📄 fat_sys.c
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chain[0].number = 1;
chain[0].cluster.w[1] = cluster; /* store first cluster */
cluster++;
cluster2start++;
fat_buf_count += 2;
if (cluster != max_cluster)
{
do /* construct the list */
{
fat_count_sector();
/*
if(fat_buf_count == fat_sector_size)
{
//fat_read_sector(fat_ptr_fats+(cluster2start/(fat_sector_size/2)));
//phy_read_open(fat_ptr_fats+(cluster2start/(fat_sector_size/2)));
phy_read_sector();
fat_buf_count = 0;
//phy_read_close();
}
*/
cluster_free = FALSE;
tmp_cluster.b[1] = gl_buffer[fat_buf_count];
tmp_cluster.b[0] = gl_buffer[fat_buf_count+1];
if (tmp_cluster.w == 0x0000)
cluster_free = TRUE;
if (cluster_free)
{ /* free cluster: add it to the list */
if (chain[index].number == MAX_CL_PER_FRAG)
{
index++;
chain[index].number = 1;
chain[index].cluster.w[1] = cluster;
}
else
{
chain[index].number++;
}
cluster++;
cluster2start++;
fat_buf_count += 2;
//count=(cluster2start%(fat_sector_size/2))*2;
}
else
{ /* cluster already used */
do /* search for next free fragment */
{
cluster++;
cluster2start++;
fat_buf_count += 2;
//count=(cluster2start%(fat_sector_size/2))*2;
fat_count_sector();
tmp_cluster.b[1] = gl_buffer[fat_buf_count];
tmp_cluster.b[0] = gl_buffer[fat_buf_count+1];
if (tmp_cluster.w == 0x0000)
{
cluster_free = TRUE;
break;
}
}
while (cluster != max_cluster);
if (!cluster_free)
{
if (chain[index].number == 1)
{ /* last cluster is the current one */
fat_last_clust_index = index;
chain[fat_last_clust_index].number = 0; /* end of list marker */
}
else
{
fat_last_clust_index = index + 1;
chain[index].number--;
chain[fat_last_clust_index].cluster.w[1] = chain[index].cluster.w[1] + chain[index].number;
chain[fat_last_clust_index].number = 0; /* end of list marker */
}
return OK; /* end of partition reached */
}
index++;
chain[index].number = 1;
chain[index].cluster.w[1] = cluster;
cluster++;
cluster2start++;
fat_buf_count +=2;
//count=(cluster2start%(fat_sector_size/2))*2;
}
nb_cluster++;
}
while ((index != (nb_frag - 1)) && (cluster < max_cluster) && (nb_cluster < fat_max_cluster_number));
}
fat_last_clust_index = index;
return OK;
}
#endif //COMPILE_FAT_16
#if COMPILE_FAT_12 == TRUE
byte fat12_set_clusters (fat_st_clust_chain xdata *chain, Byte nb_frag)
{
Byte cluster_free;//,flag;
Byte fat12_parity;
Byte temp;
Byte index;
// Uint16 count;
//word sector_count; // 2004.2.25 modify
Uint16 cluster;
Uint16 max_cluster;
// Union16 tmp_cluster;
// Union32 cluster,cluster2start;
// Union32 tmp_cluster;
// Union32 max_cluster;
Uint16 nb_cluster;
Uint16 max,min,mid;
byte start_pos;
Uint16 pos;
byte sector_count ;
byte max_sector;
max_cluster = fat_count_of_clusters;
//max_cluster = fat_max_cluster_number;//2004.3.13 modify
index = 0;
nb_cluster = 0;
cluster_free = FALSE;
phy_read_open(fat_ptr_fats);
phy_read_sector();
fat12_parity=0; /*if is 0,then clusterNum is even,else is odd */
