mail archive of the barebox mailing list
 help / color / mirror / Atom feed
From: Sascha Hauer <s.hauer@pengutronix.de>
To: Antony Pavlov <antonynpavlov@gmail.com>
Cc: barebox@lists.infradead.org
Subject: Re: [PATCH 0/5] MIPS: xburst: add initial JZ4770 SoC support
Date: Mon, 13 Apr 2015 10:02:55 +0200	[thread overview]
Message-ID: <20150413080255.GD9742@pengutronix.de> (raw)
In-Reply-To: <1428708181-12506-1-git-send-email-antonynpavlov@gmail.com>

Hi Antony,

On Sat, Apr 11, 2015 at 02:22:56AM +0300, Antony Pavlov wrote:
> This patchseries adds initial JZ4770 SoC and Ainol Novo7 Paladin tablet support.
> 
> The patchseries can be found on github:
>     https://github.com/frantony/barebox/tree/20150411.jz4770
> 
> The most notable problems and todos:
> 
>   * no PBL support; I have a PBL-enabled barebox version
>     for the tablet, so barebox can be used as only bootloader for tablet.
>     But this version is based on some dirty hacks
>     e.g. it uses special pre-compiled X-Boot blob for bootstraping.
> 
>     Nowadays barebox mips PBL is written in assembler
>     and I see no way to switch it to C. gcc-4.9.1 for mips has no __naked
>     directive support, see this gcc output
> 
>         $ cat > 1.c <<EOF;
>         int __attribute__((naked)) __attribute__((no_instrument_function)) main()
>         {
>         }
>         EOF
> 
>         $ /opt/mips-2014.11/bin/mips-linux-gnu-gcc -o 1.o 1.c
>         1.c:2:1: warning: 'naked' attribute directive ignored [-Wattributes]
>          {
>          ^
> 
>     So for moving X-Boot bootstrap C-code into barebox PBL we have to convert it
>     from C to assembler language :(

Is this really necessary? Only the entry point up to the point where you
setup the stack needs to be assembly, from then on C can be used.


> 
>     Please see JZ4770 bootstrap code in these repos:
> 
>         https://github.com/gcwnow/UBIBoot/
>         https://github.com/IngenicSemiconductor/X-BOOT_NPM801
> 
>   * no clk support just now; we can easely steal it from linux
>     JZ4780 support code (see wip-ci20-v4.1 branch in https://github.com/paulburton/linux);
> 
>   * no hardware clocksource support; this can be easely fixed,
>     see linux JZ4780 support code again;
>     also see https://github.com/frantony/barebox/blob/next.xburst.jz4770.20130511/arch/mips/mach-xburst/csrc-jz4770.c

Before merging this series I'd like to have clocksource support. Using
the dummy clocksource is fine during initial bringup, but I think merged
code should not depend on it.

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

      parent reply	other threads:[~2015-04-13  8:03 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-10 23:22 Antony Pavlov
2015-04-10 23:22 ` [PATCH 1/5] MIPS: xburst: add " Antony Pavlov
2015-04-10 23:22 ` [PATCH 2/5] MIPS: xburst: debug_ll: add JZ4770 support Antony Pavlov
2015-04-10 23:22 ` [PATCH 3/5] MIPS: xburst: add Ainol Novo7 Paladin support Antony Pavlov
2015-04-10 23:23 ` [PATCH 4/5] MIPS: add ainol-novo7-paladin_defconfig Antony Pavlov
2015-04-10 23:23 ` [PATCH 5/5] Documentation: add Ainol Novo7 Paladin board mini-howto Antony Pavlov
2015-04-13  8:02 ` Sascha Hauer [this message]

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=20150413080255.GD9742@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