From 1af3e134bf5a6005c7860832d3d6b559cabd78e7 Mon Sep 17 00:00:00 2001
From: sbosse <sbosse@uni-bremen.de>
Date: Mon, 14 Oct 2024 23:08:44 +0200
Subject: [PATCH] Mon 14 Oct 23:06:38 CEST 2024

---
 kernel/diskfs.h | 65 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 kernel/diskfs.h

diff --git a/kernel/diskfs.h b/kernel/diskfs.h
new file mode 100644
index 0000000..ee63efb
--- /dev/null
+++ b/kernel/diskfs.h
@@ -0,0 +1,65 @@
+/*
+Copyright (C) 2016-2019 The University of Notre Dame
+This software is distributed under the GNU General Public License.
+See the file LICENSE for details.
+*/
+
+#ifndef DISKFS_H
+#define DISKFS_H
+
+#include "kernel/types.h"
+
+#define DISKFS_MAGIC 0xabcd4321
+#define DISKFS_BLOCK_SIZE 4096
+#define DISKFS_DIRECT_POINTERS 6
+#define DISKFS_INODES_PER_BLOCK (DISKFS_BLOCK_SIZE/sizeof(struct diskfs_inode))
+#define DISKFS_ITEMS_PER_BLOCK (DISKFS_BLOCK_SIZE/sizeof(struct diskfs_item))
+#define DISKFS_POINTERS_PER_BLOCK (DISKFS_BLOCK_SIZE/sizeof(uint32_t))
+
+struct diskfs_superblock {
+	uint32_t magic;
+	uint32_t block_size;
+	uint32_t inode_start;
+	uint32_t inode_blocks;
+	uint32_t bitmap_start;
+	uint32_t bitmap_blocks;
+	uint32_t data_start;
+	uint32_t data_blocks;
+};
+
+struct diskfs_inode {
+	uint32_t inuse; // reserve for broader use.
+	uint32_t size;
+	uint32_t direct[DISKFS_DIRECT_POINTERS];
+	uint32_t indirect;
+};
+
+#define DISKFS_ITEM_BLANK 0
+#define DISKFS_ITEM_FILE 1
+#define DISKFS_ITEM_DIR 2
+
+/* Maximum name length chosen so that diskfs_item is 32 bytes. */
+#define DISKFS_NAME_MAX 26
+
+#pragma pack(1)
+struct diskfs_item {
+	uint32_t inumber;
+	uint8_t  type;
+	uint8_t  name_length;
+	char     name[DISKFS_NAME_MAX];
+};
+#pragma pack()
+
+struct diskfs_block {
+	union {
+		struct diskfs_superblock superblock;
+		struct diskfs_inode inodes[DISKFS_INODES_PER_BLOCK];
+		struct diskfs_item items[DISKFS_ITEMS_PER_BLOCK];
+		uint32_t pointers[DISKFS_POINTERS_PER_BLOCK];
+		char     data[DISKFS_BLOCK_SIZE];
+	};
+};
+
+int diskfs_init(void);
+
+#endif