52f631e558
This allows you to find the cluster number of a file in the root directory by name. The main program is a simple demo where you can type in a filename and it will tell you the cluster number.
123 lines
2.8 KiB
C
123 lines
2.8 KiB
C
#ifndef _FAT_H
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#define _FAT_H
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#include <stdint.h>
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extern uint8_t fat_buf[];
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#define FAT_MAX_FILE_NAME 255
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#define FAT_CLUSTERS_PER_SECTOR 128
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#define FAT_CLUSTERMASK 0x0fffffff
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#define FAT_EOC_CLUSTERMASK 0x0ffffff8
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#define FAT_LAST_LFN_MASK (1 << 6)
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#define FAT_LFN_ENTRY_MASK 0x1f
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typedef struct {
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uint16_t bytes_per_sector;
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uint8_t sectors_per_cluster;
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uint16_t reserved_sectors;
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uint8_t fat_count;
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uint16_t max_dir_entries;
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uint16_t total_sector_count;
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uint8_t media_descriptor;
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uint16_t sectors_per_fat;
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} dos_2_bpb_t;
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typedef struct {
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dos_2_bpb_t bpb2;
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uint16_t sectors_per_track;
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uint16_t head_count;
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uint32_t hidden_sector_count;
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uint32_t logical_sector_count;
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uint32_t sectors_per_fat;
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uint16_t extended_flags;
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uint16_t version;
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uint32_t root_cluster;
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uint16_t system_information;
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uint16_t backup_boot_sector;
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uint8_t reserved[12];
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} dos_3_bpb_t;
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typedef struct {
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dos_3_bpb_t bpb3;
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uint8_t drive_num;
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uint8_t reserved;
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uint8_t extended_signature;
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uint32_t volume_id;
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uint8_t partition_label[11];
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uint8_t filesystem_type[8];
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} ebpb_t;
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typedef struct {
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uint16_t bytes_per_sector;
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uint8_t sectors_per_cluster;
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uint16_t reserved_sectors;
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uint8_t fat_count;
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uint16_t max_dir_entries;
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uint16_t total_sector_count;
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uint8_t media_descriptor;
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uint16_t sectors_per_fat_16;
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uint16_t sectors_per_track;
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uint16_t head_count;
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uint32_t hidden_sector_count;
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uint32_t logical_sector_count;
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uint32_t sectors_per_fat_32;
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uint16_t extended_flags;
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uint16_t version;
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uint32_t root_cluster;
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uint16_t system_information;
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uint16_t backup_boot_sector;
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uint8_t reserved[12];
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uint8_t drive_num;
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uint8_t reserved2;
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uint8_t extended_signature;
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uint32_t volume_id;
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uint8_t partition_label[11];
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uint8_t filesystem_type[8];
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} full_bpb_t;
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typedef struct {
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uint32_t sig;
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uint8_t reserved[480];
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uint32_t sig2;
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uint32_t free_data_clusters;
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uint32_t last_allocated_data_cluster;
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uint32_t reserved2;
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uint32_t sig3;
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} fs_info_sector_t;
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typedef struct {
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uint8_t sequence_number;
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uint16_t filename0[5];
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uint8_t attributes;
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uint8_t type;
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uint8_t checksum;
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uint16_t filename1[6];
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uint16_t reserved;
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uint16_t filename2[2];
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} vfat_dentry_t;
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typedef struct {
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uint8_t filename[8];
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uint8_t extension[3];
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uint8_t attributes;
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uint8_t reserved;
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uint8_t create_time_10ms;
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uint32_t create_date;
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uint16_t access_date;
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uint16_t first_cluster_h;
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uint32_t modify_cluster;
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uint16_t first_cluster_l;
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uint32_t file_size;
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} dos_dentry_t;
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void fat_print_pbp_info(full_bpb_t* bpb);
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void fat_init();
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void fat_read(char* filename, void* buf);
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uint16_t fat_parse_path_to_cluster(char* filename);
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#endif
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