main accessibility page: accessibility
Braille
Starting from version 0.9.1-4, debian's qemu-kvm has support for a virtual braille device. That means that you can very easily (i.e. without any braille hardware) test the debian installer support for braille devices by just installing brltty-x11 (at least version 3.10~r3715-1) and running:
$ /sbin/brltty -b xw -x no -A auth=none,host=127.0.0.1:1 $ BRLAPI_HOST=127.0.0.1:1 kvm -usbdevice braille -cdrom mini.iso
The first command will show a window that displays what would be displayed on a braille device. If you have issues with it, add -l debug -n -e to the command line to get more debugging details. If it's complaining about the font, try to append -B font='-*-fixed-*-*-*-*-*-*-*-*-*-*-iso10646-1' or even -B font='-*-fixed-*-*-*-*-*-*-*-*-*-*-iso8859-1' .
The second command starts the installer (without harddisk so only the first few installation steps can be tested). If qemu/kvm complains that it doesn't find the "braille" backend, it was probably built without brlapi support. Make sure to have the libbrlapi devel package installed when building qemu/kvm. The isolinux boot menu does not show on the braille device. Just "blindly" hit enter.
After the installer has booted you should see:
- the newt frontend being used without framebuffer
- the language list limited to languages using only Latin1 characters (accented characters may not show correctly in the brltty window, that's a known limitation of the virtual braille device being shown)
- the currently selected line from the language list visible in the brltty window
- changing selections or tabbing to buttons reflected in the brltty window
- If the braille window is still showing the version of BrlTTY, just click on it to bypass that greeting message.
Serial braille support
To test the serial device support, replace
-usbdevice braille
with
-serial braille
and append
brltty=bm,ttyS0
to the kernel command line.
braille hotplug support
To test hotplug support (new in wheezy with brltty 4.2-9), replace
-usbdevice braille
with
-usbdevice mouse
to remove the braille device but keep the USB tree initialized by qemu/kvm, and after d-i startup, press ctrl-alt-2 to get into the qemu/kvm console, and there type
usb_add braille
and use ctrl-alt-1 to switch back to the installer. Debconf should get killed and restart in text mode.
After installation
On reboot into the newly-installed system, nothing more should be needed to get braille output again. This should work when installing without a network mirror too. If the (gnome) graphical desktop task was chosen, orca should get started to read gdm's chooser, and sound effects should be enabled. The user created during d-i should get orca and sound effects enabled in its session too.
Low vision
There is a high contrast them which can be enabled by adding
theme=dark
to the kernel command line. This is supported by both the "newt" and "gtk" frontends. TODO: the low vision parameter should get applied to gdm and the created user.
Starting from Debian installer Stretch Alpha 5, Zoom can be obtained by pressing control +/-.
TODO: bigger mouse cursor
Speech
Hardware Speech
Run
kvm -serial stdio -cdrom image.iso
choose the GTK installer, and append
speakup.synth=dummy
to the kernel command line. You will then get on stdio what would be spoken.
Software Speech
To test software speech synthesis, simply pass -soundhw ac97 , and select speech synthesis in the boot menu (last item, s shortcut). As soon as the first debconf question you should get spoken feedback from the sound board.
Also test with EFI (requires ovmf from non-free):
kvm -soundhw ac97 -cdrom image.iso -bios OVMF.fd
After installation
On reboot into the newly-installed system, nothing more should be needed to get output again. This should work when installing without a network mirror too. If the (gnome) graphical desktop task was chosen, orca should get started to read gdm's chooser, and sound effects should be enabled. The user created during d-i should get orca and sound effects enabled in its session too.