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Boot Loader Services


Harold Grovesteen
 

SATK now provides a set of reusable boot loaders for each of the
Hercules targeted architectures: S/360 (uses S/370 in BC-mode), S/370,
ESA/390, and z/Arch.

A set of programs in the guide directory, pgm5, use these boot loaders
and are provided illustrating the usage. In particular, these booted
programs use the boot loader services provided with the boot loader.

The Boot Loader Services are documented in the new manuals doc/BLS.odt
and doc/BLS.pdf. This manual discusses the concepts used in creation
of the boot loader services, how to use each service and the macros
supplied for use within booted programs, and to a lesser degree the
macros used in construction of the boot loaders themselves. The
multiple CPU and I/O architectures drives towards a lot of conditional
code supplied by internal loader macros.

Manuals doc/SATK.odt, doc/SATK.pdf, doc/io.odt, and doc/io.pdf have
been updated with a few additional general and I/O related macros
developed for the boot loader services.

I encourage the user to peruse the new capabilities. This is the
direction SATK is taking for boot loaders in general. The intention is
to extend the device types supported by the loaders and add services
that make sense.

If you are interested in a particular environment, review the assembly
listings provided. These are much easier to follow than the macros
themselves.

Your input would be appreciated.

Thanks,
Harold Grovesteen