NAME
srec_binary - binary file format
DESCRIPTION
It is possible to read and write binary files using 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‐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 /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, 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‐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 -n -o foo.bin -binary
where n is the lowest address present in the foo.s19 file, as reported
by srec_info(1). The negative offset serves to move the data down to
have an origin of zero.
COPYRIGHT
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‐Mail: pmiller@opensource.org.au
/\/\* WWW: http://miller.emu.id.au/pmiller/