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source: trunk/kernel/vfs/fatfs.c @ 316

Last change on this file since 316 was 315, checked in by alain, 7 years ago
Redefine the fuctions ppm_base2page() / ppm_page2base() / ppm_page2ppn() / ppm_ppn2page() / ppm_base2ppn() / ppm_ppn2base(), to use explicitely extended pointers.
File size: 26.1 KB

Line
1	/*
2	* fatfs.c - FATFS file system API implementation.
3	*
4	* Author Alain Greiner (2016,2017)
5	*
6	* Copyright (c) UPMC Sorbonne Universites
7	*
8	* This file is part of ALMOS-MKH.
9	*
10	* ALMOS-MKH is free software; you can redistribute it and/or modify it
11	* under the terms of the GNU General Public License as published by
12	* the Free Software Foundation; version 2.0 of the License.
13	*
14	* ALMOS-MKH is distributed in the hope that it will be useful, but
15	* WITHOUT ANY WARRANTY; without even the implied warranty of
16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17	* General Public License for more details.
18	*
19	* You should have received a copy of the GNU General Public License
20	* along with ALMOS-MKH; if not, write to the Free Software Foundation,
21	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22	*/
23
24
25	#include <hal_types.h>
26	#include <hal_special.h>
27	#include <printk.h>
28	#include <kmem.h>
29	#include <ppm.h>
30	#include <vfs.h>
31	#include <string.h>
32	#include <rpc.h>
33	#include <mapper.h>
34	#include <cluster.h>
35	#include <dev_ioc.h>
36	#include <fatfs.h>
37
38
39	//////////////////////////////////////////////////////////////////////////////////////////
40	// Extern variables
41	//////////////////////////////////////////////////////////////////////////////////////////
42
43	extern vfs_ctx_t fs_context[FS_TYPES_NR]; // allocated in vfs.c file
44
45	extern remote_barrier_t global_barrier; // allocated in kernel_init.c
46
47	//////////////////////////////////////////////////////////////////////////////////////////
48	// FATFS specific and static functions
49	//////////////////////////////////////////////////////////////////////////////////////////
50
51	//////////////////////////////////////////////////////////////////////////////////////////
52	// These functions return the "offset" and "length" values of an
53	// [offset,length] constant defined in the fatfs.h file.
54	//////////////////////////////////////////////////////////////////////////////////////////
55
56	static inline int get_length( int offset , int length ) { return length; }
57
58	static inline int get_offset( int offset , int length ) { return offset; }
59
60
61	//////////////////////////////////////////////////////////////////////////////////////////
62	// This function returns the LBA of the first sector of a FAT cluster.
63	// This function can be called by any thread running in any cluster.
64	//////////////////////////////////////////////////////////////////////////////////////////
65	// @ ctx : pointer on FATFS context.
66	// @ cluster : cluster index in FATFS.
67	// @ return the lba value.
68	//////////////////////////////////////////////////////////////////////////////////////////
69	static inline uint32_t fatfs_lba_from_cluster( fatfs_ctx_t * ctx,
70	uint32_t cluster )
71	{
72	return (ctx->cluster_begin_lba + ((cluster - 2) << 3));
73	}
74
75	//////////////////////////////////////////////////////////////////////////////////////////
76	// This function return an integer record value (one, two, or four bytes)
77	// from a memory buffer, taking into account endianness.
78	//////////////////////////////////////////////////////////////////////////////////////////
79	// @ offset : first byte of record in buffer.
80	// @ size : record length in bytes (1/2/4).
81	// @ buffer : pointer on buffer base.
82	// @ little endian : the most significant byte has the highest address when true.
83	// @ return the integer value in a 32 bits word.
84	//////////////////////////////////////////////////////////////////////////////////////////
85	static uint32_t fatfs_get_record( uint32_t offset,
86	uint32_t size,
87	uint8_t * buffer,
88	uint32_t little_endian )
89	{
90	uint32_t n;
91	uint32_t res = 0;
92
93	if ( little_endian)
94	{
95	for( n = size ; n > 0 ; n-- ) res = (res<<8) \| buffer[offset+n-1];
96	}
97	else
98	{
99	for( n = 0 ; n < size ; n++ ) res = (res<<8) \| buffer[offset+n];
100	}
101	return res;
102
103	} // end fatfs_get_record()
104
105	//////////////////////////////////////////////////////////////////////////////////////////
106	// This static function retun in the <name> buffer a short name stored in
107	// a SFN FATFS directory entry.
