diff --git a/bdk/storage/nx_emmc_bis.c b/bdk/storage/nx_emmc_bis.c
index 28bdc6fb..3fbc4d8d 100644
--- a/bdk/storage/nx_emmc_bis.c
+++ b/bdk/storage/nx_emmc_bis.c
@@ -56,6 +56,7 @@ static u32 emu_offset = 0;
 static emmc_part_t *system_part = NULL;
 static u32 *cache_lookup_tbl = (u32 *)NX_BIS_LOOKUP_ADDR;
 static bis_cache_t *bis_cache = (bis_cache_t *)NX_BIS_CACHE_ADDR;
+static sdmmc_storage_t *emu_storage = NULL;
 
 static int nx_emmc_bis_write_block(u32 sector, u32 count, void *buff, bool flush)
 {
@@ -95,10 +96,10 @@ static int nx_emmc_bis_write_block(u32 sector, u32 count, void *buff, bool flush
 		return 1; // Encryption error.
 
 	// If not reading from cache, do a regular read and decrypt.
-	if (!emu_offset)
+	if (!emu_storage)
 		res = emmc_part_write(system_part, sector, count, bis_cache->dma_buff);
 	else
-		res = sdmmc_storage_write(&sd_storage, emu_offset + system_part->lba_start + sector, count, bis_cache->dma_buff);
+		res = sdmmc_storage_write(emu_storage, emu_offset + system_part->lba_start + sector, count, bis_cache->dma_buff);
 	if (!res)
 		return 1; // R/W error.
 
@@ -155,10 +156,10 @@ static int nx_emmc_bis_read_block_normal(u32 sector, u32 count, void *buff)
 	u32  sector_in_cluster = sector % BIS_CLUSTER_SECTORS;
 
 	// If not reading from cache, do a regular read and decrypt.
-	if (!emu_offset)
+	if (!emu_storage)
 		res = emmc_part_read(system_part, sector, count, bis_cache->dma_buff);
 	else
-		res = sdmmc_storage_read(&sd_storage, emu_offset + system_part->lba_start + sector, count, bis_cache->dma_buff);
+		res = sdmmc_storage_read(emu_storage, emu_offset + system_part->lba_start + sector, count, bis_cache->dma_buff);
 	if (!res)
 		return 1; // R/W error.
 
@@ -212,10 +213,10 @@ static int nx_emmc_bis_read_block_cached(u32 sector, u32 count, void *buff)
 	cache_lookup_tbl[cluster] = bis_cache->top_idx;
 
 	// Read the whole cluster the sector resides in.
-	if (!emu_offset)
+	if (!emu_storage)
 		res = emmc_part_read(system_part, cluster_sector, BIS_CLUSTER_SECTORS, bis_cache->dma_buff);
 	else
-		res = sdmmc_storage_read(&sd_storage, emu_offset + system_part->lba_start + cluster_sector, BIS_CLUSTER_SECTORS, bis_cache->dma_buff);
+		res = sdmmc_storage_read(emu_storage, emu_offset + system_part->lba_start + cluster_sector, BIS_CLUSTER_SECTORS, bis_cache->dma_buff);
 	if (!res)
 		return 1; // R/W error.
 
@@ -292,10 +293,11 @@ int nx_emmc_bis_write(u32 sector, u32 count, void *buff)
 	return 1;
 }
 
-void nx_emmc_bis_init(emmc_part_t *part, bool enable_cache, u32 emummc_offset)
+void nx_emmc_bis_init(emmc_part_t *part, bool enable_cache, sdmmc_storage_t *storage, u32 emummc_offset)
 {
 	system_part = part;
 	emu_offset = emummc_offset;
+	emu_storage = storage;
 
 	_nx_emmc_bis_cluster_cache_init(enable_cache);
 
@@ -322,4 +324,6 @@ void nx_emmc_bis_end()
 {
 	_nx_emmc_bis_flush_cache();
 	system_part = NULL;
+	emu_storage = NULL;
+	emu_offset = 0;
 }
diff --git a/bdk/storage/nx_emmc_bis.h b/bdk/storage/nx_emmc_bis.h
index 7cdacfc1..c0bfcdaa 100644
--- a/bdk/storage/nx_emmc_bis.h
+++ b/bdk/storage/nx_emmc_bis.h
@@ -229,7 +229,8 @@ typedef struct _nx_emmc_cal0_t
 
 int  nx_emmc_bis_read(u32 sector, u32 count, void *buff);
 int  nx_emmc_bis_write(u32 sector, u32 count, void *buff);
-void nx_emmc_bis_init(emmc_part_t *part, bool enable_cache, u32 emummc_offset);
+// when storage == NULL, use active emummc config, otherwise, access storage at offset
+void nx_emmc_bis_init(emmc_part_t *part, bool enable_cache, sdmmc_storage_t *storage, u32 emummc_offset);
 void nx_emmc_bis_end();
 
 #endif
diff --git a/nyx/nyx_gui/frontend/fe_emummc_tools.c b/nyx/nyx_gui/frontend/fe_emummc_tools.c
index 49d44f08..b4034712 100644
--- a/nyx/nyx_gui/frontend/fe_emummc_tools.c
+++ b/nyx/nyx_gui/frontend/fe_emummc_tools.c
@@ -673,7 +673,7 @@ static int _dump_emummc_raw_part(emmc_tool_gui_t *gui, int active_part, int part
 		user_part.lba_start = user_offset;
 		user_part.lba_end = user_offset + user_sectors - 1;
 		strcpy(user_part.name, "USER");
-		nx_emmc_bis_init(&user_part, true, sd_sector_off);
+		nx_emmc_bis_init(&user_part, true, &sd_storage, sd_sector_off);
 
 		s_printf(gui->txt_buf, "Formatting USER... \n");
 		lv_label_ins_text(gui->label_log, LV_LABEL_POS_LAST, gui->txt_buf);
@@ -787,7 +787,7 @@ static int _emummc_raw_derive_bis_keys(emmc_tool_gui_t *gui, u32 resized_count)
 	LIST_INIT(gpt);
 	emmc_gpt_parse(&gpt);
 	emmc_part_t *cal0_part = emmc_part_find(&gpt, "PRODINFO"); // check if null
-	nx_emmc_bis_init(cal0_part, false, 0);
+	nx_emmc_bis_init(cal0_part, false, NULL,  0);
 	nx_emmc_bis_read(0, 0x40, cal0_buff);
 	nx_emmc_bis_end();
 	emmc_gpt_free(&gpt);
diff --git a/nyx/nyx_gui/hos/hos.c b/nyx/nyx_gui/hos/hos.c
index ba23bdd8..3f5e8bc0 100644
--- a/nyx/nyx_gui/hos/hos.c
+++ b/nyx/nyx_gui/hos/hos.c
@@ -700,7 +700,7 @@ int hos_dump_cal0()
 	LIST_INIT(gpt);
 	emmc_gpt_parse(&gpt);
 	emmc_part_t *cal0_part = emmc_part_find(&gpt, "PRODINFO"); // check if null
-	nx_emmc_bis_init(cal0_part, false, 0);
+	nx_emmc_bis_init(cal0_part, false, NULL, 0);
 	nx_emmc_bis_read(0, 0x40, cal0_buf);
 	nx_emmc_bis_end();
 	emmc_gpt_free(&gpt);