Re: [PATCH 1/2 v2] x86_64/earlyprintk: setup earlyprintk as early as possible

From: Ingo Molnar
Date: Tue Apr 07 2015 - 10:03:26 EST



* Alexander Kuleshov <kuleshovmail@xxxxxxxxx> wrote:

> 2015-04-07 17:35 GMT+06:00 Ingo Molnar <mingo@xxxxxxxxxx>:
> >
> >
> > So if you set up earlyprintk via CONFIG_CMDLINE_OVERRIDE it just
> > works?
> >
>
> Look, how i did it. I set:
>
> CONFIG_CMDLINE_BOOL =y
> CONFIG_CMDLINE_OVERRIDE =y
>
> and passed following string:
>
> [=root=/dev/sdb earlyprintk=ttyS0 loglevel=7 debug rdinit=/sbin/init
> root=/dev/ram memblock=debug]
>
> to the CONFIG_CMDLINE.
>
> Now i put two early_printk calls before and after earlyprintk initialization:
>
> early_printk("before setup_early_printk \n");
> setup_early_printk(boot_command_line);
> early_printk("after setup_early_printk \n");
>
> And i don't see first string, but see last.
>
> Did i make something wrong?

Yes, you need to check how and where in the arch init code
boot_command_line is set up in the CONFIG_CMDLINE_OVERRIDE=y case.

Thanks,

Ingo
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