108	/////////////////////////i////////////////////////////////////////////////////////////////
109	// @ buffer : pointer on buffer containing the directory entry.
110	// @ name : [out] buffer allocated by the caller.
111	//////////////////////////////////////////////////////////////////////////////////////////
112	static void fatfs_get_name_from_short( uint8_t * buffer,
113	char * name )
114	{
115	uint32_t i;
116	uint32_t j = 0;
117
118	// get name
119	for ( i = 0; i < 8 && buffer[i] != ' '; i++ )
120	{
121	name[j] = to_lower( buffer[i] );
122	j++;
123	}
124
125	// get extension
126	for ( i = 8; i < 8 + 3 && buffer[i] != ' '; i++ )
127	{
128	// we entered the loop so there is an extension. add the dot
129	if ( i == 8 )
130	{
131	name[j] = '.';
132	j++;
133	}
134
135	name[j] = to_lower( buffer[i] );
136	j++;
137	}
138
139	name[j] = '\0';
140	}
141
142	//////////////////////////////////////////////////////////////////////////////////////////
143	// This static function retun in the <name> buffer a partial name stored in
144	// a LFN FATFS directory entry.
145	/////////////////////////i////////////////////////////////////////////////////////////////
146	// @ buffer : pointer on buffer containing the directory entry.
147	// @ name : [out] buffer allocated by the caller.
148	//////////////////////////////////////////////////////////////////////////////////////////
149	static void fatfs_get_name_from_long( uint8_t * buffer,
150	char * name )
151	{
152	uint32_t name_offset = 0;
153	uint32_t buffer_offset = get_length(LDIR_ORD);
154	uint32_t l_name_1 = get_length(LDIR_NAME_1);
155	uint32_t l_name_2 = get_length(LDIR_NAME_2);
156	uint32_t l_name_3 = get_length(LDIR_NAME_3);
157	uint32_t l_attr = get_length(LDIR_ATTR);
158	uint32_t l_type = get_length(LDIR_TYPE);
159	uint32_t l_chksum = get_length(LDIR_CHKSUM);
160	uint32_t l_rsvd = get_length(LDIR_RSVD);
161
162	uint32_t j = 0;
163	uint32_t eof = 0;
164
165	while ( (buffer_offset != DIR_ENTRY_SIZE) && (!eof) )
166	{
167	while (j != l_name_1 && !eof )
168	{
169	if ( (buffer[buffer_offset] == 0x00) \|\|
170	(buffer[buffer_offset] == 0xFF) )
171	{
172	eof = 1;
173	continue;
174	}
175	name[name_offset] = buffer[buffer_offset];
176	buffer_offset += 2;
177	j += 2;
178	name_offset++;
179	}
180
181	buffer_offset += (l_attr + l_type + l_chksum);
182	j = 0;
183
184	while (j != l_name_2 && !eof )
185	{
186	if ( (buffer[buffer_offset] == 0x00) \|\|
187	(buffer[buffer_offset] == 0xFF) )
188	{
189	eof = 1;
190	continue;
191	}
192	name[name_offset] = buffer[buffer_offset];
193	buffer_offset += 2;
194	j += 2;
195	name_offset++;
196	}
197
198	buffer_offset += l_rsvd;
199	j = 0;
200
201	while (j != l_name_3 && !eof )
202	{
203	if ( (buffer[buffer_offset] == 0x00) \|\|
204	(buffer[buffer_offset] == 0xFF) )
205	{
206	eof = 1;
207	continue;
208	}
209	name[name_offset] = buffer[buffer_offset];
210	buffer_offset += 2;
211	j += 2;
212	name_offset++;
213	}
214	}
215	name[name_offset] = 0;
216
217	} // end get_name_from_long()
218
219
220	//////////////////////////////////////////////////////////////////////////////////////////
221	// FATFS specific but extern functions
222	//////////////////////////////////////////////////////////////////////////////////////////
223
224	//////////////////////////////////////////////////////////////////////////////////////////
225	void fatfs_ctx_display()
226	{
227	vfs_ctx_t * vfs_ctx = &fs_context[FS_TYPE_FATFS];
228	fatfs_ctx_t * fatfs_ctx = (fatfs_ctx_t *)vfs_ctx->extend;
