Mail Archives: djgpp/1999/03/07/06:16:39

Date: Sun, 7 Mar 1999 13:14:50 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
X-Sender: eliz AT is
To: Wojciech Zabolotny <wzab AT ise DOT pw DOT edu DOT pl>
cc: djgpp AT delorie DOT com
Subject: Re: HELP! Assembly language dual mode interrupt handler for djgpp program
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On Thu, 4 Mar 1999, Wojciech Zabolotny wrote:

> irq_handler	push	eax
> 		mov	ax,[cs:apps_cs]
> 		mov	ds,ax
> However I don't know how to fill the "apps_cs" variable.

You probably meant apps_ds, right?  Because CS is already set when you
enter the handler.

Use cs:___djgpp_ds_alias (3 leading underscores), this is what it's
there for.  You should always use the DS alias, not the DS itself,
since the latter is invalidated (by making its limit be 4KB) when a
signal is pending.

> Particularly the "___djgpp_app_DS" seems to be very promissing. Is it safe
> to use it?

No, see above.  Use the alias.

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