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Date:      Wed, 10 Dec 2008 20:52:48 -0800 (PST)
From:      Won De Erick <won.derick@yahoo.com>
To:        Christoph Mallon <christoph.mallon@gmx.de>
Cc:        freebsd-hackers@freebsd.org, Rink Springer <rink@FreeBSD.org>, freebsd-hardware@freebsd.org
Subject:   Re: Watchdog for Boser (HS-7001)
Message-ID:  <832968.75350.qm@web45816.mail.sp1.yahoo.com>
References:  <547602.79284.qm@web45809.mail.sp1.yahoo.com> <4933A29B.8060907@gmx.de> <20081201090421.GA99082@rink.nu> <611173.7111.qm@web45805.mail.sp1.yahoo.com> <4933AFD4.3070501@gmx.de>

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Christoph Mallon wrote:

>
>
Won De Erick schrieb:
>>> ----- Original Message ----
>> 
>>> From: Rink Springer <rink@FreeBSD.org>
>>> 
>>> 
>> On Mon, Dec 01, 2008 at 09:38:51AM +0100, Christoph Mallon wrote:
>>>> Userland is not allowed to write to ports. That's the bus error you see. Also without a call to the exit syscall at the end, it will segfault.
>>> Note that you can write to ports from userland by opening /dev/io - if
>>> you have it opened, you can write to the ports.
>>> 
>> 
>> I've added the following at the end
>> 
>>   mov eax, 1 ; SYS_exit
>>   call doint
>> 
>>   doint:
>>      int 0x80
>>      ret
>> 
>> Besides, I can see the following at /dev
>> crw-------   1 root   wheel       0,  16 Nov 27 01:53 io
>> 
>> How should I make this open? do i need to %include this?
>
> You're probably better of writing this in C. Here is a wrapper for the out instruction:
>
> static inline outb(unsigned short port, unsigned char data)
> {
>  asm("outb %0, %1" : : "a" (data), "dN" (port));
> }
>
> As Rink mentioned, you have to open /dev/io. The process must have super-user privileges, see io(4).
>
>

OK thanks for all the tips. I have now a working watchdog. :)


      




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