diff --git a/include/PR/pfs.h b/include/PR/pfs.h
index 135a6b56c7..596fafbfee 100644
--- a/include/PR/pfs.h
+++ b/include/PR/pfs.h
@@ -134,6 +134,7 @@ typedef struct {
     /* 0x101 */ u8 map[PFS_INODE_DIST_MAP];
 } __OSInodeCache; // size = 0x202
 
+s32 __osCheckPackId(OSPfs* pfs, __OSPackId* check);
 s32 __osGetId(OSPfs* pfs);
 s32 osPfsChecker(OSPfs* pfs);
 
diff --git a/src/libultra/io/pfsinitpak.c b/src/libultra/io/pfsinitpak.c
index 6d8a59c1ae..cc226f834d 100644
--- a/src/libultra/io/pfsinitpak.c
+++ b/src/libultra/io/pfsinitpak.c
@@ -1,5 +1,124 @@
+#include "PR/pfs.h"
 #include "global.h"
 
-#pragma GLOBAL_ASM("asm/non_matchings/boot/pfsinitpak/osPfsInitPak.s")
+s32 __osPfsCheckRamArea(OSPfs* pfs);
 
-#pragma GLOBAL_ASM("asm/non_matchings/boot/pfsinitpak/__osPfsCheckRamArea.s")
+s32 osPfsInitPak(OSMesgQueue* queue, OSPfs* pfs, s32 channel) {
+    s32 ret;
+    u16 sum;
+    u16 isum;
+    u8 buf[BLOCKSIZE];
+    __OSPackId* id;
+    __OSPackId newid;
+
+    __osSiGetAccess();
+
+    ret = __osPfsGetStatus(queue, channel);
+
+    __osSiRelAccess();
+
+    if (ret != 0) {
+        return ret;
+    }
+
+    pfs->queue = queue;
+    pfs->channel = channel;
+    pfs->status = 0;
+
+    ret = __osPfsCheckRamArea(pfs);
+    if (ret != 0) {
+        return ret;
+    }
+
+    ret = __osPfsSelectBank(pfs, PFS_ID_BANK_256K);
+    if (ret != 0) {
+        return ret;
+    }
+
+    ret = __osContRamRead(pfs->queue, pfs->channel, PFS_ID_0AREA, buf);
+    if (ret != 0) {
+        return ret;
+    }
+
+    __osIdCheckSum((u16*)buf, &sum, &isum);
+    id = (__OSPackId*)buf;
+    if ((id->checksum != sum) || (id->invertedChecksum != isum)) {
+        ret = __osCheckPackId(pfs, id);
+        if (ret != 0) {
+            pfs->status |= PFS_ID_BROKEN;
+            return ret;
+        }
+    }
+
+    if (!(id->deviceid & 1)) {
+        ret = __osRepairPackId(pfs, id, &newid);
+        if (ret != 0) {
+            if (ret == PFS_ERR_ID_FATAL) {
+                pfs->status |= PFS_ID_BROKEN;
+            }
+            return ret;
+        }
+        id = &newid;
+        if (!(id->deviceid & 1)) {
+            return PFS_ERR_DEVICE;
+        }
+    }
+
+    bcopy(id, pfs->id, BLOCKSIZE);
+
+    pfs->version = id->version;
+    pfs->banks = id->banks;
+    pfs->inodeStartPage = 1 + DEF_DIR_PAGES + (2 * pfs->banks);
+    pfs->dir_size = DEF_DIR_PAGES * PFS_ONE_PAGE;
+    pfs->inode_table = 1 * PFS_ONE_PAGE;
+    pfs->minode_table = (1 + pfs->banks) * PFS_ONE_PAGE;
+    pfs->dir_table = pfs->minode_table + (pfs->banks * PFS_ONE_PAGE);
+
+    ret = __osContRamRead(pfs->queue, pfs->channel, PFS_LABEL_AREA, pfs->label);
+    if (ret != 0) {
+        return ret;
+    }
+
+    ret = osPfsChecker(pfs);
+    pfs->status |= PFS_INITIALIZED;
+
+    return ret;
+}
+
+s32 __osPfsCheckRamArea(OSPfs* pfs) {
+    s32 i = 0;
+    s32 ret = 0;
+    u8 writeBuf[BLOCKSIZE];
+    u8 readBuf[BLOCKSIZE];
+    u8 saveReg[BLOCKSIZE];
+
+    ret = __osPfsSelectBank(pfs, PFS_ID_BANK_256K);
+    if (ret != 0) {
+        return ret;
+    }
+
+    ret = __osContRamRead(pfs->queue, pfs->channel, 0, saveReg);
+    if (ret != 0) {
+        return ret;
+    }
+
+    for (i = 0; i < BLOCKSIZE; i++) {
+        writeBuf[i] = i;
+    }
+
+    ret = __osContRamWrite(pfs->queue, pfs->channel, 0, writeBuf, 0);
+    if (ret != 0) {
+        return ret;
+    }
+
+    ret = __osContRamRead(pfs->queue, pfs->channel, 0, readBuf);
+    if (ret != 0) {
+        return ret;
+    }
+
+    if (bcmp(writeBuf, readBuf, BLOCKSIZE) != 0) {
+        return PFS_ERR_DEVICE;
+    }
+
+    return __osContRamWrite(pfs->queue, pfs->channel, 0, saveReg, 0);
+}