installer/doc/boot-parameters.txt

This is a list of all the boot parameters for the installer. These
environment variables are typically set on the boot loader command line.
For example:
  boot: linux DEBCONF_PRIORITY=low BOOT_DEBUG=1

DEBCONF_PRIORITY

        Control how many questions the installer asks. Default is high, use
        medium or low for more control, critical to make as few decisions
        as possible.

DEBCONF_FRONTEND

        Pick the frontend to use. Default is newt. Other frontends are not
        available on default install media, so this is not very useful.

DEBCONF_DEBUG

        Control how much debugging output goes in the log. 5 for a lot, 0
        for none.

BOOT_DEBUG

        Use this if the installer is not booting up properly, to get a more
        verbose boot process. It's set to a number:
                0 = not much, the default
                1 = more verbose
                2 = lots of debugging information
                3 = shells are run at various points in the boot
                    exit the shell to continue the boot
        Not supported by all boot methods currently.

bootkbd
        
        Specify the keyboard maping to use. For example, bootkbd=us

INSTALL_MEDIA_DEV

        The value of the parameter is the path to the device to load the
        Debian installer from. For example:
                INSTALL_MEDIA_DEV=/dev/floppy/0
        
        The boot floppy, which normally scans all floppys and USB storage
        devices it can to find the root floppy, can be overridden by this
        parameter to only look at the one device.

In addition to the above, any debconf variable in debian-installer can have
its default value overridden on the command line. For example:

  boot: linux debconf/priority=low

There is not a complete list of all available debconf variables, and some
variables cannot be overridden at boot time. Here are some particularly
useful ones that are known to work:

debian-installer/framebuffer

        Set to "false" if enabling the frame buffer console causes problems.

debian-installer/probe/usb

        Set to "false" to prevent probing for USB on boot, if that causes
        problems.

netcfg/disable_dhcp

        Set to "true" to prevent configuring the network with DHCP and to
        enter the information manually, if DHCP causes problems.

hw-detect/start_pcmcia

        Set to "false" to prevent starting PCMCIA services, if
        that causes problems.
1	This is a list of all the boot parameters for the installer. These
2	environment variables are typically set on the boot loader command line.
3	For example:
4	boot: linux DEBCONF_PRIORITY=low BOOT_DEBUG=1
5
6	DEBCONF_PRIORITY
7
8	Control how many questions the installer asks. Default is high, use
9	medium or low for more control, critical to make as few decisions
10	as possible.
11
12	DEBCONF_FRONTEND
13
14	Pick the frontend to use. Default is newt. Other frontends are not
15	available on default install media, so this is not very useful.
16
17	DEBCONF_DEBUG
18
19	Control how much debugging output goes in the log. 5 for a lot, 0
20	for none.
21
22	BOOT_DEBUG
23
24	Use this if the installer is not booting up properly, to get a more
25	verbose boot process. It's set to a number:
26	0 = not much, the default
27	1 = more verbose
28	2 = lots of debugging information
29	3 = shells are run at various points in the boot
30	exit the shell to continue the boot
31	Not supported by all boot methods currently.
32
33	bootkbd
34
35	Specify the keyboard maping to use. For example, bootkbd=us
36
37	INSTALL_MEDIA_DEV
38
39	The value of the parameter is the path to the device to load the
40	Debian installer from. For example:
41	INSTALL_MEDIA_DEV=/dev/floppy/0
42
43	The boot floppy, which normally scans all floppys and USB storage
44	devices it can to find the root floppy, can be overridden by this
45	parameter to only look at the one device.
46
47	In addition to the above, any debconf variable in debian-installer can have
48	its default value overridden on the command line. For example:
49
50	boot: linux debconf/priority=low
51
52	There is not a complete list of all available debconf variables, and some
53	variables cannot be overridden at boot time. Here are some particularly
54	useful ones that are known to work:
55
56	debian-installer/framebuffer
57
58	Set to "false" if enabling the frame buffer console causes problems.
59
60	debian-installer/probe/usb
61
62	Set to "false" to prevent probing for USB on boot, if that causes
63	problems.
64
65	netcfg/disable_dhcp
66
67	Set to "true" to prevent configuring the network with DHCP and to
68	enter the information manually, if DHCP causes problems.
69
70	hw-detect/start_pcmcia
71
72	Set to "false" to prevent starting PCMCIA services, if
73	that causes problems.