?? smc_ecc.c
字號(hào):
/*
**********************************************************************
* Micrium, Inc.
* 949 Crestview Circle
* Weston, FL 33327-1848
*
* uC/FS
*
* (c) Copyright 2001 - 2003, Micrium, Inc.
* All rights reserved.
*
***********************************************************************
----------------------------------------------------------------------
File : smc_ecc.c
Purpose : ECC functions for SMC driver
----------------------------------------------------------------------
Known problems or limitations with current version
----------------------------------------------------------------------
None.
---------------------------END-OF-HEADER------------------------------
*/
/*********************************************************************
*
* #include Section
*
**********************************************************************
*/
#include "fs_port.h"
#ifndef FS_FARCHARPTR
#define FS_FARCHARPTR char *
#endif
#include "fs_dev.h"
#include "fs_conf.h"
#if FS_USE_SMC_DRIVER
#include "smc.h"
/*********************************************************************
*
* #define constants
*
**********************************************************************
*/
#define SUCCESS 0 /* SUCCESS */
#define ERROR -1 /* ERROR */
#define CORRECT 1 /* CORRECTABLE */
#define BIT7 0x80
#define BIT6 0x40
#define BIT5 0x20
#define BIT4 0x10
#define BIT3 0x08
#define BIT2 0x04
#define BIT1 0x02
#define BIT0 0x01
#define BIT1BIT0 0x03
#define BIT23 0x00800000L
#define MASK_CPS 0x3f
#define CORRECTABLE 0x00555554L
/*********************************************************************
*
* Local Variables
*
**********************************************************************
*/
static const unsigned char _FS_SMC_ecctable[256] = {
0x00,0x55,0x56,0x03,0x59,0x0C,0x0F,0x5A,0x5A,0x0F,0x0C,0x59,0x03,0x56,0x55,0x00,
0x65,0x30,0x33,0x66,0x3C,0x69,0x6A,0x3F,0x3F,0x6A,0x69,0x3C,0x66,0x33,0x30,0x65,
0x66,0x33,0x30,0x65,0x3F,0x6A,0x69,0x3C,0x3C,0x69,0x6A,0x3F,0x65,0x30,0x33,0x66,
0x03,0x56,0x55,0x00,0x5A,0x0F,0x0C,0x59,0x59,0x0C,0x0F,0x5A,0x00,0x55,0x56,0x03,
0x69,0x3C,0x3F,0x6A,0x30,0x65,0x66,0x33,0x33,0x66,0x65,0x30,0x6A,0x3F,0x3C,0x69,
0x0C,0x59,0x5A,0x0F,0x55,0x00,0x03,0x56,0x56,0x03,0x00,0x55,0x0F,0x5A,0x59,0x0C,
0x0F,0x5A,0x59,0x0C,0x56,0x03,0x00,0x55,0x55,0x00,0x03,0x56,0x0C,0x59,0x5A,0x0F,
0x6A,0x3F,0x3C,0x69,0x33,0x66,0x65,0x30,0x30,0x65,0x66,0x33,0x69,0x3C,0x3F,0x6A,
0x6A,0x3F,0x3C,0x69,0x33,0x66,0x65,0x30,0x30,0x65,0x66,0x33,0x69,0x3C,0x3F,0x6A,
0x0F,0x5A,0x59,0x0C,0x56,0x03,0x00,0x55,0x55,0x00,0x03,0x56,0x0C,0x59,0x5A,0x0F,
0x0C,0x59,0x5A,0x0F,0x55,0x00,0x03,0x56,0x56,0x03,0x00,0x55,0x0F,0x5A,0x59,0x0C,
0x69,0x3C,0x3F,0x6A,0x30,0x65,0x66,0x33,0x33,0x66,0x65,0x30,0x6A,0x3F,0x3C,0x69,
0x03,0x56,0x55,0x00,0x5A,0x0F,0x0C,0x59,0x59,0x0C,0x0F,0x5A,0x00,0x55,0x56,0x03,
0x66,0x33,0x30,0x65,0x3F,0x6A,0x69,0x3C,0x3C,0x69,0x6A,0x3F,0x65,0x30,0x33,0x66,
0x65,0x30,0x33,0x66,0x3C,0x69,0x6A,0x3F,0x3F,0x6A,0x69,0x3C,0x66,0x33,0x30,0x65,
0x00,0x55,0x56,0x03,0x59,0x0C,0x0F,0x5A,0x5A,0x0F,0x0C,0x59,0x03,0x56,0x55,0x00
};
static const unsigned char _FS_SMC_cis[]={ 0x01,0x03,0xD9,0x01,0xFF,0x18,0x02,0xDF,0x01,0x20 };
/*********************************************************************
*
* Local functions
*
**********************************************************************
*/
/*********************************************************************
*
* _FS_SMC_StringCmp
*/
static int _FS_SMC_StringCmp(FS_FARCHARPTR stringA, FS_FARCHARPTR stringB, int count)
{
int i;
for (i=0;i<count;i++)
if (*stringA++ != *stringB++) return(ERROR);
return(SUCCESS);
}
/*********************************************************************
*
* _FS_SMC_trans_result
*
Transfer result
LP14,12,10,... & LP15,13,11,... -> LP15,14,13,... & LP7,6,5,..
