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source: trunk/kernel/fs/fatfs.c @ 521

Last change on this file since 521 was 519, checked in by viala@…, 6 years ago
fat/boot_fat32 use unused attribute
File size: 27.5 KB

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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_kernel_types.h>
26	#include <hal_special.h>
27	#include <printk.h>
28	#include <thread.h>
29	#include <kmem.h>
30	#include <ppm.h>
31	#include <vfs.h>
32	#include <string.h>
33	#include <rpc.h>
34	#include <mapper.h>
35	#include <cluster.h>
36	#include <dev_ioc.h>
37	#include <fatfs.h>
38
39
40	//////////////////////////////////////////////////////////////////////////////////////////
41	// Extern variables
42	//////////////////////////////////////////////////////////////////////////////////////////
43
44	extern vfs_ctx_t fs_context[FS_TYPES_NR]; // allocated in vfs.c file
45
46	extern remote_barrier_t global_barrier; // allocated in kernel_init.c
47
48	//////////////////////////////////////////////////////////////////////////////////////////
49	// FATFS specific and static functions
50	//////////////////////////////////////////////////////////////////////////////////////////
51
52	//////////////////////////////////////////////////////////////////////////////////////////
53	// These functions return the "offset" and "length" values of an
54	// [offset,length] constant defined in the fatfs.h file.
55	//////////////////////////////////////////////////////////////////////////////////////////
56
57	static inline
58	int get_length(
59	int offset __attribute__((unused) ),
60	int length)
61	{
62	return length;
63	}
64
65	static inline
66	int get_offset(
67	int offset,
68	int length __attribute__((unused)) )
69	{
70	return offset;
71	}
72
73	//////////////////////////////////////////////////////////////////////////////////////////
74	// This static function returns the LBA of the first sector of a FAT cluster.
75	// This function can be called by any thread running in any cluster.
76	//////////////////////////////////////////////////////////////////////////////////////////
77	// @ ctx : pointer on FATFS context.
78	// @ cluster : cluster index in FATFS.
79	// @ return the lba value.
80	//////////////////////////////////////////////////////////////////////////////////////////
81	static inline uint32_t fatfs_lba_from_cluster( fatfs_ctx_t * ctx,
82	uint32_t cluster )
83	{
84	return (ctx->cluster_begin_lba + ((cluster - 2) << 3));
85	}
86
87	//////////////////////////////////////////////////////////////////////////////////////////
88	// This function return an integer record value (one, two, or four bytes)
89	// from a memory buffer, taking into account endianness.
90	//////////////////////////////////////////////////////////////////////////////////////////
91	// @ offset : first byte of record in buffer.
92	// @ size : record length in bytes (1/2/4).
93	// @ buffer : pointer on buffer base.
94	// @ little endian : the most significant byte has the highest address when true.
95	// @ return the integer value in a 32 bits word.
96	//////////////////////////////////////////////////////////////////////////////////////////
97	static uint32_t fatfs_get_record( uint32_t offset,
98	uint32_t size,
99	uint8_t * buffer,
100	uint32_t little_endian )
101	{
102	uint32_t n;
103	uint32_t res = 0;
104
105	if ( little_endian)
106	{
107	for( n = size ; n > 0 ; n-- ) res = (res<<8) \| buffer[offset+n-1];
108	}
109	else
110	{
111	for( n = 0 ; n < size ; n++ ) res = (res<<8) \| buffer[offset+n];
112	}
113	return res;
114
115	} // end fatfs_get_record()
116
117	//////////////////////////////////////////////////////////////////////////////////////////
118	// This static function retun in the <name> buffer a short name stored in
119	// a SFN FATFS directory entry.
120	/////////////////////////i////////////////////////////////////////////////////////////////
121	// @ buffer : pointer on buffer containing the directory entry.
122	// @ name : [out] buffer allocated by the caller.
