Date: Fri, 8 Nov 2002 11:10:09 +0200 From: Valentin Nechayev <netch@netch.kiev.ua> To: Anton Shcherbinin <useperl@fastmail.fm> Cc: freebsd-questions@freebsd.org Subject: Re: [freebsd] System calls: int $0x80 vs. lcall $7, $0 Message-ID: <20021108091009.GI54767@netch.kiev.ua> In-Reply-To: <12523076531.20021028155722@fastmail.fm> References: <12523076531.20021028155722@fastmail.fm>
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Mon, Oct 28, 2002 at 15:57:22, useperl wrote about "[freebsd] System calls: int $0x80 vs. lcall $7, $0": Извините, здесь лучше по-русски. > Gentlemen, I am new to FreeBSD programming and going to write a simple > program which will not use libc. I tried to find out how to make a > system call of FreeBSD kernel. But 2 different sources of information, a > book on assembly programming and FreeBSD Developers' Handbook, say > contrary things, and I got completely confused. Работают оба метода - и int $0x80, и lcall $7, $0. > My assembly book says (trying to translate from Russian into English): Лучше не переводить.;) > ``Numbers of system calls (which are in /usr/include/sys/syscall.h file) > and way of getting to entry point (long call to 0007:00000000) are > standardized in SysV/386 ABI, but for example Linux uses another > convention -- interrupt 80H. [...] Как ни странно, lcall $7, $0 работает и в линуксе. > So what's the truth? int $0x80 or lcall $7,$0 ? Or are both possible? int $0x80 стал доступен на FreeBSD начиная с 3.0. В 2.* и 1.*, был только lcall. Часть источников может отставать. > If both, which is better? What is "SysV/386 ABI standard" and does > FreeBSD follow it? Он оговаривает метод вызова (тот же lcall), метод передачи параметров, метод передачи номера вызова. Есть разные уровни соответствия. Полное - требуется только для iBCS, иначе можно делать как угодно. Для собственных сред Linux и FreeBSD не требуется никакого соответствия;) > If it follows this standard, where could I get > this standard from? (I did try Google search, but found nothing > resembling a standard or official documents). Это не нужно. Достаточно посмотреть существующую реализацию. > Thanks a lot for any clues. If this maillist is not the most appropriate > place to ask questions like this, please direct me to the right place. /netch To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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