Multiple consoles for Linux

[johnpgarry]

Hi,

I am attempting to setup linux in my embedded environment.

I wanted to output the console display though the tty serial port and the vt.

Since I don't have a frambuffer hw driver yet, I just wanted to use the vfb as a temp. solution.

So, this is what I did in my configuration file:
CONFIG_CMDLINE="console=ttyS0,115200n8 console=tty0 mem=126M video=vfb:"
CONFIG_VT=y
CONFIG_FB=y
CONFIG_FB_VIRTUAL=y
CONFIG_DUMMY_CONSOLE=n
CONFIG_FRAMEBUFFER_CONSOLE=y
CONFIG_VGA_CONSOLE=n

I would expect the tty output to go to the uart as well as the virtual-console; this does not seem to be the case, as no vt functions are called when I execute prompt commads - I can see the console in my serial terminal, and this all works fine.

Here are extracts from my boot:
Kernel command line: console=ttyS0,115200n8 console=tty0 mem=126M video=vfb:
...
Console: colour dummy device 80x30
console [tty0] enabled
...
Console: switching to colour frame buffer device 80x25
fb0: Virtual frame buffer device, using 1024K of video memory
Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
serial8250.0: ttyS0 at MMIO 0x3e000000 (irq = 99) is a 16550A
console [ttyS0] enabled
serial8250.0: ttyS1 at MMIO 0x3e001000 (irq = 9 is a 16550A
serial8250.0: ttyS2 at MMIO 0x3e002000 (irq = 97) is a 16550A
...

Here are my console binding results:
/ #
cat /sys/class/vtconsole/vtcon0/bind
0
/ # cat /sys/class/vtconsole/vtcon0/name
(S) dummy device
/ # cat /sys/class/vtconsole/vtcon1/bind
1
/ # cat /sys/class/vtconsole/vtcon1/name
(M) frame buffer device
/ #

Please advise.

thanks,
John

[Rubberman]

Please put your system commands and output inside code blocks, like this:

CONFIG_CMDLINE="console=ttyS0,115200n8 console=tty0 mem=126M video=vfb:"
CONFIG_VT=y
CONFIG_FB=y
CONFIG_FB_VIRTUAL=y
CONFIG_DUMMY_CONSOLE=n
CONFIG_FRAMEBUFFER_CONSOLE=y
CONFIG_VGA_CONSOLE=n

I would expect the tty output to go to the uart as well as the virtual-console; this does
not seem to be the case, as no vt functions are called when I execute prompt
commads  - I can see the console in my serial terminal, and this all works fine.

Here are extracts from my boot:
Kernel command line: console=ttyS0,115200n8 console=tty0 mem=126M video=vfb:
...
Console: colour dummy device 80x30
console [tty0] enabled
...
Console: switching to colour frame buffer device 80x25
fb0: Virtual frame buffer device, using 1024K of video memory
Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
serial8250.0: ttyS0 at MMIO 0x3e000000 (irq = 99) is a 16550A
console [ttyS0] enabled
serial8250.0: ttyS1 at MMIO 0x3e001000 (irq = 98) is a 16550A
serial8250.0: ttyS2 at MMIO 0x3e002000 (irq = 97) is a 16550A
...

Here are my console binding results:
/ # 
cat /sys/class/vtconsole/vtcon0/bind
0
/ # cat /sys/class/vtconsole/vtcon0/name
(S) dummy device
/ # cat /sys/class/vtconsole/vtcon1/bind
1
/ # cat /sys/class/vtconsole/vtcon1/name
(M) frame buffer device
/ #

As you can see, it reads better as special character sequences, such as those for smileys, won't be misinterpreted.

[Rubberman]

So, anyway I am confused. What exactly is your problem? You can see the output on your serial terminal. Do you think the virtual framebuffer isn't working? Why? Do you expect all output to go to the vfb and not to the serial console port?

[johnpgarry]

I had hoped that the console output would go to the serial tty and the vt, which doesn't seem to be the case. I only seem to be getting output from the serial terminal. As for the vt, in my debugging env I can't see any proof that vt is being exercised.

For the vt, I would expect the this to be connected to the fbcon, which is then connected to the vfb. I wanted to setup this env before creating my own FB dev driver, as a proof of concept.

Ultimately I want to put the console output through the FB.

cheers,
John