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lxdream.org :: lxdream/src/vmu/vmuvol.c
lxdream 0.9.1
released Jun 29
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filename src/vmu/vmuvol.c
changeset 1034:7044e01148f0
next1035:e3093fd7d1da
author nkeynes
date Wed Jun 24 02:41:12 2009 +0000 (13 years ago)
permissions -rw-r--r--
last change Add initial VMU support
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     1 /**
     2  * $Id: vmuvol.h 869 2008-09-08 07:56:33Z nkeynes $
     3  *
     4  * VMU volume (ie block device) support
     5  *
     6  * Copyright (c) 2009 Nathan Keynes.
     7  *
     8  * This program is free software; you can redistribute it and/or modify
     9  * it under the terms of the GNU General Public License as published by
    10  * the Free Software Foundation; either version 2 of the License, or
    11  * (at your option) any later version.
    12  *
    13  * This program is distributed in the hope that it will be useful,
    14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
    15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    16  * GNU General Public License for more details.
    17  */
    19 #include <glib/gmem.h>
    20 #include <glib/gstrfuncs.h>
    21 #include <string.h>
    22 #include <stdio.h>
    23 #include <fcntl.h>
    24 #include <errno.h>
    26 #include "vmu/vmuvol.h"
    27 #include "dream.h"
    29 #define VMU_MAX_PARTITIONS 256
    30 #define VMU_MAX_BLOCKS 65536 /* Actually slightly less than this, but it'll do */
    32 typedef struct vmu_partition {
    33     struct vmu_volume_metadata metadata;
    34     uint32_t block_count;
    35     char *blocks;
    36 } *vmu_partition_t;
    38 struct vmu_volume {
    39     const gchar *display_name;
    40     vmu_partnum_t part_count;
    41     gboolean dirty;
    42     struct vmu_partition part[0];
    43 };
    45 /* On-VMU structures, courtesy of Marcus Comstedt */ 
    46 struct vmu_superblock {
    47     char magic[16];
    48     uint8_t colour_flag;
    49     uint8_t bgra[4];
    50     uint8_t pad1[27];
    51     char timestamp[8];
    52     char pad2[8];
    53     char unknown[6];
    54     uint16_t fat_block;
    55     uint16_t fat_size;
    56     uint16_t dir_block;
    57     uint16_t dir_size;
    58     uint16_t icon_shape;
    59     uint16_t user_size;
    60     /* remainder unknown */
    61 };
    63 struct vmu_direntry {
    64     uint8_t filetype;
    65     uint8_t copy_flag;
    66     uint16_t blkno;
    67     char filename[12];
    68     char timestamp[8];
    69     uint16_t blksize; /* Size in blocks*/
    70     uint16_t hdroff; /* Header offset in blocks */
    71     char pad[4];
    72 };
    74 #define MD(vmu,ptno) ((vmu)->part[ptno].metadata)
    76 #define VMU_BLOCK(vmu,ptno,blkno) (&(vmu)->part[ptno].blocks[(blkno)*VMU_BLOCK_SIZE])
    78 #define VMU_FAT_ENTRY(vmu,pt,ent)  ((uint16_t *)VMU_BLOCK(vmu, pt, (MD(vmu,pt).fat_block - ((ent)>>8))))[(ent)&0xFF]
    80 #define FAT_EMPTY 0xFFFC
    81 #define FAT_EOF   0xFFFA
    83 static const struct vmu_volume_metadata default_metadata = { 255, 255, 254, 1, 253, 13, 0, 200, 31, 0, 128 };
    85 vmu_volume_t vmu_volume_new_default( const gchar *display_name )
    86 {
    87     vmu_volume_t vol = g_malloc0( sizeof(struct vmu_volume) + sizeof(struct vmu_partition) );
    88     vol->part_count = 1;
    89     vol->dirty = FALSE;
    90     memcpy( &vol->part[0].metadata, &default_metadata, sizeof(struct vmu_volume_metadata) );
    91     vol->part[0].block_count = VMU_DEFAULT_VOL_BLOCKS;
    92     vol->part[0].blocks = g_malloc0( VMU_DEFAULT_VOL_BLOCKS * VMU_BLOCK_SIZE );
    93     vol->display_name = display_name == NULL ? NULL : g_strdup(display_name);
    94     vmu_volume_format( vol, 0, TRUE );
    95     return vol;
    96 }
    98 void vmu_volume_destroy( vmu_volume_t vol )
    99 {
   100     int i;
   101     if( vol == NULL )
   102         return;
   104     for( i=0; i<vol->part_count; i++ ) {
   105         g_free( vol->part[i].blocks );
   106         vol->part[i].blocks = NULL;
   107     }
   108     if( vol->display_name ) {
   109         g_free( (char *)vol->display_name );
   110         vol->display_name = NULL;
   111     }
   112     g_free(vol);
   113 }
   115 void vmu_volume_format( vmu_volume_t vol, vmu_partnum_t pt, gboolean quick )
   116 {
   117     if( pt >= vol->part_count ) {
   118         return;
   119     }
   121     if( !quick ) {
   122         /* Wipe it completely first */
   123         memset( vol->part[pt].blocks, 0, (vol->part[pt].block_count) * VMU_BLOCK_SIZE );
   124     }
   126     struct vmu_volume_metadata *meta = &vol->part[pt].metadata;
   127     unsigned int fatblkno = meta->fat_block;
   128     unsigned int dirblkno = meta->dir_block;
   130     /* Write superblock */
   131     struct vmu_superblock *super = (struct vmu_superblock *)VMU_BLOCK(vol,pt, meta->super_block);
   132     memset( super->magic, 0x55, 16 );
   133     memset( &super->colour_flag, 0, 240 ); /* Blank the rest for now */
   134     super->fat_block = meta->fat_block;
   135     super->fat_size = meta->fat_size;
   136     super->dir_block = meta->dir_block;
   137     super->user_size = meta->user_size;
   139     /* Write file allocation tables */
   140     int i,j;
   141     for( j=0; j<meta->fat_size; j++ ) {
   142         uint16_t *fat = (uint16_t *)VMU_BLOCK(vol,pt,fatblkno-j); 
   143         for( i=0; i<256; i++ ) {
   144             fat[i] = FAT_EMPTY;
   145         }
   146     }
   148     /* Fill in the system allocations in the FAT */
   149     for( i=0; i<meta->fat_size-1; i++ ) {
   150         VMU_FAT_ENTRY(vol,pt,fatblkno-i) = fatblkno-i-1;
   151     }
   152     VMU_FAT_ENTRY(vol,pt,fatblkno - i) = FAT_EOF;
   153     for( i=0; i<meta->dir_size-1; i++ ) {
   154         VMU_FAT_ENTRY(vol,pt,dirblkno-i) = dirblkno-i-1;
   155     }
   156     VMU_FAT_ENTRY(vol,pt,dirblkno-i) = FAT_EOF;
   158     /* If quick-format, blank the directory. Otherwise it's already been done */
   159     if( quick ) {
   160         memset( VMU_BLOCK(vol,pt,dirblkno-meta->dir_size+1),
   161                 0, meta->dir_size * VMU_BLOCK_SIZE );
   162     }
   163 }
   165 /*************************** File load/save ********************************/
   167 /**
   168  * Current file has 1 META chunk for all volume metadata, followed by a
   169  * DATA chunk for each partition's block data. The META chunk is required to
   170  * occur before any DATA blocks.
