avdevice.c

ST5518机顶盒系统文件系统源代码！绝对超值！

/******************************************************************************

    File Name   : avdevice.c

    Description : Generic device functions. These fuctions are related to
                  the layout of data in the files system.

******************************************************************************/

/* Includes ---------------------------------------------------------------- */

#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <assert.h>
#include <string.h>
#include "root.h"
#include "avdevice.h"
#include "hal.h"
#include "cat.h"
#include "sttbx.h"

/* Private Types ----------------------------------------------------------- */

/* Private Constants ------------------------------------------------------- */

/* Private Variables ------------------------------------------------------- */

/* Private Macros ---------------------------------------------------------- */

/* Private Function Prototypes --------------------------------------------- */

/* Functions --------------------------------------------------------------- */




/******************************************************************************
Function Name : stavfs_GetBackupLBA
  Description : Locate the backup area for any given LBA address in the partition
                (The root sector is handled separatly as a special case).
   Parameters :
******************************************************************************/
void stavfs_GetBackupLBA(stavfs_Device_t *Device_p, U64 const *LBA_p, U64 *BackupLBA_p)
{
    assert (Device_p    != NULL);
    assert (LBA_p       != NULL);
    assert (BackupLBA_p != NULL);
    
    if (INT_I64_AreEqual(*LBA_p, Device_p->RootSectorLBA))
    {
        *BackupLBA_p = Device_p->RootSectorLBA;
        INT_I64_AddLit(*BackupLBA_p, 1, *BackupLBA_p);
    }
    else if (INT_I64_IsGreaterOrEqual(*LBA_p, Device_p->DataStartLBA))
    {
        U64 Offset;
        U64 Modulus;
        
        /* File data - find the Block and its backup LBA */
        INT_I64_SetValue(0, 0, *BackupLBA_p);
        
        /* Find the LBA offset */
        
        INT_I64_Sub(*LBA_p, Device_p->DataStartLBA, Offset);
        
        /* Reset to the start of block */
        
        INT_I64_ModLit(Offset, CLUSTER_BLOCK_SIZE(Device_p), Modulus);
        INT_I64_Sub   (Offset, Modulus, Offset);
        
        /* Get the absolute LBA address */
        
        INT_I64_Add(Device_p->DataStartLBA, Offset, *BackupLBA_p);
    }
    else
    {
        /* Non-File data - Return the default backup */
        /* Default backup area is the first section of the Master CAT */
        /* Which starts immediatly after the root sector area */
        
        *BackupLBA_p = Device_p->RootSectorLBA;
        INT_I64_AddLit(*BackupLBA_p, ROOT_SECTOR_AREA_SIZE, *BackupLBA_p);
    }
}



/******************************************************************************
Function Name : stavfs_GetBackupLBA
  Description : Locate the backup area for any given LBA address in the partition
                (The root sector is handled separatly as a special case).
   Parameters :
******************************************************************************/
void stavfs_GetLocalCatLBA(stavfs_Device_t *Device_p, U64 const *LBA_p, U64 *CatLBA_p)
{
    U64 Modulus;
    
    assert (Device_p != NULL);
    assert (LBA_p    != NULL);
    assert (CatLBA_p != NULL);
    
    if (!INT_I64_IsGreaterOrEqual(*LBA_p, Device_p->DataStartLBA))
    {
        /* Not in the file data area */
        /* Use the first Local CAT  */
        INT_I64_SetValue(CLUSTER_BLOCK_SIZE(Device_p) - LOCAL_CAT_SIZE, 0, *CatLBA_p);
    }
    else
    {
        /* Find the LBA offset */
        
        INT_I64_SetValue(0, 0, *CatLBA_p);
        INT_I64_Sub(*LBA_p, Device_p->DataStartLBA, *CatLBA_p);
        
        /* Reset to the start of block */
        
        INT_I64_ModLit(*CatLBA_p, CLUSTER_BLOCK_SIZE(Device_p), Modulus);
        INT_I64_Sub   (*CatLBA_p, Modulus, *CatLBA_p);
        
