Amateur OS
boot up
The boot
up of Amateur OS has under gone a
change. The way I had originally
planed to boot
worked on the floppy but was hard
to install
and would not have worked on a
hard drive..The
old layout can be seen here.
So I'm
back to a standard boot loader, written
from code found on Matthew Vea's
web site.
http://www.geocities.com/mvea/bootstrap.htm
The bootstrap
has been modified to load
a loader file at 8000:0000. This
loader does
the following:
-
Clears the screen.
-
Loads a banner image.
-
Checks for a 486 or greater.
-
Sets the A20 line.
-
Tests the A20 line.
-
Sets up flat real mode.
-
Test real flat mode with a video write.
-
Loads the FAT and directory into memory.
-
Scans dir for kernel name.
-
Loads kernel to 0050:0000
-
Jumps to kernel.
At this time,
I have the BPB copied into the
loader file. Since both it and
the bootstrap load
the FAT and dir into memory, it
should be possible
to read them from the loader.
If you have a comment or question,
please feel free
to send me an Email.