1:12351";
-  char buf[FETCH_BUF_SIZE] = "",
-       *data = mg_file_read(&mg_fs_posix, "Makefile", NULL);
+  char buf[FETCH_BUF_SIZE],
+      *data = mg_file_read(&mg_fs_posix, "Makefile", NULL);
   mg_mgr_init(&mgr);
   mg_http_listen(&mgr, url, eh7, NULL);
 
   // Load top level file directly
+  fetch(&mgr, buf, url, "GET /Makefile HTTP/1.0\n\n");
+  printf("---> %s\n", buf);
   ASSERT(fetch(&mgr, buf, url, "GET /Makefile HTTP/1.0\n\n") == 200);
   ASSERT(cmpbody(buf, data) == 0);
   free(data);
@@ -1720,7 +1722,7 @@ static void eh6(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
   (void) c, (void) ev_data;
 }
 
-#ifdef __arm__
+#if defined(__arm__) || defined(__riscv)
 int send(int sock, const void *buf, size_t len, int flags);
 int send(int sock, const void *buf, size_t len, int flags) {
   (void) sock, (void) buf, (void) len, (void) flags;