Re: [PATCH] initramfs: Expose retained initrd as sysfs file

[Alexander Graf <graf@amazon.com>]

On 06.12.23 21:00, Andrew Morton wrote:
> On Wed, 6 Dec 2023 14:16:27 +0000 Alexander Graf <graf@amazon.com> wrote:
>
>> When the kernel command line option "retain_initrd" is set, we do not
>> free the initrd memory. However, we also don't expose it to anyone for
>> consumption. That leaves us in a weird situation where the only user of
>> this feature is ppc64 and arm64 specific kexec tooling.
>>
>> To make it more generally useful, this patch adds a kobject to the
>> firmware object that contains the initrd context when "retain_initrd"
>> is set. That way, we can access the initrd any time after boot from
>> user space and for example hand it into kexec as --initrd parameter
>> if we want to reboot the same initrd. Or inspect it directly locally.
> I think it would be helpful if the changelog were mention and describe
> the new /sys/firmware/initrd.  And I assume we should add a
> Documentation/ABI/testing/sysfs-firmware-initrd.


Thanks a bunch for the suggestions - let me send v2 with both addressed :)

Alex




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