diff options
Diffstat (limited to 'perl-install/resize_fat/boot_sector.pm')
| -rw-r--r-- | perl-install/resize_fat/boot_sector.pm | 76 |
1 files changed, 40 insertions, 36 deletions
diff --git a/perl-install/resize_fat/boot_sector.pm b/perl-install/resize_fat/boot_sector.pm index c236b1617..4ed4a73f7 100644 --- a/perl-install/resize_fat/boot_sector.pm +++ b/perl-install/resize_fat/boot_sector.pm @@ -1,69 +1,73 @@ -package resize_fat::boot_sector; +package resize_fat::boot_sector; # $Id$ use diagnostics; use strict; -use common qw(:common :system :constant); +use common qw(:common :system :constant :functional); use resize_fat::io; use resize_fat::any; use resize_fat::directory; +#- Oops, this will be unresizable on big-endian machine. trapped by signature. my $format = "a3 a8 S C S C S S C S S S I I I S S I S S a458 S"; my @fields = ( - 'boot_jump', # boot strap short or near jump - 'system_id', # Name - can be used to special case partition manager volumes - 'sector_size', # bytes per logical sector - 'cluster_size_in_sectors', # sectors/cluster - 'nb_reserved', # reserved sectors - 'nb_fats', # number of FATs - 'nb_root_dir_entries', # number of root directory entries - 'small_nb_sectors', # number of sectors: big_nb_sectors supersedes - 'media', # media code - 'fat16_fat_length', # sectors/FAT for FAT12/16 + 'boot_jump', #- boot strap short or near jump + 'system_id', #- Name - can be used to special case partition manager volumes + 'sector_size', #- bytes per logical sector + 'cluster_size_in_sectors', #- sectors/cluster + 'nb_reserved', #- reserved sectors + 'nb_fats', #- number of FATs + 'nb_root_dir_entries', #- number of root directory entries + 'small_nb_sectors', #- number of sectors: big_nb_sectors supersedes + 'media', #- media code + 'fat16_fat_length', #- sectors/FAT for FAT12/16 'sectors_per_track', 'nb_heads', - 'nb_hidden', # (unused) - 'big_nb_sectors', # number of sectors (if small_nb_sectors == 0) - -# FAT32-only entries - 'fat32_fat_length', # size of FAT in sectors - 'fat32_flags', # bit8: fat mirroring, - # low4: active fat - 'fat32_version', # minor * 256 + major + 'nb_hidden', #- (unused) + 'big_nb_sectors', #- number of sectors (if small_nb_sectors == 0) + +#- FAT32-only entries + 'fat32_fat_length', #- size of FAT in sectors + 'fat32_flags', #- bit8: fat mirroring, + #- low4: active fat + 'fat32_version', #- minor * 256 + major 'fat32_root_dir_cluster', 'info_offset_in_sectors', 'fat32_backup_sector', -# Common again... - 'boot_code', # Boot code (or message) - 'boot_sign', # 0xAA55 +#- Common again... + 'boot_code', #- Boot code (or message) + 'boot_sign', #- 0xAA55 ); 1; -# trimfs_init_boot_sector() - reads in the boot sector - gets important info out -# of boot sector, and puts in main structure - performs sanity checks - returns 1 -# on success, 0 on failureparameters: filesystem an empty structure to fill. +#- trimfs_init_boot_sector() - reads in the boot sector - gets important info out +#- of boot sector, and puts in main structure - performs sanity checks - returns 1 +#- on success, 0 on failureparameters: filesystem an empty structure to fill. sub read($) { my ($fs) = @_; - + my $boot = eval { resize_fat::io::read($fs, 0, $SECTORSIZE) }; $@ and die "reading boot sector failed on device $fs->{fs_name}"; @{$fs}{@fields} = unpack $format, $boot; $fs->{nb_sectors} = $fs->{small_nb_sectors} || $fs->{big_nb_sectors}; - $fs->{cluster_size} = $fs->{cluster_size_in_sectors} * $fs->{sector_size}; + $fs->{cluster_size} = $fs->{cluster_size_in_sectors} * $fs->{sector_size}; - $fs->{boot_sign} == 0xAA55 or die "Invalid signature for a MS-based filesystem."; - $fs->{nb_fats} == 2 or die "Weird number of FATs: $fs->{nb_fats}, not 2.", + $fs->{boot_sign} == 0xAA55 or die "Invalid signature for a MS-based filesystem.\n"; $fs->{nb_sectors} < 32 and die "Too few sectors for viable file system\n"; + $fs->{nb_fats} == 2 or cdie "Weird number of FATs: $fs->{nb_fats}, not 2.\n"; + $fs->{sector_size} == 512 or cdie "Strange sector_size != 512\n"; if ($fs->{fat16_fat_length}) { - # asserting FAT16, will be verified later on + #- asserting FAT16, will be verified later on + $resize_fat::isFAT32 = 0; $fs->{fs_type} = 'FAT16'; $fs->{fs_type_size} = 16; $fs->{fat_length} = $fs->{fat16_fat_length}; + $resize_fat::bad_cluster_value = 0xfff7; #- 2**16 - 1 } else { $resize_fat::isFAT32 = 1; $fs->{fs_type} = 'FAT32'; @@ -72,9 +76,9 @@ sub read($) { $fs->{nb_root_dir_entries} = 0; $fs->{info_offset} = $fs->{info_offset_in_sectors} * $fs->{sector_size}; + $resize_fat::bad_cluster_value = 0x0ffffff7; } - $resize_fat::bad_cluster_value = (1 << $fs->{fs_type_size}) - 9; - + $fs->{fat_offset} = $fs->{nb_reserved} * $fs->{sector_size}; $fs->{fat_size} = $fs->{fat_length} * $fs->{sector_size}; $fs->{root_dir_offset} = $fs->{fat_offset} + $fs->{fat_size} * $fs->{nb_fats}; @@ -83,12 +87,12 @@ sub read($) { $fs->{nb_fat_entries} = divide($fs->{fat_size}, $fs->{fs_type_size} / 8); - # - 2 because clusters 0 & 1 doesn't exist + #- - 2 because clusters 0 & 1 doesn't exist $fs->{nb_clusters} = divide($fs->{nb_sectors} * $fs->{sector_size} - $fs->{cluster_offset}, $fs->{cluster_size}) - 2; $fs->{dir_entries_per_cluster} = divide($fs->{cluster_size}, psizeof($format)); - $fs->{nb_clusters} >= resize_fat::any::min_cluster_count($fs) or die "error: not enough sectors for a $fs->{fs_type}\n"; +#- $fs->{nb_clusters} >= resize_fat::any::min_cluster_count($fs) or die "error: not enough sectors for a $fs->{fs_type}\n"; $fs->{nb_clusters} < resize_fat::any::max_cluster_count($fs) or die "error: too many sectors for a $fs->{fs_type}\n"; } @@ -99,7 +103,7 @@ sub write($) { eval { resize_fat::io::write($fs, 0, $SECTORSIZE, $boot) }; $@ and die "writing the boot sector failed on device $fs->{fs_name}"; if ($resize_fat::isFAT32) { - # write backup + #- write backup eval { resize_fat::io::write($fs, $fs->{fat32_backup_sector} * $SECTORSIZE, $SECTORSIZE, $boot) }; $@ and die "writing the backup boot sector (#$fs->{fat32_backup_sector}) failed on device $fs->{fs_name}"; } |