• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 198
  • Last Modified:

Can I implement these function when reboot

In my project,there is a PCI card which controls two harddisk's power. Each of the harddisk has a operating system.I want to write a program, in which I click the button and a signal will be sent to the card. Then the card will let the PC reboot,  and switch the power from one harddisk to another.
In this way, the machine is abnormally reboot .Can I let the PC normally reboot and implement this function? In a word, what is the right time that I send a signal to the card after I let the windows normally reboot(The card has a pin connected to the reset line)
1 Solution
this doesn't sound like a C++ programming question .. more of a operating system / hardware question.

good luck getting an answer here.
I'll answer it anyway ...

....you need to patch into the boot process fairly early (for windows) or into the reboot code fairly late (Linux).

For windows 95/98/Win31/DOS:

1) replace the autoexec.bat file with one which calls a program which:
    a) restores the original autoexec.bat file
    b) flips whatever needs flipping on the card
    c) reboots the computer to use the other hard-drive
2) Cause windows to reboot the computer (many ways to do this).

For NT:
I don't know

For Linux (and most other UNI):
1) You'll need a bit of research here, but you need to find the init.d script which controls the shutdown process, and insert code to flip the card information right before the machine is rebooted (I'd trigger it on the presence of a file in the root directory, which is deleted right before the flip [after it's seen of course]), and then all you have to do is create the file and issue a reboot ('init 6' I think).
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Featured Post

The 14th Annual Expert Award Winners

The results are in! Meet the top members of our 2017 Expert Awards. Congratulations to all who qualified!

Tackle projects and never again get stuck behind a technical roadblock.
Join Now