using the bootstrap loader

USING THE BOOTSTRAP LOADER
2-6
Although bootstrap loading usually occurs in response to an external event (such as a
system reset or a monitor command), an executing program can also initiate it. Such a
program can load another system by calling the PUBLIC symbol BOOTSTRAP_ENTRY.
To prepare for such a call, do the following:
1. Define BOOTSTRAP_ENTRY as an EXTERNAL symbol in the code of the
invoking program.
2. Place a call to BOOTSTRAP_ENTRY in the code of the invoking program. The
form of the call is
where:
CALL BOOTSTRAP _ ENTRY(@filename)
filename An ASCII string containing either the pathname of the
target file followed by a CARRIAGE RETURN, or a
CARRIAGE RETURN only. If the string contains a
pathname, the named file is loaded. If the string
contains a CARRIAGE RETURN only, the default file,
as defined by the %DEFAULTFILE macro in the
BS1.A86 or BSIMB2.A86 configuration file, is loaded.
(Chapter 3 describes the BS1.A86 and BS1MB2.A86
files.)
The call must follow the PL/M-86 LARGE model of segmentation. (Even though
this is a call, rather than a jump, it does not return.)
3. Link the calling program to a version of the first stage of the Bootstrap Loader. You
can do this by using the BS1.CSD file as a model and making the following changes:
• Add the calling program to the list of modules that are linked in BS 1.CSD.
• "Comment out" the locate sequence if you want to use any code other than
absolute code. To comment out a line, precede it with a semicolon. For more
details on absolute code, refer to the iAPX 86,88 Family Utilities Guide.
Refer to Chapter 3 for more information on the BS 1.CSD file.
Bootstrap Loader