On Thu, 8 May 2008, Satya Kalyan wrote:
> Hi,
>
> I am porting a system software from Linux(32) to OpenSolaris-10. During the
> feasibility study it is found that the following 4 system calls, are not
> supported on Solaris.
>
> iopl: changes the I/O privilege level of the current process, as specified
> in level
>
> ioperm: sets the port access permission bits for the process
No equivalent. Solaris deliberately does not allow applications to access
arbitrary device state from userland without the help of a device driver.
That means two things:
a) iopl() isn't ever necessary; I/O access privilege is equivalent to
device access privilege since "all you need" is the ability to open
device nodes directly. The latter is PRIV_SYS_DEVICES, see the
manpages to privileges(5) and ppriv(1) for further information on
how privileges work in Solaris.
b) ioperm() is something that device drivers must do for you when you
open the device. Even then, it's up to the bus nexus (driver) to
decide which ports will be made available when the leaf driver
does ddi_map_regs_setup(9F) to get the handle for them. So you may
not be able to write a single driver that allows you to access all
I/O ports.
In short, porting Linux application software that uses iopl / ioperm and
direct I/O port access requires creating at least one device driver.
For memory-mapped I/O, that's different, you can just mmap /dev/allkmem
and will be able to read/write anywhere in the physical address space,
from userland.
More details on that should be queried via [EMAIL PROTECTED]
that's the more knowledgeable crowd for such questions.
>
> clone: creates a new process and allows the child process to share parts of
> its execution context with the calling process
Hmm, why use unportable interfaces if there are perfectly-suitable
portable ones available ...
Generally, it'd be a good idea to change application code that uses
clone() directly to use POSIX threads instead. Doing so would create
portable code.
It's possible to emulate most potential uses of clone() in Solaris, see
section 3.5.1. of the BrandZ design guide:
http://opensolaris.org/os/community/brandz/design/
but if you'd want to apply such changes to the sourcecode of an app that
uses clone(), you could just as well change that to use pthreads, for the
better.
>
> setup: setup devices and file systems, mount root file system
That's a _systemcall_ under Linux ?
How can you use that, given that applications can only start once that
task is already done ?
Maybe Linux' booting design allows apps to start before, e.g. loading
them directly from the initrd without any devs / any filesystems, I'm not
sure on that one. Solaris booting doesn't work this way, even init(1m)
only starts up _after_ devices and root filesystem have already been
initialized.
In short: Linux apps that use this you cannot port to Solaris.
Initializing devices / root filesystems is not triggered by a systemcall
in Solaris.
>
> I am interested to know whether any equivalent implementation for these
> system calls for OpenSolaris is available. It would be great if someone can
> guide me on this.
The question, apart from the iopl/ioperm thing, seems largely academic in
nature ?
FrankH.
k
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