srec_binary

Langue: en

Autres versions - même langue

Version: SRecord (fedora - 01/12/10)

Section: 5 (Format de fichier)

Sommaire

NAME

srec_binary - binary file format

DESCRIPTION

It is possible to read and write binary files using I]srec_cat(1).

File Holes

A file hole is a portion of a regular file that contains null characters and is not stored in any data block on disk. Holes are a long[hy]standing feature of Unix files. For instance, the following Unix command creates a file in which the first bytes are a hole: 
 $ echo -n "X" | dd of=/tmp/hole bs=1024 seek=6
Now CW]/tmp/hole has 6,145 characters (6,144 null characters plus an X character), yet the file occupies just one data block on disk.

File holes were introduced to avoid wasting disk space. They are used extensively by database applications and, more generally, by all applications that perform hashing on files.

See http://www.oreilly.com/catalog/linuxkernel2/chapter/ch17.pdf for more information.

Reading

The size of binary files is taken from the size of the file on the file system. If the file has "holes" these will read as blocks of zero data, as there is no elegant way to detect Unix file holes. In general, you probably want to use the -unfill filter to find and remove large swathes of zero bytes.

Writing

In producing a binary file, I]srec_cat(1) honours the address information and places the data into the binary file at the addresses specified in the hex file. This usually results on "holes" in the file. Sometimes alarmingly large file sizes are reported as a result.

If you are on a brain[hy]dead operating system without file "holes" then there are going to be real data blocks containing real zero bytes, and consuming real amounts of disk space. Upgrade - I suggest Linux.

To make a file of the size you expect, use

srec_info foo.s19
to find the lowest address, then use
srec_cat foo.s19 -intel -offset -I]n -o foo.bin -binary
where I]n is the lowest address present in the CW]foo.s19 file, as reported by I]srec_info(1). The B]negative offset serves to move the data down to have an origin of zero.
srec_binary version 1.55
Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Peter Miller

The srec_binary program comes with ABSOLUTELY NO WARRANTY; for details use the 'srec_binary -VERSion License' command. This is free software and you are welcome to redistribute it under certain conditions; for details use the 'srec_binary -VERSion License' command.

AUTHOR

Peter Miller E[hy]Mail: pmiller@opensource.org.au
/\/\* WWW: http://miller.emu.id.au/pmiller/