WebSVN – HelenOS – Blame – /trunk/tools/mkfat.py

Rev	Author	Line No.	Line
3264	decky	1	#!/usr/bin/env python
		2	#
		3	# Copyright (c) 2008 Martin Decky
		4	# All rights reserved.
		5	#
		6	# Redistribution and use in source and binary forms, with or without
		7	# modification, are permitted provided that the following conditions
		8	# are met:
		9	#
		10	# - Redistributions of source code must retain the above copyright
		11	# notice, this list of conditions and the following disclaimer.
		12	# - Redistributions in binary form must reproduce the above copyright
		13	# notice, this list of conditions and the following disclaimer in the
		14	# documentation and/or other materials provided with the distribution.
		15	# - The name of the author may not be used to endorse or promote products
		16	# derived from this software without specific prior written permission.
		17	#
		18	# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
		19	# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
		20	# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
		21	# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
		22	# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
		23	# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
		24	# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
		25	# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
		26	# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
		27	# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
		28	#
		29	"""
		30	FAT creator
		31	"""
		32
		33	import sys
		34	import os
		35	import random
		36	import xstruct
		37
3509	decky	38	def align_up(size, alignment):
		39	"Return size aligned up to alignment"
		40
		41	if (size % alignment == 0):
		42	return size
		43
		44	return (((size / alignment) + 1) * alignment)
		45
		46	def subtree_size(root, cluster_size):
		47	"Recursive directory walk and calculate size"
		48
		49	size = 0
		50	files = 0
		51
		52	for name in os.listdir(root):
		53	canon = os.path.join(root, name)
		54
		55	if (os.path.isfile(canon)):
		56	size += align_up(os.path.getsize(canon), cluster_size)
		57	files += 1
		58
		59	if (os.path.isdir(canon)):
		60	size += subtree_size(canon, cluster_size)
		61	files += 1
		62
		63	return size + align_up(files * 32, cluster_size)
		64
		65	def root_entries(root):
		66	"Return number of root directory entries"
		67
		68	return len(os.listdir(root))
		69
3264	decky	70	BOOT_SECTOR = """little:
		71	uint8_t jmp[3] /* jump instruction */
		72	char oem[8] /* OEM string */
		73	uint16_t sector /* bytes per sector */
		74	uint8_t cluster /* sectors per cluster */
		75	uint16_t reserved /* reserved sectors */
		76	uint8_t fats /* number of FATs */
		77	uint16_t rootdir /* root directory entries */
		78	uint16_t sectors /* total number of sectors */
		79	uint8_t descriptor /* media descriptor */
		80	uint16_t fat_sectors /* sectors per single FAT */
		81	uint16_t track_sectors /* sectors per track */
		82	uint16_t heads /* number of heads */
		83	uint32_t hidden /* hidden sectors */
		84	uint32_t sectors_big /* total number of sectors (if sectors == 0) */
		85
		86	/* Extended BIOS Parameter Block */
		87	uint8_t drive /* physical drive number */
		88	padding[1] /* reserved (current head) */
		89	uint8_t extboot_signature /* extended boot signature */
		90	uint32_t serial /* serial number */
		91	char label[11] /* volume label */
		92	char fstype[8] /* filesystem type */
		93	padding[448] /* boot code */
		94	uint8_t boot_signature[2] /* boot signature */
		95	"""
		96
		97	def usage(prname):
		98	"Print usage syntax"
		99	print prname + " <PATH> <IMAGE>"
		100
		101	def main():
		102	if (len(sys.argv) < 3):
		103	usage(sys.argv[0])
		104	return
		105
		106	path = os.path.abspath(sys.argv[1])
		107	if (not os.path.isdir(path)):
		108	print "<PATH> must be a directory"
		109	return
		110
3509	decky	111	sector_size = 512
		112	cluster_size = 4096
		113
		114	root_size = align_up(root_entries(sys.argv[1]) * 32, sector_size)
		115	size = subtree_size(sys.argv[1], cluster_size)
		116	fat_size = align_up(size / cluster_size * 2, sector_size)
		117
		118	sectors = (cluster_size + 2 * fat_size + root_size + size) / sector_size
		119
3264	decky	120	outf = file(sys.argv[2], "w")
		121
		122	boot_sector = xstruct.create(BOOT_SECTOR)
		123	boot_sector.jmp = [0xEB, 0x3C, 0x90]
		124	boot_sector.oem = "MSDOS5.0"
3509	decky	125	boot_sector.sector = sector_size
		126	boot_sector.cluster = cluster_size / sector_size
		127	boot_sector.reserved = cluster_size / sector_size
3264	decky	128	boot_sector.fats = 2
3509	decky	129	boot_sector.rootdir = root_size / 32
		130	boot_sector.sectors = (sectors if (sectors <= 65535) else 0)
3264	decky	131	boot_sector.descriptor = 0xF8
3509	decky	132	boot_sector.fat_sectors = fat_size / sector_size
		133	boot_sector.track_sectors = 63
		134	boot_sector.heads = 6
3264	decky	135	boot_sector.hidden = 0
3509	decky	136	boot_sector.sectors_big = (sectors if (sectors > 65535) else 0)
3264	decky	137
3509	decky	138	boot_sector.drive = 0x80
3264	decky	139	boot_sector.extboot_signature = 0x29
		140	boot_sector.serial = random.randint(0, 0xFFFFFFFF)
		141	boot_sector.label = "HELENOS"
		142	boot_sector.fstype = "FAT16 "
		143	boot_sector.boot_signature = [0x55, 0xAA]
		144
		145	outf.write(boot_sector.pack())
		146
		147	outf.close()
		148
		149	if __name__ == '__main__':
		150	main()

Subversion Repositories HelenOS

(root)/trunk/tools/mkfat.py – Rev 3509