   171  * Unknown chunks are skipped to allow for forwards compatibility if/when
   172  * we add the VMU runtime side of things
   173  */
   175 struct vmu_file_header {
   176     char magic[16];
   177     uint32_t version;
   178     uint32_t head_len;
   179     uint32_t part_count;
   180     uint32_t display_name_len;
   181     char display_name[0];
   182 };
   184 struct vmu_chunk_header {
   185     char name[4];
   186     uint32_t length;
   187 };
   191 gboolean vmu_volume_save( const gchar *filename, vmu_volume_t vol, gboolean create_only )
   192 {
   193     struct vmu_file_header head;
   194     struct vmu_chunk_header chunk;
   195     int i;
   197     FILE *f = fopen( filename, (create_only ? "wx" : "w") ); /* Portable? */
   198     if( f == NULL ) {
   199         return FALSE;
   200     }
   202     /* File header */
   203     memcpy( head.magic, VMU_FILE_MAGIC, 16 );
   204     head.version = VMU_FILE_VERSION;
   205     head.part_count = vol->part_count;
   206     head.display_name_len = vol->display_name == NULL ? 0 : (strlen(vol->display_name)+1);
   207     head.head_len = sizeof(head) + head.display_name_len;
   208     fwrite( &head, sizeof(head), 1, f );
   209     if( vol->display_name != NULL ) {
   210         fwrite( vol->display_name, head.display_name_len, 1, f );
   211     }
   213     /* METAdata chunk */
   214     memcpy( chunk.name, "META", 4 );
   215     chunk.length = sizeof(struct vmu_volume_metadata) * vol->part_count;
   216     fwrite( &chunk, sizeof(chunk), 1, f );
   217     for( i=0; i < vol->part_count; i++ ) {
   218         fwrite( &vol->part[i].metadata, sizeof(struct vmu_volume_metadata), 1, f );
   219     }
   221     /* partition DATA chunks */
   222     for( i=0; i< vol->part_count; i++ ) {
   223         memcpy( chunk.name, "DATA", 4 );
   224         chunk.length = 0;
   225         fwrite( &chunk, sizeof(chunk), 1, f );
   226         long posn = ftell(f);
   227         fwrite( &vol->part[i].block_count, sizeof(vol->part[i].block_count), 1, f );
   228         fwrite_gzip( vol->part[i].blocks, vol->part[i].block_count, VMU_BLOCK_SIZE, f );
   229         long end = ftell(f);
   230         fseek( f, posn - sizeof(chunk.length), SEEK_SET );
   231         chunk.length = end-posn;
   232         fwrite( &chunk.length, sizeof(chunk.length), 1, f );
   233         fseek( f, end, SEEK_SET );
   234     }
   235     fclose(f);
   236     vol->dirty = FALSE;
   237     return TRUE;
   238 }
   240 vmu_volume_t vmu_volume_load( const gchar *filename )
   241 {
   242     struct vmu_file_header head;
   243     struct vmu_chunk_header chunk;
   244     vmu_volume_t vol;
   245     int i;
   247     FILE *f = fopen( filename, "ro" );
   248     if( f == NULL ) {
   249         ERROR( "Unable to open VMU file '%s': %s", filename, strerror(errno) );
   250         return FALSE;
   251     }
   253     if( fread( &head, sizeof(head), 1, f ) != 1 ||
   254         memcmp(head.magic, VMU_FILE_MAGIC, 16) != 0 ||
   255         head.part_count > VMU_MAX_PARTITIONS || 
   256         head.head_len < (sizeof(head) + head.display_name_len) )  {
   257         fclose(f);
   258         ERROR( "Unable to load VMU '%s': bad file header", filename );
   259         return NULL;
   260     }
   262     vol = (vmu_volume_t)g_malloc0( sizeof(struct vmu_volume) + sizeof(struct vmu_partition)*head.part_count );
   263     vol->part_count = head.part_count;
   264     vol->dirty = FALSE;
   265     if( head.display_name_len != 0 ) {
   266         vol->display_name = g_malloc( head.display_name_len );
   267         fread( (char *)vol->display_name, head.display_name_len, 1, f );
   268     }
   269     fseek( f, head.head_len, SEEK_SET );
   271     gboolean have_meta = FALSE;
   272     int next_part = 0;
   273     while( !feof(f) && fread( &chunk, sizeof(chunk), 1, f ) == 1 ) {
   274         if( memcmp( &chunk.name, "META", 4 ) == 0 ) {
   275             if( have_meta || chunk.length != head.part_count * sizeof(struct vmu_volume_metadata) ) {
   276                 vmu_volume_destroy(vol);
   277                 fclose(f);
   278                 ERROR( "Unable to load VMU '%s': bad metadata size (expected %d but was %d)", filename,
   279                        head.part_count * sizeof(struct vmu_volume_metadata), chunk.length );
   280                 return NULL;
   281             }
   282             for( i=0; i<head.part_count; i++ ) {
   283                 fread( &vol->part[i].metadata, sizeof(struct vmu_volume_metadata), 1, f );
   284             }
   285             have_meta = TRUE;
   286         } else if( memcmp( &chunk.name, "DATA", 4 ) == 0 ) {
   287             uint32_t block_count;
   288             fread( &block_count, sizeof(block_count), 1, f );
   289             if( next_part >= vol->part_count || block_count >= VMU_MAX_BLOCKS ) {
   290                 // Too many partitions / blocks
   291                 vmu_volume_destroy(vol);
   292                 fclose(f);
   293                 ERROR( "Unable to load VMU '%s': too large (%d/%d)", filename, next_part, block_count );
   294                 return NULL;
   295             }
   296             vol->part[next_part].block_count = block_count;
   297             vol->part[next_part].blocks = g_malloc(block_count*VMU_BLOCK_SIZE);
   298             fread_gzip(vol->part[next_part].blocks, VMU_BLOCK_SIZE, block_count, f );
   299             next_part++;
   300         } else {
   301             // else skip unknown block
   302             fseek( f, SEEK_CUR, chunk.length );
   303             WARN( "Unexpected VMU data chunk: '%4.4s'", chunk.name );
   304         }
   305     }
   307     fclose(f);
   309     if( !have_meta || next_part != vol->part_count ) {
   310         vmu_volume_destroy( vol );
   311         return NULL;
   312     }
   314     return vol;
   315 }
   317 /*************************** Accessing data ********************************/
   318 const char *vmu_volume_get_display_name( vmu_volume_t vol ) 
   319 {
   320     return vol->display_name;
   321 }
   323 void vmu_volume_set_display_name( vmu_volume_t vol, const gchar *name )
   324 {
   325     if( vol->display_name != NULL ) {
   326         g_free( (char *)vol->display_name );
   327     }
   328     if( name == NULL ) {
   329         vol->display_name = NULL;
   330     } else {
   331         vol->display_name = g_strdup(name);
   332     }
   333 }
   335 gboolean vmu_volume_is_dirty( vmu_volume_t vol )
   336 {
   337     return vol->dirty;
   338 }
   340 gboolean vmu_volume_read_block( vmu_volume_t vol, vmu_partnum_t pt, unsigned int block, unsigned char *out )
   341 {
   342     if( pt >= vol->part_count || block >= vol->part[pt].block_count ) {
   343         return FALSE;
   344     }
   346     memcpy( out, VMU_BLOCK(vol,pt,block), VMU_BLOCK_SIZE );
   347     return TRUE;
   348 }
   350 gboolean vmu_volume_write_block( vmu_volume_t vol, vmu_partnum_t pt, unsigned int block, unsigned char *in )
   351 {
   352     if( pt >= vol->part_count || block >= vol->part[pt].block_count ) {
   353         return FALSE;
   354     }
   355     memcpy( VMU_BLOCK(vol,pt,block), in, VMU_BLOCK_SIZE );
   356     vol->dirty = TRUE;
   357 }
   359 gboolean vmu_volume_write_phase( vmu_volume_t vol, vmu_partnum_t pt, unsigned int block, unsigned int phase, unsigned char *in )
   360 {
   361     if( pt >= vol->part_count || block >= vol->part[pt].block_count || phase >= 4 ) {
   362         return FALSE;
   363     }
   364     memcpy( VMU_BLOCK(vol,pt,block) + (phase*128), in, VMU_BLOCK_SIZE/4 );
   365     vol->dirty = TRUE;
   366 }
   368 const struct vmu_volume_metadata *vmu_volume_get_metadata( vmu_volume_t vol, vmu_partnum_t partition )
   369 {
   370     if( partition >= vol->part_count ) {
   371         return NULL;
   372     } else {
   373         return &vol->part[partition].metadata;
   374     }
   375 }
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