123	//////////////////////////////////////////////////////////////////////////////////////////
124	static void fatfs_get_name_from_short( uint8_t * buffer,
125	char * name )
126	{
127	uint32_t i;
128	uint32_t j = 0;
129
130	// get name
131	for ( i = 0; i < 8 && buffer[i] != ' '; i++ )
132	{
133	name[j] = to_lower( buffer[i] );
134	j++;
135	}
136
137	// get extension
138	for ( i = 8; i < 8 + 3 && buffer[i] != ' '; i++ )
139	{
140	// we entered the loop so there is an extension. add the dot
141	if ( i == 8 )
142	{
143	name[j] = '.';
144	j++;
145	}
146
147	name[j] = to_lower( buffer[i] );
148	j++;
149	}
150
151	name[j] = '\0';
152	}
153
154	//////////////////////////////////////////////////////////////////////////////////////////
155	// This static function retun in the <name> buffer a partial name stored in
156	// a LFN FATFS directory entry.
157	/////////////////////////i////////////////////////////////////////////////////////////////
158	// @ buffer : pointer on buffer containing the directory entry.
159	// @ name : [out] buffer allocated by the caller.
160	//////////////////////////////////////////////////////////////////////////////////////////
161	static void fatfs_get_name_from_long( uint8_t * buffer,
162	char * name )
163	{
164	uint32_t name_offset = 0;
165	uint32_t buffer_offset = get_length(LDIR_ORD);
166	uint32_t l_name_1 = get_length(LDIR_NAME_1);
167	uint32_t l_name_2 = get_length(LDIR_NAME_2);
168	uint32_t l_name_3 = get_length(LDIR_NAME_3);
169	uint32_t l_attr = get_length(LDIR_ATTR);
170	uint32_t l_type = get_length(LDIR_TYPE);
171	uint32_t l_chksum = get_length(LDIR_CHKSUM);
172	uint32_t l_rsvd = get_length(LDIR_RSVD);
173
174	uint32_t j = 0;
175	uint32_t eof = 0;
176
177	while ( (buffer_offset != DIR_ENTRY_SIZE) && (!eof) )
178	{
179	while (j != l_name_1 && !eof )
180	{
181	if ( (buffer[buffer_offset] == 0x00) \|\|
182	(buffer[buffer_offset] == 0xFF) )
183	{
184	eof = 1;
185	continue;
186	}
187	name[name_offset] = buffer[buffer_offset];
188	buffer_offset += 2;
189	j += 2;
190	name_offset++;
191	}
192
193	buffer_offset += (l_attr + l_type + l_chksum);
194	j = 0;
195
196	while (j != l_name_2 && !eof )
197	{
198	if ( (buffer[buffer_offset] == 0x00) \|\|
199	(buffer[buffer_offset] == 0xFF) )
200	{
201	eof = 1;
202	continue;
203	}
204	name[name_offset] = buffer[buffer_offset];
205	buffer_offset += 2;
206	j += 2;
207	name_offset++;
208	}
209
210	buffer_offset += l_rsvd;
211	j = 0;
212
213	while (j != l_name_3 && !eof )
214	{
215	if ( (buffer[buffer_offset] == 0x00) \|\|
216	(buffer[buffer_offset] == 0xFF) )
217	{
218	eof = 1;
219	continue;
220	}
221	name[name_offset] = buffer[buffer_offset];
222	buffer_offset += 2;
223	j += 2;
224	name_offset++;
225	}
226	}
227	name[name_offset] = 0;
228
229	} // end get_name_from_long()
230
231
232	//////////////////////////////////////////////////////////////////////////////////////////
233	// FATFS specific but extern functions
234	//////////////////////////////////////////////////////////////////////////////////////////
235
236	//////////////////////////////////////////////////////////////////////////////////////////
237	void fatfs_ctx_display( void )
238	{
239	vfs_ctx_t * vfs_ctx = &fs_context[FS_TYPE_FATFS];
240	fatfs_ctx_t * fatfs_ctx = (fatfs_ctx_t *)vfs_ctx->extend;
241
242	printk("\n* FAT context *\n"
243	"- fat_sectors = %d\n"
244	"- sector size = %d\n"
245	"- cluster size = %d\n"
246	"- fat_first_lba = %d\n"
