From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-io1-f68.google.com ([209.85.166.68]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hC6kF-0001sp-R2 for kexec@lists.infradead.org; Thu, 04 Apr 2019 18:05:49 +0000 Received: by mail-io1-f68.google.com with SMTP id s7so2759188iom.12 for ; Thu, 04 Apr 2019 11:05:46 -0700 (PDT) MIME-Version: 1.0 References: <20190328094910.12368-1-kasong@redhat.com> <20190404072529.GB5708@dhcp-128-65.nay.redhat.com> In-Reply-To: <20190404072529.GB5708@dhcp-128-65.nay.redhat.com> From: Kairui Song Date: Fri, 5 Apr 2019 02:05:33 +0800 Message-ID: Subject: Re: [PATCH] x86: Always to to fill acpi_rsdp_addr in boot params List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Dave Young Cc: Simon Horman , kexec@lists.infradead.org, Lianbo Jiang , Baoquan He On Thu, Apr 4, 2019 at 3:25 PM Dave Young wrote: > > Hello Kairui > On 03/28/19 at 05:49pm, Kairui Song wrote: > > Since kernel commit e6e094e053af75 ("x86/acpi, x86/boot: Take RSDP address > > from boot params if available"), kernel accept a acpi_rsdp_addr param in > > boot_params. Sync the x86_linux_param_header to support this param. > > > > And previously we are already appending 'acpi_rsdp=' command line only for > > loading crash kernel on EFI systems, it will be better to try to set the > > boot param for any kernel get loaded, to help the kernel finding the > > RSDP value more stably. Otherwise if the user decide to disable EFI > > service in second kernel, it will fail to boot. > > > > There is no better way to find the RSDP address from legacy BIOS > > interface rather than scanning the memory region and search for it, > > which will always be done by the kernel as a fallback, so we only > > look for RSDP in previous boot params, cmdline and EFI firmware. > > It would be good to always pass acpi_rsdp= kernel cmdline in case > efi=old_map. (or maybe efi=noruntime as well, but I did not remember > the behavior of noruntime now), no matter kexec or kdump.. > > And if you want, maybe fill the boot_params instead of passing cmdline > for new kernel which supports the new boot_param field. > > Split the patch to small patches would be better. > > Thanks > Dave Thanks for the review! I'll update in V2 accordingly. -- Best Regards, Kairui Song _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec