QNX 4 filesystem

For a QNX 4 filesystem, the secondary boot loader displays a message to start loading the operating system.

Hit Esc for .altboot

If you let it time out, the loader loads the operating system image file from /.boot; if you press Escape, the loader gets the image from /.altboot instead. As the loader reads the image, it prints a series of periods. If an error occurs, the loader prints one of the following characters, and the boot process halts:

S

No OS signature was found.

D or ?

An error occurred reading the disk.

The only difference between the default installed images is that /.boot uses DMA for accessing the EIDE controller, while /.altboot doesn't.

You can find the buildfiles for these images in /boot/build:

• qnxbasedma.build for .boot (see the Examples appendix)
• qnxbase.build for .altboot

You can't rename, unlink, or delete /.boot and /.altboot, although you can change the contents or copy another file to these files. For example, these commands don't work:

mv /.altboot oldaltboot
mv newboot /.altboot

but these do:

cp /.altboot oldaltboot
cp newboot /.altboot