Add shared_folder INI option.

MiSTer.ini

@@ -119,3 +119,9 @@ sniper_mode=0
 
 ; 0 - disable MiSTer logo in Menu core
 logo=1
+
+; Custom shared folder for core supporting this feature (currently minimig only)
+; Can be relative to core's home dir or absolute path.
+; Path must exist before core start to use it, or it will fail.
+; Make sure USB device is mounted before use shared folder on USB!
+shared_folder=

cfg.cpp

@@ -71,6 +71,7 @@ static const ini_var_t ini_vars[] =
 	{ "SNIPER_MODE", (void*)(&(cfg.sniper_mode)), UINT8, 0, 1 },
 	{ "BROWSE_EXPAND", (void*)(&(cfg.browse_expand)), UINT8, 0, 1 },
 	{ "LOGO", (void*)(&(cfg.logo)), UINT8, 0, 1 },
+	{ "SHARED_FOLDER", (void*)(&(cfg.shared_folder)), STRING, 0, sizeof(cfg.shared_folder) - 1 },
 };
 
 static const int nvars = (int)(sizeof(ini_vars) / sizeof(ini_var_t));

cfg.h

@@ -50,6 +50,7 @@ typedef struct {
 	char video_conf_pal[1024];
 	char video_conf_ntsc[1024];
 	char font[1024];
+	char shared_folder[1024];
 } cfg_t;
 
 extern cfg_t cfg;

support/minimig/minimig_share.cpp

@@ -16,6 +16,7 @@
 #include "../../file_io.h"
 #include "../../user_io.h"
 #include "../../spi.h"
+#include "../../cfg.h"
 #include "miminig_fs_messages.h"
 
 #define SHMEM_ADDR      0x27FF4000
@@ -235,12 +236,35 @@ static int process_request(void *reqres_buffer)
 
 	if (!baselen)
 	{
-		strcpy(basepath, HomeDir());
-		strcat(basepath, "/shared");
+		if (strlen(cfg.shared_folder))
+		{
+			if(cfg.shared_folder[0] == '/') strcpy(basepath, cfg.shared_folder);
+			else
+			{
+				strcpy(basepath, HomeDir());
+				strcat(basepath, "/");
+				strcat(basepath, cfg.shared_folder);
+			}
+		}
+		else
+		{
+			strcpy(basepath, HomeDir());
+			strcat(basepath, "/shared");
+		}
+
 		baselen = strlen(basepath);
-		FileCreatePath(basepath);
+		if (baselen && basepath[baselen - 1] == '/')
+		{
+			basepath[baselen - 1] = 0;
+			baselen--;
+		}
+
+		if(baselen) FileCreatePath(basepath);
 	}
 
+	// no base path => force fail
+	if (!baselen) rtype = ACTION_NIL;
+
 	switch (rtype)
 	{
 		case ACTION_LOCATE_OBJECT: