diff --git a/ld/libfiles.inc b/ld/libfiles.inc
index 0eaffe341..b5bff31a2 100644
--- a/ld/libfiles.inc
+++ b/ld/libfiles.inc
@@ -149,7 +149,7 @@
 	build/ROMID/lib/ultra/io/conteepwrite.o (section); \
 	build/ROMID/lib/lib_4c090.o (section); \
 	build/ROMID/lib/lib_4cc10.o (section); \
-	build/ROMID/lib/lib_4cde0.o (section); \
+	build/ROMID/lib/ultra/io/pfsselectbank.o (section); \
 	build/ROMID/lib/lib_4ce60.o (section); \
 	build/ROMID/lib/lib_4d000.o (section); \
 	build/ROMID/lib/lib_4d480.o (section); \
diff --git a/src/include/PR/os_misc.h b/src/include/PR/os_misc.h
index 78a57a4ef..b6755f370 100644
--- a/src/include/PR/os_misc.h
+++ b/src/include/PR/os_misc.h
@@ -35,6 +35,14 @@
 #define FLAGS_HASH 8
 #define FLAGS_ZERO 16
 
+#define BLOCKSIZE 32
+
+#define ARRLEN(x) ((s32)(sizeof(x) / sizeof(x[0])))
+
+#define ERRCK(fn) \
+    ret = fn;     \
+    if (ret != 0) \
+        return ret;
 
 typedef struct {
     union {
diff --git a/src/include/lib/lib_4cde0.h b/src/include/lib/lib_4cde0.h
deleted file mode 100644
index 606ca729a..000000000
--- a/src/include/lib/lib_4cde0.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#ifndef _IN_LIB_LIB_4CDE0_H
-#define _IN_LIB_LIB_4CDE0_H
-#include <ultra64.h>
-#include "types.h"
-
-u32 func0004cde0(void);
-
-#endif
diff --git a/src/include/libultra_internal.h b/src/include/libultra_internal.h
index 14c1af293..885c61f5c 100644
--- a/src/include/libultra_internal.h
+++ b/src/include/libultra_internal.h
@@ -48,4 +48,6 @@ s32 __osAiDeviceBusy();
 void __osDispatchThread();
 u32 __osGetCause();
 s32 __osAtomicDec(u32*);
+s32 __osPfsSelectBank(OSPfs *pfs, u8 bank);
+
 #endif
diff --git a/src/lib/lib_06550.c b/src/lib/lib_06550.c
index 49486918d..790706b57 100644
--- a/src/lib/lib_06550.c
+++ b/src/lib/lib_06550.c
@@ -12,7 +12,6 @@
 #include "lib/lib_4b170.h"
 #include "lib/lib_4c090.h"
 #include "lib/lib_4cc10.h"
-#include "lib/lib_4cde0.h"
 #include "lib/lib_4ce60.h"
 #include "lib/lib_4d000.h"
 #include "lib/lib_4d480.h"
@@ -100,7 +99,7 @@ glabel func00006550
 /*     6660:	00002825 */ 	or	$a1,$zero,$zero
 /*     6664:	51600008 */ 	beqzl	$t3,.L00006688
 /*     6668:	8eac005c */ 	lw	$t4,0x5c($s5)
-/*     666c:	0c013378 */ 	jal	func0004cde0
+/*     666c:	0c013378 */ 	jal	__osPfsSelectBank
 /*     6670:	a2a00065 */ 	sb	$zero,0x65($s5)
 /*     6674:	50400004 */ 	beqzl	$v0,.L00006688
 /*     6678:	8eac005c */ 	lw	$t4,0x5c($s5)
@@ -638,7 +637,7 @@ glabel func00006d60
 /*     6dcc:	1000006e */ 	b	.L00006f88
 /*     6dd0:	8fbf001c */ 	lw	$ra,0x1c($sp)
 .L00006dd4:
-/*     6dd4:	0c013378 */ 	jal	func0004cde0
+/*     6dd4:	0c013378 */ 	jal	__osPfsSelectBank
 /*     6dd8:	00002825 */ 	or	$a1,$zero,$zero
 /*     6ddc:	10400003 */ 	beqz	$v0,.L00006dec
 /*     6de0:	24060001 */ 	addiu	$a2,$zero,0x1
@@ -769,7 +768,7 @@ glabel func00006f98
 /*     6f9c:	afbf0024 */ 	sw	$ra,0x24($sp)
 /*     6fa0:	afb00020 */ 	sw	$s0,0x20($sp)
 /*     6fa4:	00808025 */ 	or	$s0,$a0,$zero
-/*     6fa8:	0c013378 */ 	jal	func0004cde0
+/*     6fa8:	0c013378 */ 	jal	__osPfsSelectBank
 /*     6fac:	00002825 */ 	or	$a1,$zero,$zero
 /*     6fb0:	10400003 */ 	beqz	$v0,.L00006fc0
 /*     6fb4:	00003025 */ 	or	$a2,$zero,$zero
diff --git a/src/lib/lib_4c090.c b/src/lib/lib_4c090.c
index 1e94097c8..edf7f8603 100644
--- a/src/lib/lib_4c090.c
+++ b/src/lib/lib_4c090.c
@@ -10,7 +10,6 @@
 #include "gvars/gvars.h"
 #include "lib/lib_4b170.h"
 #include "lib/lib_4c090.h"
-#include "lib/lib_4cde0.h"
 #include "lib/lib_4d6f0.h"
 #include "types.h"
 
@@ -150,7 +149,7 @@ glabel func0004c200
 /*    4c268:	924f0065 */ 	lbu	$t7,0x65($s2)
 /*    4c26c:	51e00008 */ 	beqzl	$t7,.L0004c290
 /*    4c270:	27b1007c */ 	addiu	$s1,$sp,0x7c
-/*    4c274:	0c013378 */ 	jal	func0004cde0
+/*    4c274:	0c013378 */ 	jal	__osPfsSelectBank
 /*    4c278:	00002825 */ 	or	$a1,$zero,$zero
 /*    4c27c:	50400004 */ 	beqzl	$v0,.L0004c290
 /*    4c280:	27b1007c */ 	addiu	$s1,$sp,0x7c
@@ -162,7 +161,7 @@ glabel func0004c200
 /*    4c294:	27b0009c */ 	addiu	$s0,$sp,0x9c
 /*    4c298:	02402025 */ 	or	$a0,$s2,$zero
 .L0004c29c:
-/*    4c29c:	0c013378 */ 	jal	func0004cde0
+/*    4c29c:	0c013378 */ 	jal	__osPfsSelectBank
 /*    4c2a0:	326500ff */ 	andi	$a1,$s3,0xff
 /*    4c2a4:	10400003 */ 	beqz	$v0,.L0004c2b4
 /*    4c2a8:	00003025 */ 	or	$a2,$zero,$zero
@@ -223,7 +222,7 @@ glabel func0004c200
 /*    4c368:	02402025 */ 	or	$a0,$s2,$zero
 /*    4c36c:	5a600013 */ 	blezl	$s3,.L0004c3bc
 /*    4c370:	26730001 */ 	addiu	$s3,$s3,0x1
-/*    4c374:	0c013378 */ 	jal	func0004cde0
+/*    4c374:	0c013378 */ 	jal	__osPfsSelectBank
 /*    4c378:	00002825 */ 	or	$a1,$zero,$zero
 /*    4c37c:	10400003 */ 	beqz	$v0,.L0004c38c
 /*    4c380:	00003025 */ 	or	$a2,$zero,$zero
@@ -253,7 +252,7 @@ glabel func0004c200
 /*    4c3cc:	02402025 */ 	or	$a0,$s2,$zero
 /*    4c3d0:	11200007 */ 	beqz	$t1,.L0004c3f0
 /*    4c3d4:	00000000 */ 	nop
-/*    4c3d8:	0c013378 */ 	jal	func0004cde0
+/*    4c3d8:	0c013378 */ 	jal	__osPfsSelectBank
 /*    4c3dc:	00002825 */ 	or	$a1,$zero,$zero
 /*    4c3e0:	10400003 */ 	beqz	$v0,.L0004c3f0
 /*    4c3e4:	00000000 */ 	nop
@@ -378,7 +377,7 @@ glabel func0004c550
 /*    4c57c:	00809825 */ 	or	$s3,$a0,$zero
 /*    4c580:	51c00008 */ 	beqzl	$t6,.L0004c5a4
 /*    4c584:	240f0001 */ 	addiu	$t7,$zero,0x1
-/*    4c588:	0c013378 */ 	jal	func0004cde0
+/*    4c588:	0c013378 */ 	jal	__osPfsSelectBank
 /*    4c58c:	00002825 */ 	or	$a1,$zero,$zero
 /*    4c590:	50400004 */ 	beqzl	$v0,.L0004c5a4
 /*    4c594:	240f0001 */ 	addiu	$t7,$zero,0x1
@@ -476,7 +475,7 @@ glabel func0004c6b4
 /*    4c6c8:	00808025 */ 	or	$s0,$a0,$zero
 /*    4c6cc:	51c00008 */ 	beqzl	$t6,.L0004c6f0
 /*    4c6d0:	8e040004 */ 	lw	$a0,0x4($s0)
-/*    4c6d4:	0c013378 */ 	jal	func0004cde0
+/*    4c6d4:	0c013378 */ 	jal	__osPfsSelectBank
 /*    4c6d8:	00002825 */ 	or	$a1,$zero,$zero
 /*    4c6dc:	50400004 */ 	beqzl	$v0,.L0004c6f0
 /*    4c6e0:	8e040004 */ 	lw	$a0,0x4($s0)
@@ -598,13 +597,13 @@ glabel func0004c860
 /*    4c870:	00808025 */ 	or	$s0,$a0,$zero
 /*    4c874:	51c0000f */ 	beqzl	$t6,.L0004c8b4
 /*    4c878:	8e040004 */ 	lw	$a0,0x4($s0)
-/*    4c87c:	0c013378 */ 	jal	func0004cde0
+/*    4c87c:	0c013378 */ 	jal	__osPfsSelectBank
 /*    4c880:	00002825 */ 	or	$a1,$zero,$zero
 /*    4c884:	24010002 */ 	addiu	$at,$zero,0x2
 /*    4c888:	14410005 */ 	bne	$v0,$at,.L0004c8a0
 /*    4c88c:	00401825 */ 	or	$v1,$v0,$zero
 /*    4c890:	02002025 */ 	or	$a0,$s0,$zero
-/*    4c894:	0c013378 */ 	jal	func0004cde0
+/*    4c894:	0c013378 */ 	jal	__osPfsSelectBank
 /*    4c898:	00002825 */ 	or	$a1,$zero,$zero
 /*    4c89c:	00401825 */ 	or	$v1,$v0,$zero
 .L0004c8a0:
@@ -690,7 +689,7 @@ glabel func0004c934
 /*    4c9ac:	02402025 */ 	or	$a0,$s2,$zero
 /*    4c9b0:	51200008 */ 	beqzl	$t1,.L0004c9d4
 /*    4c9b4:	93a30067 */ 	lbu	$v1,0x67($sp)
-/*    4c9b8:	0c013378 */ 	jal	func0004cde0
+/*    4c9b8:	0c013378 */ 	jal	__osPfsSelectBank
 /*    4c9bc:	00002825 */ 	or	$a1,$zero,$zero
 /*    4c9c0:	50400004 */ 	beqzl	$v0,.L0004c9d4
 /*    4c9c4:	93a30067 */ 	lbu	$v1,0x67($sp)
diff --git a/src/lib/lib_4cde0.c b/src/lib/lib_4cde0.c
deleted file mode 100644
index fb59d8d43..000000000
--- a/src/lib/lib_4cde0.c
+++ /dev/null
@@ -1,49 +0,0 @@
-#include <ultra64.h>
-#include "constants.h"
-#include "game/data/data_000000.h"
-#include "game/data/data_0083d0.h"
-#include "game/data/data_00e460.h"
-#include "game/data/data_0160b0.h"
-#include "game/data/data_01a3a0.h"
-#include "game/data/data_020df0.h"
-#include "game/data/data_02da90.h"
-#include "gvars/gvars.h"
-#include "types.h"
-
-GLOBAL_ASM(
-glabel func0004cde0
-/*    4cde0:	27bdffa8 */ 	addiu	$sp,$sp,-88
-/*    4cde4:	afb00020 */ 	sw	$s0,0x20($sp)
-/*    4cde8:	30b000ff */ 	andi	$s0,$a1,0xff
-/*    4cdec:	afbf0024 */ 	sw	$ra,0x24($sp)
-/*    4cdf0:	afa40058 */ 	sw	$a0,0x58($sp)
-/*    4cdf4:	afa5005c */ 	sw	$a1,0x5c($sp)
-/*    4cdf8:	27a20038 */ 	addiu	$v0,$sp,0x38
-/*    4cdfc:	27a30058 */ 	addiu	$v1,$sp,0x58
-.L0004ce00:
-/*    4ce00:	24420004 */ 	addiu	$v0,$v0,0x4
-/*    4ce04:	a050fffd */ 	sb	$s0,-0x3($v0)
-/*    4ce08:	a050fffe */ 	sb	$s0,-0x2($v0)
-/*    4ce0c:	a050ffff */ 	sb	$s0,-0x1($v0)
-/*    4ce10:	1443fffb */ 	bne	$v0,$v1,.L0004ce00
-/*    4ce14:	a050fffc */ 	sb	$s0,-0x4($v0)
-/*    4ce18:	8fae0058 */ 	lw	$t6,0x58($sp)
-/*    4ce1c:	24060400 */ 	addiu	$a2,$zero,0x400
-/*    4ce20:	27a70038 */ 	addiu	$a3,$sp,0x38
-/*    4ce24:	8dc40004 */ 	lw	$a0,0x4($t6)
-/*    4ce28:	8dc50008 */ 	lw	$a1,0x8($t6)
-/*    4ce2c:	0c012d84 */ 	jal	__osContRamWrite
-/*    4ce30:	afa00010 */ 	sw	$zero,0x10($sp)
-/*    4ce34:	14400003 */ 	bnez	$v0,.L0004ce44
-/*    4ce38:	00401825 */ 	or	$v1,$v0,$zero
-/*    4ce3c:	8faf0058 */ 	lw	$t7,0x58($sp)
-/*    4ce40:	a1f00065 */ 	sb	$s0,0x65($t7)
-.L0004ce44:
-/*    4ce44:	8fbf0024 */ 	lw	$ra,0x24($sp)
-/*    4ce48:	8fb00020 */ 	lw	$s0,0x20($sp)
-/*    4ce4c:	27bd0058 */ 	addiu	$sp,$sp,0x58
-/*    4ce50:	03e00008 */ 	jr	$ra
-/*    4ce54:	00601025 */ 	or	$v0,$v1,$zero
-/*    4ce58:	00000000 */ 	nop
-/*    4ce5c:	00000000 */ 	nop
-);
\ No newline at end of file
diff --git a/src/lib/lib_4d480.c b/src/lib/lib_4d480.c
index e010d73bd..200bfb179 100644
--- a/src/lib/lib_4d480.c
+++ b/src/lib/lib_4d480.c
@@ -11,7 +11,6 @@
 #include "lib/libc/ll.h"
 #include "lib/lib_4c090.h"
 #include "lib/lib_4cc10.h"
-#include "lib/lib_4cde0.h"
 #include "lib/lib_4d480.h"
 #include "types.h"
 
@@ -50,7 +49,7 @@ glabel func0004d480
 /*    4d4ec:	02402025 */ 	or	$a0,$s2,$zero
 /*    4d4f0:	53200008 */ 	beqzl	$t9,.L0004d514
 /*    4d4f4:	8e48005c */ 	lw	$t0,0x5c($s2)
-/*    4d4f8:	0c013378 */ 	jal	func0004cde0
+/*    4d4f8:	0c013378 */ 	jal	__osPfsSelectBank
 /*    4d4fc:	00002825 */ 	or	$a1,$zero,$zero
 /*    4d500:	50400004 */ 	beqzl	$v0,.L0004d514
 /*    4d504:	8e48005c */ 	lw	$t0,0x5c($s2)
diff --git a/src/lib/lib_4d6f0.c b/src/lib/lib_4d6f0.c
index 0e56d80a2..379660deb 100644
--- a/src/lib/lib_4d6f0.c
+++ b/src/lib/lib_4d6f0.c
@@ -10,7 +10,6 @@
 #include "gvars/gvars.h"
 #include "lib/libc/ll.h"
 #include "lib/lib_4c090.h"
-#include "lib/lib_4cde0.h"
 #include "lib/lib_4d6f0.h"
 #include "types.h"
 
@@ -168,7 +167,7 @@ glabel func0004d6f0
 /*    4d90c:	02602025 */ 	or	$a0,$s3,$zero
 /*    4d910:	51c00008 */ 	beqzl	$t6,.L0004d934
 /*    4d914:	8e6d005c */ 	lw	$t5,0x5c($s3)
-/*    4d918:	0c013378 */ 	jal	func0004cde0
+/*    4d918:	0c013378 */ 	jal	__osPfsSelectBank
 /*    4d91c:	00002825 */ 	or	$a1,$zero,$zero
 /*    4d920:	50400004 */ 	beqzl	$v0,.L0004d934
 /*    4d924:	8e6d005c */ 	lw	$t5,0x5c($s3)
diff --git a/src/lib/lib_4f5e0.c b/src/lib/lib_4f5e0.c
index 18ae7d226..8630841b9 100644
--- a/src/lib/lib_4f5e0.c
+++ b/src/lib/lib_4f5e0.c
@@ -9,7 +9,6 @@
 #include "game/data/data_02da90.h"
 #include "gvars/gvars.h"
 #include "lib/lib_16110.h"
-#include "lib/lib_4cde0.h"
 #include "lib/lib_4f5e0.h"
 #include "lib/lib_51d50.h"
 #include "types.h"
@@ -203,13 +202,13 @@ glabel func0004f854
 /*    4f87c:	aca00000 */ 	sw	$zero,0x0($a1)
 /*    4f880:	00a02025 */ 	or	$a0,$a1,$zero
 /*    4f884:	acaf0008 */ 	sw	$t7,0x8($a1)
-/*    4f888:	0c013378 */ 	jal	func0004cde0
+/*    4f888:	0c013378 */ 	jal	__osPfsSelectBank
 /*    4f88c:	240500fe */ 	addiu	$a1,$zero,0xfe
 /*    4f890:	24010002 */ 	addiu	$at,$zero,0x2
 /*    4f894:	14410005 */ 	bne	$v0,$at,.L0004f8ac
 /*    4f898:	00401825 */ 	or	$v1,$v0,$zero
 /*    4f89c:	02002025 */ 	or	$a0,$s0,$zero
-/*    4f8a0:	0c013378 */ 	jal	func0004cde0
+/*    4f8a0:	0c013378 */ 	jal	__osPfsSelectBank
 /*    4f8a4:	24050080 */ 	addiu	$a1,$zero,0x80
 /*    4f8a8:	00401825 */ 	or	$v1,$v0,$zero
 .L0004f8ac:
@@ -238,7 +237,7 @@ glabel func0004f854
 /*    4f8f8:	10000028 */ 	b	.L0004f99c
 /*    4f8fc:	2402000b */ 	addiu	$v0,$zero,0xb
 .L0004f900:
-/*    4f900:	0c013378 */ 	jal	func0004cde0
+/*    4f900:	0c013378 */ 	jal	__osPfsSelectBank
 /*    4f904:	24050080 */ 	addiu	$a1,$zero,0x80
 /*    4f908:	24010002 */ 	addiu	$at,$zero,0x2
 /*    4f90c:	14410002 */ 	bne	$v0,$at,.L0004f918
diff --git a/src/lib/lib_50480.c b/src/lib/lib_50480.c
index 33e6b057c..fe6359ba0 100644
--- a/src/lib/lib_50480.c
+++ b/src/lib/lib_50480.c
@@ -9,7 +9,6 @@
 #include "game/data/data_02da90.h"
 #include "gvars/gvars.h"
 #include "lib/lib_4c090.h"
-#include "lib/lib_4cde0.h"
 #include "lib/lib_50480.h"
 #include "types.h"
 
@@ -133,7 +132,7 @@ glabel func00050554
 /*    50604:	02402025 */ 	or	$a0,$s2,$zero
 /*    50608:	51200008 */ 	beqzl	$t1,.L0005062c
 /*    5060c:	8e4a005c */ 	lw	$t2,0x5c($s2)
-/*    50610:	0c013378 */ 	jal	func0004cde0
+/*    50610:	0c013378 */ 	jal	__osPfsSelectBank
 /*    50614:	00002825 */ 	or	$a1,$zero,$zero
 /*    50618:	50400004 */ 	beqzl	$v0,.L0005062c
 /*    5061c:	8e4a005c */ 	lw	$t2,0x5c($s2)
@@ -251,7 +250,7 @@ glabel func00050554
 /*    50798:	02402025 */ 	or	$a0,$s2,$zero
 /*    5079c:	53280008 */ 	beql	$t9,$t0,.L000507c0
 /*    507a0:	93a90049 */ 	lbu	$t1,0x49($sp)
-/*    507a4:	0c013378 */ 	jal	func0004cde0
+/*    507a4:	0c013378 */ 	jal	__osPfsSelectBank
 /*    507a8:	03202825 */ 	or	$a1,$t9,$zero
 /*    507ac:	50400004 */ 	beqzl	$v0,.L000507c0
 /*    507b0:	93a90049 */ 	lbu	$t1,0x49($sp)
@@ -300,7 +299,7 @@ glabel func00050554
 /*    50848:	02402025 */ 	or	$a0,$s2,$zero
 /*    5084c:	53000008 */ 	beqzl	$t8,.L00050870
 /*    50850:	8e48005c */ 	lw	$t0,0x5c($s2)
-/*    50854:	0c013378 */ 	jal	func0004cde0
+/*    50854:	0c013378 */ 	jal	__osPfsSelectBank
 /*    50858:	00002825 */ 	or	$a1,$zero,$zero
 /*    5085c:	50400004 */ 	beqzl	$v0,.L00050870
 /*    50860:	8e48005c */ 	lw	$t0,0x5c($s2)
@@ -368,7 +367,7 @@ glabel func000508d0
 /*    5092c:	02202025 */ 	or	$a0,$s1,$zero
 /*    50930:	53000008 */ 	beqzl	$t8,.L00050954
 /*    50934:	8e390050 */ 	lw	$t9,0x50($s1)
-/*    50938:	0c013378 */ 	jal	func0004cde0
+/*    50938:	0c013378 */ 	jal	__osPfsSelectBank
 /*    5093c:	00002825 */ 	or	$a1,$zero,$zero
 /*    50940:	50400004 */ 	beqzl	$v0,.L00050954
 /*    50944:	8e390050 */ 	lw	$t9,0x50($s1)
diff --git a/src/lib/lib_50a00.c b/src/lib/lib_50a00.c
index 528382b6c..8d73db18d 100644
--- a/src/lib/lib_50a00.c
+++ b/src/lib/lib_50a00.c
@@ -12,7 +12,6 @@
 #include "lib/lib_06330.h"
 #include "lib/lib_4b170.h"
 #include "lib/lib_4c090.h"
-#include "lib/lib_4cde0.h"
 #include "lib/lib_4d6f0.h"
 #include "lib/lib_50a00.h"
 #include "lib/lib_513b0.h"
@@ -58,7 +57,7 @@ glabel func00050a00
 /*    50a7c:	02602025 */ 	or	$a0,$s3,$zero
 /*    50a80:	53200008 */ 	beqzl	$t9,.L00050aa4
 /*    50a84:	8e68005c */ 	lw	$t0,0x5c($s3)
-/*    50a88:	0c013378 */ 	jal	func0004cde0
+/*    50a88:	0c013378 */ 	jal	__osPfsSelectBank
 /*    50a8c:	00002825 */ 	or	$a1,$zero,$zero
 /*    50a90:	50400004 */ 	beqzl	$v0,.L00050aa4
 /*    50a94:	8e68005c */ 	lw	$t0,0x5c($s3)
diff --git a/src/lib/lib_513b0.c b/src/lib/lib_513b0.c
index 92a6c96f9..8a34d5789 100644
--- a/src/lib/lib_513b0.c
+++ b/src/lib/lib_513b0.c
@@ -10,7 +10,6 @@
 #include "gvars/gvars.h"
 #include "lib/lib_4b170.h"
 #include "lib/lib_4c090.h"
-#include "lib/lib_4cde0.h"
 #include "lib/lib_4d6f0.h"
 #include "lib/lib_513b0.h"
 #include "lib/lib_52360.h"
@@ -170,7 +169,7 @@ glabel func000513b0
 /*    515d8:	10000063 */ 	b	.L00051768
 /*    515dc:	8fbf001c */ 	lw	$ra,0x1c($sp)
 .L000515e0:
-/*    515e0:	0c013378 */ 	jal	func0004cde0
+/*    515e0:	0c013378 */ 	jal	__osPfsSelectBank
 /*    515e4:	00002825 */ 	or	$a1,$zero,$zero
 /*    515e8:	10400003 */ 	beqz	$v0,.L000515f8
 /*    515ec:	24060001 */ 	addiu	$a2,$zero,0x1
@@ -290,7 +289,7 @@ glabel func00051778
 /*    5177c:	afbf0024 */ 	sw	$ra,0x24($sp)
 /*    51780:	afb00020 */ 	sw	$s0,0x20($sp)
 /*    51784:	00808025 */ 	or	$s0,$a0,$zero
-/*    51788:	0c013378 */ 	jal	func0004cde0
+/*    51788:	0c013378 */ 	jal	__osPfsSelectBank
 /*    5178c:	00002825 */ 	or	$a1,$zero,$zero
 /*    51790:	10400003 */ 	beqz	$v0,.L000517a0
 /*    51794:	00003025 */ 	or	$a2,$zero,$zero
diff --git a/src/lib/ultra/io/pfsselectbank.c b/src/lib/ultra/io/pfsselectbank.c
new file mode 100644
index 000000000..145152726
--- /dev/null
+++ b/src/lib/ultra/io/pfsselectbank.c
@@ -0,0 +1,24 @@
+#include <ultra64.h>
+
+s32 __osPfsSelectBank(OSPfs *pfs, u8 bank)
+{
+	u8 temp[8][4];
+	int i;
+	s32 ret;
+	ret = 0;
+
+	for (i = 0; i < 8; i++) {
+		temp[i][1] = bank;
+		temp[i][2] = bank;
+		temp[i][3] = bank;
+		temp[i][0] = bank;
+	}
+
+	ret = __osContRamWrite(pfs->queue, pfs->channel, 1024, (u8*)temp, FALSE);
+
+	if (ret == 0) {
+		pfs->activebank = bank;
+	}
+
+	return ret;
+}