229
230	printk("\n* FAT context *\n"
231	"- fat_sectors = %d\n"
232	"- sector size = %d\n"
233	"- cluster size = %d\n"
234	"- fat_first_lba = %d\n"
235	"- data_first_lba = %d\n"
236	"- root_dir_cluster = %d\n"
237	"- mapper_xp = %l\n",
238	fatfs_ctx->fat_sectors_count,
239	fatfs_ctx->bytes_per_sector,
240	fatfs_ctx->sectors_per_cluster * fatfs_ctx->bytes_per_sector,
241	fatfs_ctx->fat_begin_lba,
242	fatfs_ctx->cluster_begin_lba,
243	fatfs_ctx->root_dir_cluster,
244	fatfs_ctx->fat_mapper_xp );
245	}
246
247	/////////////////////////////////////////////
248	error_t fatfs_get_cluster( mapper_t * mapper,
249	uint32_t first_cluster_id,
250	uint32_t page_index,
251	uint32_t * searched_cluster_id )
252	{
253	page_t * current_page_desc; // pointer on current page descriptor
254	uint32_t * current_page_buffer; // pointer on current page (array of uint32_t)
255	uint32_t current_page_index; // index of current page in mapper
256	uint32_t current_page_offset; // offset of slot in current page
257	uint32_t page_count_in_file; // index of page in file (index in linked list)
258	uint32_t current_cluster_id; // content of current FAT slot
259
260	assert( (page_index > 0) , __FUNCTION__ , "no FAT access required for first page\n");
261
262	fatfs_dmsg("\n[INFO] %s : enters / mapper = %x / first_cluster_id = %d / page_index = %d\n",
263	__FUNCTION__ , first_cluster_id , page_index );
264
265	#if (CONFIG_FATFS_DEBUG > 1)
266	uint32_t * buf = (uint32_t *)ppm_page2vaddr( mapper_get_page ( mapper , 0 ) );
267	uint32_t line , word;
268	printk("\n* FAT mapper content for first 256 entries *\n");
269	for( line = 0 ; line < 16 ; line++ )
270	{
271	printk("%X : ", line );
272	for( word = 0 ; word < 16 ; word++ ) printk("%X ", buf[(line<<4) + word] );
273	printk("\n");
274	}
275	#endif
276
277	// compute number of FAT slots per page
278	uint32_t slots_per_page = CONFIG_PPM_PAGE_SIZE >> 2;
279
280	// initialize loop variable
281	current_page_index = first_cluster_id / slots_per_page;
282	current_page_offset = first_cluster_id % slots_per_page;
283	page_count_in_file = 0;
284
285	// scan FAT (i.e. traverse FAT linked list)
286	while( page_count_in_file <= page_index )
287	{
288
289	fatfs_dmsg("\n[INFO] %s : page_index = %d / page_offset = %d / count = %d\n",
290	__FUNCTION__ , current_page_index , current_page_offset , page_count_in_file );
291
292	// get pointer on current page descriptor
293	current_page_desc = mapper_get_page( mapper , current_page_index );
294
295	if( current_page_desc == NULL ) return EIO;
296
297	// get pointer on buffer for current page
298	xptr_t base_xp = ppm_page2base( XPTR( local_cxy , current_page_desc ) );
299	current_page_buffer = (uint32_t *)GET_PTR( base_xp );
300
301	// get FAT slot content
302	current_cluster_id = current_page_buffer[current_page_offset];
303
304	// update loop variables
305	current_page_index = current_cluster_id / slots_per_page;
306	current_page_offset = current_cluster_id % slots_per_page;
307	page_count_in_file++;
308	}
309
310	fatfs_dmsg("\n[INFO] %s : exit / cluster_id = %d\n",
311	__FUNCTION__ , current_cluster_id );
312
313	*searched_cluster_id = current_cluster_id;
314	return 0;
315
316	} // end fatfs_get_cluster()
317
318
319
320	///////////////////////////////////////////////////////////////////////////////////////
321	// Generic API : the following functions are called by the kernel (VFS)
322	// and must be defined by all supported file systems.
