From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B838C10F9 for ; Tue, 20 Sep 2022 08:04:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6EDD7C433D7 for ; Tue, 20 Sep 2022 08:04:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663661076; bh=KCb3KEV2j4i/ljqBhx3p+EKW0P16iJioNTv+YaHNaxk=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=p9LFQy/qsYFcpYBWeeDENuNKn7QlrBE05JCykz4R5cSh4Tc3iY74O7S7oa5iWKJpx hPQk4f//K2sKNZ+OU3hmTmcWB0YZI2V1qVBQxeF4xkZS7Bqz6K4Ubh9OTtQJUk2G4p BAiQ1Pm8hNHkPYrrkhU1yH73wZ7W6kVnFWuS07zR9DJJ+LJBIiF+FFguOEtECWO5Wi RrRHqt/4oEHr46DwgBU/+8Mx+0tM/VrN9P0/A9z7iPIMs6ex5zOHQeM8RMTey1lLo5 ztSHb8fwIiCe8JaZ9q7qSxAYS7wpoKeRp8bWcsgp7G2FwHEQU8OUzopRP8Ufx80O9b JQ/V5HIaWySPQ== Received: by mail-lj1-f177.google.com with SMTP id h3so2055807lja.1 for ; Tue, 20 Sep 2022 01:04:36 -0700 (PDT) X-Gm-Message-State: ACrzQf1yf+v33FyiyJWGnLZoTD5PAs6dyWDERenkb9Btr5ndXrm9SYBx NKsDjBtqYigi2D46mSuEzb8CdS5z41u5OTS5Uhg= X-Google-Smtp-Source: AMsMyM7k9Pb9mha5f41WT9b5l2xpREI+WwxzNzEyuW893eaJq99Bu2knRtri7AWvesiLGmewM0U7wAHaRxSBtFbMbBY= X-Received: by 2002:a2e:7314:0:b0:26a:ca18:60eb with SMTP id o20-20020a2e7314000000b0026aca1860ebmr6036923ljc.69.1663661074420; Tue, 20 Sep 2022 01:04:34 -0700 (PDT) Precedence: bulk X-Mailing-List: loongarch@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20220918213544.2176249-1-ardb@kernel.org> <20220918213544.2176249-12-ardb@kernel.org> In-Reply-To: From: Ard Biesheuvel Date: Tue, 20 Sep 2022 10:04:22 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 11/12] efi/loongarch: libstub: remove dependency on flattened DT To: Huacai Chen Cc: linux-efi , loongarch@lists.linux.dev, "Russell King (Oracle)" , Arnd Bergmann , Ilias Apalodimas , Huacai Chen , Xi Ruoyao Content-Type: text/plain; charset="UTF-8" On Tue, 20 Sept 2022 at 03:45, Huacai Chen wrote: > > Hi, Ard, > ... > I'm very sorry, after an offline discussion with my colleagues, > non-EFI DT boot is still needed (very sadly, we want to drop non-EFI > firmware but we can't do that). However, for non-EFI DT boot we will > use the same parameter passing method (a0=efi boot flag, a1=cmdline, > a2=systemtable), firmware will generate a simple systemtable only for > DT. In this way all boot methods share the same logic, and also make > kexec easy to implement. > OK, that should work. So I suppose you create a EFI system table along with EFI configuration tables for DT, SMBIOS, etc? In this case, I suggest you omit the MEMMAP config table that I am adding here, so that there is no ambiguity between the EFI provided memory map and the one provided by DT. I think that should be a clean way to implement this. > So, let's make a0 the real "efi boot flag" and let it control > EFI_BOOT, for efistub, we can just pass "true" unconditionally > (whether support efi_novamap is not as important as the efi boot flag > for us, as you said, efi_novamap is just for broken firmware). Indeed. So as before, I will just set efi_novamap to false. You can still use noefi or efi=noruntime to turn off the EFI runtime pieces if needed (e.g., PREEMPT_RT tends to disable those by default to preserve their bounded worst case latency)