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// ext2 minidriver
// based on osdev wiki article: http://wiki.osdev.org/Ext2
#include "lib/int/stdint.h"
typedef struct ext2_superblock_struct
{
uint32_t inodes_count;
uint32_t blocks_count;
uint32_t blocks_reserved_count;
uint32_t inodes_unalloc_count;
uint32_t blocks_unalloc_count;
uint32_t superblock_number;
uint32_t block_size;
uint32_t fragment_size;
uint32_t blocks_per_group;
uint32_t fragments_per_group;
uint32_t inodes_per_group;
uint8_t skip[12]; // maybe we will look at these fields later...
uint16_t ext2_sig; // 0xef5
uint16_t fs_state;
uint16_t error_handle;
uint16_t version_minor;
uint8_t skip2[8]; // maybe we will look at these fields later...
uint32_t os_id;
uint32_t version_major;
uint16_t uid_reserved;
uint16_t gid_reserved;
}ext2_superblock;
typedef struct ext2_superblock_ext_struct
{
uint32_t first_inode;
uint16_t size_inode;
uint16_t blockgroup;
uint32_t features_opt;
uint32_t features_req;
uint32_t features_write;
uint32_t blkid[4];
char vol_name[16];
char last_path[64];
uint32_t compression;
uint8_t prealloc_files;
uint8_t prealloc_dirs;
uint8_t unused[2];
uint32_t journalid[4];
uint32_t journal_inode;
uint32_t journal_device;
uint32_t orpan_head;
}ext2_superblock_ext;
typedef struct ext2_blockgroup_desc_struct
{
uint32_t addr_block_bitmap;
uint32_t addr_inode_bitmap;;
uint32_t addr_inode_table;
uint16_t unalloc_blocks_count;
uint16_t unalloc_inodes_count;
uint16_t dir_count;
uint8_t unused[14];
}ext2_blockgroup_desc;
typedef struct ext2_dir_struct
{
uint32_t inode;
uint16_t size;
uint8_t name_length_low;
uint8_t name_length_high;
// name follows
}ext2_dir;
typedef struct ext2_inode_struct
{
uint16_t permissions;
uint16_t user_id;
uint32_t size_low;
uint32_t skip[4];
uint16_t group_id;
uint16_t hardlink_count;
uint32_t disk_sectors;
uint32_t flags;
uint32_t os_specific;
uint32_t direct_pointer[12];
uint32_t indirect1;
uint32_t indirect2;
uint32_t indirect3;
uint32_t gen_num;
uint32_t later1; // will be implemented later by the fooldriver
uint32_t size_high;
uint32_t frag;
uint32_t os_spec2[3];
}ext2_inode;
/*
int main()
{
ext2_superblock super;
ext2_superblock_ext super_ext;
printf("ext2 fools driver\n");
printf("reading superblock...\n\n");
fseek(stdin,1024,SEEK_SET);
fread(&super,sizeof(super),1,stdin);
printf("block size: %i\n",1024<<super.block_size);
printf("block count: %i\n",super.blocks_count);
printf("inode count: %i\n\n",super.inodes_count);
printf("blocks/group: %i\n",super.blocks_per_group);
printf("inodes/group: %i\n\n",super.inodes_per_group);
printf("signature: 0x%x\n",super.ext2_sig);
printf("fs state: %i\n",super.fs_state);
printf("version: %i.%i\n\n",super.version_major,super.version_minor);
if(super.version_major>=1)
{
printf("getting extended fields...\n\n");
fread(&super_ext,sizeof(super_ext),1,stdin);
printf("first (non reserved) inode: %i\n",super_ext.first_inode);
printf("inode size: %i\n\n",super_ext.size_inode);
printf("opt_features: %i\n",super_ext.features_opt);
printf("req_features: %i\n",super_ext.features_req);
printf("write_features: %i\n\n",super_ext.features_write);
printf("volume name: %s\n",super_ext.vol_name);
printf("mount path: %s\n\n",super_ext.last_path);
}
ext2_blockgroup_desc desc;
printf("getting block group descriptors...\n\n");
//TODO: only correct for 1024bytes/block. read more than one!!!
int block_size=1024;
int descriptor_start_block=2;
fseek(stdin,block_size*descriptor_start_block,SEEK_SET);
fread(&desc,sizeof(desc),1,stdin);
printf("block usage bitmap: 0x%x\n",desc.addr_block_bitmap);
printf("inode usage bitmap: 0x%x\n",desc.addr_inode_bitmap);
printf("inode table: 0x%x\n\n",desc.addr_inode_table);
printf("unalloc blocks: %i\n",desc.unalloc_blocks_count);
printf("unalloc inodes: %i\n",desc.unalloc_inodes_count);
printf("directories: %i\n\n",desc.dir_count);
//TODO: check for version >1
int inode_size=128;
ext2_inode inode;
printf("reading inode 2 (root dir)...\n\n");
fseek(stdin,block_size*desc.addr_inode_table,SEEK_SET);
fread(&inode,sizeof(inode),1,stdin);
fread(&inode,sizeof(inode),1,stdin);
printf("---------- root ---------\n");
printf("uid/gid: %i/%i\n",inode.user_id,inode.group_id);
printf("hardlinks: %i\n",inode.hardlink_count);
printf("size low/high: %i/%i\n",inode.size_low,inode.size_high);
printf("direct block pointer 0: %i\n\n",inode.direct_pointer[0]);
// read dir
char buf[256];
fseek(stdin,block_size*inode.direct_pointer[0],SEEK_SET);
int pos=0;
while(pos<inode.size_low)
{
ext2_dir dir;
fread(&dir,sizeof(dir),1,stdin);
printf("inode: %i\n",dir.inode);
printf("total size: %i\n",dir.size);
printf("length low/high: %i/%i\n\n",dir.name_length_low,dir.name_length_high);
int l=fread(buf,sizeof(char),dir.name_length_low,stdin);
buf[l]=0;
printf("name: %s\n\n",buf);
fseek(stdin,dir.size-8-dir.name_length_low,SEEK_CUR);
pos+=dir.size;
}
puts("");
puts("");
}
*/
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