Automount initial steps

CMakeLists.txt

@@ -12,4 +12,7 @@ add_library(embpart embpart.c
         MassStorage.c
         MassStorage.h
         file_interface.c
-        file_interface.h)
+        file_interface.h
+        mount/mount.c
+        mount/mount.h
+        fs/fs_driver.h)

fs/fat32/fat32.c

@@ -1,7 +1,3 @@
-//
-// Created by epagris on 2023.09.28..
-//
-
 #include <memory.h>
 #include <stdbool.h>
 #include "fat32.h"
@@ -655,3 +651,7 @@ uint32_t fat32_read_file_stream(const Fat32_CtrlBlock *ctrl, Fat32_FileHelper *f
 
     return read_len;
 }
+
+// ----------------------
+
+Fs_Driver fat32_driver = { (fs_drv_open) fat32_open_file };

fs/fat32/fat32.h

@@ -6,6 +6,7 @@
 #ifdef __linux
 #include <stdio.h>
 #include "../../MassStorage.h"
+#include "../fs_driver.h"
 
 #define MSG(...) printf(__VA_ARGS__)
 #endif
@@ -100,12 +101,14 @@ typedef struct {
 } Fat32_SeekHint;
 
 typedef struct {
-    const Fat32_CtrlBlock * ctrl; // pointer FAT32 control block
+    const Fat32_CtrlBlock * ctrl; // pointer to FAT32 control block
     Fat32_SeekHint last_pos; // last read position
     uint32_t entry_ba; // FileEntry byte address on the mass storage
     uint32_t size; // file size
 } Fat32_FileHelper;
 
+extern Fs_Driver fat32_driver;
+
 int fat32_load(Fat32_CtrlBlock *ctrl, uint32_t bpb_s, const MassStorage * mstg);
 
 int fat32_list_dir(const Fat32_CtrlBlock *ctrl, const char * dir);
@@ -120,4 +123,5 @@ uint32_t fat32_seek_stream(const Fat32_CtrlBlock *ctrl, uint32_t pos, Fat32_File
 
 uint32_t fat32_read_file_stream(const Fat32_CtrlBlock *ctrl, Fat32_FileHelper *file_helper, uint32_t len, uint8_t *p);
 
+
 #endif //EMBPART_FAT32_H

fs/fs_driver.h

@@ -0,0 +1,15 @@
+#ifndef EMBPART_FS_DRIVER_H
+#define EMBPART_FS_DRIVER_H
+
+typedef int (*fs_drv_open)(const void * ctrl, const char * path, void * file);
+typedef int (*fs_drv_seek)(const void * ctrl, void * file, unsigned long pos);
+typedef int (*fs_drv_read)(const void * ctrl, void * file, unsigned long len, void * buf);
+
+// File system driver
+typedef struct {
+    fs_drv_open open;
+    fs_drv_seek seek;
+    fs_drv_read read;
+} Fs_Driver;
+
+#endif //EMBPART_FS_DRIVER_H

mbr/mbr.c

@@ -1,7 +1,18 @@
 #include "mbr.h"
 
+#include <stddef.h>
+
 #define MBR_PART_TABLE_OFFSET (446)
+#define MBR_BOOT_SIGNATURE_OFFSET (510)
+#define MBR_BOOT_SIGNATURE0 (0x55)
+#define MBR_BOOT_SIGNATURE1 (0xAA)
 
 const PartEntry *mbr_get_partitions(const uint8_t *mbr_sec) {
-    return (PartEntry *)(mbr_sec + MBR_PART_TABLE_OFFSET);
+    // check if disk is MBR type
+    if ((mbr_sec[MBR_BOOT_SIGNATURE_OFFSET] != MBR_BOOT_SIGNATURE0) ||
+        (mbr_sec[MBR_BOOT_SIGNATURE_OFFSET + 1] != MBR_BOOT_SIGNATURE1)) {
+        return NULL; // if not
+    } else {
+        return (PartEntry *) (mbr_sec + MBR_PART_TABLE_OFFSET); // if it is
+    }
 }

mbr/mbr.h

@@ -12,7 +12,7 @@ typedef struct {
     uint8_t chsa_la[3]; // CHS address of last absolute sector in partition
     uint32_t lba_fa; // LBA of first absolute sector
     uint32_t sector_count; // number of sectors the partition includes
-} PartEntry;
+} __attribute__((packed)) PartEntry;
 
 /**
  * Get pointer to partition table

mount/mount.c

@@ -0,0 +1,5 @@
+#include "mount.h"
+
+int mnt_automount_disk() {
+
+}

mount/mount.h

@@ -0,0 +1,19 @@
+#ifndef EMBPART_MOUNT_H
+#define EMBPART_MOUNT_H
+
+#include <stdint.h>
+
+#define MNT_MAX_MOUNTED_VOLUMES (4)
+#define MNT_MAX_MOUNT_NAME_LENGTH (15)
+
+typedef struct {
+    void * fs_control_block; // pointer to file system control block
+    uint32_t part_size; // partition size
+    char mnt_name[MNT_MAX_MOUNT_NAME_LENGTH + 1]; // name of the mount
+} Mnt_MountEntry;
+
+typedef struct {
+    Mnt_MountEntry vols[MNT_MAX_MOUNTED_VOLUMES]; // volume slots
+} Mnt_MountTable;
+
+#endif //EMBPART_MOUNT_H