247	"- data_first_lba = %d\n"
248	"- root_dir_cluster = %d\n"
249	"- mapper_xp = %l\n",
250	fatfs_ctx->fat_sectors_count,
251	fatfs_ctx->bytes_per_sector,
252	fatfs_ctx->sectors_per_cluster * fatfs_ctx->bytes_per_sector,
253	fatfs_ctx->fat_begin_lba,
254	fatfs_ctx->cluster_begin_lba,
255	fatfs_ctx->root_dir_cluster,
256	fatfs_ctx->fat_mapper_xp );
257	}
258
259	/////////////////////////////////////////////
260	error_t fatfs_get_cluster( mapper_t * mapper,
261	uint32_t first_cluster_id,
262	uint32_t searched_page_index,
263	uint32_t * searched_cluster_id )
264	{
265	page_t * current_page_desc; // pointer on current page descriptor
266	uint32_t * current_page_buffer; // pointer on current page (array of uint32_t)
267	uint32_t current_page_index; // index of current page in FAT
268	uint32_t current_page_offset; // offset of slot in current page
269	uint32_t page_count_in_file; // index of page in file (index in linked list)
270	uint32_t next_cluster_id; // content of current FAT slot
271
272	assert( (searched_page_index > 0) ,
273	"no FAT access required for first page\n");
274
275	#if DEBUG_FATFS_GET_CLUSTER
276	uint32_t cycle = (uint32_t)hal_get_cycles();
277	if( DEBUG_FATFS_GET_CLUSTER < cycle )
278	printk("\n[DBG] %s : thread %x enter / first_cluster_id %d / searched_index / cycle %d\n",
279	__FUNCTION__, CURRENT_THREAD, first_cluster_id, searched_page_index, cycle );
280	#endif
281
282	// get number of FAT slots per page
283	uint32_t slots_per_page = CONFIG_PPM_PAGE_SIZE >> 2;
284
285	// initialize loop variable
286	current_page_index = first_cluster_id / slots_per_page;
287	current_page_offset = first_cluster_id % slots_per_page;
288	page_count_in_file = 0;
289	next_cluster_id = 0xFFFFFFFF;
290
291	// scan FAT (i.e. traverse FAT linked list)
292	while( page_count_in_file < searched_page_index )
293	{
294	// get pointer on current page descriptor
295	current_page_desc = mapper_get_page( mapper , current_page_index );
296
297	if( current_page_desc == NULL ) return EIO;
298
299	// get pointer on buffer for current page
300	xptr_t base_xp = ppm_page2base( XPTR( local_cxy , current_page_desc ) );
301	current_page_buffer = (uint32_t *)GET_PTR( base_xp );
302
303	// get FAT slot content
304	next_cluster_id = current_page_buffer[current_page_offset];
305
306	#if (DEBUG_FATFS_GET_CLUSTER & 1)
307	if( DEBUG_FATFS_GET_CLUSTER < cycle )
308	printk("\n[DBG] %s : traverse FAT / current_page_index = %d\n"
309	"current_page_offset = %d / next_cluster_id = %d\n",
310	__FUNCTION__, current_page_index, current_page_offset , next_cluster_id );
311	#endif
312
313	// update loop variables
314	current_page_index = next_cluster_id / slots_per_page;
315	current_page_offset = next_cluster_id % slots_per_page;
316	page_count_in_file++;
317	}
318
319	if( next_cluster_id == 0xFFFFFFFF ) return EIO;
320
321	#if DEBUG_FATFS_GET_CLUSTER
322	cycle = (uint32_t)hal_get_cycles();
323	if( DEBUG_FATFS_GET_CLUSTER < cycle )
324	printk("\n[DBG] %s : thread %x exit / searched_cluster_id = %d / cycle %d\n",
325	__FUNCTION__, CURRENT_THREAD, next_cluster_id / cycle );
326	#endif
327
328	*searched_cluster_id = next_cluster_id;
329	return 0;
330
331	} // end fatfs_get_cluster()
332
333
334
335	///////////////////////////////////////////////////////////////////////////////////////
336	// Generic API : the following functions are called by the kernel (VFS)
337	// and must be defined by all supported file systems.
