Throughout your PA-RISC experience, you will be often told about consoles. This section aims at de-obfuscating what this word means and how to use said consoles.
In order to boot your PA-RISC system with the PA/Linux kernel, you must first set up a console. A console is basically the device where the kernel (and the firmware) will display its output, and where input can by sent to control the system at an early boot stage. You can use either graphic console, which requires having a monitor and a keyboard attached to the system, or serial console, which allows serial line communication between the system and another Linux machine, or any VT system.
Please note that the firmware console and kernel console are not necessarily the same. For instance, it is possible to interact with BOOT_ADMIN using keyboard & monitor, and once PA/Linux is up, to have kernel output sent to serial port only. By default, PA LOader (PALO) will try to use firmware console as the kernel one.
Workstations usually boot in graphic mode, whereas servers boot in serial mode. Some boxes will also automatically switch to serial if no keyboard is connected, or if you hold down TOC switch while powering the system on.
If you don't know what the actual console of your box is, it's quite simple: find the place where first output is sent when the box is turned on (serial line or monitor output, if any), that is the console.
If you are trying to setup a PA-RISC workstation and have a monitor handy, the easiest method is to use graphic console. If you get into troubles, or are trying to configure a server, choose serial console.
To use the graphic console, you must first ensure that the Linux kernel supports your system's graphic card.
There are two ways to deal with the graphic console. If you think about bug-reporting any trouble, you must know how to differentiate both. First, the STI console is the classical video text console, like VGA on a common PC for example. This name is due to the fact that each PA-RISC box with graphical capabilities features the Standard Text Interface (STI) which defines some standardized ways to access the video memory. The other graphic console is the well known framebuffer console (which on HP-PA uses STI in a special manner, hence the name STIfb). In this case, when booting, you will see a characteristic little penguin appearing on the top-left corner. This is the easiest way to differentiate the two graphic modes.
Obviously, if you can use graphic console, it is the easiest way to proceed. Nevertheless, you must be sure that your hardware is supported.
The serial console is a good way to obtain all console messages, including the BCH ones. It is very useful for bug reports, as its output can be easily dumped. Moreover, most of the PA-RISC servers can only be managed with serial console.
The only cases where serial console HAS TO be used is either if you don't have a monitor handy, or if the machine doesn't support graphics. It is also possible that the kernel can NOT handle some specific graphics hardware present in the machine, but that is pretty rare (STIcon should work everywhere).
Here is the procedure to setup serial console support.
To connect a PA-RISC machine to a PC's RS232 port, you need a 9-pin-to-9-pin female plugs null-modem cable. You should be able to obtain such a cable at your local computer hardware reseller. Obviously, you can also choose to connect the other end of the cable to a terminal (in this case it will probably need a 25-pin male plug). Anyway, the most practical method is to connect it to another box running minicom or cu, which makes all output easily available for further usage (dump report, session log, and so on).
In order to communicate with a PA-RISC machine on a serial line, you have to set it up in serial console mode (see below), and configure a serial communication program. We recommend minicom, which can be found in most Linux distributions. If you don't have minicom on your system, you can find the latest package on any major Linux software website.
Most of the minicom configuration is machine dependent. However, you must ensure that:
The baud rate is set to 9600
Protocol is set to 8-N-1 (8bit data, No parity check, 1 stop bit)
Don't worry too much as these are the default values on PA/Linux. If you are running minicom on a PC, you will probably need to change the baud rate.
It might prove useful that you learn how to manage the console mode on a PA-RISC box. The following section will explain the various operations regarding console modes.
Type: path console to see the current console mode.
If it's graphic console mode, it will return something like: 'Console path = graphic_1'.
If it's serial console, it will return: 'Console path = rs232_a.9600.8.none' or something similar.
On some models, there can be slight differences in the naming, but the idea stays the same. If you want to see more descriptions here, please send us a message describing the box you use and what you get.
To change to serial console mode, type the following command at the 'BOOT_ADMIN>' command prompt:
path console rs232_a.9600.8.none
or, like on B132L+
path console serial_1
Anyway, on most boxes if you try to setup an invalid path for the console, you will be warned and prompted again for a valid path. To verify that the console path has been correctly set, type path console. This should return something like 'Console path = rs232_a.9600.8.none', indicating that the system is now set up to boot using serial console, on RS232 port 'A'. If your machine has only one, this is OK, if not, take care to use the right one. reset will reboot your system with the new parameters.
Unfortunately, it is *normally* not possible. Although 712s are configured for in-house HP development to use serial, this cannot be set in BOOT_ADMIN. You will have to use graphic console on 712s. And why the hell would we use this beautiful 712 with serial console when we can have X on it?!
Anyway, if you feel like trying bleeding edge solutions, there is a tip at the PA/Linux mailing list archive. This explains how to change the console from an HP/UX ISL prompt. Since you actually need HP/UX to be able to do the serial trick, you can find a small HP/UX lifimage here: http://www.pateam.org/archive/uxbootlf. (See further Section 4.3 to learn how to netboot a lifimage). In fact, serial console on 712 is especially useful if you want to boot the box without having a keyboard attached to it, which is otherwise not possible.
The following takedown is highly unofficial, unsupported and in a general way a bad idea, as you can make your 712 unbootable, needing intervention from a HP-techie, if something goes wrong. Beware!
Here is the procedure:
Turn the box on and when in BOOT_ADMIN, boot into HP/UX ISL. For example:
BOOT_ADMIN> boot lan isl
Once you get the 'ISL>' prompt, type the following:
Switching to serial: conspath 2/0/4.0x283
Switching to graphic: conspath 1/0/0.0
Still at the 'ISL>' prompt, type disp, and check that console path is either '(hex) 2/0/4.2184.108.40.206.0.0' for serial, or '(hex) 1/0/0.0.0.0.0.0.0' for graphic.
Power cycle the system to bring it up on the new console.
This is the reverse of the previous operation. By checking your console path, you should see 'Console path = rs232_a.9600.8.none'. Now, you can switch to the graphic mode by issuing the following command at 'BOOT_ADMIN>' prompt:
path console graphic_1
The actual switch will happen after a reset. If the monitor does not seem to work properly, try to press the Tab key (on the keyboard attached to the box of course) at the beginning of the boot sequence to change the resolution of the display. By pressing this key, the monitor resolution cycles from one to another.
Keep that in mind when changing monitors.