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

ignored. If the verification fails, the LOC parameters are not accepted, and a
message is sent to the user who entered the command.
DL datalinks
identifies the data to be traced. There are six character groups that can be used
to make up a data link string:
1. Addresses: substrings consisting of characters 0 to 9 and A to F.
2. Registers: substrings beginning with G or GG (for general purpose registers)
or X or XG (for control registers) followed by a hexadecimal digit. A range of
registers may be specified by using a colon between the two registers, such
as G0:4 .
3. Indirection: a percentage sign (%) or an ampersand (&). Indirection means
that the contents of an address are used instead of the address itself. A
percentage sign uses a four-byte indirect address; an ampersand uses an
eight-byte indirect address.
4. Address type: L or R. L indicates that the address derived from the
preceding expression, and all subsequently derived addresses, should be
treated as host Logical addresses. R indicates that the address derived from
the preceding expression, and all subsequently derived addresses, should
be treated as host Real addresses. For each Datalink, addresses are
treated as host Logical addresses until the first occurrence of R, if any.
5. Arithmetic: a plus sign (+) or a minus sign (−).
6. Length delimiter: a period (.).
7. Mnemonic marker: an equals sign (=).
The data link strings specify how to combine these groups to reach the data to
be traced. The following is a Backus-Naur definition of the syntax of data link
strings:
::= | =
::= | | . |
. |
::= | 0...FFFFFFFFFFFFFFFF
::= |
::= + | − | + | − | % | & | R | L
::= 0...F00
::= G: | X: | GG:
| XG:
::= G | X | GG | XG
::= 0...15 | 0...9, A, B, C, D, E, F
::= 0...7FFF
::= mmmmmmmm
TRSOURCE ID (Definition Operands)
where mmmmmmmm indicates a user-generated 1- to 8-character
alphanumeric string.
Data can be identified by either using the current register contents as pointers
or knowing the real location of the data to be traced. Data links define the
procedure to be used to locate the desired data.
Chapter 2. CP Commands 1687