The OFS file system, developed specifically for OpenKernel, has been added.

Author: OpenSoftware-World

OFS/ofs.c

@@ -0,0 +1,116 @@
+#include "ofs.h"
+#include "../Drivers/Ata/ata.h"
+#include "../SystemLib/Std/std.h"
+#include "../SystemLib/Std/types.h"
+#include "../SystemLib/Memory/mem.h"
+#include "../Drivers/Vga/vga.h"
+
+ofs_t ofs;
+
+#define SECTOR_SIZE 512
+#define FTABLE_SECTORS 8
+
+void ofs_init() {
+    ata_sys_disk_read(0, (uint8_t*)&ofs.superb);
+
+    if (memcmp(ofs.superb.signature, "OFS1", 4) != 0) {
+        memset(&ofs, 0, sizeof(ofs));
+
+        ofs.superb.signature[0] = 'O';
+        ofs.superb.signature[1] = 'F';
+        ofs.superb.signature[2] = 'S';
+        ofs.superb.signature[3] = '1';
+
+        ofs.superb.version = 1;
+        ofs.superb.total_sectors = 0;
+        ofs.superb.file_table_start = 1;
+        ofs.superb.data_start = 1 + FTABLE_SECTORS;
+
+        ata_sys_disk_write(0, (uint8_t*)&ofs.superb);
+
+        memset(ofs.file_table, 0, sizeof(ofs.file_table));
+
+        for (int i = 0; i < FTABLE_SECTORS; i++) {
+            ata_sys_disk_write(1 + i, (uint8_t*)(ofs.file_table + (i * SECTOR_SIZE)));
+        }
+    }
+    for (int i = 0; i < FTABLE_SECTORS; i++) {
+        ata_sys_disk_read(1 + i, (uint8_t*)(ofs.file_table + (i * SECTOR_SIZE)));
+    }
+}
+
+void ofs_create_file(const char* name, uint32_t size) {
+
+    for (int i = 0; i < OFS_MAX_FILES; i++) {
+
+        if (!ofs.file_table[i].used) {
+
+            memset(ofs.file_table[i].name, 0, OFS_NAME_MAX_LENGTH);
+            strncpy(ofs.file_table[i].name, name, OFS_NAME_MAX_LENGTH - 1);
+
+            ofs.file_table[i].size_bytes = size;
+            ofs.file_table[i].used = 1;
+            ofs.file_table[i].flags = 0;
+
+            ofs.file_table[i].start_sector =
+                ofs.superb.data_start + (i * 8);
+
+            return;
+        }
+    }
+}
+
+void ofs_read_file(const char* name, uint8_t* buffer) {
+    for (int i = 0; i < OFS_MAX_FILES; i++) {
+        if (ofs.file_table[i].used &&
+            strncmp(ofs.file_table[i].name, name, OFS_NAME_MAX_LENGTH) == 0) {
+
+            uint32_t sectors_to_read =
+                (ofs.file_table[i].size_bytes + SECTOR_SIZE - 1) / SECTOR_SIZE;
+
+            for (uint32_t s = 0; s < sectors_to_read; s++) {
+                ata_sys_disk_read(ofs.file_table[i].start_sector + s,
+                                  buffer + (s * SECTOR_SIZE));
+            }
+            return;
+        }
+    }
+}
+
+void ofs_write_file(const char* name, const uint8_t* data, uint32_t size) {
+
+    for (int i = 0; i < OFS_MAX_FILES; i++) {
+
+        if (ofs.file_table[i].used && strncmp(ofs.file_table[i].name, name, OFS_NAME_MAX_LENGTH) == 0) {
+
+            ofs.file_table[i].size_bytes = size;
+
+            uint32_t sectors =
+                (size + SECTOR_SIZE - 1) / SECTOR_SIZE;
+
+            for (uint32_t s = 0; s < sectors; s++) {
+                ata_sys_disk_write(ofs.file_table[i].start_sector + s, data + (s * SECTOR_SIZE));
+            }
+            return;
+        }
+    }
+}
+
+void ofs_delete_file(const char* name) {
+    for (int i = 0; i < OFS_MAX_FILES; i++) {
+        if (ofs.file_table[i].used && strncmp(ofs.file_table[i].name, name, OFS_NAME_MAX_LENGTH) == 0) {
+            ofs.file_table[i].used = 0;
+            return;
+        }
+    }
+}
+
+void ofs_list_files() {
+    for (int i = 0; i < OFS_MAX_FILES; i++) {
+        if (ofs.file_table[i].used) {
+            vga_print_scr("FILE: ");
+            vga_print_scr(ofs.file_table[i].name);
+            vga_print_scr("\n");
+        }
+    }
+}

OFS/ofs.h

@@ -0,0 +1,40 @@
+#ifndef OFS_H
+#define OFS_H
+
+#include "../SystemLib/Std/types.h"
+
+#define OFS_NAME_MAX_LENGTH 32
+#define OFS_MAX_FILES 128
+
+typedef struct {
+    char signature[4];
+    uint32_t total_sectors;
+    uint32_t file_table_start;
+    uint32_t data_start;
+    uint32_t version;
+} ofs_superblock_t;
+
+typedef struct {
+    char name[OFS_NAME_MAX_LENGTH];
+    uint32_t start_sector;
+    uint32_t size_bytes;
+    uint8_t used;
+    uint8_t flags;
+    uint8_t reserved;
+} ofs_file_t;
+
+typedef struct {
+    ofs_superblock_t superb;
+    ofs_file_t file_table[OFS_MAX_FILES];
+} ofs_t;
+
+extern ofs_t ofs;
+
+void ofs_init();
+void ofs_create_file(const char* name, uint32_t size);
+void ofs_read_file(const char* name, uint8_t* buffer);
+void ofs_write_file(const char* name, const uint8_t* data, uint32_t size);
+void ofs_delete_file(const char* name);
+void ofs_list_files();
+
+#endif