Finally, It can do some work.

yeah, It can compile correctly, but somehow with some bugs, like it can correctly open
the /ldlinux.sys file. So I need do more debug tomorrow.
What's make me happy is that it can handle long file name:), so it can work somehow.

1 files changed, 47 insertions, 36 deletions

diff --git a/ldlinux.c b/ldlinux.c
index 9203283..8e697fb 100644
--- a/ldlinux.c
+++ b/ldlinux.c
@@ -47,6 +47,8 @@ __u8  ClustByteShift; /* Shift count for bytes/cluster */
 /* for SYSLINUX, the block size equal to the sector size */
 __u32 blk_size = 1 << SECTOR_SHIFT;
 
+/* used for long name dir entry */
+char *NameStart;
 int NameLen;
 
 
@@ -174,7 +176,7 @@ __u32 nextcluster(__u32 clust_num)
         case FAT12:
                 fat_sector = (clust_num + clust_num / 2) >> SECTOR_SHIFT;
                 cs = getfatsector(fat_sector);
-                next_cluster = ((__u16 *)cs->data)[clust_num];
+                next_cluster = *(__u16 *)(cs->data + (clust_num*3/2) % 512);
                 if ( clust_num & 0x0001 )
                         next_cluster >>= 4;         /* cluster number is ODD */
                 else
@@ -231,7 +233,7 @@ __u32 nextsector(__u32 sector)
         }
 
         
-        data_sector -= DataArea;
+        data_sector = sector - DataArea;
         if ( !data_sector & ClustMask )      /* in a cluster */
                 return (++sector);
 
@@ -250,7 +252,7 @@ __u32 nextsector(__u32 sector)
 
 
 /**
- * __getfssec_edx:
+ * __getfssec:
  *
  * get multiple sectors from a file
  *
@@ -263,7 +265,7 @@ __u32 nextsector(__u32 sector)
  * @param: sectors
  *
  */
-void __getfssec(char *buf, __u32 curr_sector, __u32 sectors, int *have_more)
+void __getfssec(char *buf, __u32 curr_sector, __u32 sectors)
 {
         __u32 frag_start , next_sector;
         __u32 con_sec_cnt;
@@ -280,17 +282,25 @@ void __getfssec(char *buf, __u32 curr_sector, __u32 sectors, int *have_more)
                         if ( sectors == 0 )
                                 break;
                         
-                        next_sector = nextsector(curr_sector, have_more);
-                        if ( ! *have_more )
+                        next_sector = nextsector(curr_sector);
+                        if ( !next_sector )
                                 break;                        
                 }while( next_sector == (++curr_sector) );
-                 
+               
+#if 1           /* Debug message */
+                printf("/**************************************************\n");
+                printf("You are reading stores at sector --0x%x--0x%x\n", 
+                       frag_start, frag_start + con_sec_cnt -1);
+                printf("**************************************************/\n");
+#endif  
                         
                 /* do read */
                 getlinsec(buf, frag_start, con_sec_cnt);
                 buf += con_sec_cnt << 9;/* adjust buffer pointer */
-        
-                curr_sector --;         /* this is the last sector actually read */
+                        
+                if ( !sectors )
+                        break;
+                //curr_sector --;         /* this is the last sector actually read */
                 curr_sector = next_sector = nextsector(curr_sector);
         }while( sectors );
         
@@ -314,26 +324,27 @@ void __getfssec(char *buf, __u32 curr_sector, __u32 sectors, int *have_more)
  */
 __u32 getfssec(char *buf, struct open_file_t *file, __u32 sectors, int *have_more)
 {
-        __u32 bytes_read;
+        __u32 bytes_read = sectors << SECTOR_SHIFT;
 
         if ( sectors > file->file_left )
                 sectors = file->file_left;
-        bytes_read = sectors << SECTOR_SHIFT;
-
-        file->file_left -= sectors;
-        __getfssec_edx(buf, file->file_sector, sectors);
+       
+        __getfssec(buf, file->file_sector, sectors);
 
         if ( bytes_read >= file->file_bytesleft ) {
                 bytes_read = file->file_bytesleft;
                 file->file_bytesleft = 0;
                 *have_more = 0;
-
                 close_file(file);
+                
         } else {
                 file->file_bytesleft -= bytes_read;
                 *have_more = 1;
         }
 
+        file->file_left -= sectors;
+        file->file_sector += sectors;
+
         return bytes_read;
 }
                 
@@ -342,7 +353,7 @@ __u32 getfssec(char *buf, struct open_file_t *file, __u32 sectors, int *have_mor
 
 
 
-char *NameStart;
+
 
 
 /**
@@ -444,13 +455,13 @@ void long_entry_name(struct fat_long_name_entry *dir)
 }
 
 
-__u8 get_checksum(char *entry_name)
+__u8 get_checksum(char *dir_name)
 {
 	int  i;
 	__u8 sum=0;
  
 	for (i=11; i; i--)
-		sum = ((sum & 1) << 7) + (sum >> 1) + *entry_name++;
+		sum = ((sum & 1) << 7) + (sum >> 1) + *dir_name++;
 	return sum;
 }
 