max = fat_sector_size/3 - 2;
min = 0;
mid = (max - min)>>1 ;
start_pos = 0;//(3 - (((Uint32)fat_sector_size) * sector_count) % 3)%3;
pos = mid * 3 + start_pos;
max_sector = max_cluster / ((fat_sector_size / 3) << 1) + 1;
sector_count = 0;
do
{
while((max - min) > 1)
{
if((gl_buffer[pos] == 0x00) && (gl_buffer[pos + 1] == 0x00))
{
max = mid;
mid = ((mid - min)>>1) + min;
pos = mid * 3 + start_pos;
}
else
{
min = mid;
mid = ((max - mid)>>1) + mid;
pos = mid * 3 + start_pos;
}
}
if(max == (fat_sector_size/3 - 2))
{
phy_read_sector();
sector_count++;
min = 0;
mid = (max - min)>>1 ;
start_pos = (3 - (((Uint32)fat_sector_size) * sector_count) % 3)%3;
pos = mid * 3 + start_pos;
}
else
{
if(max == 1)
{
if((gl_buffer[pos] == 0x00) && (gl_buffer[pos + 1] == 0x00))
max = 0;
}
fat_buf_count = start_pos + max * 3 + 2;
//count += 2;
temp = gl_buffer[fat_buf_count - 1];
//cluster =
//cluster2start = ((((Uint32)fat_sector_size) * sector_count)/3) * 2 + (min + 1)*2;
cluster = ((((Uint32)fat_sector_size) * sector_count)/3) * 2 + max*2 -2; //(max-1) * 2 ;//+ (((start_pos%3) == 0)?(0:1));
if(start_pos%3 != 0)
cluster += 2;
cluster_free = TRUE;
break;
}
}while(sector_count < max_sector);
if((cluster_free==FALSE) || (cluster >= max_cluster))
{
return KO; /* no free cluster found */
}
if(fat_buf_count >= fat_sector_size)
{
phy_read_sector();
sector_count++;
fat_buf_count = fat_buf_count - fat_sector_size;
}
/* At least we find one free cluster */
chain[0].number = 1;
chain[0].cluster.w[1] = cluster; /* store the first cluster */
cluster++;
if(cluster != max_cluster)
{
do /* construct the list */
{
cluster_free = FALSE;
if(fat12_parity == 0)
{
fat12_parity = 1;
if(gl_buffer[fat_buf_count++] == 0x00)
{
fat_count_sector();
/*
if(fat_buf_count == fat_sector_size)
{
phy_read_sector();
fat_buf_count = 0;
}
*/
temp=gl_buffer[fat_buf_count++];
if((temp & 0x0f)==0x00)
{
cluster_free=TRUE;
}
}
else
{
fat_count_sector();
temp=gl_buffer[fat_buf_count++];
}
}
else
{
fat12_parity=0;
if((temp & 0xf0)==0x00)
{
if(gl_buffer[fat_buf_count++]==0x00)
{
cluster_free=TRUE;
}
}
else
{
fat_buf_count++;
}
}
//2004.2.26 modify
fat_count_sector();
if(cluster_free) /* free cluster: add it to the list */
{
if(chain[index].number == MAX_CL_PER_FRAG)
{
index++;
chain[index].number=1;
chain[index].cluster.w[1]=cluster;
cluster++;
}
else
{
chain[index].number++;
cluster++;
}
}
else /* cluster already used */
{
do /* search for next free cluster */
{
if(fat12_parity==0)
{
fat12_parity=1;
if(gl_buffer[fat_buf_count++]==0x00)
{
fat_count_sector();
temp=gl_buffer[fat_buf_count++];
//2004.2.26 modify
fat_count_sector();
if((temp & 0x0f)==0x00)
{
cluster_free=TRUE;
break;
}
else
{
cluster++;
fat_buf_count++;
}
}
else
{
fat_count_sector();
temp=gl_buffer[fat_buf_count++];
cluster++;
}
}
else
{
fat12_parity=0;
if((temp & 0xf0)==0x00)
{
fat_count_sector();
