Execute BIOS function

From: Phil Schulz <ph.schulz_at_gmx.de>
Date: Mon, 07 Jun 2004 00:09:19 +0200
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?

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)
);
Received on Sun Jun 06 2004 - 13:09:54 UTC

This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:37:56 UTC