Re: [PATCH V9 21/24] LoongArch: Add zboot (compressed kernel) support

[Russell King (Oracle)]

On Sun, May 01, 2022 at 01:22:25PM +0800, Huacai Chen wrote:
> Hi, Arnd,
> 
> On Sat, Apr 30, 2022 at 7:02 PM Arnd Bergmann <arnd@xxxxxxxx> wrote:
> >
> > On Sat, Apr 30, 2022 at 11:05 AM Huacai Chen <chenhuacai@xxxxxxxxxxx> wrote:
> > >
> > > This patch adds zboot (self-extracting compressed kernel) support, all
> > > existing in-kernel compressing algorithm and efistub are supported.
> > >
> > > Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
> >
> > I have no objections to adding a decompressor in principle, and
> > the implementation seems reasonable. However, I think we should try to
> > be consistent between architectures. On both arm64 and riscv, the
> > maintainers decided to not include a decompressor and instead leave
> > it up to the boot loader to decompress the kernel and enter it from there.
> X86, ARM32 and MIPS already support self-extracting kernel, and in
> 5.17 we even support self-extracting modules. So I think a
> self-extracting kernel is better than a pure compressed kernel.

FYI, kernel modules are not self-extracting. They don't contain the code
to do the decompression - that is contained within the kernel, and it is
the kernel that does the decompression. The userspace tooling tells the
kernel that the module is compressed.

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