Documentation/filesystems/romfs.rst

1 .. SPDX-License-Identifier: GPL-2.0
4 ROMFS - ROM File System
26 As the name suggests, romfs could be also used (space-efficiently) on
27 various read-only media, like (E)EPROM disks if someone will have the
32 later, with the current module utilities.  It can also be used to run
34 floppy drives can be loaded later if you use the "initrd"--initial
35 RAM disk--feature of the kernel.  This would not be really news
53 name).  The maximum overhead for any non-empty file is the header, and
62 	+---+---+---+---+
63   0	| - | r | o | m |  \
64 	+---+---+---+---+	The ASCII representation of those bytes
65   4	| 1 | f | s | - |  /	(i.e. "-rom1fs-")
66 	+---+---+---+---+
68 	+---+---+---+---+
70 	+---+---+---+---+
73 	+---+---+---+---+
95      	+---+---+---+---+
97 	+---+---+---+---+	  (zero if no more files)
99 	+---+---+---+---+
101 	+---+---+---+---+
103 	+---+---+---+---+	  name, and padding
106 	+---+---+---+---+
129  5	char device		    - " -
147 device drivers are unable to cope with smaller than block-sized data.
163 to romfs-subscribe@shadow.banki.hu, the content is irrelevant.
167 - Permissions and owner information are pretty essential features of a
169   I have never found this limiting, but others might.
171 - The file system is read only, so it can be very small, but in case
174   solutions: implement write access as a compile-time option, or a new,
177 - Since the files are only required to have alignment on a 16 byte
184 - Compression might be an useful feature, but memory is quite a
185   limiting factor in my eyes.
187 - Where it is used?
189 - Does it work on other architectures than intel and motorola?