@@ -459,7 +470,7 @@ __u32 first_sector(struct fat_dir_entry *dir)
         __u32 first_clust, sector;
         
         first_clust = (dir->first_cluster_high << 16) + dir->first_cluster_low;
-        sector = (first_clust - 2) << ClustShift + DataArea;
+        sector = ((first_clust - 2) << ClustShift) + DataArea;
 
         return sector;
 }
@@ -487,7 +498,7 @@ __u32 first_sector(struct fat_dir_entry *dir)
  * @out:  dh, clobbered.
  *
  */
-struct open_file_t* search_dos_dir(char *MangleBuf, __u32 dir_sector, 
+struct open_file_t* search_dos_dir(char *MangleBuf, __u32 dir_sector, \
                                    __u32 *file_len, __u8 *attr)
 {
         struct open_file_t*  file;
@@ -528,7 +539,7 @@ struct open_file_t* search_dos_dir(char *MangleBuf, __u32 dir_sector,
 
                 /* scan all the entries in a sector */
                 do {
-                        if ( *(char *)dir == 0 )
+                        if ( dir->name[0] == 0 )
                                 return NULL;    /* Hit directory high water mark */
                        
                         if ( dir->attr == 0x0f ) {
@@ -577,7 +588,7 @@ struct open_file_t* search_dos_dir(char *MangleBuf, __u32 dir_sector,
                                          * the match is only valid if the checksum matchs.
                                          */
                                         checksum = get_checksum(dir->name);
-                                        if ( checksum = VFATCsum )
+                                        if ( checksum == VFATCsum )
                                                 goto found;        /* got a match on long name */
                                
                                 } else { 
@@ -594,7 +605,7 @@ struct open_file_t* search_dos_dir(char *MangleBuf, __u32 dir_sector,
                         
                 }while ( --entries );
                 
-                dir_sector = nextsector(dir_sector, &have_more);
+                dir_sector = nextsector(dir_sector);
 
         }while ( dir_sector ); /* scan another secotr */
 
@@ -621,9 +632,10 @@ __u32 CurrentDir = 0;
  * @return: return the file structure on successful, or NULL.
  *
  */
-struct open_file_t* searchdir(char *filename, __u32 *file_len)
+struct open_file_t* searchdir(char *filename)
 {
         __u32 dir_sector, prev_dir;
+        __u32 file_len;
         __u8  attr;
         char  *p;
 
@@ -648,16 +660,16 @@ struct open_file_t* searchdir(char *filename, __u32 *file_len)
                 prev_dir = dir_sector;
                 
                 mangle_dos_name(MangleBuf, filename);
-                file = search_dos_dir(MangleBuf, dir_sector, file_len, &attr);
+                file = search_dos_dir(MangleBuf, dir_sector, &file_len, &attr);
                 if ( !file ) {
-                        *file_len = 0;
+                        file_len = 0;
                         return NULL;
                 }
                 
                 if ( *p != '/' )   /* we got a file */                        
                         break;
                 
-                if ( attr & 0x10 ) /* subdirectory */
+                if ( (attr & 0x10) == 0 ) /* subdirectory */
                         return NULL;
                 
                 dir_sector = file->file_sector;
@@ -669,8 +681,8 @@ struct open_file_t* searchdir(char *filename, __u32 *file_len)
         if ( (attr & 0x18) || (file_len == 0) ) 
                 return NULL;
                 
-        file->file_bytesleft = *file_len;
-        file->file_left = ( *file_len + SECTOR_SIZE -1 ) >> SECTOR_SHIFT;
+        file->file_bytesleft = file_len;
+        file->file_left = ( file_len + SECTOR_SIZE -1 ) >> SECTOR_SHIFT;
                         
         return file; 
 }
@@ -779,10 +791,10 @@ struct open_file_t * readdir(struct open_file_t* dir_file, char* filename,
                 entries_left --;
                 
                 if ( !entries_left ) {
-                        sector = next_sector(sector, &have_more);
+                        sector = nextsector(sector);
                         if ( !sector )
                                 goto fail;
-                        cs = (struct cache_struct *)get_cache_sector(sector);
+                        cs = (struct cache_struct *)get_cache_block(sector);
                         dir = (struct fat_dir_entry *)cs->data;
                 }
         }
@@ -790,7 +802,7 @@ struct open_file_t * readdir(struct open_file_t* dir_file, char* filename,
         /* finally , we get what we want */
         entries_left --;
         if ( !entries_left ) {
-                sector = next_sector(sector, &have_more);
+                sector = nextsector(sector);
                 if ( !sector )
                         goto fail;
         }
@@ -813,9 +825,8 @@ struct open_file_t * readdir(struct open_file_t* dir_file, char* filename,
 struct open_file_t* open_file(char *filename)
 {
         struct open_file_t *file;
-        int file_len;
-
-        file = searchdir(filename, &file_len);
+        
+        file = searchdir(filename);
         
         /* if we failed, we also will get a NULL value */
         return file;
@@ -830,7 +841,7 @@ __u32 read_file(struct open_file_t *file, char *buf, int size, int *have_more)
 
 void bsr(__u8 *res, int num)
 {
-        *res = 2;
+        *res = 0;
 }
 
 /* init. the fs meta data */