Modifying init to create /dev/console ?

[Terry Barnaby]

David Daney wrote:
> Terry Barnaby wrote:
>> Mike Frysinger wrote:
>>> On Tuesday 27 February 2007, Terry Barnaby wrote:
>>>> However, init and other programs obviously require /dev/console (and
>>>> other /dev entries).
>>> they dont require /dev/console
>>>
>>>> I was wondering about adding an option to init where it would create a
>>>> tmpfs file system, mount it on /dev and create a /dev/console node 
>>>> if no
>>>> /dev/console was found. I guess it could do a bit more and function as
>>>> udev as well.
>>> it wouldnt work ... the kernel opens up /dev/console before executing 
>>> init, so even if /sbin/init created the device node, it wouldnt matter
>>>
>>> also, this is what init scripts are for ... such / policy handling 
>>> does not belong hardcoded in the C code
>>> -mike
>>
>> No, they don't require /dev/console just to operate, but if you want 
>> debug printout they do :)
>>
>> Init could easily reopen its controlling terminal to the created 
>> /dev/console and continue ...
>>
>> The reason I was looking at getting init to create /dev/console was so 
>> that I could debug my init scripts that are not working when 
>> /dev/console does not exist ...
>>
> 
> Why do you think what Make says is false?  All your posts on this 
> subject are premised on that false belief.
> 
> I think it is time that you change your assumption that you can boot a 
> system that does not contain /dev/console in its root file system.  You 
> cannot do it with a standard Linux kernel.
> 
> As I see it you have two choices:
> 
> 1) Put /dev/console in your root filesystem.
> 2) Hack up your kernel so that /dev/console is not needed.
> 
> David Daney

Hi,

Because, you can !
You can boot a system without /dev/console and get init to create the 
basic /dev/console and continue. At least with the 2.6.19 kernel. My 
patch to the Busybox init later in this thread does this and with an 
un-modified kernel (in fact a standard Fedora 6 binary kernel).

I can now boot my system without any /dev nodes in sight. Init mounts a 
tmpfs file system on /dev and creates the two necessary nodes 
/dev/console and /dev/null and the rcS init script creates the rest.
However, being new to Busybox I'm not sure that this is the best 
approach ...

Cheers

Terry