79 lines
1.7 KiB
C
79 lines
1.7 KiB
C
#ifndef _FAT16_H
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#define _FAT16_H
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#include <stdint.h>
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#include <string.h>
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#include <ctype.h>
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#define FAT16_MAX_FILENAME 12 /* 8.3 + null */
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#define SECTOR_SIZE 512
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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_sector_count;
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uint8_t num_fats;
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uint16_t root_entry_count;
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uint16_t total_sectors_16;
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uint16_t sectors_per_fat;
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uint32_t fat_start_lba;
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uint32_t root_dir_lba;
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uint32_t data_start_lba;
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uint32_t total_sectors;
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} fat16_fs_t;
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typedef struct {
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char name[FAT16_MAX_FILENAME]; /* 8.3 format */
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uint8_t attr;
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uint16_t first_cluster;
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uint32_t size;
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} fat16_file_t;
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int fat16_mount(uint8_t drive);
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int fat16_find_file(const char* name, fat16_file_t* out_file);
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int fat16_create_file(const char* name, fat16_file_t* out_file);
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int fat16_delete_file(const char* filename);
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int fat16_read_file(fat16_file_t* file, void* buffer);
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int fat16_write_file(fat16_file_t* file, const void* buffer, uint32_t size);
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/*
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Small helper function that converts a normal filename like "test.txt" into FAT16 8.3 uppercase format padded with spaces.
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This makes creating and writing files much easier.
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*/
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static void filename_to_83(const char* input, char out[12])
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{
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memset(out, ' ', 11);
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out[11] = '\0';
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/* Find dot */
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const char* dot = strchr(input, '.');
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size_t name_len = dot ? (size_t) (dot - input) : strlen(input);
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if (name_len > 8)
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{
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name_len = 8;
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}
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for (size_t i = 0; i < name_len; i++)
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{
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out[i] = toupper((unsigned char)input[i]);
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}
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if (dot)
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{
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size_t ext_len = strlen(dot + 1);
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if (ext_len > 3) ext_len = 3;
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for (size_t i = 0; i < ext_len; i++)
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{
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out[8 + i] = toupper((unsigned char)dot[1 + i]);
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}
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}
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}
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#endif
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