323	///////////////////////////////////////////////////////////////////////////////////////
324
325	///////////////////////////////
326	fatfs_ctx_t * fatfs_ctx_alloc()
327	{
328	kmem_req_t req;
329	req.type = KMEM_FATFS_CTX;
330	req.size = sizeof(fatfs_ctx_t);
331	req.flags = AF_KERNEL \| AF_ZERO;
332
333	return (fatfs_ctx_t *)kmem_alloc( &req );
334	}
335
336	//////////////////////////////////////////////
337	void fatfs_ctx_init( fatfs_ctx_t * fatfs_ctx )
338	{
339	error_t error;
340	kmem_req_t req;
341	uint8_t * buffer;
342
343	fatfs_dmsg("\n[INFO] %s : enter for fatfs_ctx = %x\n",
344	__FUNCTION__ , fatfs_ctx );
345
346	assert( (fatfs_ctx != NULL) , __FUNCTION__ ,
347	"cannot allocate memory for FATFS context\n" );
348
349	// allocate a 512 bytes buffer to store the boot record
350	req.type = KMEM_512_BYTES;
351	req.flags = AF_KERNEL \| AF_ZERO;
352	buffer = (uint8_t *)kmem_alloc( &req );
353
354	assert( (buffer != NULL) , __FUNCTION__ ,
355	"cannot allocate memory for 512 bytes buffer\n" );
356
357	fatfs_dmsg("\n[INFO] %s : allocated 512 bytes buffer\n", __FUNCTION__ );
358
359	// load the boot record from device
360	// using a synchronous access to IOC device
361	error = dev_ioc_sync_read( buffer , 0 , 1 );
362
363	fatfs_dmsg("\n[INFO] %s : buffer loaded\n", __FUNCTION__ );
364
365	assert( (error == 0) , __FUNCTION__ ,
366	"cannot access boot record\n" );
367
368	#if (CONFIG_FATFS_DEBUG > 1)
369	uint32_t line;
370	uint32_t byte = 0;
371	printk("\n* boot record at cycle %d *\n", hal_get_cycles() );
372	for ( line = 0 ; line < 32 ; line++ )
373	{
374	printk(" %X \| %x %x %x %x %x %x %x %x %x %x %x %x %x %x %x %x \|\n",
375	byte,
376	buffer[byte+ 0],buffer[byte+ 1],buffer[byte+ 2],buffer[byte+ 3],
377	buffer[byte+ 4],buffer[byte+ 5],buffer[byte+ 6],buffer[byte+ 7],
378	buffer[byte+ 8],buffer[byte+ 9],buffer[byte+10],buffer[byte+11],
379	buffer[byte+12],buffer[byte+13],buffer[byte+14],buffer[byte+15] );
380
381	byte += 16;
382	}
383	#endif
384
385	// check sector size from boot record
386	uint32_t sector_size = fatfs_get_record( BPB_BYTSPERSEC , buffer , 1 );
387
388	assert( (sector_size == 512) , __FUNCTION__ ,
389	"sector size must be 512 bytes\n" );
390
391	// check cluster size from boot record
392	uint32_t nb_sectors = fatfs_get_record( BPB_SECPERCLUS , buffer , 1 );
393
394	assert( (nb_sectors == 8) , __FUNCTION__ ,
395	"cluster size must be 8 sectors\n" );
396
397	// check number of FAT copies from boot record
398	uint32_t nb_fats = fatfs_get_record( BPB_NUMFATS , buffer , 1 );
399
400	assert( (nb_fats == 1) , __FUNCTION__ ,
401	"number of FAT copies must be 1\n" );
402
403	// get & check number of sectors in FAT from boot record
404	uint32_t fat_sectors = fatfs_get_record( BPB_FAT32_FATSZ32 , buffer , 1 );
405
406	assert( ((fat_sectors & 0xF) == 0) , __FUNCTION__ ,
407	"FAT not multiple of 16 sectors\n");
408
409	// get and check root cluster from boot record
410	uint32_t root_cluster = fatfs_get_record( BPB_FAT32_ROOTCLUS , buffer , 1 );
411
412	assert( (root_cluster == 2) , __FUNCTION__ ,
413	"root cluster index must be 2\n");
414
415	// get FAT lba from boot record
416	uint32_t fat_lba = fatfs_get_record( BPB_RSVDSECCNT , buffer , 1 );
417
418	// release the 512 bytes buffer
