#include <stdint.h>

typedef uint8_t u8;
typedef uint16_t u16;
typedef uint32_t u32;

// Copied from the manual

struct fat32hdr {
    u8  BS_jmpBoot[3];
    u8  BS_OEMName[8];
    u16 BPB_BytsPerSec;
    u8  BPB_SecPerClus;
    u16 BPB_RsvdSecCnt;
    u8  BPB_NumFATs;
    u16 BPB_RootEntCnt;
    u16 BPB_TotSec16;
    u8  BPB_Media;
    u16 BPB_FATSz16;
    u16 BPB_SecPerTrk;
    u16 BPB_NumHeads;
    u32 BPB_HiddSec;
    u32 BPB_TotSec32;
    u32 BPB_FATSz32;
    u16 BPB_ExtFlags;
    u16 BPB_FSVer;
    u32 BPB_RootClus;
    u16 BPB_FSInfo;
    u16 BPB_BkBootSec;
    u8  BPB_Reserved[12];
    u8  BS_DrvNum;
    u8  BS_Reserved1;
    u8  BS_BootSig;
    u32 BS_VolID;
    u8  BS_VolLab[11];
    u8  BS_FilSysType[8];
    u8  __padding_1[420];
    u16 Signature_word;
} __attribute__((packed));

struct fat32dent {
    u8  DIR_Name[11];
    u8  DIR_Attr;
    u8  DIR_NTRes;
    u8  DIR_CrtTimeTenth;
    u16 DIR_CrtTime;
    u16 DIR_CrtDate;
    u16 DIR_LastAccDate;
    u16 DIR_FstClusHI;
    u16 DIR_WrtTime;
    u16 DIR_WrtDate;
    u16 DIR_FstClusLO;
    u32 DIR_FileSize;
} __attribute__((packed));

#define CLUS_INVALID   0xffffff7

#define ATTR_READ_ONLY 0x01
#define ATTR_HIDDEN    0x02
#define ATTR_SYSTEM    0x04
#define ATTR_VOLUME_ID 0x08
#define ATTR_DIRECTORY 0x10
#define ATTR_ARCHIVE   0x20