From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Mon, 08 Jan 2024 08:23:45 +0100 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1rMjz7-008Vjc-23 for lore@lore.pengutronix.de; Mon, 08 Jan 2024 08:23:45 +0100 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1rMjz6-0004n7-RM for lore@pengutronix.de; Mon, 08 Jan 2024 08:23:45 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Cc:Content-ID:Content-Description:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=BgoMokpb/HRpZ67ZdqFWCQPfB47+3mag1I6xm4Vls+Y=; b=o5rCffqkj8VllTmO8mq8BSvchs sosdt86GiIETQg9F/qCWl3v6Jk2x3uVQnp7Vk/QJSdhrF4uZthtWXNNs4oWV4A8qmDXGnuUhltOaN 2QbuCk21OnKDO26VNlB1bJ8bsIGDx1MgLkERj3sXgvlzET5L2zsTisdw1yHOSce3RNHRYKU4pHmzr JWOFhZTNfvEOWy/xt+u9cn1VQ7r9ALb+Rnj4sDtfJ+QQgm7UV52X9MIPqQF6/kDcxEYSbvhmMRb/x gsJngUlvuAGBYN69KS7wkqQNi1TpX9T3+xNL12xscjfXkaJNNfI4sfsnE7h1DFFzINDwufai1nbDu o3EZSe/g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rMjy1-004AFm-1L; Mon, 08 Jan 2024 07:22:37 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1rMjxx-004AF4-0Q for barebox@lists.infradead.org; Mon, 08 Jan 2024 07:22:35 +0000 Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=[127.0.0.1]) by metis.whiteo.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1rMjxv-0004cm-Up for barebox@lists.infradead.org; Mon, 08 Jan 2024 08:22:32 +0100 Message-ID: Date: Mon, 8 Jan 2024 08:22:31 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: en-US To: barebox@lists.infradead.org References: <20240103181312.409668-1-a.fatoum@pengutronix.de> <20240103181312.409668-60-a.fatoum@pengutronix.de> <3c4fc4ee-a4fe-44e5-a4c5-7a8f086a1124@pengutronix.de> From: Ahmad Fatoum In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240107_232233_324788_AEB5BC72 X-CRM114-Status: GOOD ( 39.48 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-6.2 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE, T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH 059/112] efi: payload: init: restrict barebox mem to first 1G only on x86 X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) On 05.01.24 15:58, Michael Olbrich wrote: > On Fri, Jan 05, 2024 at 11:41:09AM +0100, Ahmad Fatoum wrote: >> On 05.01.24 10:31, Michael Olbrich wrote: >>> On Fri, Jan 05, 2024 at 10:14:33AM +0100, Ahmad Fatoum wrote: >>>> On 04.01.24 19:10, Michael Olbrich wrote: >>>>> On Thu, Jan 04, 2024 at 12:17:12PM +0100, Ahmad Fatoum wrote: >>>>>> On 03.01.24 19:58, Michael Olbrich wrote: >>>>>>> On Wed, Jan 03, 2024 at 07:12:19PM +0100, Ahmad Fatoum wrote: >>>>>>>> When run as EFI payload, barebox will not have full access to DRAM and will >>>>>>>> have to ask the EFI firmware for memory. It does so once at the beginning >>>>>>>> and since commit 356aaef5a37d ("efi: improve malloc pool allocation"), >>>>>>>> the buffer was always placed beneath the 1G boundary. >>>>>>>> >>>>>>>> Aforementioned commit didn't elaborate why a maximum of 1G in particular >>>>>>>> was chosen. Anyways, non-PC architectures have different memory maps, so >>>>>>>> a 1G limit doesn't make sense there. Therefore restrict the limit to >>>>>>>> ARCH_X86. On non-x86, we allow the memory pages to be located anywhere. >>>>>>> >>>>>>> The 1G is somewhat arbitrary but if you don't restrict the memory to 32bit, >>>>>>> then loading the kernel may fail: The addresses in "struct >>>>>>> linux_kernel_header" are only 32bit. So if you impose no restrictions at >>>>>>> all, then this memory cannot be used for the kernel and initrd. >>>>>> >>>>>> The limit for x86 remains at 1G. It's only for other architectures, that we >>>>>> remove the limit. I suspect that other architectures won't have this kind >>>>>> of problems though , because they would boot the kernel image via EFI load >>>>>> and start image boot services, where the EFI firmware takes care to layout >>>>>> the boot artifacts. >>>>>> >>>>>> Once we have that in place, we could even use it on x86 instead of >>>>>> using struct linux_kernel_header, but I haven't investigated this yet. >>>>> >>>>> How do you load the initrd via EFI? As far as I know, that only works as a >>>>> filename in the EFI boot partition. >>>> >>>> This