docs: early-userspace: convert docs to ReST and rename to *.rst

The two files there describes a Kernel API feature, used to
support early userspace stuff. Prepare for moving them to
the kernel API book by converting to ReST format.

The conversion itself was quite trivial: just add/mark a few
titles as such, add a literal block markup, add a table markup
and a few blank lines, in order to make Sphinx to properly parse it.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

1 files changed, 0 insertions, 112 deletions

diff --git a/Documentation/early-userspace/buffer-format.txt b/Documentation/early-userspace/buffer-format.txt
deleted file mode 100644
index e1fd7f9dad16..000000000000
--- a/Documentation/early-userspace/buffer-format.txt
+++ /dev/null
@@ -1,112 +0,0 @@
-		       initramfs buffer format
-		       -----------------------
-
-		       Al Viro, H. Peter Anvin
-		      Last revision: 2002-01-13
-
-Starting with kernel 2.5.x, the old "initial ramdisk" protocol is
-getting {replaced/complemented} with the new "initial ramfs"
-(initramfs) protocol.  The initramfs contents is passed using the same
-memory buffer protocol used by the initrd protocol, but the contents
-is different.  The initramfs buffer contains an archive which is
-expanded into a ramfs filesystem; this document details the format of
-the initramfs buffer format.
-
-The initramfs buffer format is based around the "newc" or "crc" CPIO
-formats, and can be created with the cpio(1) utility.  The cpio
-archive can be compressed using gzip(1).  One valid version of an
-initramfs buffer is thus a single .cpio.gz file.
-
-The full format of the initramfs buffer is defined by the following
-grammar, where:
-	*	is used to indicate "0 or more occurrences of"
-	(|)	indicates alternatives
-	+	indicates concatenation
-	GZIP()	indicates the gzip(1) of the operand
-	ALGN(n)	means padding with null bytes to an n-byte boundary
-
-	initramfs  := ("\0" | cpio_archive | cpio_gzip_archive)*
-
-	cpio_gzip_archive := GZIP(cpio_archive)
-
-	cpio_archive := cpio_file* + (<nothing> | cpio_trailer)
-
-	cpio_file := ALGN(4) + cpio_header + filename + "\0" + ALGN(4) + data
-
-	cpio_trailer := ALGN(4) + cpio_header + "TRAILER!!!\0" + ALGN(4)
-
-
-In human terms, the initramfs buffer contains a collection of
-compressed and/or uncompressed cpio archives (in the "newc" or "crc"
-formats); arbitrary amounts zero bytes (for padding) can be added
-between members.
-
-The cpio "TRAILER!!!" entry (cpio end-of-archive) is optional, but is
-not ignored; see "handling of hard links" below.
-
-The structure of the cpio_header is as follows (all fields contain
-hexadecimal ASCII numbers fully padded with '0' on the left to the
-full width of the field, for example, the integer 4780 is represented
-by the ASCII string "000012ac"):
-
-Field name    Field size	 Meaning
-c_magic	      6 bytes		 The string "070701" or "070702"
-c_ino	      8 bytes		 File inode number
-c_mode	      8 bytes		 File mode and permissions
-c_uid	      8 bytes		 File uid
-c_gid	      8 bytes		 File gid
-c_nlink	      8 bytes		 Number of links
-c_mtime	      8 bytes		 Modification time
-c_filesize    8 bytes		 Size of data field
-c_maj	      8 bytes		 Major part of file device number
-c_min	      8 bytes		 Minor part of file device number
-c_rmaj	      8 bytes		 Major part of device node reference
-c_rmin	      8 bytes		 Minor part of device node reference
-c_namesize    8 bytes		 Length of filename, including final \0
-c_chksum      8 bytes		 Checksum of data field if c_magic is 070702;
-				 otherwise zero
-
-The c_mode field matches the contents of st_mode returned by stat(2)
-on Linux, and encodes the file type and file permissions.
-
-The c_filesize should be zero for any file which is not a regular file
-or symlink.
-
-The c_chksum field contains a simple 32-bit unsigned sum of all the
-bytes in the data field.  cpio(1) refers to this as "crc", which is
-clearly incorrect (a cyclic redundancy check is a different and
-significantly stronger integrity check), however, this is the
-algorithm used.
-
-If the filename is "TRAILER!!!" this is actually an end-of-archive
-marker; the c_filesize for an end-of-archive marker must be zero.
-
-
-*** Handling of hard links
-
-When a nondirectory with c_nlink > 1 is seen, the (c_maj,c_min,c_ino)
-tuple is looked up in a tuple buffer.  If not found, it is entered in
-the tuple buffer and the entry is created as usual; if found, a hard
-link rather than a second copy of the file is created.  It is not
-necessary (but permitted) to include a second copy of the file
-contents; if the file contents is not included, the c_filesize field
-should be set to zero to indicate no data section follows.  If data is
-present, the previous instance of the file is overwritten; this allows
-the data-carrying instance of a file to occur anywhere in the sequence
-(GNU cpio is reported to attach the data to the last instance of a
-file only.)
-
-c_filesize must not be zero for a symlink.
-
-When a "TRAILER!!!" end-of-archive marker is seen, the tuple buffer is
-reset.  This permits archives which are generated independently to be
-concatenated.
-
-To combine file data from different sources (without having to
-regenerate the (c_maj,c_min,c_ino) fields), therefore, either one of
-the following techniques can be used:
-
-a) Separate the different file data sources with a "TRAILER!!!"
-   end-of-archive marker, or
-
-b) Make sure c_nlink == 1 for all nondirectory entries.