Re: [DistroKit] [PATCH 1/5] v8a: enable initrd generation

["Jan Lübbe" <jlu@pengutronix.de>]

On Tue, 2023-06-06 at 16:44 +0200, Johannes Zink wrote:
> Hi Ahmad,
> 
> On 6/6/23 16:37, Ahmad Fatoum wrote:
> > On 06.06.23 16:31, Johannes Zink wrote:
> > > also generate rootfs as cpio.gz, as this allows loading it as initramfs.
> > 
> > You enable both CONFIG_RD_GZIP and CONFIG_RD_ZSTD (which I am fine with),
> > but you decide here for cpio.gz. Any particular reason?
> 
> afaik ZSTD support is rather new and I wanted to have maximum flexibility when 
> reusing the initramfs, even with older kernels - i.e. being able to mix a 
> ptxdist-built initramfs with older kernels. I opted to also support zstd, to 
> allow booting future initramfs' on current kernels, should gzip support ever be 
> dropped in the future.
> 
> However, I think we could probably drop the zstd support, if you are concerned 
> about image size.

CONFIG_KERNEL_ZSTD is supported since 5.9:
https://cateee.net/lkddb/web-lkddb/KERNEL_ZSTD.html

In cases where an old kernel should be booted with this new initramfs, you can
just recompress it with gz on the host (which is trivial compared to building it
in the first place).

I'd suggest just going with zstd only.

Jan
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