Messages in this thread | | | Date | Thu, 11 Aug 2011 16:23:23 +0200 | Subject | Re: [PATCH] scripts: add extract-vmlinux | From | Corentin Chary <> |
| |
On Thu, Aug 11, 2011 at 3:33 PM, Michal Marek <mmarek@suse.cz> wrote: > On 11.8.2011 15:08, Corentin Chary wrote: >> On Thu, Aug 11, 2011 at 1:28 PM, Paul Bolle <pebolle@tiscali.nl> wrote: >>> On Thu, 2011-08-11 at 10:53 +0200, Corentin Chary wrote: >>>> +try_decompress() >>>> +{ >>>> + for pos in `tr "$1\n$2" "\n$2=" < "$img" | grep -abo "^$2"` >>>> + do >>>> + pos=${pos%%:*} >>>> + tail -c+$pos "$img" | $3 > $tmp 2> /dev/null >>> >>> Perhaps a few comments on the above lines would be nice. Without those >>> comments I must guess you're finding compressed data somewhere in the >>> input file. It also seems you're looping through the entire input file. >>> Or are (sequences of) commands like the above considered obvious? >> >> It's copied from extract-ikconfig, there was no comment in it, so I >> assumed it's obvious. >> Basically it uses brute force (tm) to find well known headers and try >> to decompress from here. > > And explanation of the "tr" trick would not hurt though. It replaces the > binary magic with an ascii sequence on a new line (for older grep > versions to get it right) and tries all occurrences of that sequence, am > I right? But I wouldn't call it "obvious" :).
It's that commented in the header of both scripts ? (I can move down the command if wanted)
> >>>> +# That didn't work, so retry after decompression. >>>> +try_decompress '\037\213\010' xy gunzip >>>> +try_decompress '\3757zXZ\000' abcde unxz >>>> +try_decompress 'BZh' xy bunzip2 >>>> +try_decompress '\135\0\0\0' xxx unlzma >>>> +try_decompress '\211\114\132' xy 'lzop -d' >>> >>> Perhaps you could first test whether these commands are available before >>> running try_decompress() with them? >> >> Same as before, if it's ok for extract-ikconfig not to check the >> command, then it's ok for me. >> If it's not, then we should patch both. > > Also, if you have lzma to build a lzma-compressed kernel, then you very > likely also have unlzma. > > Michal >
-- Corentin Chary http://xf.iksaif.net -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |