From: Sascha Hauer <s.hauer@pengutronix.de>
To: Antony Pavlov <antonynpavlov@gmail.com>
Cc: barebox@lists.infradead.org
Subject: Re: picopng does not support big-endian CPUs
Date: Mon, 26 Jan 2015 08:58:25 +0100 [thread overview]
Message-ID: <20150126075825.GG12209@pengutronix.de> (raw)
In-Reply-To: <20150125222629.c52501c7d776cabf4317c82f@gmail.com>
On Sun, Jan 25, 2015 at 10:26:29PM +0400, Antony Pavlov wrote:
> Hi All!
>
> Current lib/gui/picopng.c has problems on big-endian CPUs.
>
> Here are two examples from PNG_readPngHeader():
>
> if (*(uint64_t *) in != PNG_SIGNATURE) {
> ...
> if (*(uint32_t *) &in[12] != CHUNK_IHDR) {
>
>
> Using memcmp in this situation is much better, e.g.
>
> + uint8_t png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
> ...
> + if (memcmp(in, png_signature, 8)) {
>
>
> + uint8_t chunk_header[4] = {0x49, 0x48, 0x44, 0x52};
> ...
> + if (memcmp(&in[12], chunk_header, 4)) {
>
>
> Current lodepng works fine on big-endian, but can we disable picopng
> in Kconfig for big-endian CPUs?
Can't we just fix it? Are there more difficult places than the ones
above? If it turns out to be difficult I'm fine with adding a dependency
to CPU_BIG_ENDIAN.
Sascha
--
Pengutronix e.K. | |
Industrial Linux Solutions | http://www.pengutronix.de/ |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox
next prev parent reply other threads:[~2015-01-26 7:58 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-25 18:26 Antony Pavlov
2015-01-26 7:58 ` Sascha Hauer [this message]
2015-01-26 9:06 ` Jean-Christophe PLAGNIOL-VILLARD
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20150126075825.GG12209@pengutronix.de \
--to=s.hauer@pengutronix.de \
--cc=antonynpavlov@gmail.com \
--cc=barebox@lists.infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox