-#define m18_drv_FlashInit() ynorsim_initialise()
-#define m18_drv_FlashDeinit() ynorsim_shutdown()
-#define m18_drv_FlashWrite32(addr,buf,nwords) ynorsim_wr32(addr,buf,nwords)
-#define m18_drv_FlashRead32(addr,buf,nwords) ynorsim_rd32(addr,buf,nwords)
-#define m18_drv_FlashEraseBlock(addr) ynorsim_erase(addr)
-#define DEVICE_BASE ynorsim_get_base()
+
+static struct nor_sim *nor_sim;
+
+#define m18_drv_FlashInit() do {nor_sim = ynorsim_initialise("emfile-m18", BLOCKS_IN_DEVICE, BLOCK_SIZE_IN_BYTES); } while(0)
+#define m18_drv_FlashDeinit() ynorsim_shutdown(nor_sim)
+#define m18_drv_FlashWrite32(addr,buf,nwords) ynorsim_wr32(nor_sim,addr,buf,nwords)
+#define m18_drv_FlashRead32(addr,buf,nwords) ynorsim_rd32(nor_sim,addr,buf,nwords)
+#define m18_drv_FlashEraseBlock(addr) ynorsim_erase(nor_sim,addr)
+#define DEVICE_BASE ynorsim_get_base(nor_sim)
+