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To: Mike Smith <mike@smith.net.au>
cc: freebsd-mobile@FreeBSD.ORG
Subject: Re: Libretto 50 - US Version and PAO 
In-reply-to: Your message of "Thu, 06 Nov 1997 17:59:20 +1030."
             <199711060729.RAA01727@word.smith.net.au> 
Date: Thu, 06 Nov 1997 13:41:32 +0100
Message-ID: <478.878820092@critter.freebsd.dk>
From: Poul-Henning Kamp <phk@critter.freebsd.dk>
Sender: owner-freebsd-mobile@FreeBSD.ORG
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In message <199711060729.RAA01727@word.smith.net.au>, Mike Smith writes:
>> In message <199711060121.LAA00464@word.smith.net.au>, Mike Smith writes:
>> 
>> >One thing I was wondering; does
>> >
>> >pnp_func(u_int16_t a, u_int16_b)
>> >
>> >construct the stack properly, or will we still get int-sized objects on 
>> >the stack?
>> 
>> You still get 32bit stuff on the stack.  C promotes them.
>
>As Shakespeare would have said, "Puck".
>
>Alright, let's try something even more ugly.
>
>/* 
> * pnpcall(int dseg, int coffs, int cseg,
> *	   int retoffs, int retseg, u_int_16 stack[PNP_MAXSTACK])
> * pass (retoffs) and (retseg) in as junk.
> */
>ENTRY(pnpcall)
>	movl	%cs,%di
>	movl	%di,(5*4)(%esp)
>	movl	pnpret,(4*4)(%esp)
>	popl	%di
>	movl	%di,%ds
>	lret
>pnpret:		/* fossick return value etc. */
>
>About all I can see here is that we don't save any registers across
>the call, which might be Bad.
>
>Comments?

Uhm, the "popl %di" comes from the wrong stack, right ?

--
Poul-Henning Kamp             FreeBSD coreteam member
phk@FreeBSD.ORG               "Real hackers run -current on their laptop."