From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Francesco Valla <francesco@valla.it>
Cc: linux-embedded@vger.kernel.org
Subject: Re: [RFC PATCH 0/1] Add driver for bootstage stash
Date: Fri, 23 May 2025 09:04:48 +0200 [thread overview]
Message-ID: <CAMuHMdXqw9igYU-iPFbA-uP8-LrmZocUKT4k9cb8+py1gFp8tA@mail.gmail.com> (raw)
In-Reply-To: <20250522224223.358881-2-francesco@valla.it>
Hi Francesco,
On Fri, 23 May 2025 at 02:25, Francesco Valla <francesco@valla.it> wrote:
> after the discussion on the "Unified Boot Log" topic during the latest
> Boot Time SIG special meeting [1], I tried to mock up a driver that
> reads a bootstage stash saved by the U-Boot bootloader in a given memory
> area and exposes the data in a user- and machine- friendly through both
> sysfs and debugfs attributes. Details on the interfaces, as well as
> example output for the debugfs interfaces, can be found on the
> documentation that is part of the patchset.
Thanks for your work!
> To use this driver, a memory area shall be reserved inside the Linux
> kernel devicetree as follows (possibly changing the address and the size
> of the memory area):
>
> bootstage@a4300000 {
> compatible = "bootstage";
> reg = <0 0xa4300000 0 0x1000>;
> no-map;
> };
>
> At U-Boot side, following configuration shall then be set:
>
> CONFIG_BOOTSTAGE=y
> CONFIG_BOOTSTAGE_STASH_ADDR=0xa4300000
> CONFIG_BOOTSTAGE_STASH_SIZE=0x1000
I think this can be simplified further, using either of these two options:
1. If the bootstage@a4300000 node would already be present in the
DTB used by U-Boot, the two CONFIG_BOOTSTAGE_STASH_*
options would no longer be needed.
2. U-Boot could add the bootstage@a4300000 to the DTB that is
passed to the kernel, just like it already adds/updates the memory
nodes.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
next prev parent reply other threads:[~2025-05-23 7:05 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-22 22:42 [RFC PATCH 0/1] Add driver for bootstage stash Francesco Valla
2025-05-22 22:42 ` [PATCH 1/1] drivers: misc: add " Francesco Valla
2025-05-23 6:29 ` Krzysztof Kozlowski
2025-05-23 19:34 ` Rob Landley
2025-05-24 6:16 ` Krzysztof Kozlowski
2025-05-23 19:43 ` Francesco Valla
2025-05-24 6:15 ` Krzysztof Kozlowski
2025-05-23 23:43 ` Bird, Tim
2025-05-24 7:18 ` kernel test robot
2025-05-23 7:04 ` Geert Uytterhoeven [this message]
2025-05-23 20:06 ` [RFC PATCH 0/1] Add " Francesco Valla
[not found] ` <PA4PR08MB604681FF6392B25A19926A11ED98A@PA4PR08MB6046.eurprd08.prod.outlook.com>
2025-05-23 7:34 ` Federico Giovanardi
2025-05-23 19:43 ` Rob Landley
2025-05-23 20:11 ` Francesco Valla
2025-05-24 0:07 ` Bird, Tim
2025-05-24 0:28 ` Bird, Tim
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=CAMuHMdXqw9igYU-iPFbA-uP8-LrmZocUKT4k9cb8+py1gFp8tA@mail.gmail.com \
--to=geert@linux-m68k.org \
--cc=francesco@valla.it \
--cc=linux-embedded@vger.kernel.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;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).