Date: Sun, 6 Jun 2004 22:05:03 -0700 (PDT) From: Doug White <dwhite@gumbysoft.com> To: Phil Schulz <ph.schulz@gmx.de> Cc: freebsd-current@freebsd.org Subject: Re: Execute BIOS function Message-ID: <20040606220342.W12662@carver.gumbysoft.com> In-Reply-To: <40C3960F.4080305@gmx.de> References: <40C3960F.4080305@gmx.de>
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On Mon, 7 Jun 2004, Phil Schulz wrote: > Hello List! > > The radio transmitter of my new centrino laptop is turned on by a BIOS > function which resides at a certain location in memory. I know how to > find the adress of the function's start but I don't yet know how to tell > the OS that I do want to execute that memory region and make it let me > do so. When running the program I get "Bus error (core dumped)". So the > question is: Can I actually execute the BIOS code from userland or do I > have to do it from kernelspace? How do I tell the kernel that I want the > memory region to be executed and make it let me do so? You'll have to do it from the kernel. The BIOS call will probably want to poke memory and I/O ports you won't have access to. You'll also need to know if its 32-bit protected mode safe or not; if not you'll have to set up VM86() to make the call. Have you checked for an ACPI method that implements the same thing? > > Any help is appreciated. > > Thanks, > Phil. > > -- > > This is a part of the code (I hope it's not going to be wrapped). > bios_code_addr holds the BIOS function's start address and dev_mem is a > file-descriptor to /dev/mem. > > ptr = mmap( 0, BIOS_CODE_SIZE, PROT_EXEC, > 0, dev_mem, bios_code_addr ); > > __asm__ __volatile__ ( > "call *%3 \t\n" > : "=a"(eax) > : "a"(eax), "b"(ebx), "c"(ptr) > ); > > > _______________________________________________ > freebsd-current@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org" > -- Doug White | FreeBSD: The Power to Serve dwhite@gumbysoft.com | www.FreeBSD.org
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