Re: [PATCH 0/4] kexec-tools RISC-V port

[Simon Horman <horms@kernel.org>]

On Wed, Apr 09, 2025 at 10:14:22PM +0200, Björn Töpel wrote:
> From: Björn Töpel <bjorn@rivosinc.com>
> 
> Hi!
> 
> This is an attempt to finally get the RISC-V patches for kexec-tools
> upstream.
> 
> Simon suggested in [1] that:
> 
> > In my mind the big question is how to move RISC-V support from that
> > branch, to being merged into main.
> >
> > IIRC there were some issues that needed to be addressed. Perhaps they
> > are all addressed by this series, and with some appropriate squashing
> > we can move forwards with a series based on main?
> 
> I talked to Nick last week, and he suggested that we'd work the RISC-V
> collab Github [2], but I think it's just easier to do it on the list.
> 
> I've been collecting a number of different trees out there, and tried
> to group them in a series.
> 
> Given that there is not support for RISC-V upstream yet, I didn't see
> the need to carry all the fixes/updates ("development history") as
> separate commits -- it doesn't help bugtracking/bisectability.

Thanks Björn,

I haven't looked over the patches yet.
But in principle I agree with this approach.

> 
> Instead the first commit message is a big one, and tries to give
> attribution to all involved parties. Input/thoughts are very much
> welcome!
> 
> To properly test this on RISC-V, the upstream Linux kernel has most
> things in 6.15-rc1, e.g.:
> commit 28093cfef5dd ("riscv/kexec_file: Handle R_RISCV_64 in purgatory relocator")
> commit 3f7023171df4 ("riscv/purgatory: 4B align purgatory_start")
> 
> To cross-build kexec-tools:
>   | ./bootstrap 
>   | ./configure --host=riscv64-linux-gnu
>   | make
> 
> For some tests, additional kernel patches are needed, that as of today
> is not in 6.15-rc1:
>  * To test "kexec -s -l Image", kexec_file_load with Image support is
>    needed [3]
>  * To test "kexec -c -l vmlinux" with CONFIG_RELOCATABLE, a kbuild fix
>    is needed [4]
>  * Typically if you load initrd, or a large kernel [5] (since a bunch
>    of Reserved regions are not properly exposed).
> 
> I've tested combinations with crashkernel (-p), and regular (-c/-s + -e) for:
>  * ACPI/UEFI
>  * DT/UEFI
>  * DT
>  * w/ initrd
>  * w/o initrd
>  * ELF (userland loader + kexec_load, and kexec_file_load)
>  * Image (userland loader + kexec_load, and kexec_file_load)
> 
> I'm sure there are combinations I've missed, but at least from my POV
> we're in a pretty good shape.
> 
> All authors: Please let me know if you prefer another split of the
> patches. Or something else for that matter! ;-)
> 
> 
> Let's get the ball rolling!
> Björn

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