*/
static void _FS_SMC_trans_result(unsigned char reg2,unsigned char reg3,
unsigned char *ecc1,unsigned char *ecc2)
{
unsigned char a; /* Working for reg2,reg3 */
unsigned char b; /* Working for ecc1,ecc2 */
unsigned char i; /* For counting */
a=BIT7; b=BIT7; /* 80h=10000000b */
*ecc1=*ecc2=0; /* Clear ecc1,ecc2 */
for(i=0; i<4; ++i) {
if ((reg3&a)!=0) *ecc1|=b; /* LP15,13,11,9 -> ecc1 */
b=b>>1; /* Right shift */
if ((reg2&a)!=0) *ecc1|=b; /* LP14,12,10,8 -> ecc1 */
b=b>>1; /* Right shift */
a=a>>1; /* Right shift */
}
b=BIT7; /* 80h=10000000b */
for(i=0; i<4; ++i) {
if ((reg3&a)!=0) *ecc2|=b; /* LP7,5,3,1 -> ecc2 */
b=b>>1; /* Right shift */
if ((reg2&a)!=0) *ecc2|=b; /* LP6,4,2,0 -> ecc2 */
b=b>>1; /* Right shift */
a=a>>1; /* Right shift */
}
}
/*********************************************************************
*
* _FS_SMC_calculate_ecc
*
Calculating ECC
data[0-255] -> ecc1,ecc2,ecc3 using CP0-CP5 code table[0-255]
*/
static void _FS_SMC_calculate_ecc(const unsigned char *table,unsigned char *data,
unsigned char *ecc1,unsigned char *ecc2,
unsigned char *ecc3)
{
unsigned int i; /* For counting */
unsigned char a; /* Working for table */
unsigned char reg1; /* D-all,CP5,CP4,CP3,... */
unsigned char reg2; /* LP14,LP12,L10,... */
unsigned char reg3; /* LP15,LP13,L11,... */
reg1=reg2=reg3=0; /* Clear parameter */
for(i=0; i<256; ++i) {
a=table[data[i]]; /* Get CP0-CP5 code from table */
reg1^=(a&MASK_CPS); /* XOR with a */
if ((a&BIT6)!=0) { /* If D_all(all bit XOR) = 1 */
reg3^=(unsigned char)i; /* XOR with counter */
reg2^=~((unsigned char)i); /* XOR with inv. of counter */
}
}
/* Trans LP14,12,10,... & LP15,13,11,... -> LP15,14,13,... & LP7,6,5,.. */
_FS_SMC_trans_result(reg2,reg3,ecc1,ecc2);
*ecc1=~(*ecc1); *ecc2=~(*ecc2); /* Inv. ecc2 & ecc3 */
*ecc3=((~reg1)<<2)|BIT1BIT0; /* Make TEL format */
}
/*********************************************************************
*
* _FS_SMC_correct_data
*/
static unsigned char _FS_SMC_correct_data(unsigned char *data,unsigned char *eccdata,
unsigned char ecc1,unsigned char ecc2,
unsigned char ecc3)
{
unsigned long l; /* Working to check d */
unsigned long d; /* Result of comparison */
unsigned int i; /* For counting */
unsigned char d1,d2,d3; /* Result of comparison */
unsigned char a; /* Working for add */
unsigned char add; /* Byte address of cor. DATA */
unsigned char b; /* Working for bit */
unsigned char bit; /* Bit address of cor. DATA */
d1=ecc1^eccdata[1]; d2=ecc2^eccdata[0]; /* Compare LP's */
d3=ecc3^eccdata[2]; /* Comapre CP's */
d=((unsigned long)d1<<16) /* Result of comparison */
+((unsigned long)d2<<8)
+(unsigned long)d3;
if (d==0) return(0); /* If No error, return */
if (((d^(d>>1))&CORRECTABLE)==CORRECTABLE) { /* If correctable */
l=BIT23;
add=0; /* Clear parameter */
a=BIT7;
for(i=0; i<8; ++i) { /* Checking 8 bit */
if ((d&l)!=0) add|=a; /* Make byte address from LP's */
l>>=2; a>>=1; /* Right Shift */
}
bit=0; /* Clear parameter */
b=BIT2;
for(i=0; i<3; ++i) { /* Checking 3 bit */
if ((d&l)!=0) bit|=b; /* Make bit address from CP's */
l>>=2; b>>=1; /* Right shift */
}
b=BIT0;
data[add]^=(b<<bit); /* Put corrected data */
return(1);
}
i=0; /* Clear count */
d&=0x00ffffffL; /* Masking */
while(d) { /* If d=0 finish counting */
if (d&BIT0) ++i; /* Count number of 1 bit */
d>>=1; /* Right shift */
}
if (i==1) { /* If ECC error */
eccdata[1]=ecc1; eccdata[0]=ecc2; /* Put right ECC code */
eccdata[2]=ecc3;
return(2);
}
return(3); /* Uncorrectable error */
}
/*********************************************************************
*
* Global functions
*
**********************************************************************
*/
/*********************************************************************
*
* FS__SMC_ECC_Chk_CISdata
*/
int FS__SMC_ECC_Chk_CISdata(unsigned char *buf, unsigned char *redundant)
{
unsigned char ecc1,ecc2,ecc3;
unsigned int err;
_FS_SMC_calculate_ecc(_FS_SMC_ecctable,buf,&ecc1,&ecc2,&ecc3);
err=_FS_SMC_correct_data(buf,redundant+0x0D,ecc1,ecc2,ecc3);
if(err==0 || err==1 || err==2)
return(_FS_SMC_StringCmp((FS_FARCHARPTR)buf,(FS_FARCHARPTR)_FS_SMC_cis,10));
buf+=0x100;
_FS_SMC_calculate_ecc(_FS_SMC_ecctable,buf,&ecc1,&ecc2,&ecc3);
err=_FS_SMC_correct_data(buf,redundant+0x08,ecc1,ecc2,ecc3);
if(err==0 || err==1 || err==2)
return(_FS_SMC_StringCmp((FS_FARCHARPTR)buf,(FS_FARCHARPTR)_FS_SMC_cis,10));
return(ERROR);
}
/*********************************************************************
*
* FS__SMC_ECC_Chk_ECCdata
*/
int FS__SMC_ECC_Chk_ECCdata(unsigned char *buf, unsigned char *redundant)
{
unsigned char ecc1,ecc2,ecc3;
unsigned int err, corr=SUCCESS;
_FS_SMC_calculate_ecc(_FS_SMC_ecctable,buf,&ecc1,&ecc2,&ecc3);
err=_FS_SMC_correct_data(buf,redundant+0x0D,ecc1,ecc2,ecc3);
if(err==1 || err==2) corr=CORRECT;
else if(err) return(ERROR);
buf+=0x100;
_FS_SMC_calculate_ecc(_FS_SMC_ecctable,buf,&ecc1,&ecc2,&ecc3);
err=_FS_SMC_correct_data(buf,redundant+0x08,ecc1,ecc2,ecc3);
if(err==1 || err==2) corr=CORRECT;
else if(err) return(ERROR);
return(corr);
}
/*********************************************************************
*
* FS__SMC_ECC_Set_ECCdata
*/
void FS__SMC_ECC_Set_ECCdata(unsigned char *buf, unsigned char *redundant)
{
_FS_SMC_calculate_ecc(_FS_SMC_ecctable,buf,redundant+0x0E,redundant+0x0D,redundant+0x0F);
buf+=0x100;
_FS_SMC_calculate_ecc(_FS_SMC_ecctable,buf,redundant+0x09,redundant+0x08,redundant+0x0A);
}
#endif /* FS_USE_SMC_DRIVER */
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