mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Ard Biesheuvel <ardb@kernel.org>
To: linux-efi@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, Ard Biesheuvel <ardb@kernel.org>,
	Vincent Mailhol <mailhol@kernel.org>,
	x86@kernel.org
Subject: [PATCH 0/7] efi/libstub: Avoid UTF-16 conversion busywork
Date: Sun,  6 Sep 2026 15:08:18 +0200	[thread overview]
Message-ID: <20260906130817.1151961-9-ardb@kernel.org> (raw)

The EFI libstub performs some redundant conversions between UTF-16 and
UTF-8 and back again, which includes dealing with surrogate pairs, which
UEFI implementations themselves simply ignore.

So drop all the homegrown code, and use the existing UCS-2 (== UTF-16
without surrogate pairs) library code where conversion to UTF-8 is
actually needed (the kernel command line).

The remaining handling involves the EFI console, which supports wide
characters natively, so just use those directly.

Cc: Vincent Mailhol <mailhol@kernel.org>
Cc: x86@kernel.org

Ard Biesheuvel (7):
  x86/boot: Drop pointless re-implementation of panic()
  lib/ucs2_string: Avoid WARN in library code
  efi/libstub: Use ucs2_string library for UTF-16 to UTF-8 conversion
  efi/libstub: Avoid efi_puts() for compile time constant strings
  efi/libstub: Output UTF-16 directly from vsnprintf()
  efi/libstub: Add support for printing human readable GUIDs
  efi/libstub: Add efi_snprintf() to construct wide strings

 arch/x86/boot/compressed/error.c               |  19 ---
 arch/x86/boot/compressed/error.h               |   1 -
 arch/x86/boot/compressed/mem.c                 |   2 +-
 drivers/firmware/efi/libstub/Makefile          |   3 +-
 drivers/firmware/efi/libstub/efi-stub-helper.c |  59 +++-----
 drivers/firmware/efi/libstub/efistub.h         |   6 +-
 drivers/firmware/efi/libstub/gop.c             |   6 +-
 drivers/firmware/efi/libstub/printk.c          |  93 ++----------
 drivers/firmware/efi/libstub/vsprintf.c        | 148 +++++++-------------
 lib/ucs2_string.c                              |   2 +-
 10 files changed, 87 insertions(+), 252 deletions(-)

-- 
2.47.3


             reply	other threads:[~2026-09-06 13:08 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-06 13:08 Ard Biesheuvel [this message]
2026-09-06 13:08 ` [PATCH 1/7] x86/boot: Drop pointless re-implementation of panic() Ard Biesheuvel
2026-09-06 13:08 ` [PATCH 2/7] lib/ucs2_string: Avoid WARN in library code Ard Biesheuvel
2026-09-06 13:08 ` [PATCH 3/7] efi/libstub: Use ucs2_string library for UTF-16 to UTF-8 conversion Ard Biesheuvel
2026-09-06 13:08 ` [PATCH 4/7] efi/libstub: Avoid efi_puts() for compile time constant strings Ard Biesheuvel
2026-09-06 13:08 ` [PATCH 5/7] efi/libstub: Output UTF-16 directly from vsnprintf() Ard Biesheuvel
2026-09-09 12:46   ` David Laight
2026-09-06 13:08 ` [PATCH 6/7] efi/libstub: Add support for printing human readable GUIDs Ard Biesheuvel
2026-09-06 13:08 ` [PATCH 7/7] efi/libstub: Add efi_snprintf() to construct wide strings Ard Biesheuvel
2026-09-06 22:14 ` [PATCH 0/7] efi/libstub: Avoid UTF-16 conversion busywork Vincent Mailhol
2026-09-08 17:24 ` [PATCH] efi: pass NUL-inclusive sizes to ucs2_as_utf8() Vincent Mailhol
2026-09-09 11:38   ` Ard Biesheuvel

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=20260906130817.1151961-9-ardb@kernel.org \
    --to=ardb@kernel.org \
    --cc=linux-efi@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mailhol@kernel.org \
    --cc=x86@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

all inboxes | Powered by JetHome®