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Date: Thu, 23 May 2019 11:17:45 +0800
From: Dave Young <dyoung@redhat.com>
Subject: Re: [PATCH v2 3/4] x86: Always try to fill acpi_rsdp_addr in boot
 params
Message-ID: <20190523031745.GC8174@dhcp-128-65.nay.redhat.com>
References: <20190514050959.21093-1-kasong@redhat.com>
 <20190514050959.21093-4-kasong@redhat.com>
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To: Kairui Song <kasong@redhat.com>
Cc: Simon Horman <horms@verge.net.au>, kexec@lists.infradead.org, Lianbo Jiang <lijiang@redhat.com>, Baoquan He <bhe@redhat.com>

On 05/14/19 at 01:09pm, Kairui Song wrote:
> Since kernel commit e6e094e053af75 ("x86/acpi, x86/boot: Take RSDP address
> from boot params if available"), kernel accept an acpi_rsdp_addr param in
> boot_params. So fill in this parameter unconditionally, ensure second
> kernel always get the right RSDP address consistently, and boot well on
> EFI system even with EFI service disabled. User no longer need to change
> the kernel cmdline to workaround the missing RSDP issue.
> 
> For older version of kernels (Before 5.0), there won't be any change of
> behavior.
> 
> Signed-off-by: Kairui Song <kasong@redhat.com>
> ---
>  kexec/arch/i386/x86-linux-setup.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/kexec/arch/i386/x86-linux-setup.c b/kexec/arch/i386/x86-linux-setup.c
> index 5ca7c25..5b00b42 100644
> --- a/kexec/arch/i386/x86-linux-setup.c
> +++ b/kexec/arch/i386/x86-linux-setup.c
> @@ -901,4 +901,7 @@ void setup_linux_system_parameters(struct kexec_info *info,
>  
>  	/* fill the EDD information */
>  	setup_edd_info(real_mode);
> +
> +	/* Always try to fill acpi_rsdp_addr */
> +	real_mode->acpi_rsdp_addr = get_acpi_rsdp();
>  }
> -- 
> 2.20.1
> 
> 
> _______________________________________________
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> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec

Seems no better way to check old kernel, then go with this way looks
acceptable.

Thanks
Dave

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