Re: Boot knoppix via rs232 terminal

["Andrew" <knoppix@rngresearch.com>]

I was hoping that someone with experience would answer this question, but
I didn't notice any answers, so here are my two cents:

1. syslinux (the boot loader that gives you the "boot:" prompt at startup)
can be configured to work via serial port.  You need to edit the
configuration file in the boot directory.  Full documentation can be found
in /usr/share/doc/syslinux/ and the following is taken from
/usr/share/doc/syslinux/syslinux.txt.gz

SERIAL port [[baudrate] flowcontrol]
        Enables a serial port to act as the console.  "port" is a
        number (0 = /dev/ttyS0 = COM1, etc.) or an I/O port address
        (e.g. 0x3F8); if "baudrate" is omitted, the baud rate defaults
        to 9600 bps.  The serial parameters are hardcoded to be 8
        bits, no parity, 1 stop bit.

        "flowcontrol" is a combination of the following bits:
        0x001 - Assert DTR
        0x002 - Assert RTS
        0x008 - Enable interrupts
        0x010 - Wait for CTS assertion
        0x020 - Wait for DSR assertion
        0x040 - Wait for RI assertion
        0x080 - Wait for DCD assertion
        0x100 - Ignore input unless CTS asserted
        0x200 - Ignore input unless DSR asserted
        0x400 - Ignore input unless RI asserted
        0x800 - Ignore input unless DCD asserted

        All other bits are reserved.

        Typical values are:

            0 - No flow control (default)
        0x303 - Null modem cable detect
        0x013 - RTS/CTS flow control
        0x813 - RTS/CTS flow control, modem input
        0x023 - DTR/DSR flow control
        0x083 - DTR/DCD flow control

        For the SERIAL directive to be guaranteed to work properly, it
        should be the first directive in the configuration file.

        NOTE: "port" values from 0 to 3 means the first four serial
        ports detected by the BIOS.  They may or may not correspond to
        the legacy port values 0x3F8, 0x2F8, 0x3E8, 0x2E8.

        Enabling interrupts (setting the 0x008 bit) may give better
        responsiveness without setting the NOHALT option, but could
        potentially cause problems with buggy BIOSes.

NOHALT flag_val
        If flag_val is 1, don't halt the processor while idle.
        Halting the processor while idle significantly reduces the
        power consumption, but can cause poor responsiveness to the
        serial console, especially when using scripts to drive the
        serial console, as opposed to human interaction.

CONSOLE flag_val
        If flag_val is 0, disable output to the normal video console.
        If flag_val is 1, enable output to the video console (this is
        the default.)

        Some BIOSes try to forward this to the serial console and
        sometimes make a total mess thereof, so this option lets you
        disable the video console on these systems.


2. After that, you'll probably want to edit /etc/inittab so you can
continue to access the machine via terminal via RS232.  /etc/inittab is
pretty well commented and includes ready-made examples in the comments.

Good luck!

Best regards,
Andrew


On Mon, May 2, 2016 05:07, Zvi Vered wrote:
> Hello,
>
> I want to boot an Atom cpu with a knoppix cd.
> I did not find a cheat code that redirect the output to rs232.
>
> Can you help ?
>
> Thank you,
> Z.V
>