z/VM: CP Commands and Utilities Reference - z/VM - IBM

Usage Notes
RESolve
tells CP to resolve the entry points associated with this exit number when the
association is first established. Any existing associated entry points are resolved
immediately.
PARM parameter
is a list of one or more parameters to be supplied to the exit. Five kinds of
tokens can be used to define a parameter:
1. Addresses: strings up to eight characters long, consisting of the
hexadecimal digits 0 through 9 and A through F.
2. General Registers: strings beginning with G or R, followed by a decimal
number between 0 and 15 or a hexadecimal digit, designating the contents
of a general register.
3. Indirection: a percent sign (%), which causes the contents of an address or
the contents of an address in a register to be used instead of the address or
register contents itself.
4. Arithmetic: a plus sign (+) or minus sign (−).
5. Displacement: strings of up to four hexadecimal digits.
Each parameter string specifies how to combine these tokens to generate a
parameter value to be passed to an exit routine. The following is a Backus-Naur
definition of the syntax of a parameter:
::= |
::= | 0...FFFFFFFF | %
::= | % |
::= + | − | + | −
::= G | R
::= 0...15 | 0...9, A...F
::= 0...7FFF
1. To define a new dynamic exit point, use the DEFINE EXIT command (page
165).
2. To load the exit processing code into CP’s system execution space, use the
CPXLOAD command (page 101).
3. To activate a new exit point, use the ENABLE EXITS command (page 431).
4. To display information about an exit point (status, entry point name, and
parameters), use the QUERY EXITS command (page 791).
5. To deactivate an exit point, use the DISABLE EXITS command (page 269).
6. To remove the exit processing code from CP’s system execution space, use
the CPXUNLOAD command (page 107).
7. Exit numbers are allocated as follows:
v X'0000' to X'7FFF' are reserved for IBM use.
v X'8000' to X'EFFF' are reserved for vendor and general use.
v X'F000' to X'FFFF' are reserved for private customer use.
MODIFY EXIT
8. The RESOLVE option ensures that the entry names associated with an exit
point are defined.
9. Each exit is passed a parameter list that begins with three standard
parameters, as described in the z/VM: CP Exit Customization book. Additional
parameters, specified by the PARM operand, are optional and follow the first
three in the order in which they are specified.
10. Errors (for example, addressing exceptions) during evaluation of user-defined
parameters when an exit is being invoked cause CP to abend.
Chapter 2. CP Commands 619