419	req.type = KMEM_512_BYTES;
420	req.ptr = buffer;
421	kmem_free( &req );
422
423	fatfs_dmsg("\n[INFO] %s : boot record read & released\n",
424	__FUNCTION__ );
425
426	// allocate a mapper for the FAT itself
427	mapper_t * fat_mapper = mapper_create( FS_TYPE_FATFS );
428
429	assert( (fat_mapper != NULL) , __FUNCTION__ , "no memory for FAT mapper" );
430
431	// WARNING : the inode field MUST be NULL for the FAT mapper
432	fat_mapper->inode = NULL;
433
434	// initialize the FATFS context
435	fatfs_ctx->fat_begin_lba = fat_lba;
436	fatfs_ctx->fat_sectors_count = fat_sectors;
437	fatfs_ctx->bytes_per_sector = sector_size;
438	fatfs_ctx->sectors_per_cluster = nb_sectors;
439	fatfs_ctx->cluster_begin_lba = fat_lba + fat_sectors;
440	fatfs_ctx->root_dir_cluster = 2;
441	fatfs_ctx->last_allocated_sector = 0; // TODO ???
442	fatfs_ctx->last_allocated_index = 0; // TODO ???
443	fatfs_ctx->fat_mapper_xp = XPTR( local_cxy , fat_mapper );
444
445	fatfs_dmsg("\n[INFO] %s : exit for fatfs_ctx = %x\n",
446	__FUNCTION__ , fatfs_ctx );
447
448	} // end fatfs_ctx_init()
449
450	/////////////////////////////////////////////////
451	void fatfs_ctx_destroy( fatfs_ctx_t * fatfs_ctx )
452	{
453	kmem_req_t req;
454	req.type = KMEM_FATFS_CTX;
455	req.ptr = fatfs_ctx;
456	kmem_free( &req );
457	}
458
459	//////////////////////////////////////////////
460	error_t fatfs_mapper_move_page( page_t * page,
461	bool_t to_mapper )
462	{
463	error_t error;
464
465	// get pointer on source mapper and page index from page descriptor
466	mapper_t * mapper = page->mapper;
467	uint32_t index = page->index;
468
469	// get VFS inode pointer from mapper
470	vfs_inode_t * inode = mapper->inode;
471
472	fatfs_dmsg("\n[INFO] %s : enter for inode %x / page_index = %d / mapper = %x\n",
473	__FUNCTION__ , inode , index , mapper );
474
475	// get memory buffer base address
476	xptr_t base_xp = ppm_page2base( XPTR( local_cxy , page ) );
477	uint8_t * buffer = (uint8_t *)GET_PTR( base_xp );
478
479	// get number of sectors from FATFS context
480	fatfs_ctx_t * fatfs_ctx = (fatfs_ctx_t *)fs_context[FS_TYPE_FATFS].extend;
481	uint32_t count = fatfs_ctx->sectors_per_cluster;
482
483	// analyse the mapper type : FAT or normal inode
484	if( inode == NULL ) // it is the FAT mapper
485	{
486	// get lba from page index
487	uint32_t lba = fatfs_ctx->fat_begin_lba + (count * index);
488
489	fatfs_dmsg("\n[INFO] %s : for FAT / lba = %d\n",
490	__FUNCTION__ , lba );
491
492	// access device
493	if( to_mapper ) error = dev_ioc_sync_read ( buffer , lba , count );
494	else error = dev_ioc_write( buffer , lba , count );
495
496	if( error ) return EIO;
497
498	fatfs_dmsg("\n[INFO] %s : exit for FAT / page_index = %d / mapper = %x\n",
499	__FUNCTION__ , index , mapper );
500	}
501	else // it is a normal inode mapper
502	{
503	uint32_t searched_cluster_id;
504
505	// get first_cluster_id from inode extension
506	uint32_t first_cluster_id = (uint32_t)(intptr_t)inode->extend;
507
508	fatfs_dmsg("\n[INFO] %s : for inode %x / first_cluster_id = %d\n",
509	__FUNCTION__ , inode , first_cluster_id );
510
511	// compute cluster_id
512	if( index == 0 ) // no need to access FAT mapper
513	{
514	searched_cluster_id = first_cluster_id;
515	}