338	///////////////////////////////////////////////////////////////////////////////////////
339
340	///////////////////////////////
341	fatfs_ctx_t * fatfs_ctx_alloc( void )
342	{
343	kmem_req_t req;
344	req.type = KMEM_FATFS_CTX;
345	req.size = sizeof(fatfs_ctx_t);
346	req.flags = AF_KERNEL \| AF_ZERO;
347
348	return (fatfs_ctx_t *)kmem_alloc( &req );
349	}
350
351	//////////////////////////////////////////////
352	void fatfs_ctx_init( fatfs_ctx_t * fatfs_ctx )
353	{
354	error_t error;
355	kmem_req_t req;
356	uint8_t * buffer;
357
358	#if DEBUG_FATFS_INIT
359	uint32_t cycle = (uint32_t)hal_get_cycles();
360	if( DEBUG_FATFS_INIT < cycle )
361	printk("\n[DBG] %s : thread %x enter for fatfs_ctx = %x / cycle %d\n",
362	__FUNCTION__ , CURRENT_THREAD , fatfs_ctx , cycle );
363	#endif
364
365	assert( (fatfs_ctx != NULL) ,
366	"cannot allocate memory for FATFS context\n" );
367
368	// allocate a 512 bytes buffer to store the boot record
369	req.type = KMEM_512_BYTES;
370	req.flags = AF_KERNEL \| AF_ZERO;
371	buffer = (uint8_t *)kmem_alloc( &req );
372
373	assert( (buffer != NULL) ,
374	"cannot allocate memory for 512 bytes buffer\n" );
375
376	// load the boot record from device
377	// using a synchronous access to IOC device
378	error = dev_ioc_sync_read( buffer , 0 , 1 );
379
380	assert( (error == 0) ,
381	"cannot access boot record\n" );
382
383	#if (DEBUG_FATFS_INIT & 0x1)
384	if( DEBUG_FATFS_INIT < cycle )
385	{
386	uint32_t line;
387	uint32_t byte = 0;
388	printk("\n***** %s : FAT boot record\n", __FUNCTION__ );
389	for ( line = 0 ; line < 32 ; line++ )
390	{
391	printk(" %X \| %x %x %x %x %x %x %x %x %x %x %x %x %x %x %x %x \|\n",
392	byte,
393	buffer[byte+ 0],buffer[byte+ 1],buffer[byte+ 2],buffer[byte+ 3],
394	buffer[byte+ 4],buffer[byte+ 5],buffer[byte+ 6],buffer[byte+ 7],
395	buffer[byte+ 8],buffer[byte+ 9],buffer[byte+10],buffer[byte+11],
396	buffer[byte+12],buffer[byte+13],buffer[byte+14],buffer[byte+15] );
397
398	byte += 16;
399	}
400	}
401	#endif
402
403	// check sector size from boot record
404	uint32_t sector_size = fatfs_get_record( BPB_BYTSPERSEC , buffer , 1 );
405
406	assert( (sector_size == 512) ,
407	"sector size must be 512 bytes\n" );
408
409	// check cluster size from boot record
410	uint32_t nb_sectors = fatfs_get_record( BPB_SECPERCLUS , buffer , 1 );
411
412	assert( (nb_sectors == 8) ,
413	"cluster size must be 8 sectors\n" );
414
415	// check number of FAT copies from boot record
416	uint32_t nb_fats = fatfs_get_record( BPB_NUMFATS , buffer , 1 );
417
418	assert( (nb_fats == 1) ,
419	"number of FAT copies must be 1\n" );
420
421	// get & check number of sectors in FAT from boot record
422	uint32_t fat_sectors = fatfs_get_record( BPB_FAT32_FATSZ32 , buffer , 1 );
423
424	assert( ((fat_sectors & 0xF) == 0) ,
425	"FAT not multiple of 16 sectors\n");
426
427	// get and check root cluster from boot record
428	uint32_t root_cluster = fatfs_get_record( BPB_FAT32_ROOTCLUS , buffer , 1 );
