Enhance USB install

  From: Vincent Legoll <vincent.legoll@idgrilles.fr>

* doc/guix.texi (USB install): add download & verify subsection,
add a section to explain how to boot a VM for guixsd installation

Signed-off-by: Vincent Legoll <vincent.legoll@gmail.com>
---
 doc/guix.texi | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 90 insertions(+), 1 deletion(-)
  

Vincent Legoll <vincent.legoll@gmail.com> skribis:

> From: Vincent Legoll <vincent.legoll@idgrilles.fr>
>
> * doc/guix.texi (USB install): add download & verify subsection,

Sorry for the delay!  First some comments on the verification, which I
think should be treated in a separate commit:

>  This image contains a single partition with the tools necessary for an
>  installation.  It is meant to be copied @emph{as is} to a large-enough
> -USB stick.
> +USB stick.  It can also be used to install GuixSD in a QEmu virtual
> +machine (@pxref{USB storage Installation in a VM}).
> +
> +To download and verify this image, follow these steps:
> +
> +@enumerate
> +@item
> +Download the image & signature files using the @command{wget} command:
> +
> +@example
> +wget ftp://alpha.gnu.org/gnu/guix/guixsd-usb-install-@value{VERSION}.@var{system}.xz
> +wget ftp://alpha.gnu.org/gnu/guix/guixsd-usb-install-@value{VERSION}.@var{system}.xz.sign
> +@end example
> +
> +@item
> +Get the PGP key using the @command{gpg} command:
> +
> +@example
> +gpg --keyserver keys.gnupg.net --recv-keys 3D9AEBB5
> +@end example
> +
> +@item
> +Check download integrity using the @command{gpg} command:
> +
> +@example
> +gpg --verify guixsd-usb-install-@value{VERSION}.@var{system}.xz.sig
> +@end example

I took a slightly different approach in commit
debc6360e111e8efc8a938b2aef28e5b3616ada8, where I essentially copied the
text from “Binary Installation”.

I’ll comment on the rest later.

Thanks,
Ludo’.
  

> I took a slightly different approach in commit
> debc6360e111e8efc8a938b2aef28e5b3616ada8, where I essentially copied the
> text from “Binary Installation”.

OK, I saw that duplication, but only after I sent the patch for review...

> I’ll comment on the rest later.

Thanks
  

Hi Vincent,

Vincent Legoll <vincent.legoll@gmail.com> skribis:

> From: Vincent Legoll <vincent.legoll@idgrilles.fr>
>
> * doc/guix.texi (USB install): add download & verify subsection,
> add a section to explain how to boot a VM for guixsd installation

I pushed this as commit c8b543741f422ecf41e7635c6a1c40b3bd55947a, with
several modifications.

> +@node USB storage Installation in a VM
> +@subsection USB storage Installation in a VM

Changed the title to “Installing GuixSD in a Virtual Machine”.

> +To boot a QEmu virtual machine for installing GuixSD in a disk image, follow
> +these steps:

s/QEmu/QEMU/

> +@item
> +Ensure your running kernel has the required CONFIG_BRIDGE option for the
> +network to work properly in the virtual machine:
> +
> +@example
> +zgrep CONFIG_BRIDGE= /proc/config.gz
> +CONFIG_BRIDGE=y
> +@end example
> +
> +If it is compiled as a module & loaded, it will also work:
> +
> +@example
> +zgrep CONFIG_BRIDGE= /proc/config.gz
> +CONFIG_BRIDGE=m
> +lsmod | grep ^bridge
> +bridge 117542 0
> +@end example

I removed this bit because in my experience it’s not necessary.  Or am I
overlooking something?

> +@item
> +Boot a virtual machine with the USB installation image
> +
> +@example
> +qemu-system-x86_64 -m 1024 -smp 1 -net default -net nic,model=virtio -boot menu=on \
> +  -drive file=guixsd-x86_64-raw.img \
> +  -drive file=guixsd-usb-install-@value{VERSION}.@var{system}
> +@end example
> +
> +In the VM console, quickly press the <F12> key to enter the boot menu.  Then
> +press the <2> key and the <ENTER> key to validate your selection.

Added a couple of @kbd.

> +@end enumerate
> +
> +You're now root in the VM, proceed with the installation process.

Added cross-ref to “Running GuixSD in a VM”.

This is a valuable addition, but I guess many people want to try GuixSD
in a VM first.

Thank you!

Ludo’.
  

Ludovic Courtès <ludo@gnu.org> writes:

> Hi Vincent,
>
> Vincent Legoll <vincent.legoll@gmail.com> skribis:
>
>> From: Vincent Legoll <vincent.legoll@idgrilles.fr>
>>
>> * doc/guix.texi (USB install): add download & verify subsection,
>> add a section to explain how to boot a VM for guixsd installation
>
> I pushed this as commit c8b543741f422ecf41e7635c6a1c40b3bd55947a, with
> several modifications.
>
...
>
>> +@item
>> +Ensure your running kernel has the required CONFIG_BRIDGE option for the
>> +network to work properly in the virtual machine:
>> +
>> +@example
>> +zgrep CONFIG_BRIDGE= /proc/config.gz
>> +CONFIG_BRIDGE=y
>> +@end example
>> +
>> +If it is compiled as a module & loaded, it will also work:
>> +
>> +@example
>> +zgrep CONFIG_BRIDGE= /proc/config.gz
>> +CONFIG_BRIDGE=m
>> +lsmod | grep ^bridge
>> +bridge 117542 0
>> +@end example
>
> I removed this bit because in my experience it’s not necessary.  Or am I
> overlooking something?

Do you mean the bit above or below your statement? The above might be
necessary to check for custom kernels on for example Gentoo based
systems as the host.
A check if what's about to be run is supported is good.
Or do I fail to see why you ommited this? Can you explain why it is not
necessary in your experience?

>
>> +@item
>> +Boot a virtual machine with the USB installation image
>> +
>> +@example
>> +qemu-system-x86_64 -m 1024 -smp 1 -net default -net nic,model=virtio -boot menu=on \
>> +  -drive file=guixsd-x86_64-raw.img \
>> +  -drive file=guixsd-usb-install-@value{VERSION}.@var{system}
>> +@end example
...
> Thank you!
>
> Ludo’.
>
  

>> +@item
>> +Ensure your running kernel has the required CONFIG_BRIDGE option for the
>> +network to work properly in the virtual machine:
>> +
>> +@example
>> +zgrep CONFIG_BRIDGE= /proc/config.gz
>> +CONFIG_BRIDGE=y
>> +@end example
>> +
>> +If it is compiled as a module & loaded, it will also work:
>> +
>> +@example
>> +zgrep CONFIG_BRIDGE= /proc/config.gz
>> +CONFIG_BRIDGE=m
>> +lsmod | grep ^bridge
>> +bridge 117542 0
>> +@end example
>
> I removed this bit because in my experience it’s not necessary.  Or am I
> overlooking something?

My experience is exactly the inverse: I first didn't have it in my kernel, and
couldn't install guixsd just because of that. guixsd needs network to install,
and you need CONFIG_BRIDGE (in the host's kernel) for network to be available
in the VM.