From f1fa0e6028d395c5f0d1a0929a795b8dc0d43295 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Mon, 17 Feb 2020 17:11:56 +0100 Subject: [PATCH] docs: filesystems: convert cramfs.txt to ReST - Add a SPDX header; - Adjust document title; - Some whitespace fixes and new line breaks; - Mark literal blocks as such; - Add table markups; - Add it to filesystems/index.rst. Signed-off-by: Mauro Carvalho Chehab Acked-by: Nicolas Pitre Link: https://lore.kernel.org/r/e87b267e71f99974b7bb3fc0a4a08454ff58165e.1581955849.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet --- .../filesystems/{cramfs.txt => cramfs.rst} | 19 ++++++++++++------- Documentation/filesystems/index.rst | 1 + 2 files changed, 13 insertions(+), 7 deletions(-) rename Documentation/filesystems/{cramfs.txt => cramfs.rst} (88%) diff --git a/Documentation/filesystems/cramfs.txt b/Documentation/filesystems/cramfs.rst similarity index 88% rename from Documentation/filesystems/cramfs.txt rename to Documentation/filesystems/cramfs.rst index 8e19a53d648b..afbdbde98bd2 100644 --- a/Documentation/filesystems/cramfs.txt +++ b/Documentation/filesystems/cramfs.rst @@ -1,12 +1,15 @@ +.. SPDX-License-Identifier: GPL-2.0 - Cramfs - cram a filesystem onto a small ROM +=========================================== +Cramfs - cram a filesystem onto a small ROM +=========================================== -cramfs is designed to be simple and small, and to compress things well. +cramfs is designed to be simple and small, and to compress things well. It uses the zlib routines to compress a file one page at a time, and allows random page access. The meta-data is not compressed, but is expressed in a very terse representation to make it use much less -diskspace than traditional filesystems. +diskspace than traditional filesystems. You can't write to a cramfs filesystem (making it compressible and compact also makes it _very_ hard to update on-the-fly), so you have to @@ -28,9 +31,9 @@ issue. Hard links are supported, but hard linked files will still have a link count of 1 in the cramfs image. -Cramfs directories have no `.' or `..' entries. Directories (like +Cramfs directories have no ``.`` or ``..`` entries. Directories (like every other file on cramfs) always have a link count of 1. (There's -no need to use -noleaf in `find', btw.) +no need to use -noleaf in ``find``, btw.) No timestamps are stored in a cramfs, so these default to the epoch (1970 GMT). Recently-accessed files may have updated timestamps, but @@ -70,9 +73,9 @@ MTD drivers are cfi_cmdset_0001 (Intel/Sharp CFI flash) or physmap (Flash device in physical memory map). MTD partitions based on such devices are fine too. Then that device should be specified with the "mtd:" prefix as the mount device argument. For example, to mount the MTD device named -"fs_partition" on the /mnt directory: +"fs_partition" on the /mnt directory:: -$ mount -t cramfs mtd:fs_partition /mnt + $ mount -t cramfs mtd:fs_partition /mnt To boot a kernel with this as root filesystem, suffice to specify something like "root=mtd:fs_partition" on the kernel command line. @@ -90,6 +93,7 @@ https://github.com/npitre/cramfs-tools For /usr/share/magic -------------------- +===== ======================= ======================= 0 ulelong 0x28cd3d45 Linux cramfs offset 0 >4 ulelong x size %d >8 ulelong x flags 0x%x @@ -110,6 +114,7 @@ For /usr/share/magic >552 ulelong x fsid.blocks %d >556 ulelong x fsid.files %d >560 string >\0 name "%.16s" +===== ======================= ======================= Hacker Notes diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst index ddd8f7b2bb25..8fe848ea04af 100644 --- a/Documentation/filesystems/index.rst +++ b/Documentation/filesystems/index.rst @@ -56,6 +56,7 @@ Documentation for filesystem implementations. bfs btrfs ceph + cramfs fuse overlayfs virtiofs