Date: Mon, 8 Aug 2005 22:09:49 +0200 From: alexander <arundel@h3c.de> To: freebsd-hackers@freebsd.org Subject: Re: Using sysarch specific syscalls in assembly? Message-ID: <20050808200949.GA92063@skatecity> In-Reply-To: <200508081550.56292.jhb@FreeBSD.org> References: <20050808191910.GA91484@skatecity> <200508081550.56292.jhb@FreeBSD.org>
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On Mon Aug 8 05, John Baldwin wrote: > On Monday 08 August 2005 03:19 pm, alexander wrote: > > Hi there. > > > > I wrote a program that needs to access I/O ports with the in/out > > machinecodes. To gain priviliges to do so I have opened /dev/io. Now > > somebody told me that I'd rather use i386_set_ioperm which will be much > > saver, because of the port range limitation. Plus it will make the program > > more portable because Linux does not have a /dev/io device node. > > > > i386_set_ioperm(2) states that this procedure is a system call. So it > > should be easily accessable through assembly language and it's specific > > syscall id. Unfortunately I wasn't able to find the syscall id in any of > > the > > syscalls.master files that are part of the source tree. > > > > <machine/sysarch.h> states that this is a sysarch specific syscall for i386 > > (hence the i386_*). The following definitions are being made: > > > > #define I386_GET_IOPERM 3 > > #define I386_SET_IOPERM 4 > > > > These syscall numbers however are already taken by read(2) and write(2). So > > how can I make use of these i386 specific syscalls? Is it even possible? > > > > Thx in advance. > > You have to call the sysarch() system call. The first argument to it would be > the operation (I386_GET_IOPERM, etc.). > > -- > John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ > "Power Users Use the Power to Serve" = http://www.FreeBSD.org Thx a lot. That worked.
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