Re: [linux-fbdev] Console on frame-buffer... how?

[James S. <jsi...@ac...>]

> > I assume you pass `console=ttyS0' (or something like that) to the kernel?
> In
> > that case no console messages are sent to the console on the frame buffer
> > device.
> 
> I dont pass anything to the kernel... in the PPC distribution, a kernel
> parameter is CONFIG_SERIAL_CONSOLE that initializes a console using the
> serial driver. No parameters are required. It only add a call in
> 'console_init()'.
> 
> I looked at the sources, but i still think there's something wrong on
> console initialization (this is 'main.c'):
> 
> CONSOLE_INIT
>     CON_INIT (vt initialization)
>     CONSOLE_8xx_INIT (serial console on the PPC)
> TTY_INIT
>     RS_8xx_INIT (serial driver on the PPC)
> VIDEO_SETUP

The above is right. console_init does early terminal setup and initializes
hardware that can be called that early. con_init and console_8xx_init are
examples of drivers that can be called early. Later tty_init initialized 
hardware that needs things like pci to be setup for it. That is why fbcon
is called later. Because fbcon can not be called early a dummy console is
setup first. Then fbcon takes over this dummy console.

> Then, i see that VT is not registered because at CON_INIT, the functions
> tests the value of 'conswitchp' before running any 'con_startup' function,
> and it is NULL. Who should initialize it if this function has to be called
> before any other one that initializes the framebuffer? I cannot change
> virtual terminal because VT is not registered, then there is something wrong
> on this, isnt it?

No. conswitchp is setup in some c file in the arch directory. For the PPC
look at linux/arch/ppc/kernel

chrp_setup.c:   conswitchp = &dummy_con;
pmac_setup.c:   conswitchp = &dummy_con;
prep_setup.c:   conswitchp = &vga_con; 

> > You may want to try `console=tty0 console=ttyS0' to get console output on
> both
> > the frame buffer device and the serial console. Input for the console will
> > come from the last console= argument (i.e. the serial console, cfr.
> > Documentation/serial-console.txt).
> 
> Sorry, but it still doesnt work!

Did you enable Support for console on virtual terminal after the Virtual
terminal option ?

MS: (n) 1. A debilitating and surprisingly widespread affliction that
renders the sufferer barely able to perform the simplest task. 2. A disease.

James Simmons  [jsi...@li...]               ____/| 
fbdev/console/gfx developer                             \ o.O| 
http://www.linux-fbdev.org                               =(_)= 
http://linuxgfx.sourceforge.net                            U
http://linuxconsole.sourceforge.net