seems to be relaxed in newer kernels, see >>>> https://lore.kernel.org/linux-efi/20200207202637.GA3464906@rani.riverdale.lan/T/ >>> >>> It's not quite clear to me how that works, but from what I can tell, >>> requires support from the firmware and barebox needs to use it. So that >>> does not help here. >>> You need to either disable the legacy handler to avoid arbitrary failures >>> or explicitly allocate the initrd memory from efi with the restriction to >>> <4G. >> >> The legacy handler wouldn't apply to other architectures: >> >> - The Kernel images for ARM64 and RISC-V have different more-specific filetypes >> than filetype_exe > > Ah, now I get it. I forgot that that code is x86 specific. So how do you > boot Linux from EFI anyways on other architectures? We don't yet. > I don't see any filetypes for EFI binaries for other architectures. I'm not > sure how that works but would expect to find some code that hands over > efi_sys_table? Or what am I missing? Only binfmt handler is registered for normal EFI start. initrd/DT will have to follow later. > And if you boot a non-EFI binary shouldn't you call RS->exit_boot_services() > before actually starting the kernel? Possibly. I remember that booting a kernel without EFI stub failed, but haven't investigated why this was the case. > And we should move setting LoaderTimeExecUSec into some kind of barebox > shutdown handler to ensure that it is set even if other bootm handlers are > used. But that's all unrelated to this patch. Yes. I'll keep that in mind for when the bootm handler is added. Thanks, Ahmad > > Regards, > Michael > >> - The Linux kernel header check will probabaly fail for every format that's not >> x86 >> >> Cheers, >> Ahmad >> >>> >>> Michael >>> >>>>> That was the reason for implementing >>>>> the "legacy" boot mode. And what about the device-tree? >>>> >>>> There is an EFI config table for FDT (DEVICE_TREE_GUID in Linux code). barebox >>>> as EFI loader can use it to provide its own DT. I have to check what's the cleanest >>>> way for barebox as EFI payload to provide a different DT, but I hope there is a way >>>> without barebox as EFI payload having to manipulate the device tree itself. >>>> >>>> Cheers, >>>> Ahmad >>>> >>>>> >>>>> Michael >>>>> >>>>>>>> This can break PCI drivers on systems that so far assumed barebox memory >>>>>>>> is located in the first 4G, but that's ok. That code will need to be >>>>>>>> fixed eventually anyway. >>>>>>>> >>>>>>>> Cc: Michael Olbrich >>>>>>>> Signed-off-by: Ahmad Fatoum >>>>>>>> --- >>>>>>>> efi/payload/init.c | 2 +- >>>>>>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>>>>> >>>>>>>> diff --git a/efi/payload/init.c b/efi/payload/init.c >>>>>>>> index 4b612e61afb3..0c2f38e9c86a 100644 >>>>>>>> --- a/efi/payload/init.c >>>>>>>> +++ b/efi/payload/init.c >>>>>>>> @@ -292,7 +292,7 @@ void efi_main(efi_handle_t image, struct efi_system_table *sys_table) >>>>>>>> BS->handle_protocol(efi_loaded_image->device_handle, >>>>>>>> &efi_device_path_protocol_guid, (void **)&efi_device_path); >>>>>>>> >>>>>>>> - mem = 0x3fffffff; >>>>>>>> + mem = IS_ENABLED(CONFIG_X86) ? 0x3fffffff : ~0ULL; >>>>>>>> for (memsize = SZ_256M; memsize >= SZ_8M; memsize /= 2) { >>>>>>>> efiret = BS->allocate_pages(EFI_ALLOCATE_MAX_ADDRESS, >>>>>>>> EFI_LOADER_DATA, >>>>>>>> -- >>>>>>>> 2.39.2 >>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>>> -- >>>>>> Pengutronix e.K. | | >>>>>> Steuerwalder Str. 21 | http://www.pengutronix.de/ | >>>>>> 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | >>>>>> Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | >>>>>> >>>>>> >>>>> >>>> >>>> -- >>>> Pengutronix e.K. | | >>>> Steuerwalder Str. 21 | http://www.pengutronix.de/ | >>>> 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | >>>> Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | >>>> >>>> >>> >> >> -- >> Pengutronix e.K. | | >> Steuerwalder Str. 21 | http://www.pengutronix.de/ | >> 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | >> Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | >> >> >> > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |