start messing with fat32

2025-03-24 22:03:19 +03:00
parent bf6ab81791
commit bb5d94bb0c
6 changed files with 2108 additions and 8 deletions
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: BSD-3-Clause
+// Copyright (c) 2025, Bjørn Brodtkorb. All rights reserved.
+
+#ifndef FAT_H
+#define FAT_H
+
+//------------------------------------------------------------------------------
+#include <stdbool.h>
+#include <stdint.h>
+//#include <stdio.h>
+#include <stdarg.h>
+
+//------------------------------------------------------------------------------
+#define SECT_SIZE 512
+
+//------------------------------------------------------------------------------
+enum
+{
+  FAT_ERR_NONE     =  0,
+  FAT_ERR_NOFAT    = -1,
+  FAT_ERR_BROKEN  = -2,
+  FAT_ERR_DISK     = -3,
+  FAT_ERR_PARAM    = -4,
+  FAT_ERR_PATH     = -5,
+  FAT_ERR_EOF      = -6,
+  FAT_ERR_DENIED   = -7,
+  FAT_ERR_FULL     = -8,
+};
+
+enum
+{
+  FAT_ATTR_NONE     = 0x00,
+  FAT_ATTR_RO       = 0x01,
+  FAT_ATTR_HIDDEN   = 0x02,
+  FAT_ATTR_SYS      = 0x04,
+  FAT_ATTR_LABEL    = 0x08,
+  FAT_ATTR_DIR      = 0x10,
+  FAT_ATTR_ARCHIVE  = 0x20,
+  FAT_ATTR_LFN      = 0x0f,
+};
+
+enum
+{
+  FAT_SEEK_SET,
+  FAT_SEEK_END,
+  FAT_SEEK_CURR,
+};
+
+//------------------------------------------------------------------------------
+typedef struct
+{
+  bool (*read)(uint8_t* buf, uint32_t sect);
+  bool (*write)(const uint8_t* buf, uint32_t sect);
+} disk_ops_t;
+
+typedef struct
+{
+  uint8_t hour;
+  uint8_t min;
+  uint8_t sec;
+
+  uint8_t day;
+  uint8_t month;
+  uint16_t year;
+} timestamp_t;
+
+typedef struct fat_t
+{
+  struct fat_t* next;
+  disk_ops_t ops;
+  char path[32];
+  int pathlen;
+
+  uint32_t sect_per_clust;
+  uint32_t clust_cnt;
+  uint32_t info_sect;
+  uint32_t fat_sect;
+  uint32_t data_sect;  
+  uint32_t root_sect;
+
+  uint32_t info_last;
+  uint32_t info_cnt;
+  bool info_dirty;
+
+  uint8_t win[SECT_SIZE];
+  uint32_t win_sect;
+  bool win_dirty;
+  
+  uint8_t name[260];
+  int namelen;
+  uint8_t crc;
+} fat_t;
+
+typedef struct
+{
+  timestamp_t created;
+  timestamp_t modified;
+
+  uint32_t size;
+  uint8_t attr;
+
+  char name[256];
+  int namelen;
+} dir_info_t;
+
+typedef struct
+{
+  fat_t* fat;
+  uint8_t attr;
+  uint32_t first_clust;
+  uint32_t clust;
+  uint32_t sect;
+  int idx;
+} dir_t;
+
+typedef struct
+{
+  dir_t dir;
+  uint32_t first_clust;
+  uint32_t clust;
+  uint32_t sect;
+  uint32_t off;
+  uint32_t size;
+
+  uint8_t buf[SECT_SIZE];
+  uint32_t buf_sect;
+  bool buf_dirty;
+
+  bool modified;
+  bool accessed;
+  bool read;
+  bool write;
+} file_t;
+
+//------------------------------------------------------------------------------
+int fat_mount(disk_ops_t* ops, int part_num, fat_t* fs, const char* path);
+int fat_umount(fat_t* fs);
+
+int fat_fopen(file_t* file, const char* path, const char* mode);
+int fat_fclose(file_t* file);
+int fat_fread(file_t* file, void* buf, int len);
+int fat_fwrite(file_t* file, const void* buf, int len);
+int fat_fprintf(file_t* file, const char* str, ...);
+int fat_fseek(file_t* file, int offset, int seek);
+int fat_ftell(file_t* file);
+int fat_fsize(file_t* file);
+int fat_fsync(file_t* file);
+int fat_unlink(const char* path);
+
+int fat_mkdir(const char* path);
+int fat_opendir(dir_t* dir, const char* path);
+int fat_readdir(dir_t* dir, dir_info_t* info);
+int fat_nextdir(dir_t* dir);
+
+const char* fat_get_error(int err);
+
+void fat_get_timestamp(timestamp_t* dt);
+
+#endif