diff options
| author | Jan Sucan <jan@jansucan.com> | 2025-01-26 16:32:28 +0100 |
|---|---|---|
| committer | Ján Sučan <jan@jansucan.com> | 2025-01-26 16:35:37 +0100 |
| commit | eded8d529441f13c71f33a45dae290d2bbc33289 (patch) | |
| tree | a2a902950aa0e94a5b3911e2b5fe79546fa5918f | |
| parent | 87b0efa4759fe8b45cf1b2210ceeb830e2e31ea1 (diff) | |
man: Document diff file format v2
| -rw-r--r-- | man/diff-dd.5 | 124 |
1 files changed, 123 insertions, 1 deletions
diff --git a/man/diff-dd.5 b/man/diff-dd.5 index c6db286..c546220 100644 --- a/man/diff-dd.5 +++ b/man/diff-dd.5 @@ -7,7 +7,129 @@ diff-dd \- the file formats This manual page describes the current and the previous formats of \%diff-dd\: differential images. -.SS Format v1 +.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. |
