6 files changed, 16 insertions, 14 deletions

diff --git a/src/flash/mflash.c b/src/flash/mflash.c
index 123d61ce..5c8ca8c1 100644
--- a/src/flash/mflash.c
+++ b/src/flash/mflash.c
@@ -1345,7 +1345,8 @@ COMMAND_HANDLER(mg_bank_cmd)
 	char *str;
 	mflash_bank->rst_pin.num = strtoul(CMD_ARGV[2], &str, 0);
 	if (*str)
-		mflash_bank->rst_pin.port[0] = (uint16_t)tolower(str[0]);
+		mflash_bank->rst_pin.port[0] = (uint16_t)
+				tolower((unsigned)str[0]);
 
 	mflash_bank->target = target;
 
diff --git a/src/helper/jim.c b/src/helper/jim.c
index c04acf09..53d1a75e 100644
--- a/src/helper/jim.c
+++ b/src/helper/jim.c
@@ -2217,7 +2217,7 @@ static Jim_Obj *JimStringToLower(Jim_Interp *interp, Jim_Obj *strObjPtr)
 
     memcpy(buf, strObjPtr->bytes, strObjPtr->length + 1);
     for (i = 0; i < strObjPtr->length; i++)
-        buf[i] = tolower(buf[i]);
+        buf[i] = tolower((unsigned)buf[i]);
     return Jim_NewStringObjNoAlloc(interp, buf, strObjPtr->length);
 }
 
@@ -2233,7 +2233,7 @@ static Jim_Obj *JimStringToUpper(Jim_Interp *interp, Jim_Obj *strObjPtr)
 
     memcpy(buf, strObjPtr->bytes, strObjPtr->length + 1);
     for (i = 0; i < strObjPtr->length; i++)
-        buf[i] = toupper(buf[i]);
+        buf[i] = toupper((unsigned)buf[i]);
     return Jim_NewStringObjNoAlloc(interp, buf, strObjPtr->length);
 }
 
@@ -2347,7 +2347,7 @@ static Jim_Obj *Jim_FormatString_Inner(Jim_Interp *interp, Jim_Obj *fmtObjPtr,
 		case '8':
 		case '9':
 			accum = 0;
-			while (isdigit(*fmt) && (fmtLen > 0)) {
+			while (isdigit((unsigned)*fmt) && (fmtLen > 0)) {
 				accum = (accum * 10) + (*fmt - '0');
 				fmt++;  fmtLen--;
 			}
diff --git a/src/server/gdb_server.c b/src/server/gdb_server.c
index 8798ae03..cf628641 100644
--- a/src/server/gdb_server.c
+++ b/src/server/gdb_server.c
@@ -943,7 +943,7 @@ void gdb_str_to_target(struct target *target, char *tstr, struct reg *reg)
 	}
 }
 
-static int hextoint(char c)
+static int hextoint(int c)
 {
 	if (c>='0'&&c<='9')
 	{
diff --git a/src/server/tcl_server.c b/src/server/tcl_server.c
index 08247686..a772c0ac 100644
--- a/src/server/tcl_server.c
+++ b/src/server/tcl_server.c
@@ -88,7 +88,7 @@ static int tcl_input(struct connection *connection)
 	const char *result;
 	int reslen;
 	struct tcl_connection *tclc;
-	char in[256];
+	unsigned char in[256];
 
 	rlen = read_socket(connection->fd, &in, sizeof(in));
 	if (rlen <= 0) {
diff --git a/src/server/telnet_server.c b/src/server/telnet_server.c
index 929c1c16..92e7480b 100644
--- a/src/server/telnet_server.c
+++ b/src/server/telnet_server.c
@@ -195,8 +195,8 @@ void telnet_clear_line(struct connection *connection, struct telnet_connection *
 int telnet_input(struct connection *connection)
 {
 	int bytes_read;
-	char buffer[TELNET_BUFFER_SIZE];
-	char *buf_p;
+	unsigned char buffer[TELNET_BUFFER_SIZE];
+	unsigned char *buf_p;
 	struct telnet_connection *t_con = connection->priv;
 	struct command_context *command_context = connection->cmd_ctx;
 
@@ -216,7 +216,7 @@ int telnet_input(struct connection *connection)
 		switch (t_con->state)
 		{
 			case TELNET_STATE_DATA:
-				if (*buf_p == '\xff')
+				if (*buf_p == 0xff)
 				{
 					t_con->state = TELNET_STATE_IAC;
 				}
@@ -395,16 +395,16 @@ int telnet_input(struct connection *connection)
 			case TELNET_STATE_IAC:
 				switch (*buf_p)
 				{
-					case '\xfe':
+					case 0xfe:
 						t_con->state = TELNET_STATE_DONT;
 						break;
-					case '\xfd':
+					case 0xfd:
 						t_con->state = TELNET_STATE_DO;
 						break;
-					case '\xfc':
+					case 0xfc:
 						t_con->state = TELNET_STATE_WONT;
 						break;
-					case '\xfb':
+					case 0xfb:
 						t_con->state = TELNET_STATE_WILL;
 						break;
 				}
diff --git a/src/svf/svf.c b/src/svf/svf.c
index 1c746f38..dfdecbcd 100644
--- a/src/svf/svf.c
+++ b/src/svf/svf.c
@@ -470,7 +470,8 @@ free_all:
 #define SVFP_CMD_INC_CNT			1024
 static int svf_read_command_from_file(int fd)
 {
-	char ch, *tmp_buffer = NULL;
+	unsigned char ch;
+	char *tmp_buffer = NULL;
 	int cmd_pos = 0, cmd_ok = 0, slash = 0, comment = 0;
 
 	while (!cmd_ok && (read(fd, &ch, 1) > 0))