ChaCha20 not working in S390 (bigendian)

mongoose.c

@@ -10877,7 +10877,9 @@ int mg_aes_gcm_decrypt(unsigned char *output, const unsigned char *input,
 
 #if MG_TLS == MG_TLS_BUILTIN
 
+#ifndef CHACHA20
 #define CHACHA20 1
+#endif
 
 /* TLS 1.3 Record Content Type (RFC8446 B.1) */
 #define MG_TLS_CHANGE_CIPHER 20

src/tls_builtin.c

@@ -12,7 +12,9 @@
 
 #if MG_TLS == MG_TLS_BUILTIN
 
+#ifndef CHACHA20
 #define CHACHA20 1
+#endif
 
 /* TLS 1.3 Record Content Type (RFC8446 B.1) */
 #define MG_TLS_CHANGE_CIPHER 20

test/Makefile

@@ -175,6 +175,7 @@ armhf: test
 s390: ASAN=
 s390: IPV6=0
 s390: CFLAGS += -Wno-stringop-overflow
+s390: DEFS += -DCHACHA20=0
 s390: CC = $(DOCKER) mdashnet/s390 cc
 s390: RUN = $(DOCKER) --init mdashnet/s390
 s390: test