root.c

ST5518机顶盒系统文件系统源代码！绝对超值！

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

    File Name   : root.c

    Description : Functions for manipulating the root sector

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

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

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

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

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

#define WIDTH   (8*sizeof(U32))
#define TOP_BIT (1U << (WIDTH-1))

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

#define CRC_POLYNOMIAL        0X04C11DB7

static U32 CRCTable[256] =
{ 
0X00000000, 0X04C11DB7, 0X09823B6E, 0X0D4326D9, 
0X130476DC, 0X17C56B6B, 0X1A864DB2, 0X1E475005, 
0X2608EDB8, 0X22C9F00F, 0X2F8AD6D6, 0X2B4BCB61, 
0X350C9B64, 0X31CD86D3, 0X3C8EA00A, 0X384FBDBD, 
0X4C11DB70, 0X48D0C6C7, 0X4593E01E, 0X4152FDA9, 
0X5F15ADAC, 0X5BD4B01B, 0X569796C2, 0X52568B75, 
0X6A1936C8, 0X6ED82B7F, 0X639B0DA6, 0X675A1011, 
0X791D4014, 0X7DDC5DA3, 0X709F7B7A, 0X745E66CD, 
0X9823B6E0, 0X9CE2AB57, 0X91A18D8E, 0X95609039, 
0X8B27C03C, 0X8FE6DD8B, 0X82A5FB52, 0X8664E6E5, 
0XBE2B5B58, 0XBAEA46EF, 0XB7A96036, 0XB3687D81, 
0XAD2F2D84, 0XA9EE3033, 0XA4AD16EA, 0XA06C0B5D, 
0XD4326D90, 0XD0F37027, 0XDDB056FE, 0XD9714B49, 
0XC7361B4C, 0XC3F706FB, 0XCEB42022, 0XCA753D95, 
0XF23A8028, 0XF6FB9D9F, 0XFBB8BB46, 0XFF79A6F1, 
0XE13EF6F4, 0XE5FFEB43, 0XE8BCCD9A, 0XEC7DD02D, 
0X34867077, 0X30476DC0, 0X3D044B19, 0X39C556AE, 
0X278206AB, 0X23431B1C, 0X2E003DC5, 0X2AC12072, 
0X128E9DCF, 0X164F8078, 0X1B0CA6A1, 0X1FCDBB16, 
0X018AEB13, 0X054BF6A4, 0X0808D07D, 0X0CC9CDCA, 
0X7897AB07, 0X7C56B6B0, 0X71159069, 0X75D48DDE, 
0X6B93DDDB, 0X6F52C06C, 0X6211E6B5, 0X66D0FB02, 
0X5E9F46BF, 0X5A5E5B08, 0X571D7DD1, 0X53DC6066, 
0X4D9B3063, 0X495A2DD4, 0X44190B0D, 0X40D816BA, 
0XACA5C697, 0XA864DB20, 0XA527FDF9, 0XA1E6E04E, 
0XBFA1B04B, 0XBB60ADFC, 0XB6238B25, 0XB2E29692, 
0X8AAD2B2F, 0X8E6C3698, 0X832F1041, 0X87EE0DF6, 
0X00A95DF3, 0X9D684044, 0X902B669D, 0X94EA7B2A, 
0XE0B41DE7, 0XE4750050, 0XE9362689, 0XEDF73B3E, 
0XF3B06B3B, 0XF771768C, 0X00325055, 0XFEF34DE2, 
0XC6BCF05F, 0XC27DEDE8, 0XCF3ECB31, 0XCBFFD686, 
0XD5B88683, 0XD1799B34, 0XDC3ABDED, 0XD8FBA05A, 
0X690CE0EE, 0X6DCDFD59, 0X608EDB80, 0X644FC637, 
0X7A089632, 0X7EC98B85, 0X738AAD5C, 0X774BB0EB, 
0X4F040D56, 0X4BC510E1, 0X46863638, 0X42472B8F, 
0X5C007B8A, 0X58C1663D, 0X558240E4, 0X51435D53, 
0X251D3B9E, 0X21DC2629, 0X2C9F00F0, 0X285E1D47, 
0X36194D42, 0X32D850F5, 0X3F9B762C, 0X3B5A6B9B, 
0X0315D626, 0X07D4CB91, 0X0A97ED48, 0X0E56F0FF, 
0X1011A0FA, 0X14D0BD4D, 0X19939B94, 0X1D528623, 
0XF12F560E, 0XF5EE4BB9, 0XF8AD6D60, 0XFC6C70D7, 
0XE22B20D2, 0XE6EA3D65, 0XEBA91BBC, 0XEF68060B, 
0XD727BBB6, 0XD3E6A601, 0XDEA580D8, 0XDA649D6F, 
0XC423CD6A, 0XC0E2D0DD, 0XCDA1F604, 0XC960EBB3, 
0XBD3E8D7E, 0XB9FF90C9, 0XB4BCB610, 0XB07DABA7, 
0XAE3AFBA2, 0XAAFBE615, 0XA7B8C0CC, 0XA379DD7B, 
0X9B3660C6, 0X9FF77D71, 0X92B45BA8, 0X9675461F, 
0X8832161A, 0X8CF30BAD, 0X81B02D74, 0X857130C3, 
0X5D8A9099, 0X594B8D2E, 0X5408ABF7, 0X50C9B640, 
0X4E8EE645, 0X4A4FFBF2, 0X470CDD2B, 0X43CDC09C, 
0X7B827D21, 0X7F436096, 0X7200464F, 0X76C15BF8, 
0X68860BFD, 0X6C47164A, 0X61043093, 0X65C52D24, 
0X119B4BE9, 0X155A565E, 0X18197087, 0X1CD86D30, 
0X029F3D35, 0X065E2082, 0X0B1D065B, 0X0FDC1BEC, 
0X3793A651, 0X3352BBE6, 0X3E119D3F, 0X3AD08088, 
0X2497D08D, 0X2056CD3A, 0X2D15EBE3, 0X29D4F654, 
0XC5A92679, 0XC1683BCE, 0XCC2B1D17, 0XC8EA00A0, 
0XD6AD50A5, 0XD26C4D12, 0XDF2F6BCB, 0XDBEE767C, 
0XE3A1CBC1, 0XE760D676, 0XEA23F0AF, 0XEEE2ED18, 
0XF0A5BD1D, 0XF464A0AA, 0XF9278673, 0XFDE69BC4, 
0X89B8FD09, 0X8D79E0BE, 0X803AC667, 0X84FBDBD0, 
0X9ABC8BD5, 0X9E7D9662, 0X933EB0BB, 0X97FFAD0C, 
0XAFB010B1, 0XAB710D06, 0XA6322BDF, 0XA2F33668, 
0XBCB4666D, 0XB8757BDA, 0XB5365D03, 0XB1F740B4,
};

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

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

#ifdef GENERATE_CRC_TABLE
static void InitCRCTable(void);
#endif

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



/******************************************************************************
Function Name : stavfs_ReadRootSector
  Description : Read the root sector.
   Parameters :
******************************************************************************/
ST_ErrorCode_t stavfs_ReadRootSector(stavfs_Device_t *Device, stavfs_RootSector_t *RootSector)
{
    ST_ErrorCode_t Error = ST_NO_ERROR;

#ifndef STAVFS_NO_BACKUP_ON_WRITE    
    U32 CRC;
#endif
    
    assert (sizeof(stavfs_RootSector_t) == DISK_SECTOR_SIZE);

    /* Read the partition's first sector (root sector) */
    if (ST_NO_ERROR != (Error = stavfs_HalRead(Device->HALData, &(Device->RootSectorLBA), 1, (char*)RootSector, FALSE)))
    {
	 STTBX_Print(("Unable to read the root sector\n"));
         Error = STAVFS_ERROR_UNREADABLE_DISK;
    }
    
#ifndef STAVFS_NO_BACKUP_ON_WRITE    
    else
    {
        /* If the CRC is wrong then read the back up */
        CRC = 0XFFFFFFFF;
        stavfs_DoBufferCRC((char*)RootSector,
                           sizeof(stavfs_RootSector_t),
                           &CRC);

        if (CRC != 0)
        {
            /* The sector is corrupt - recover from backup */
            
            U64 LBA = {1, 0};
            
            I64_Add(Device->RootSectorLBA, LBA, LBA);
 
            if (ST_NO_ERROR != (Error = stavfs_HalRead(Device->HALData, &LBA, 1, (char*)RootSector, FALSE)))
            {
                 STTBX_Print(("Unable to read the backup root sector\n"));
                 Error = STAVFS_ERROR_UNREADABLE_DISK;
            }
            else
            {
                /* If the CRC is wrong then report a corrupt system */
                CRC = 0XFFFFFFFF;
                stavfs_DoBufferCRC((char*)RootSector,
                                   sizeof(stavfs_RootSector_t),
                                   &CRC);
 
                if (CRC != 0)
                {
                     STTBX_Print(("Root sector corrupt\n"));
                     Error = STAVFS_ERROR_CORRUPT_DISK;
                }
                else
                {
                    /* Write back the recovered data */
                    
                    if (ST_NO_ERROR != (Error = stavfs_HalWrite(Device->HALData, &(Device->RootSectorLBA), 1, (char*)RootSector, FALSE)))
                    {
                         STTBX_Print(("Unable to write the root sector\n"));
                         Error = STAVFS_ERROR_UNWRITABLE_DISK;
                    }
                }
            }
        }
    }
#endif
      
    return (Error);
}




/******************************************************************************
Function Name : stavfs_WriteRootSector
  Description : Writes the partition's root sector information
   Parameters :
******************************************************************************/
ST_ErrorCode_t stavfs_WriteRootSector(stavfs_Device_t *Device, stavfs_RootSector_t *RootSector)
{
    ST_ErrorCode_t Error = ST_NO_ERROR;
    
