From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: Dmitry Osipenko <digetx@gmail.com>
Cc: "Jens Axboe" <axboe@kernel.dk>,
"Davidlohr Bueso" <dave@stgolabs.net>,
"Colin Cross" <ccross@android.com>,
"Thierry Reding" <thierry.reding@gmail.com>,
"Jonathan Hunter" <jonathanh@nvidia.com>,
"Michał Mirosław" <mirq-linux@rere.qmqm.pl>,
"David Heidelberg" <david@ixit.cz>,
"Peter Geis" <pgwipeout@gmail.com>,
linux-efi <linux-efi@vger.kernel.org>,
linux-tegra@vger.kernel.org, linux-block@vger.kernel.org,
"Linux Doc Mailing List" <linux-doc@vger.kernel.org>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v1] partitions/efi: Add 'gpt_sector' kernel cmdline parameter
Date: Wed, 19 Feb 2020 17:26:57 +0100 [thread overview]
Message-ID: <CAKv+Gu9vOh5vmHTGLYA9nszQfGq-yMRPvyYUhSzwcYJD+ZYKHA@mail.gmail.com> (raw)
In-Reply-To: <20200219162339.16192-1-digetx@gmail.com>
On Wed, 19 Feb 2020 at 17:25, Dmitry Osipenko <digetx@gmail.com> wrote:
>
> The gpt_sector=<sector> causes the GPT partition search to look at the
> specified sector for a valid GPT header if the GPT is not found at the
> beginning or the end of block device.
>
> In particular this is needed for NVIDIA Tegra consumer-grade Android
> devices in order to make them usable with the upstream kernel because
> these devices use a proprietary / closed-source partition table format
> for the EMMC and it's impossible to change the partition's format. Luckily
> there is a GPT table in addition to the proprietary table, which is placed
> in uncommon location of the EMMC storage and bootloader passes the
> location to kernel using "gpt gpt_sector=<sector>" cmdline parameters.
>
> This patch is based on the original work done by Colin Cross for the
> downstream Android kernel.
>
> Cc: Colin Cross <ccross@android.com>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Which block device is this parameter applied to?
> ---
> Documentation/admin-guide/kernel-parameters.txt | 5 +++++
> block/partitions/efi.c | 15 +++++++++++++++
> 2 files changed, 20 insertions(+)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 50138e6826a1..ee4781daa379 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -1382,6 +1382,11 @@
> primary GPT is corrupted, it enables the backup/alternate
> GPT to be used instead.
>
> + gpt_sector [EFI] Forces GPT partition search to look at the
> + specified sector for a valid GPT header if the GPT is
> + not found at the beginning or the end of the block
> + device.
> +
> grcan.enable0= [HW] Configuration of physical interface 0. Determines
> the "Enable 0" bit of the configuration register.
> Format: 0 | 1
> diff --git a/block/partitions/efi.c b/block/partitions/efi.c
> index db2fef7dfc47..0c8926d76d7a 100644
> --- a/block/partitions/efi.c
> +++ b/block/partitions/efi.c
> @@ -103,6 +103,17 @@ force_gpt_fn(char *str)
> }
> __setup("gpt", force_gpt_fn);
>
> +/* This allows a kernel command line option 'gpt_sector=<sector>' to
> + * enable GPT header lookup at a non-standard location.
> + */
> +static u64 force_gpt_sector;
> +static int __init
> +force_gpt_sector_fn(char *str)
> +{
> + WARN_ON(kstrtoull(str, 10, &force_gpt_sector) < 0);
> + return 1;
> +}
> +__setup("gpt_sector=", force_gpt_sector_fn);
>
> /**
> * efi_crc32() - EFI version of crc32 function
> @@ -621,6 +632,10 @@ static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt,
> if (!good_agpt && force_gpt)
> good_agpt = is_gpt_valid(state, lastlba, &agpt, &aptes);
>
> + if (!good_agpt && force_gpt && force_gpt_sector)
> + good_agpt = is_gpt_valid(state, force_gpt_sector,
> + &agpt, &aptes);
> +
> /* The obviously unsuccessful case */
> if (!good_pgpt && !good_agpt)
> goto fail;
> --
> 2.24.0
>
next prev parent reply other threads:[~2020-02-19 16:27 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-19 16:23 [PATCH v1] partitions/efi: Add 'gpt_sector' kernel cmdline parameter Dmitry Osipenko
2020-02-19 16:26 ` Ard Biesheuvel [this message]
2020-02-19 16:36 ` Dmitry Osipenko
2020-02-19 16:27 ` Christoph Hellwig
2020-02-19 16:38 ` Dmitry Osipenko
2020-02-19 16:59 ` Stephen Warren
2020-02-19 17:44 ` Dmitry Osipenko
2020-02-24 16:33 ` Karel Zak
2020-02-24 17:23 ` Dmitry Osipenko
2020-02-24 18:22 ` Dmitry Osipenko
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=CAKv+Gu9vOh5vmHTGLYA9nszQfGq-yMRPvyYUhSzwcYJD+ZYKHA@mail.gmail.com \
--to=ard.biesheuvel@linaro.org \
--cc=axboe@kernel.dk \
--cc=ccross@android.com \
--cc=dave@stgolabs.net \
--cc=david@ixit.cz \
--cc=digetx@gmail.com \
--cc=jonathanh@nvidia.com \
--cc=linux-block@vger.kernel.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-efi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tegra@vger.kernel.org \
--cc=mirq-linux@rere.qmqm.pl \
--cc=pgwipeout@gmail.com \
--cc=thierry.reding@gmail.com \
/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 NNTP newsgroup(s).