initramfs: drop comment against multiple formats

Message ID 20190126001901.3090-1-vivien.didelot@gmail.com
State New
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Series
  • initramfs: drop comment against multiple formats
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Commit Message

Vivien Didelot Jan. 26, 2019, 12:19 a.m.
This patch removes an old comment against having multiple filesystem
formats which doesn't bring any value.

It is also wrong per-se: one may want to use Buildroot to prepare a
custom distribution containing a kernel+initramfs and a persistent
default rootfs to pivot to.

Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com>
---
 fs/initramfs/Config.in | 5 -----
 1 file changed, 5 deletions(-)

Comments

Peter Korsgaard Jan. 26, 2019, 9:56 a.m. | #1
>>>>> "Vivien" == Vivien Didelot <vivien.didelot@gmail.com> writes:

 > This patch removes an old comment against having multiple filesystem
 > formats which doesn't bring any value.

 > It is also wrong per-se: one may want to use Buildroot to prepare a
 > custom distribution containing a kernel+initramfs and a persistent
 > default rootfs to pivot to.

Yes, but in that case the final persistent rootfs would contain
different files than the initramfs, right?

E.G. I handle such a use case by two different defconfigs, one building
the Linux kernel + initramfs and another for the final persistent
rootfs.

> Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com>

> ---
 >  fs/initramfs/Config.in | 5 -----
 >  1 file changed, 5 deletions(-)

 > diff --git a/fs/initramfs/Config.in b/fs/initramfs/Config.in
 > index 9d5a3f92e6..42a9d60524 100644
 > --- a/fs/initramfs/Config.in
 > +++ b/fs/initramfs/Config.in
 > @@ -13,10 +13,5 @@ config BR2_TARGET_ROOTFS_INITRAMFS
 >  	  is used, regardless of how buildroot's cpio archive is
 >  	  configured.
 
 > -	  Note that enabling initramfs together with another filesystem
 > -	  formats doesn't make sense: you would end up having two
 > -	  identical root filesystems, one embedded inside the kernel
 > -	  image, and one separately.
 > -
 >  comment "initramfs needs a Linux kernel to be built"
 >  	depends on !BR2_LINUX_KERNEL
 > -- 
 > 2.20.1

 > _______________________________________________
 > buildroot mailing list
 > buildroot@busybox.net
 > http://lists.busybox.net/mailman/listinfo/buildroot
Vivien Didelot Jan. 26, 2019, 4:59 p.m. | #2
Hi Peter,

On Sat, 26 Jan 2019 10:56:59 +0100, Peter Korsgaard <peter@korsgaard.com> wrote:
> >>>>> "Vivien" == Vivien Didelot <vivien.didelot@gmail.com> writes:
> 
>  > This patch removes an old comment against having multiple filesystem
>  > formats which doesn't bring any value.
> 
>  > It is also wrong per-se: one may want to use Buildroot to prepare a
>  > custom distribution containing a kernel+initramfs and a persistent
>  > default rootfs to pivot to.
> 
> Yes, but in that case the final persistent rootfs would contain
> different files than the initramfs, right?

Not necessarily. You can prepare one rootfs base containing an init logic
which detects the initrd and eventually formats a partition, extracts a
persistent version, pivots root etc.

The persistent storage can evolve from there by the mean of a package manager
or whatever the board is meant to do with the persistent storage.

> E.G. I handle such a use case by two different defconfigs, one building
> the Linux kernel + initramfs and another for the final persistent
> rootfs.

My point is that it is actually possible to do so, and Buildroot allows that,
so this message has currently no value. So I suggest either we prevent one
to have a built-in initramfs enabled as well as other rootfs formats (which
seems to be a subjective limitation to me) or we get rid of this message
and let the user generate all formats she wants.


Best,

	Vivien

Patch

diff --git a/fs/initramfs/Config.in b/fs/initramfs/Config.in
index 9d5a3f92e6..42a9d60524 100644
--- a/fs/initramfs/Config.in
+++ b/fs/initramfs/Config.in
@@ -13,10 +13,5 @@  config BR2_TARGET_ROOTFS_INITRAMFS
 	  is used, regardless of how buildroot's cpio archive is
 	  configured.
 
-	  Note that enabling initramfs together with another filesystem
-	  formats doesn't make sense: you would end up having two
-	  identical root filesystems, one embedded inside the kernel
-	  image, and one separately.
-
 comment "initramfs needs a Linux kernel to be built"
 	depends on !BR2_LINUX_KERNEL