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Added support for building file-sector mappings

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Jeff Parsons 2014-12-24 16:46:05 -08:00 • committed by jeffpar
commit aaebc5856e
3 changed files with 427 additions and 120 deletions
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27
modules/shared/lib/diskapi.js
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@ -97,13 +97,36 @@ DiskAPI.BPB = {
RESERVED_SECS: 0x0E, // 2 bytes: reserved sectors; ie, # sectors preceding the first FAT--usually just the boot sector (eg, 1)
FAT_TOTAL: 0x10, // 1 byte: FAT copies (eg, 2)
ROOT_ENTRIES: 0x11, // 2 bytes: root directory entries (eg, 0x40 or 64) 0x40 * 0x20 = 0x800 (1 sector is 0x200 bytes, total of 4 sectors)
SECTOR_TOTAL: 0x13, // 2 bytes: number of sectors (eg, 0x140 or 320); if zero, refer to LARGE_SECS
TOTAL_SECS: 0x13, // 2 bytes: number of sectors (eg, 0x140 or 320); if zero, refer to LARGE_SECS
MEDIA_TYPE: 0x15, // 1 byte: media type (eg, 0xFF: 320Kb, 0xFE: 160Kb, 0xFD: 360Kb, 0xFC: 180Kb)
FAT_SECS: 0x16, // 2 bytes: sectors per FAT (eg, 1)
TRACK_SECS: 0x18, // 2 bytes: sectors per track (eg, 8)
HEAD_TOTAL: 0x1A, // 2 bytes: number of heads (eg, 1)
HIDDEN_SECS: 0x1C, // 4 bytes: number of hidden sectors (always 0 for non-partitioned media)
LARGE_SECS: 0x20 // 4 bytes: number of sectors if SECTOR_TOTAL is zero
LARGE_SECS: 0x20 // 4 bytes: number of sectors if TOTAL_SECS is zero
};
/*
* Directory Entry offsets in FAT-based disk images
*/
DiskAPI.DIR = {
NAME: 0x00, // 8 bytes
EXT: 0x08, // 3 bytes
ATTR: 0x0B, // 1 byte
MODTIME: 0x16, // 2 bytes
MODDATE: 0x18, // 2 bytes
CLUSTER: 0x1A, // 2 bytes
SIZE: 0x1C, // 4 bytes (typically zero for subdirectories)
LENGTH: 0x20 // 32 bytes total
};
DiskAPI.ATTR = {
READONLY: 0x01, // PC-DOS 2.0 and up
HIDDEN: 0x02,
SYSTEM: 0x04,
LABEL: 0x08, // PC-DOS 2.0 and up
SUBDIR: 0x10, // PC-DOS 2.0 and up
ARCHIVE: 0x20 // PC-DOS 2.0 and up
};
if (typeof module !== 'undefined') module.exports = DiskAPI;