Re: [Clax86list] Syscall interface


"Robert Redelmeier" <redelm@xxxxxxxxxxxxxxx> wrote in message
news:7ri3g.74808$dW3.58360@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Charles A. Crayne <spamtrap@xxxxxxxxxx> wrote in part:
"Thomas Worthington" <spamtrap@xxxxxxxxxx> wrote:

:I've written a Forth compiler in assembly using the old Int80 mechanism
:and I want to convert to the new system, which I'm told is faster and
:cleaner but I can't find any useful info on accessing it via AL.

I use the system call interface when programming in assembler under
Linux,
and it has indeed changed a lot over the years. The number of functions
is
now nearing 300, and some of the old calls have been replaced with newer
versions. However, ultimately, they are all invoked by int 80h, so I
don't
understand what you are asking for. Please give me a few more clues.

I believe he's talking about the SYSENTER/SYSEXIT instructions
(SYSCALL/SYSRET on AMD). There's lots on Google:
http://www.ussg.iu.edu/hypermail/linux/kernel/0105.0/0727.html

And you can find /usr/src/linux/arch/i386/kernel/sysenter.c and
/usr/src/linux/arch/x86_64/kernel/syscall.c


Ah, sysenter. Then these may help (but, may be out of date too):
http://lkml.org/lkml/2002/12/17/5
http://lkml.org/lkml/2002/12/18/218

The first indicates that 'int 0x80' can be replaced by 'call 0xfffff000'

The v2.5 changelog seems to confirm that.
http://www.us.kernel.org/pub/linux/kernel/v2.5/ChangeLog-2.5.53


Rod Pemberton


.

Relevant Pages

  • Re: [Clax86list] Syscall interface
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