MPE/iX System Utilities Reference Manual (32650-90882)

Chapter 20 177
SAINT
The input files required to build the boot image are all identified by one of the load
commands (LOADCME, LOADMILLI, LOADSXRT, or LOADSYSLIB).
SOMs and system libraries
The system library is the primary input file used by the SAINT utility to produce boot
images. Libraries contain SOM files, which are the primary output files of system
compilers and assemblers, as well as the system linker. Libraries are built by the link
editor, which invokes the linker.
In addition to executable code, SOMs contain an initialization pointer area, which is used
to define the page allocation and access rights of both code and data. An initialization
pointer record defines either the location of code or data within the SOM, or the value and
length of a data area required by the SOM. These records are used to allocate pages within
the boot image file and to build the page information table, or PIT, for the boot image.
The library symbol table, or LST, contains records defining the location of procedures
within the SOMs contained in the library, and these records are copied directly over to the
boot image for use by a symbolic debugger when the system is being booted up.
The system object module ACD defines the format of the SOM and the system library.