On Fri, Jun 08, 2007 at 10:08:28PM -0400, Christopher Cordahi wrote:
> On 05/06/07, Sergei Gavrikov <[EMAIL PROTECTED]> wrote:
> >On Tue, Jun 05, 2007 at 01:49:36PM -0400, Christopher Cordahi wrote:
> >> Hello ecos
> >>
> >> I'd like to add some sort of checksum into the .elf files.
> >> Is there a standard way of doing this?
> >>
> >> Googling I see some mention of a .dynamic tag DT_CHECKSUM
> >> but not how to use it properly
> >> and a short discussion in
> >> http://ecos.sourceware.org/ml/binutils/2003-02/msg00242.html
> >> but it doesn't seem very standard.
> >>
> >> Any ideas?
> >
> >It seems, it's more suitable to verify ELF using a parallel md5sum file
> >That is 128-bit! There are sources http://www.ietf.org/rfc/rfc1321.txt.
>
> Thanks,
> However I only want it to detect accidental file corruption, something that
> can be added to the file at file creation and can be easily verified by the
> program loader (redboot). At most I was thinking about implementing a
> 32 bit CRC algorithm and probably only a 16 bits. Maintaining and
> distributing only 1 file is much easier than 2 so I am hoping to add the
> CRC to the file in a standard way. If there is no such standard I'll have
> to resort to a method similar to that mentioned in the discussion.
I have an idea to do it with no blood. You won't need tweak ELF. You can
use zipped ELF and use RedBoot's [fis load] command with -d option
(decompress). Any corruption in your gzip file will be found by gzip
layer as well. Gzip has a nice crc checking. It quite works. There is a
demo below
Let's do it in shell
make hello
gzip hello
nano hello.gz ; imitate a corruption :-)
and this one let's do in RedBoot
load -r -b %{freememlo}
fis create hello.gz
fis load -d hello.gz
decompression error: invalid literal/lengths set
If you can see, we catch that corruption before a run! More that, I
build-in GUNZIP behavior in RedBoot every time to decrease an upload
time when I use Ymodem to load ELFs. Gzipped, even non-stripped ELF
files don't eat my FLASH.
Note: your redboot_ROM.ecm should contain such things
cdl_configuration eCos {
...
package CYGPKG_COMPRESS_ZLIB current ;
};
...
cdl_option CYGBLD_BUILD_REDBOOT_WITH_GUNZIP {
user_value 1
};
-- Sergei
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