.TH DIFF-DD 5

.SH NAME
diff-dd \- the file formats

.SH DESCRIPTION
This manual page describes the current and the previous formats of \%diff-dd\:
differential images.

.SS Format v2
.I i
is an index of data in a differential image starting from 0.

.I si
is a size of data
.I i
in bytes.
.I s
is greater or equal 1, and less than or equal the buffer size.

The multibyte values are big-endian. This is different from the Format
v1. Big-endian values are easier to read by humans when examining the image
files.

.TS
tab(;) allbox;
l l l
l l l
l l l
l l l
l l l
l l l
l l l
l l l
l l l
l s s
l l l.
T{
.B Offset (bytes)
T};T{
.B Size (bytes)
T};T{
.B Description
T}
.\" --------
0;13;T{
File signature (magic number). ASCII string without terminating null byte. Value "diff-dd image".
T}
13;1;T{
Format version. Unsigned integer. Value 2.
T}
.\" --------
14;8;T{
Offset of data 0 in the output file
T}
22;4;Size of data 0
26;T{
.I s0
T};Data 0
.\" --------
T{
26 +
.I s0
T};8;T{
Offset of data 1 in the output file
T}
T{
34 +
.I s0
T};4;Size of data 1
T{
38 +
.I s0
T};T{
.I s1
T};Data 1
.\" --------
\[char46]\[char46]\[char46]
.\" --------
T{
14 + (12 *
.I i
) +
.I s0
+
.I s1
+
\[char46]\[char46]\[char46]
+
.I s(i-1)
T};8;T{
Offset of data
.I i
in the output file
T}
T{
14 + (20 *
.I i
) +
.I s0
+
.I s1
+
\[char46]\[char46]\[char46]
+
.I s(i-1)
T};4;T{
Size of data
.I i
T}
T{
14 + (24 *
.I i
) +
.I s0
+
.I s1
+
\[char46]\[char46]\[char46]
+
.I s(i-1)
T};T{
.I si
T};T{
Data
.I i
T}
.TE

.SS Format v1 (Deprecated)
This format was being used by diff-dd major version 2.

.I s
is a sector size in bytes specified by the user on the command line when the
image was being created.
.I s
is greater or equal 1.

.I i
is an index of data in a differential image starting from 0.

The offsets are 64-bit little-endian.

.TS
tab(;) allbox;
l l l
l l l
l l l
l l l
l l l
l s s
l l l.
T{
.B Offset (bytes)
T};T{
.B Size (bytes)
T};T{
.B Description
T}
.\" --------
0;8;Offset of data 0 in the output file
8;T{
.I s
T};Data 0
.\" --------
T{
8 +
.I s
T};8;Offset of data 1 in the output file
T{
16 +
.I s
T};T{
.I s
T};Data 1
.\" --------
\[char46]\[char46]\[char46]
.\" --------
T{
(8 +
.I s
) *
.I i
T};8;T{
Offset of data
.I i
in the output file
T}
T{
(8 +
.I s
) *
.I i
+ 8
T};T{
.I s
T};T{
Data
.I i
T}
.TE