Code to change BIOS boot sequence
Posted: Tue May 06, 2008 8:02 am
Hi,
I have written a code to change boot sequence (sometimes want my system to boot from network) using C program, using port 70 h and 71H. I followed the following procedure:
1. Dumped the CMOS contents with the current boot sequence into a file.
2. Changed the boot sequence manually and again read the CMOS contents into a file.
3. From these two file contents I observed values are being changed at 3 locations ( 1 for boot sequence and other 2 boot sequence).
4. wrote C code to write into these 3 locations
5. I was able to write successfully
6. When I restarted, I got the error. System CMOS checksum error and BIOS was updated with default value.
Can anybody help me out with this.. Is this the correct method or is their any other way??
I have written a code to change boot sequence (sometimes want my system to boot from network) using C program, using port 70 h and 71H. I followed the following procedure:
1. Dumped the CMOS contents with the current boot sequence into a file.
2. Changed the boot sequence manually and again read the CMOS contents into a file.
3. From these two file contents I observed values are being changed at 3 locations ( 1 for boot sequence and other 2 boot sequence).
4. wrote C code to write into these 3 locations
5. I was able to write successfully
6. When I restarted, I got the error. System CMOS checksum error and BIOS was updated with default value.
Can anybody help me out with this.. Is this the correct method or is their any other way??