429
430	assert( (root_cluster == 2) ,
431	"root cluster index must be 2\n");
432
433	// get FAT lba from boot record
434	uint32_t fat_lba = fatfs_get_record( BPB_RSVDSECCNT , buffer , 1 );
435
436	// release the 512 bytes buffer
437	req.type = KMEM_512_BYTES;
438	req.ptr = buffer;
439	kmem_free( &req );
440
441	// allocate a mapper for the FAT itself
442	mapper_t * fat_mapper = mapper_create( FS_TYPE_FATFS );
443
444	assert( (fat_mapper != NULL) ,
445	"no memory for FAT mapper" );
446
447	// WARNING : the inode field MUST be NULL for the FAT mapper
448	fat_mapper->inode = NULL;
449
450	// initialize the FATFS context
451	fatfs_ctx->fat_begin_lba = fat_lba;
452	fatfs_ctx->fat_sectors_count = fat_sectors;
453	fatfs_ctx->bytes_per_sector = sector_size;
454	fatfs_ctx->sectors_per_cluster = nb_sectors;
455	fatfs_ctx->cluster_begin_lba = fat_lba + fat_sectors;
456	fatfs_ctx->root_dir_cluster = 2;
457	fatfs_ctx->last_allocated_sector = 0; // TODO ???
458	fatfs_ctx->last_allocated_index = 0; // TODO ???
459	fatfs_ctx->fat_mapper_xp = XPTR( local_cxy , fat_mapper );
460
461	#if DEBUG_FATFS_INIT
462	cycle = (uint32_t)hal_get_cycles();
463	if( DEBUG_FATFS_INIT < cycle )
464	printk("\n[DBG] %s : thread %x exit for fatfs_ctx = %x / cycle %d\n",
465	__FUNCTION__ , CURRENT_THREAD , fatfs_ctx , cycle );
466	#endif
467
468	} // end fatfs_ctx_init()
469
470	/////////////////////////////////////////////////
471	void fatfs_ctx_destroy( fatfs_ctx_t * fatfs_ctx )
472	{
473	kmem_req_t req;
474	req.type = KMEM_FATFS_CTX;
475	req.ptr = fatfs_ctx;
476	kmem_free( &req );
477	}
478
479	//////////////////////////////////////////////
480	error_t fatfs_mapper_move_page( page_t * page,
481	bool_t to_mapper )
482	{
483	error_t error;
484	vfs_inode_t * inode;
485	mapper_t * mapper;
486	uint32_t index; // page index in mapper
487	uint8_t * buffer; // page base address in mapper
488	uint32_t count; // number of sectors in a page
489	uint32_t lba; // block address on device
490	fatfs_ctx_t * fatfs_ctx; // pointer on local FATFS context
491
492	// get pointer on mapper and page index from page descriptor
493	mapper = page->mapper;
494	index = page->index;
495
496	// get inode pointer from mapper
497	inode = mapper->inode;
498
499	#if DEBUG_FATFS_MOVE
500	uint32_t cycle = (uint32_t)hal_get_cycles();
501	if( DEBUG_FATFS_MOVE < cycle )
502	printk("\n[DBG] %s : thread %x enter / page %d / inode %x / mapper %x / cycle %d\n",
503	__FUNCTION__ , CURRENT_THREAD , index , inode , mapper , cycle );
504	#endif
505
506	// get page base address
507	xptr_t base_xp = ppm_page2base( XPTR( local_cxy , page ) );
508	buffer = (uint8_t *)GET_PTR( base_xp );
509
510	// get number of sectors for one page (from FATFS context)
511	fatfs_ctx = (fatfs_ctx_t *)fs_context[FS_TYPE_FATFS].extend;
512	count = fatfs_ctx->sectors_per_cluster;
513
514	// test FAT/normal inode
515	if( inode == NULL ) // it is the FAT mapper
516	{
517	// get lba from page index
