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| author | H. Peter Anvin <hpa@zytor.com> | 2010-01-25 11:34:33 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2010-01-25 11:34:33 -0800 |
| commit | 217683b7fca9672293d997829fdbc25d7f667e79 (patch) | |
| tree | 19837028a0d7dd0d5b797846c0340052dcfcd20a | |
| parent | 67cd8b349590cc0090dffc6ef7439378d8e71206 (diff) | |
| download | syslinux-217683b7fca9672293d997829fdbc25d7f667e79.tar.gz | |
FAT: deal with non-mirrored FATs for FAT32
FAT32 has the option of non-mirrored FATs, used to improve atomicity
of some operations. If we have non-mirrored FATs, we need to make
sure to read the one FAT which is currently marked active.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| -rw-r--r-- | core/fs/fat/fat.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/core/fs/fat/fat.c b/core/fs/fat/fat.c index c89ed78a..b036ead4 100644 --- a/core/fs/fat/fat.c +++ b/core/fs/fat/fat.c @@ -743,8 +743,14 @@ static int vfat_fs_init(struct fs_info *fs) sbi->fat_type = FAT16; } else { sbi->fat_type = FAT32; + if (clusters > 0x0ffffff4) clusters = 0x0ffffff4; /* Maximum possible */ + + if (fat.fat32.extended_flags & 0x80) { + /* Non-mirrored FATs, we need to read the active one */ + sbi->fat += (fat.fat32.extended_flags & 0x0f) * sectors_per_fat; + } } sbi->clusters = clusters; |