if(gl_buffer[fat_buf_count++]==0x00)
{
cluster_free=TRUE;
break;
}
else
{
cluster++;
}
}
else
{
fat_buf_count++;
cluster++;
}
}
fat_count_sector();
}
while((cluster+1)!=max_cluster);
if (!cluster_free) /* In this new fragment, we don't find any free cluster */
{
if (chain[index].number == 1)
{ /* last cluster is the current one */
fat_last_clust_index = index;
chain[fat_last_clust_index].number = 0; /* end of list marker */
}
else
{
fat_last_clust_index = index + 1;
chain[index].number--;
chain[fat_last_clust_index].cluster.w[1] = chain[index].cluster.w[1] + chain[index].number;
chain[fat_last_clust_index].number = 0; /* end of list marker */
}
return OK; /* end of partition reached */
}
cluster++;
index++;
chain[index].number = 1;
chain[index].cluster.w[1] = cluster;
cluster++;
} //else
nb_cluster++ ;
}
while((index != (nb_frag - 1)) && ( (cluster + 1) < max_cluster) && (nb_cluster < fat_max_cluster_number));
}
fat_last_clust_index = index;
return OK;
}
#endif //COMPILE_FAT_12
#if COMPILE_FAT_32 == TRUE
byte fat32_set_clusters (fat_st_clust_chain xdata *chain, Byte nb_frag)
{
Byte cluster_free;//,flag;
Byte index;
// Uint16 max_cluster;
Union32 cluster,cluster2start;
Union32 tmp_cluster;
Uint16 nb_cluster;
Uint16 max,min;
// max_cluster = fat_count_of_clusters;
//max_cluster = fat_max_cluster_number;//2004.3.13 modify
index = 0;
nb_cluster = 0;
cluster_free = FALSE;
phy_read_open(fat_ptr_fats);
phy_read_sector();
cluster.l = 0;
cluster2start.l=0;//2;
max = fat_sector_size>>2;
min = 0;
fat_buf_count = fat_sector_size>>3;
do
{
while((max - min) > 1)
{
tmp_cluster.b[3] = gl_buffer[fat_buf_count<<2];
tmp_cluster.b[2] = gl_buffer[(fat_buf_count<<2)+1];
tmp_cluster.b[1] = gl_buffer[(fat_buf_count<<2)+2];
tmp_cluster.b[0] = gl_buffer[(fat_buf_count<<2)+3];
if(tmp_cluster.l == 0x00000000)
{
max = fat_buf_count;
fat_buf_count = ((fat_buf_count - min) >> 1) + min ;
}
else
{
min = fat_buf_count;
fat_buf_count = ((max - fat_buf_count) >> 1) + fat_buf_count;
}
}
if(max == 1)
{
tmp_cluster.b[3] = gl_buffer[0];
tmp_cluster.b[2] = gl_buffer[1];
tmp_cluster.b[1] = gl_buffer[2];
tmp_cluster.b[0] = gl_buffer[3];
if(tmp_cluster.l == 0x00000000)
{
max = max - 1;
}
} //min =
if(max == (fat_sector_size>>2))
{
phy_read_sector();
max = fat_sector_size>>2;
min = 0;
fat_buf_count = fat_sector_size>>3;
cluster.l += max;
//cluster2start += n;
}
else
{
fat_buf_count = max<<2;
cluster.l += max; //count / 2;
//cluster2start += count / 2;
cluster_free = TRUE;
break;
}
}while(cluster.l < fat_count_of_clusters);
cluster2start.l = cluster.l;
cluster.l -= 2;
if(!cluster_free)
{
return KO;
}
chain[0].number = 1;
chain[0].cluster.l = cluster.l; /* store first cluster */
cluster.l++;
cluster2start.l++;
fat_buf_count += 4;
do
{
if(fat_buf_count == fat_sector_size)
{
fat_buf_count = 0;
phy_read_sector();
}
cluster_free = FALSE;
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