Date: Mon, 28 Oct 2002 15:57:22 +0300 From: Anton Shcherbinin <useperl@fastmail.fm> To: freebsd-questions@freebsd.org Subject: System calls: int $0x80 vs. lcall $7, $0 Message-ID: <12523076531.20021028155722@fastmail.fm>
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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. My assembly book says (trying to translate from Russian into English): ``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. [...] In more traditional Unix systems -- FreeBSD and Solaris -- system calls are implemented according to common SysV/386 standard.'' On the other hand, http://www.freebsd.org/doc/en/books/developers-handbook/x86-system-calls.html says: ``Further, although the kernel is accessed using int 80h [...]'' So what's the truth? int $0x80 or lcall $7,$0 ? Or are both possible? If both, which is better? What is "SysV/386 ABI standard" and does FreeBSD follow it? 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). 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. -- Anton To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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