z/TPF Program Management - IBM

present, the program or programs are loaded below the 2-GB bar; if the symbol is
not there, the program or programs are loaded above the 2-GB bar. The
CGCC_31BIT symbol is added during the link-edit phase of the build process only
when CGCC_31BIT=0 is set as a link edit flag in an individual makefile or in a
MakeTPF configuration file (maketpf.cfg).
Note: You cannot specify where to load a program at load time.
See “Create a C shared object” on page 64 for more information about creating a C
shared object, including where to load programs. For more information about
Makefiles, enter man maketpf.mak on your Linux build system for a complete list
of Makefile variables that can be coded.
Offline general file loader component (ALDR)
ELF objects
and libraries
from the HFS
Loader input file
Begin process
General file
loader
offline component
(TPFLDR – ALDR)
End process
LDCRL = Loader control record
Primary process
Data flow
General
file
LDCRL
Figure 3. General file load using the general file loader offline component (ALDR)
22 z/TPF Program Management
When you create your z/TPF system for the first time, you must initialize and format
the loader general file, initialize and format the online modules, and load IPLA and
the volume ID (VOLID) to the loader general file before you can load system
components to the loader general file. See “Initialize and format the loader general
file and online modules” on page 73 for more information.
Figure 3 shows how the remainder of the loader general file is loaded by the offline
general file loader (ALDR). ALDR loads all the records and programs specified in
the loader input file and creates a loader control record (LDCRL) on the loader
general file. This control record indicates the components to load from the loader
general file to the online modules during the online general file load (ACPL).
The general file loader is only necessary at system generation time or in an
emergency load condition in which no fallback image exists.
Note: The general file loader always overwrites image 1, which must be defined to
use program area 1 and IPL area 1. Therefore, ensure that you reserve
image 1, program area 1, and IPL area 1 for emergency general file loads.