516	else // FAT mapper access required
517	{
518	// get cluster and local pointer on FAT mapper
519	xptr_t fat_mapper_xp = fatfs_ctx->fat_mapper_xp;
520	cxy_t fat_mapper_cxy = GET_CXY( fat_mapper_xp );
521	mapper_t * fat_mapper_ptr = (mapper_t *)GET_PTR( fat_mapper_xp );
522
523	// access FAT mapper
524	if( fat_mapper_cxy == local_cxy ) // FAT mapper is local
525	{
526	error = fatfs_get_cluster( fat_mapper_ptr,
527	first_cluster_id,
528	index,
529	&searched_cluster_id );
530	}
531	else // FAT mapper is remote
532	{
533	rpc_fatfs_get_cluster_client( fat_mapper_cxy,
534	fat_mapper_ptr,
535	first_cluster_id,
536	index,
537	&searched_cluster_id,
538	&error );
539	}
540
541	if( error ) return EIO;
542	}
543
544	// get lba from cluster_id
545	uint32_t lba = fatfs_lba_from_cluster( fatfs_ctx , searched_cluster_id );
546
547	fatfs_dmsg("\n[INFO] %s : for inode %x / page = %d / cluster_id = %d / lba = %x\n",
548	__FUNCTION__ , inode , index , searched_cluster_id , lba );
549
550	// access device
551	if( to_mapper ) error = dev_ioc_sync_read ( buffer , lba , count );
552	else error = dev_ioc_write( buffer , lba , count );
553
554	if( error ) return EIO;
555
556	fatfs_dmsg("\n[INFO] %s : exit for inode %x / page = %x / mapper = %x\n",
557	__FUNCTION__ , inode , page , mapper );
558	}
559
560	return 0;
561
562	} // end fatfs_mapper_move_page()
563
564	/////////////////////////////////////////////////////
565	error_t fatfs_inode_load( vfs_inode_t * parent_inode,
566	char * name,
567	xptr_t child_inode_xp )
568	{
569	// Two embedded loops:
570	// - scan the parent mapper pages
571	// - scan the directory entries in each 4 Kbytes page
572
573	fatfs_dmsg("\n[INFO] %s : enter for child <%s> in parent inode %l\n",
574	__FUNCTION__ , name , XPTR( local_cxy , parent_inode ) );
575
576	mapper_t * mapper = parent_inode->mapper;
577
578	assert( (mapper != NULL) , __FUNCTION__ , "parent mapper undefined\n");
579
580	char cname[CONFIG_VFS_MAX_NAME_LENGTH]; // name extracter from each directory entry
581
582	char lfn1[16]; // buffer for one partial cname
583	char lfn2[16]; // buffer for one partial cname
584	char lfn3[16]; // buffer for one partial cname
585	page_t * page; // pointer on current page descriptor
586	uint8_t * base; // pointer on current page base
587	uint32_t offset = 0; // byte offset in page
588	uint32_t index = 0; // page index in mapper
589	uint32_t attr; // directory entry ATTR field
590	uint32_t ord; // directory entry ORD field
591	uint32_t seq; // sequence index
592	uint32_t lfn = 0; // LFN entries number
593	uint32_t size = 0; // searched file/dir size (bytes)
594	uint32_t cluster = 0; // searched file/dir cluster index
595	uint32_t is_dir = 0; // searched file/dir type
596	uint32_t dentry; // directory entry index
597	int32_t found = 0; // not found (0) / name found (1) / end of dir (-1)
598
599	// scan the parent directory mapper
600	while ( found == 0 )
601	{
602	// get one page
603	page = mapper_get_page( mapper , index );
604
605	assert( (page != NULL) , __FUNCTION__ , "bad parent mapper\n");
606
607	// get page base
608	xptr_t base_xp = ppm_page2base( XPTR( local_cxy , page ) );
609	base = (uint8_t *)GET_PTR( base_xp );
610
611	#if (CONFIG_FATFS_DEBUG > 1)
612	uint32_t * buf = (uint32_t *)base;
