File ch341eepromtool-extern_readbuf.patch of Package ch341eepromtool
diff --git a/ch341funcs.c b/ch341funcs.c
index 3bed06b..55ba7cf 100644
--- a/ch341funcs.c
+++ b/ch341funcs.c
@@ -30,7 +30,7 @@ extern FILE *debugout, *verbout;
uint32_t getnextpkt; // set by the callback function
uint32_t syncackpkt; // synch / ack flag used by BULK OUT cb function
uint16_t byteoffset;
-uint8_t *readbuf;
+extern uint8_t *readbuf;
// --------------------------------------------------------------------------
// ch341configure()