fs.c

用于汇编领域的,运用于OS的MAIN函数.基于硬件基础的源代码

#include "fs.h"
struct BitVect d_ibm; // disk inode bit map 
struct BitVect d_dbm; // disk datablock bit map 
struct DITable d_itable; // disk inode table
struct BitVect ibm; // on-mem inode bit map 
struct BitVect dbm; // on-mem datablock bit map 
struct ITable itable; // on-mem inode table
struct FBTable fbtable; // file block table
struct FPTable fptable; // file ptr table

void init_d_ibm(){
  // inode 0,1 are reserved
  BitVect_init(&d_ibm); // make all bits free first
  BitVect_set_bit(&d_ibm,0);  // inode 0 is reserved
  BitVect_set_bit(&d_ibm,1);  // inode 1 is reserved
  BitVect_set_bit(&d_ibm,2);  // inode 2 is for root dir file 
}


void init_d_dbm(){
  BitVect_init(&d_dbm); // make all bits free first
  BitVect_set_bit(&d_dbm,0);  // blk 0 for bootcode 
  BitVect_set_bit(&d_dbm,1);  // blk 1 for superblock 
  BitVect_set_bit(&d_dbm,2);  // blk 2 for ibm 
  BitVect_set_bit(&d_dbm,3);  // blk 3 for dbm 
  BitVect_set_bit(&d_dbm,4);  // blk 4 for inode table 
  BitVect_set_bit(&d_dbm,5);  // blk 5 for root dir 
}

// functions for d_itable
void init_d_itable(){
// inode 0,1 is reserved. inode 2 is for root dir
   DITable_make_inode(2,5);
}

void test_fs(){
   int x,y; char buf[20], buf1[20]; 
   //x=do_creat("/f1");
   //printk("aft do_creat /f1\n"); //for(;;);
   //do_write(x, "hello", 5);
   //printk("aft do_write\n"); //for(;;);
   y=do_open("/f1");
   printk("aft do_open"); //for(;;);
   do_read(y,buf,5);
   printk("aft do_read"); //for(;;);
   buf[5]=0;
   printk("f1 is %s\n", buf); //for(;;);
   // x=do_mkdir("/d1");
   // y=do_creat("/d1/f2");
   // now test executable
   printk("now creating /p1\n");
   x = do_creat("/p1");
   // mov $0x4, %eax; write
   buf[0]=0xb8; buf[1]=0x04; buf[2]=0x0; buf[3]=0x0; buf[4]=0x0;
   // int $0x80
   buf[5]=0xcd; buf[6]=0x80;
   // mov $0x1, %eax ; exit
   buf[7]=0xb8; buf[8]=0x01; buf[9]=0x0; buf[10]=0x0; buf[11]=0x0;
   // int $0x80
   buf[12]=0xcd; buf[13]=0x80;
   buf[14]=0x0; // end of data
   do_write(x, buf, 15);
   // confirm
   y=do_open("/p1");
   do_read(y,buf1,14);
   printk("/p1 is: ");
   for(x=0;x<14;x++) printk("%x ",buf1[x]);

}

// system functions
void init_fs(){
   FPTable_init();
   FBTable_init();
   //printk("bef format_disk"); //for(;;);
   //format_disk();
   //printk("aft format_disk\n"); //for(;;);
   mount_root_fs();
   // test fs
   printk("aft mount_root\n"); //for(;;);
   test_fs();
}

void format_disk(){
// format disk
   struct DirBlock rdir;
   printk("formatting...to start hit anykey\n");
   wait_for_anykey();
   init_d_ibm();
   init_d_dbm();
   init_d_itable();
   DirBlk_set_empty(&rdir,2,2);//make an empty directory file block
   WriteRelativeSector(2, (char *)&d_ibm, (char *)&d_ibm);
   WriteRelativeSector(3, (char *)&d_dbm, (char *)&d_dbm);
   WriteRelativeSector(4, (char *)&d_itable, (char *)&d_itable);
   WriteRelativeSector(5, (char *)&rdir, (char *)&rdir);
   printk("aft writing. rdir is\n");
   FB_dump((char *)&rdir);
}

void mount_root_fs(){
// load ibm, dbm, itable from the disk
   char buf[512];
   printk("insert root disk and hit any key\n");
   wait_for_anykey();
   ReadRelativeSector(2, (char *)&d_ibm, (char *)&d_ibm);
   ReadRelativeSector(3, (char *)&d_dbm, (char *)&d_dbm);
   ReadRelativeSector(4, (char *)&itable, (char *)&itable);
   ReadRelativeSector(5, (char *)buf, (char *)buf);
   FB_dump(buf);
   FBTable_retrieve_block_from_disk(5);
   printk("aft retrieval\n");
   FBTable_dump_blk(5);
}

void flush_to_disk(){
// write ibm, dbm, itable, and all file blocks back to disk. 
//for now call this whenever there is
// a change in ibm,dbm,itable, or file blocks.
   printk("writing back to disk\n");
   WriteRelativeSector(2, (char *)&d_ibm, (char *)&d_ibm);
   WriteRelativeSector(3, (char *)&d_dbm, (char *)&d_dbm);
   WriteRelativeSector(4, (char *)&itable, (char *)&itable);
   FBTable_flush_file_blocks();
}