613	uint32_t line , word;
614	printk("\n* DIRECTORY content for first 16 entries *\n");
615	for( line = 0 ; line < 16 ; line++ )
616	{
617	printk("%X : ", line );
618	for( word = 0 ; word < 8 ; word++ ) printk("%X ", buf[(line<<4) + word] );
619	printk("\n");
620	}
621	#endif
622
623
624	// scan this page until end of directory, end of page, or name found
625	while( (offset < 4096) && (found == 0) )
626	{
627	attr = fatfs_get_record( DIR_ATTR , base + offset , 0 );
628	ord = fatfs_get_record( LDIR_ORD , base + offset , 0 );
629
630	if (ord == NO_MORE_ENTRY) // no more entry => break
631	{
632	found = -1;
633	}
634	else if ( ord == FREE_ENTRY ) // free entry => skip
635	{
636	offset = offset + 32;
637	}
638	else if ( attr == ATTR_LONG_NAME_MASK ) // LFN entry => get partial cname
639	{
640	seq = ord & 0x3;
641	lfn = (seq > lfn) ? seq : lfn;
642	if ( seq == 1 ) fatfs_get_name_from_long( base + offset, lfn1 );
643	else if ( seq == 2 ) fatfs_get_name_from_long( base + offset, lfn2 );
644	else if ( seq == 3 ) fatfs_get_name_from_long( base + offset, lfn3 );
645	offset = offset + 32;
646	}
647	else // NORMAL entry
648	{
649	// build the extracted name
650	if ( lfn == 0 )
651	{
652	fatfs_get_name_from_short( base + offset , cname );
653	}
654	else if ( lfn == 1 )
655	{
656	strcpy( cname , lfn1 );
657	}
658	else if ( lfn == 2 )
659	{
660	strcpy( cname , lfn1 );
661	strcpy( cname + 13 , lfn2 );
662	}
663	else if ( lfn == 3 )
664	{
665	strcpy( cname , lfn1 );
666	strcpy( cname + 13 , lfn2 );
667	strcpy( cname + 26 , lfn3 );
668	}
669
670	// get dentry arguments if extracted cname == searched name
671	if ( strcmp( name , cname ) == 0 )
672	{
673	cluster = (fatfs_get_record( DIR_FST_CLUS_HI , base + offset , 1 ) << 16) \|
674	(fatfs_get_record( DIR_FST_CLUS_LO , base + offset , 1 ) ) ;
675	dentry = ((index<<12) + offset)>>5;
676	is_dir = ((attr & ATTR_DIRECTORY) == ATTR_DIRECTORY);
677	size = fatfs_get_record( DIR_FILE_SIZE , base + offset , 1 );
678	found = 1;
679	}
680	offset = offset + 32;
681	lfn = 0;
682	}
683	} // end loop on directory entries
684	index++;
685	offset = 0;
686	} // end loop on pages
687
688	// analyse the result of scan
689
690	if ( found == -1 ) // found end of directory => failure
691	{
692	fatfs_dmsg("\n[INFO] %s : exit / child <%s> not found in parent inode %l\n",
693	__FUNCTION__ , name , XPTR( local_cxy , parent_inode ) );
694
695	return ENOENT;
696	}
697	else // found searched child name
698	{
699	// get child inode cluster and local pointer
700	cxy_t child_cxy = GET_CXY( child_inode_xp );
701	vfs_inode_t * child_ptr = (vfs_inode_t *)GET_PTR( child_inode_xp );
702
703	// update the child inode "type", "size", and "extend" fields
704	vfs_inode_type_t type = (is_dir) ? INODE_TYPE_DIR : INODE_TYPE_FILE;
705
706	hal_remote_sw( XPTR( child_cxy , &child_ptr->type ) , type );
707	hal_remote_sw( XPTR( child_cxy , &child_ptr->size ) , size );
708	hal_remote_sw( XPTR( child_cxy , &child_ptr->extend ) , cluster );
709
710	fatfs_dmsg("\n[INFO] %s : exit / child <%s> found in parent inode %l\n",
711	__FUNCTION__ , name , XPTR( local_cxy , parent_inode ) );
712
713	return 0;
714	}
715	} // end fatfs_inode_load()

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