maint: Create an ISO9660 installation image in the 'release' target.

* Makefile.am (GUIXSD_IMAGE_BASE): Adapt target file name.
(release): Use file-system-type iso9660.
* doc/guix.texi: Document installation from DVD.

Makefile.am

@@ -577,7 +577,7 @@ GUIXSD_SUPPORTED_SYSTEMS ?= x86_64-linux i686-linux
 GUIXSD_VM_SYSTEMS ?= x86_64-linux
 
 # Prefix of the GuixSD installation image file name.
-GUIXSD_IMAGE_BASE = guixsd-usb-install-$(PACKAGE_VERSION)
+GUIXSD_IMAGE_BASE = guixsd-install-$(PACKAGE_VERSION)
 
 # Prefix of the GuixSD VM image file name.
 GUIXSD_VM_IMAGE_BASE = guixsd-vm-image-$(PACKAGE_VERSION)
@@ -628,6 +628,7 @@ release: dist
 	for system in $(GUIXSD_SUPPORTED_SYSTEMS) ; do					\
 	  image=`$(top_builddir)/pre-inst-env						\
 	    guix system disk-image							\
+	    --file-system-type=iso9660							\
             --system=$$system								\
 	    gnu/system/install.scm` ;							\
 	  if [ ! -f "$$image" ] ; then							\

doc/guix.texi

@@ -7465,6 +7465,7 @@ available.
 * Limitations::                 What you can expect.
 * Hardware Considerations::     Supported hardware.
 * USB Stick Installation::      Preparing the installation medium.
+* DVD Installation::            Preparing the installation medium.
 * Preparing for Installation::  Networking, partitioning, etc.
 * Proceeding with the Installation::  The real thing.
 * Installing GuixSD in a VM::   GuixSD playground.
@@ -7554,7 +7555,7 @@ about their support in GNU/Linux.
 @subsection USB Stick Installation
 
 An installation image for USB sticks can be downloaded from
-@indicateurl{ftp://alpha.gnu.org/gnu/guix/guixsd-usb-install-@value{VERSION}.@var{system}.xz},
+@indicateurl{ftp://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.xz},
 where @var{system} is one of:
 
 @table @code
@@ -7570,8 +7571,8 @@ Make sure to download the associated @file{.sig} file and to verify the
 authenticity of the image against it, along these lines:
 
 @example
-$ wget ftp://alpha.gnu.org/gnu/guix/guixsd-usb-install-@value{VERSION}.@var{system}.xz.sig
+$ wget ftp://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.xz.sig
-$ gpg --verify guixsd-usb-install-@value{VERSION}.@var{system}.xz.sig
+$ gpg --verify guixsd-install-@value{VERSION}.@var{system}.xz.sig
 @end example
 
 If that command fails because you do not have the required public key,
@@ -7585,9 +7586,8 @@ $ gpg --keyserver pgp.mit.edu --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
 and rerun the @code{gpg --verify} command.
 @c end duplication
 
-This image contains a single partition with the tools necessary for an
+This image contains the tools necessary for an installation.
-installation.  It is meant to be copied @emph{as is} to a large-enough
+It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
-USB stick.
 
 To copy the image to a USB stick, follow these steps:
 
@@ -7596,7 +7596,7 @@ To copy the image to a USB stick, follow these steps:
 Decompress the image using the @command{xz} command:
 
 @example
-xz -d guixsd-usb-install-@value{VERSION}.@var{system}.xz
+xz -d guixsd-install-@value{VERSION}.@var{system}.xz
 @end example
 
 @item
@@ -7605,7 +7605,7 @@ its device name.  Assuming that the USB stick is known as @file{/dev/sdX},
 copy the image with:
 
 @example
-dd if=guixsd-usb-install-@value{VERSION}.x86_64 of=/dev/sdX
+dd if=guixsd-install-@value{VERSION}.x86_64 of=/dev/sdX
 sync
 @end example
 
@@ -7619,12 +7619,79 @@ UEFI boot menu, where you can choose to boot from the USB stick.
 @xref{Installing GuixSD in a VM}, if, instead, you would like to install
 GuixSD in a virtual machine (VM).
 
+@node DVD Installation
+@subsection DVD Installation
+
+An installation image for DVDs can be downloaded from
+@indicateurl{ftp://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.xz},
+where @var{system} is one of:
+
+@table @code
+@item x86_64-linux
+for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
+
+@item i686-linux
+for a 32-bit GNU/Linux system on Intel-compatible CPUs.
+@end table
+
+@c start duplication of authentication part from ``Binary Installation''
+Make sure to download the associated @file{.sig} file and to verify the
+authenticity of the image against it, along these lines:
+
+@example
+$ wget ftp://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.xz.sig
+$ gpg --verify guixsd-install-@value{VERSION}.@var{system}.xz.sig
+@end example
+
+If that command fails because you do not have the required public key,
+then run this command to import it:
+
+@example
+$ gpg --keyserver pgp.mit.edu --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
+@end example
+
+@noindent
+and rerun the @code{gpg --verify} command.
+@c end duplication
+
+This image contains the tools necessary for an installation.
+It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
+
+To copy the image to a DVD, follow these steps:
+
+@enumerate
+@item
+Decompress the image using the @command{xz} command:
+
+@example
+xz -d guixsd-install-@value{VERSION}.@var{system}.xz
+@end example
+
+@item
+Insert a blank DVD into your machine, and determine
+its device name.  Assuming that the DVD drive is known as @file{/dev/srX},
+copy the image with:
+
+@example
+growisofs -dvd-compat -Z /dev/srX=guixsd-install-@value{VERSION}.x86_64
+@end example
+
+Access to @file{/dev/srX} usually requires root privileges.
+@end enumerate
+
+Once this is done, you should be able to reboot the system and boot from
+the DVD.  The latter usually requires you to get in the BIOS or
+UEFI boot menu, where you can choose to boot from the DVD.
+
+@xref{Installing GuixSD in a VM}, if, instead, you would like to install
+GuixSD in a virtual machine (VM).
+
 @node Preparing for Installation
 @subsection Preparing for Installation
 
-Once you have successfully booted the image on the USB stick, you should
+Once you have successfully booted your computer using the installation medium,
-end up with a root prompt.  Several console TTYs are configured and can
+you should end up with a root prompt.  Several console TTYs are configured
-be used to run commands as root.  TTY2 shows this documentation,
+and can be used to run commands as root.  TTY2 shows this documentation,
 browsable using the Info reader commands (@pxref{Top,,, info-stnd,
 Stand-alone GNU Info}).  The installation system runs the GPM mouse
 daemon, which allows you to select text with the left mouse button and
@@ -7979,7 +8046,7 @@ Boot the USB installation image in an VM:
 @example
 qemu-system-x86_64 -m 1024 -smp 1 \
   -net user -net nic,model=virtio -boot menu=on \
-  -drive file=guixsd-usb-install-@value{VERSION}.@var{system} \
+  -drive file=guixsd-install-@value{VERSION}.@var{system} \
   -drive file=guixsd.img
 @end example