linux: Set SO_REUSEADDR on gdb server socket.

Renamed HOST environment variable to PROBE_HOST.

Thanks to Michael Smith for the patch.

src/Makefile

@@ -1,14 +1,14 @@
-ifndef HOST
-HOST = stm32
+ifndef PROBE_HOST
+PROBE_HOST = stm32
 endif
 
-VPATH += $(HOST)
+VPATH += $(PROBE_HOST)
 
 BUILDDATE := `date +"%Y%m%d"`
 
 CFLAGS += -Wall -Wextra -Wno-pointer-sign -Wno-char-subscripts\
 	-O0 -std=gnu99 -g3 -DBUILDDATE=\"$(BUILDDATE)\"\
-	-I. -Iinclude -I$(HOST) \
+	-I. -Iinclude -I$(PROBE_HOST) \
 	-DVERSION_SUFFIX=\"`../scripts/setlocalversion`\"
 
 SRC = 	gdb_if.c	\
@@ -30,7 +30,7 @@ SRC = 	gdb_if.c	\
 	arm7tdmi.c	\
 	stm32f4.c	\
 
-include $(HOST)/Makefile.inc
+include $(PROBE_HOST)/Makefile.inc
 
 OBJ = $(SRC:.c=.o)
 

src/linux/gdb_if.c

@@ -47,12 +47,16 @@ int gdb_if_init(void)
 	WSAStartup(MAKEWORD(2, 2), &wsaData);
 #endif
 	struct sockaddr_in addr;
+	int opt;
 
 	addr.sin_family = AF_INET;
 	addr.sin_port = htons(2000);
 	addr.sin_addr.s_addr = htonl(INADDR_ANY);
 
 	assert((gdb_if_serv = socket(PF_INET, SOCK_STREAM, 0)) != -1);
+	opt = 1;
+	assert(setsockopt(gdb_if_serv, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) != -1);
+
 	assert(bind(gdb_if_serv, (void*)&addr, sizeof(addr)) != -1);
 	assert(listen(gdb_if_serv, 1) != -1);