518	lba = fatfs_ctx->fat_begin_lba + (count * index);
519
520	#if (DEBUG_FATFS_MOVE & 0x1)
521	if( DEBUG_FATFS_MOVE < cycle )
522	printk("\n[DBG] %s : access FAT on device / lba = %d\n", __FUNCTION__ , lba );
523	#endif
524
525	// access device
526	if( to_mapper ) error = dev_ioc_sync_read ( buffer , lba , count );
527	else error = dev_ioc_write( buffer , lba , count );
528
529	if( error ) return EIO;
530	}
531	else // it is a normal inode mapper
532	{
533	uint32_t searched_cluster_id;
534
535	// get first_cluster_id from inode extension
536	uint32_t first_cluster_id = (uint32_t)(intptr_t)inode->extend;
537
538	// compute cluster_id
539	if( index == 0 ) // no need to access FAT mapper
540	{
541	searched_cluster_id = first_cluster_id;
542	}
543	else // FAT mapper access required
544	{
545	// get cluster and local pointer on FAT mapper
546	xptr_t fat_mapper_xp = fatfs_ctx->fat_mapper_xp;
547	cxy_t fat_mapper_cxy = GET_CXY( fat_mapper_xp );
548	mapper_t * fat_mapper_ptr = (mapper_t *)GET_PTR( fat_mapper_xp );
549
550	// access FAT mapper
551	if( fat_mapper_cxy == local_cxy ) // FAT mapper is local
552	{
553
554	#if (DEBUG_FATFS_MOVE & 0x1)
555	if( DEBUG_FATFS_MOVE < cycle )
556	printk("\n[DBG] %s : access local FAT mapper\n"
557	"fat_mapper_cxy = %x / fat_mapper_ptr = %x / first_cluster_id = %d / index = %d\n",
558	__FUNCTION__ , fat_mapper_cxy , fat_mapper_ptr , first_cluster_id , index );
559	#endif
560	error = fatfs_get_cluster( fat_mapper_ptr,
561	first_cluster_id,
562	index,
563	&searched_cluster_id );
564	}
565	else // FAT mapper is remote
566	{
567
568	#if (DEBUG_FATFS_MOVE & 0x1)
569	if( DEBUG_FATFS_MOVE < cycle )
570	printk("\n[DBG] %s : access remote FAT mapper\n"
571	"fat_mapper_cxy = %x / fat_mapper_ptr = %x / first_cluster_id = %d / index = %d\n",
572	__FUNCTION__ , fat_mapper_cxy , fat_mapper_ptr , first_cluster_id , index );
573	#endif
574	rpc_fatfs_get_cluster_client( fat_mapper_cxy,
575	fat_mapper_ptr,
576	first_cluster_id,
577	index,
578	&searched_cluster_id,
579	&error );
580	}
581
582	if( error ) return EIO;
583	}
584
585	#if (DEBUG_FATFS_MOVE & 0x1)
586	if( DEBUG_FATFS_MOVE < cycle )
587	printk("\n[DBG] %s : access device for inode %x / cluster_id %d\n",
588	__FUNCTION__ , inode , searched_cluster_id );
589	#endif
590
591	// get lba from cluster_id
592	lba = fatfs_lba_from_cluster( fatfs_ctx , searched_cluster_id );
593
594	// access device
595	if( to_mapper ) error = dev_ioc_sync_read ( buffer , lba , count );
596	else error = dev_ioc_write( buffer , lba , count );
597
598	if( error ) return EIO;
599	}
600
601	#if DEBUG_FATFS_MOVE
602	cycle = (uint32_t)hal_get_cycles();
603	if( DEBUG_FATFS_MOVE < cycle )
604	printk("\n[DBG] %s : thread %x exit / page %d / inode %x / mapper %x / cycle %d\n",
605	__FUNCTION__ , CURRENT_THREAD , index , inode , mapper , cycle );
606	#endif
607
608	#if (DEBUG_FATFS_MOVE & 0x1)
609	if( DEBUG_FATFS_MOVE < cycle )
610	{
611	uint32_t * tab = (uint32_t *)buffer;
612	uint32_t line , word;
613	printk("\n***** %s : First 64 words of loaded page\n", __FUNCTION__ );
614	for( line = 0 ; line < 8 ; line++ )
615	{
616	printk("%X : ", line );
617	for( word = 0 ; word < 8 ; word++ ) printk("%X ", tab[(line<<3) + word] );
618	printk("\n");
619	}
620	}
621	#endif
622
623	return 0;
624
625	} // end fatfs_mapper_move_page()
626
627	/////////////////////////////////////////////////////
628	error_t fatfs_inode_load( vfs_inode_t * parent_inode,
629	char * name,
630	xptr_t child_inode_xp )
631	{
632	// Two embedded loops:
633	// - scan the parent mapper pages
634	// - scan the directory entries in each 4 Kbytes page
635
636	#if DEBUG_FATFS_LOAD
637	uint32_t cycle = (uint32_t)hal_get_cycles();
638	if( DEBUG_FATFS_LOAD < cycle )
639	printk("\n[DBG] %s : thread %x enter for child <%s> in parent inode %x / cycle %d\n",
640	__FUNCTION__ , CURRENT_THREAD , name , parent_inode , cycle );
641	#endif
642
643	mapper_t * mapper = parent_inode->mapper;
644
645	assert( (mapper != NULL) , "parent mapper undefined\n");
646
647	char cname[CONFIG_VFS_MAX_NAME_LENGTH]; // name extracter from each directory entry
648
649	char lfn1[16]; // buffer for one partial cname
650	char lfn2[16]; // buffer for one partial cname
651	char lfn3[16]; // buffer for one partial cname
652	page_t * page; // pointer on current page descriptor
653	uint8_t * base; // pointer on current page base
654	uint32_t offset = 0; // byte offset in page
655	uint32_t index = 0; // page index in mapper
656	uint32_t attr; // directory entry ATTR field
657	uint32_t ord; // directory entry ORD field
658	uint32_t seq; // sequence index
659	uint32_t lfn = 0; // LFN entries number
660	uint32_t size = 0; // searched file/dir size (bytes)
661	uint32_t cluster = 0; // searched file/dir cluster index
662	uint32_t is_dir = 0; // searched file/dir type
663	uint32_t dentry; // directory entry index
664	int32_t found = 0; // not found (0) / name found (1) / end of dir (-1)
665
666	// scan the parent directory mapper
667	while ( found == 0 )
668	{
669	// get one page
670	page = mapper_get_page( mapper , index );
671
672	assert( (page != NULL) , "bad parent mapper\n");
673
674	// get page base
675	xptr_t base_xp = ppm_page2base( XPTR( local_cxy , page ) );
676	base = (uint8_t *)GET_PTR( base_xp );
677
678	#if (DEBUG_FATFS_LOAD & 0x1)
679	if( DEBUG_FATFS_LOAD < cycle )
680	{
681	uint32_t * buf = (uint32_t *)base;
682	uint32_t line , word;
683	printk("\n***** %s : First 16 dentries for parent inode %x\n",
684	__FUNCTION__ , parent_inode );
685	for( line = 0 ; line < 16 ; line++ )
686	{
687	printk("%X : ", line );
688	for( word = 0 ; word < 8 ; word++ ) printk("%X ", buf[(line<<4) + word] );
689	printk("\n");
690	}
691	}
692	#endif
693	// scan this page until end of directory, end of page, or name found
694	while( (offset < 4096) && (found == 0) )
695	{
696	attr = fatfs_get_record( DIR_ATTR , base + offset , 0 );
