banan-os/kernel/include/kernel/FS/FAT/Definitions.h

159 lines
3.3 KiB
C++

#pragma once
#include <BAN/String.h>
namespace Kernel::FAT
{
struct ExtBPB_12_16
{
uint8_t drive_number;
uint8_t __reserved0;
uint8_t boot_signature;
uint32_t volume_id;
uint8_t volume_label[11];
uint8_t filesystem_type[8];
uint8_t __reserved1[448];
} __attribute__((packed));
static_assert(sizeof(ExtBPB_12_16) == 510 - 36);
struct ExtBPB_32
{
uint32_t fat_size32;
uint16_t extended_flags;
uint16_t filesystem_version;
uint32_t root_cluster;
uint16_t filesystem_info;
uint16_t backup_boot_sector;
uint8_t __reserved0[12];
uint8_t drive_number;
uint8_t __reserved1;
uint8_t boot_signature;
uint32_t volume_id;
uint8_t volume_label[11];
uint8_t filesystem_type[8];
uint8_t __reserved2[420];
} __attribute__((packed));
static_assert(sizeof(ExtBPB_32) == 510 - 36);
struct BPB
{
uint8_t jump_op[3];
uint8_t oem_name[8];
uint16_t bytes_per_sector;
uint8_t sectors_per_cluster;
uint16_t reserved_sector_count;
uint8_t number_of_fats;
uint16_t root_entry_count;
uint16_t total_sectors16;
uint8_t media_type;
uint16_t fat_size16;
uint16_t sectors_per_track;
uint16_t number_of_heads;
uint32_t hidden_sector_count;
uint32_t total_sectors32;
union
{
ExtBPB_12_16 ext_12_16;
ExtBPB_32 ext_32;
};
uint16_t Signature_word;
} __attribute__((packed));
static_assert(sizeof(BPB) == 512);
struct Date
{
uint16_t day : 5;
uint16_t month : 4;
uint16_t year : 7;
};
struct Time
{
uint16_t second : 5;
uint16_t minute : 6;
uint16_t hour : 5;
};
struct DirectoryEntry
{
uint8_t name[11];
uint8_t attr;
uint8_t ntres;
uint8_t creation_time_hundreth;
Time creation_time;
Date creation_date;
Date last_access_date;
uint16_t first_cluster_hi;
Time write_time;
Date write_date;
uint16_t first_cluster_lo;
uint32_t file_size;
BAN::String name_as_string() const
{
static_assert(BAN::String::sso_capacity >= 8 + 3 + 1);
BAN::String short_name;
MUST(short_name.append(BAN::StringView((const char*)&name[0], 8)));
while (short_name.back() == ' ')
short_name.pop_back();
MUST(short_name.push_back('.'));
MUST(short_name.append(BAN::StringView((const char*)&name[8], 3)));
while (short_name.back() == ' ')
short_name.pop_back();
if (short_name.back() == '.')
short_name.pop_back();
return short_name;
}
} __attribute__((packed));
static_assert(sizeof(DirectoryEntry) == 32);
struct LongNameEntry
{
uint8_t order;
uint16_t name1[5];
uint8_t attr;
uint8_t type;
uint8_t checksum;
uint16_t name2[6];
uint16_t first_cluster_lo;
uint16_t name3[2];
BAN::String name_as_string() const
{
static_assert(BAN::String::sso_capacity >= 13);
BAN::String result;
for (uint16_t ch : name1) {
if (ch == 0)
return result;
MUST(result.push_back(ch));
}
for (uint16_t ch : name2) {
if (ch == 0)
return result;
MUST(result.push_back(ch));
}
for (uint16_t ch : name3) {
if (ch == 0)
return result;
MUST(result.push_back(ch));
}
return result;
}
} __attribute__((packed));
static_assert(sizeof(LongNameEntry) == 32);
enum FileAttr : uint8_t
{
READ_ONLY = 0x01,
HIDDEN = 0x02,
SYSTEM = 0x04,
VOLUME_ID = 0x08,
DIRECTORY = 0x10,
ARCHIVE = 0x20,
};
}