using the bootstrap loader

CONFIGURING THE THIRD STAGE
This macro is used to generate the generic third stage used to boot the Operating System
from diskettes. The %INSTALLA nON macro allows one diskette, which contains only
the Operating System boot file and the third stage to be used to load the system from
diskette into memory. In entering the monitor, it allows a second diskette, which contains
the necessary system commands, to be used as the system device when the system is
initialized.
4.3.10 %END Macro
The %END macro is required at the end of the BS3.A86, BS3MB2.A86, BG3.A86, and
BR3.A86 files. The syntax of this macro is as follows:
%END
There are no parameters associated with the %END macro.
4.3.11 User-Supplied Drivers
If you want to use the device-specific third stage to load your system from a device other
than one for which Intel supplies a third-stage driver, you must write your own device
driver procedures that the third stage will call. Chapter 6 describes how to do this. In
addition, take the following actions to add the procedures to the Bootstrap Loader:
• Specify the names of the device initialization procedure, the device read procedure,
and the driver's data segment in a %DEVICE macro in the BS3.A86 file.
• If there are configurable parameters associated with your device (such as base
addresses or wakeup ports), you might want to create your own configuration macro
and include it in a special configuration file, just like the Intel devices do. Chapter 5
describes how to set up such a macro. You will probably use the same configuration
file for both the first- and third-stage drivers.
• Assemble your device initialization procedure, your device read procedure, and your
configuration file (if you have one), and link the resulting object code to the rest of the
Bootstrap Loader object files and libraries.
Bootstrap Loader 4-15