#ifndef STAVFS_NO_BACKUP_ON_WRITE    
    U64 BackupLBA = {1, 0};
    U32 CRC;
#endif

    int i;
    
    assert (sizeof(stavfs_RootSector_t) == DISK_SECTOR_SIZE);

    
    /* Clear unused fields */
    
    RootSector->Unused16_1 = 0;
    RootSector->Unused8_1  = 0;
    RootSector->Unused32_1 = 0;
    
    for (i = 0; (i < TABLE_LEN(RootSector->Unused64)); i++)
    {
        INT_I64_SetValue(0, 0, RootSector->Unused64[i]);
    }
    
    /* Set the partition name */
    
    strncpy((char*)RootSector->Name, PARTITION_NAME, sizeof(RootSector->Name));

#ifndef STAVFS_NO_BACKUP_ON_WRITE    
    /* Correct the CRC */
    CRC = 0XFFFFFFFF;
    stavfs_DoBufferCRC((char*)RootSector,
                       sizeof(stavfs_RootSector_t)-sizeof(RootSector->CRC),
                       &CRC);
    
    /* Copy the CRC with byte swap for big-endian to little-endian */
    RootSector->CRC = (CRC >> 24) | (CRC << 24) | ((CRC >> 8) & 0X0000FF00) | ((CRC << 8) & 0X00FF0000);
    
    
    /* Write the backup data to the second sector of the partition (root sector) */
    
    I64_Add(Device->RootSectorLBA, BackupLBA, BackupLBA);    
    if (ST_NO_ERROR != (Error = stavfs_HalWrite(Device->HALData, &BackupLBA, 1, (char*)RootSector, FALSE)))
    {
	 STTBX_Print(("Unable to write the back up sector\n"));
         Error = STAVFS_ERROR_UNWRITABLE_DISK;
    }
#endif
      
    /* Write the data to the first sector of the partition (root sector) */
   
    if (ST_NO_ERROR != (Error = stavfs_HalWrite(Device->HALData, &(Device->RootSectorLBA), 1, (char*)RootSector, FALSE)))
    {
	 STTBX_Print(("Unable to write the root sector\n"));
         Error = STAVFS_ERROR_UNWRITABLE_DISK;
    }

    return (Error);
}



/******************************************************************************
Function Name : stavfs_DoBufferCRC
  Description : Generate a CRC solution.
   Parameters :
******************************************************************************/
int stavfs_DoBufferCRC(char *Buff, int Length, U32 *CRCRemainder)
{
#ifdef GENERATE_CRC_TABLE
    static BOOL Initialised = FALSE;
#endif
    
    U8  Byte;
    int i;
            
    assert(NULL != Buff);
    assert(NULL != CRCRemainder);
    
#ifdef GENERATE_CRC_TABLE
    if (!Initialised)
    {
        InitCRCTable();
        Initialised = TRUE;
    }
#endif
    
    for (i = 0; (i < Length); i++)
    {
        Byte = ((*CRCRemainder) >> (WIDTH -8)) ^ Buff[i];
        *CRCRemainder = CRCTable[Byte] ^ ((*CRCRemainder) << 8);
    }
    
    return 0;
}







#ifdef GENERATE_CRC_TABLE
/******************************************************************************
Function Name : InitCRCTable
  Description : Generate a table of partial CRC solutions.
   Parameters :
******************************************************************************/
static void InitCRCTable()
{
    U32 Remainder;
    U32 Dividend;
    int  Bit;
    
    for (Dividend = 0; (Dividend < 256); Dividend++)
    {
        /* Init Remainder */
        
        Remainder = Dividend << (WIDTH -8);
        
        /* Shift XOR with the polynomial */
        
        for (Bit = 0; (Bit < 8); Bit++)
        {
            /* Divide the current data bit */
            
            if (Remainder & TOP_BIT)
            {
                Remainder = (Remainder << 1) ^ CRC_POLYNOMIAL;
            }
            else
            {
                Remainder = (Remainder << 1);
            }
        }
        
        /* Store it */
        
        CRCTable[Dividend] = Remainder;
    }
    
    for (Dividend = 0; (Dividend < 256); Dividend++)
    {
        if (Dividend%4 == 0) STTBX_Print(("\n"));
        STTBX_Print(("0X%08X, ", CRCTable[Dividend]));
    }
    STTBX_Print(("\n"));
}
#endif