From: Russell King - ARM Linux admin <linux@armlinux.org.uk>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: Linus Walleij <linus.walleij@linaro.org>,
linux-efi@vger.kernel.org,
Geert Uytterhoeven <geert+renesas@glider.be>,
linux-arm-kernel@lists.infradead.org,
Nicolas Pitre <nico@fluxnic.net>
Subject: Re: [PATCH v2 0/5] ARM: simplify handover from UEFI to decompressor
Date: Mon, 13 Apr 2020 17:41:30 +0100 [thread overview]
Message-ID: <20200413164130.GP25745@shell.armlinux.org.uk> (raw)
In-Reply-To: <20200413162135.14955-1-ardb@kernel.org>
On Mon, Apr 13, 2020 at 06:21:30PM +0200, Ard Biesheuvel wrote:
> The EFI stub in the ARM kernel runs in the context of the firmware, which
> means it runs with the caches and MMU on. Currently, we relocate the zImage
> so it appears in the first 128 MiB, disable the MMU and caches and invoke
> the decompressor via its ordinary entry point. However, since we can pass
> the base of DRAM directly, there is no need to relocate the zImage, which
> also means there is no need to disable and re-enable the caches and create
> new page tables etc.
>
> This simplification is implemented by patch #5. Patches #1 - #4 are
> prerequisite changes to permit the decompressor to execute from the
> offset chosen by the UEFI firmware.
Why? The decompressor is already fully relocatable, so this doesn't
explain why all these changes breaking up the single place where data
is stored into multiple smaller pieces, making the code more complex
is really necessary. To me, this seems ot be change for change sake.
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 10.2Mbps down 587kbps up
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-04-13 16:42 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-13 16:21 [PATCH v2 0/5] ARM: simplify handover from UEFI to decompressor Ard Biesheuvel
2020-04-13 16:21 ` [PATCH v2 1/5] ARM: decompressor: move headroom variable out of LC0 Ard Biesheuvel
2020-04-13 16:21 ` [PATCH v2 2/5] ARM: decompressor: split off _edata and stack base into separate object Ard Biesheuvel
2020-04-13 16:21 ` [PATCH v2 3/5] ARM: decompressor: defer loading of the contents of the LC0 structure Ard Biesheuvel
2020-04-13 16:21 ` [PATCH v2 4/5] ARM: decompressor: move GOT into .data for EFI enabled builds Ard Biesheuvel
2020-04-13 16:21 ` [PATCH v2 5/5] ARM: decompressor: run decompressor in place if loaded via UEFI Ard Biesheuvel
2020-04-13 16:41 ` Russell King - ARM Linux admin [this message]
2020-04-13 16:47 ` [PATCH v2 0/5] ARM: simplify handover from UEFI to decompressor Ard Biesheuvel
2020-04-13 16:56 ` Nicolas Pitre
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=20200413164130.GP25745@shell.armlinux.org.uk \
--to=linux@armlinux.org.uk \
--cc=ardb@kernel.org \
--cc=geert+renesas@glider.be \
--cc=linus.walleij@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-efi@vger.kernel.org \
--cc=nico@fluxnic.net \
/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).