        /* Add in the offset within the File Block */
        
        INT_I64_AddLit(*CatLBA_p,
                       CLUSTER_BLOCK_SIZE(Device_p) - LOCAL_CAT_SIZE,
                       *CatLBA_p);
    }
    
    /* Get the absolute LBA address */
    
    INT_I64_Add(Device_p->DataStartLBA, *CatLBA_p, *CatLBA_p);
}



/******************************************************************************
Function Name : stavfs_GetClusterIdx
  Description : Get the Cluster Block index for this LBA
   Parameters :
******************************************************************************/
void stavfs_GetClusterIdx(stavfs_Device_t *Device_p, U32 *BlockId_p, U32 *Idx_p, U64 const *LBA_p)
{
    if (!INT_I64_IsGreaterOrEqual(*LBA_p, Device_p->DataStartLBA))
    {
        /* Not in the file data area */
        /* Default to the first Block */
        *BlockId_p = 0;
        *Idx_p     = 0;
    }
    else
    {
        U64 Offset;
        U64 Idx;
        U64 Mod;
        /* Find the LBA offset */
        
        INT_I64_Sub(*LBA_p, Device_p->DataStartLBA, Offset);
        
        /* Find the index */
        
        INT_I64_DivLit(Offset, CLUSTER_BLOCK_SIZE(Device_p), Idx);
        INT_I64_ModLit(Offset, CLUSTER_BLOCK_SIZE(Device_p), Mod);
        INT_I64_SubLit(Mod,    FILE_BACKUP_SIZE(Device_p),   Mod);
        INT_I64_DivLit(Mod,    Device_p->ClusterSize,        Mod);
        
        *BlockId_p = Idx.LSW;
        *Idx_p     = Mod.LSW;
        
        /* Check that it is in the file area */
        if (*BlockId_p >= Device_p->NumClusterBlock)
        {
            *BlockId_p = Device_p->NumClusterBlock-1;
            *Idx_p     = CLUSTERS_PER_BLOCK(Device_p);
        }
    }
}



/******************************************************************************
Function Name : stavfs_GetClusterLBA
  Description : LBA for the Cluster in the Cluster Block
   Parameters :
******************************************************************************/
void stavfs_GetClusterLBA  (stavfs_Device_t *Device_p, U32 BlockId, U8 Idx, U64 *LBA_p)
{
    /* Find the indexed LBA address */
    
    INT_I64_SetValue(BlockId, 0, *LBA_p);
    INT_I64_MulLit  (*LBA_p, CLUSTER_BLOCK_SIZE(Device_p), *LBA_p);
    
    INT_I64_AddLit(*LBA_p, FILE_BACKUP_SIZE(Device_p), *LBA_p);
    INT_I64_AddLit(*LBA_p, Idx*Device_p->ClusterSize,  *LBA_p);
    
    INT_I64_Add(*LBA_p, Device_p->DataStartLBA, *LBA_p);
}



/******************************************************************************
Function Name : stavfs_GetLCatLBA
  Description : LBA for the Local CAT in the Cluster Block
   Parameters :
******************************************************************************/
void  stavfs_GetLCatLBA(stavfs_Device_t *Device_p, U32 BlockId, U64 *LBA_p)
{
    /* Find the indexed LBA address */
    
    INT_I64_SetValue(BlockId, 0, *LBA_p);
    INT_I64_MulLit  (*LBA_p, CLUSTER_BLOCK_SIZE(Device_p), *LBA_p);
    
    INT_I64_AddLit(*LBA_p, FILE_BACKUP_SIZE(Device_p), *LBA_p);
    INT_I64_AddLit(*LBA_p, CLUSTERS_PER_BLOCK(Device_p)*Device_p->ClusterSize, *LBA_p);
    
    INT_I64_Add(*LBA_p, Device_p->DataStartLBA, *LBA_p);
}