From owner-freebsd-hackers  Sun May 12 11:26:53 2002
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Date: Sun, 12 May 2002 11:26:13 -0700
From: Terry Lambert <tlambert2@mindspring.com>
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To: Dmitry Mottl <dima@sinp.msu.ru>
Cc: freebsd-hackers@FreeBSD.org
Subject: Re: question: hacking init_main.c
References: <Pine.BSF.4.43.0205121758360.38560-100000@BigKing.sinp.msu.ru>
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Dmitry Mottl wrote:
> 
> I got a page fault (page not present, supervisor read) when I try to
> modify /sys/kern/init_main.c
> 
> I want kernel print each subsytem name when it called from mi_startup.
> So I define char *sysinit_desct[] array and populate it with
> description strings.
> 
> After I boot kernel I saw expected '*** mi_startup ***' (see patch)
> and pagefault after that.
> 
> Where is my fault?

[ ... ]
> +        printf("*** mi_startup ***\n");
*** BOGUS

[ ... ]
> +               printf("SYSINIT: %s\n", sysinit_descr[(*sipp)->subsystem]);
*** BOGUS


Your console must be initialized before you can call printf.

Try this *one line* instead:

201a202,204
> if ((*sipp)->subsystem > SI_SUB_CONSOLE)
>       printf("SYSINIT: %s\n", sysinit_descr[(*sipp)->subsystem]);
> 

Notice that with this patch, it only does printf's after console
initialization has taken place (unlike your patch).


-- Terry

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