697	ord = fatfs_get_record( LDIR_ORD , base + offset , 0 );
698
699	if (ord == NO_MORE_ENTRY) // no more entry => break
700	{
701	found = -1;
702	}
703	else if ( ord == FREE_ENTRY ) // free entry => skip
704	{
705	offset = offset + 32;
706	}
707	else if ( attr == ATTR_LONG_NAME_MASK ) // LFN entry => get partial cname
708	{
709	seq = ord & 0x3;
710	lfn = (seq > lfn) ? seq : lfn;
711	if ( seq == 1 ) fatfs_get_name_from_long( base + offset, lfn1 );
712	else if ( seq == 2 ) fatfs_get_name_from_long( base + offset, lfn2 );
713	else if ( seq == 3 ) fatfs_get_name_from_long( base + offset, lfn3 );
714	offset = offset + 32;
715	}
716	else // NORMAL entry
717	{
718	// build the extracted name
719	if ( lfn == 0 )
720	{
721	fatfs_get_name_from_short( base + offset , cname );
722	}
723	else if ( lfn == 1 )
724	{
725	strcpy( cname , lfn1 );
726	}
727	else if ( lfn == 2 )
728	{
729	strcpy( cname , lfn1 );
730	strcpy( cname + 13 , lfn2 );
731	}
732	else if ( lfn == 3 )
733	{
734	strcpy( cname , lfn1 );
735	strcpy( cname + 13 , lfn2 );
736	strcpy( cname + 26 , lfn3 );
737	}
738
739	// get dentry arguments if extracted cname == searched name
740	if ( strcmp( name , cname ) == 0 )
741	{
742	cluster = (fatfs_get_record( DIR_FST_CLUS_HI , base + offset , 1 ) << 16) \|
743	(fatfs_get_record( DIR_FST_CLUS_LO , base + offset , 1 ) ) ;
744	dentry = ((index<<12) + offset)>>5;
745	is_dir = ((attr & ATTR_DIRECTORY) == ATTR_DIRECTORY);
746	size = fatfs_get_record( DIR_FILE_SIZE , base + offset , 1 );
747	found = 1;
748	}
749	offset = offset + 32;
750	lfn = 0;
751	}
752	} // end loop on directory entries
753	index++;
754	offset = 0;
755	} // end loop on pages
756
757	// analyse the result of scan
758
759	if ( found == -1 ) // found end of directory => failure
760	{
761
762	#if DEBUG_FATFS_LOAD
763	cycle = (uint32_t)hal_get_cycles();
764	if( DEBUG_FATFS_LOAD < cycle )
765	printk("\n[DBG] %s : thread %x exit / child <%s> not found / cycle %d\n",
766	__FUNCTION__ , CURRENT_THREAD, name, cycle );
767	#endif
768
769	return ENOENT;
770	}
771	else // found searched child name
772	{
773	// get child inode cluster and local pointer
774	cxy_t child_cxy = GET_CXY( child_inode_xp );
775	vfs_inode_t * child_ptr = (vfs_inode_t *)GET_PTR( child_inode_xp );
776
777	// update the child inode "type", "size", and "extend" fields
778	vfs_inode_type_t type = (is_dir) ? INODE_TYPE_DIR : INODE_TYPE_FILE;
779
780	hal_remote_sw( XPTR( child_cxy , &child_ptr->type ) , type );
781	hal_remote_sw( XPTR( child_cxy , &child_ptr->size ) , size );
782	hal_remote_sw( XPTR( child_cxy , &child_ptr->extend ) , cluster );
783
784	#if DEBUG_FATFS_LOAD
785	cycle = (uint32_t)hal_get_cycles();
786	if( DEBUG_FATFS_LOAD < cycle )
787	printk("\n[DBG] %s : thread %x exit / child <%s> loaded / cycle %d\n",
788	__FUNCTION__ , CURRENT_THREAD, name, cycle );
789	#endif
790
791	return 0;
792	}
793	} // end fatfs_inode_load()

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