RUNUNIT - examine and patch a run-unit.

boff RUNUnit filename [options]

filename: is the name of the file containing the run-unit you want to examine/patch.
ManiFest=filename: specifies a manifest file. For more details, see "expl boff manifest".
Name=runame: specifies the name of the run-unit you want to examine/patch, if the file contains several run-units.
-Write: indicates that BOFF should not access the file with write permissions (i.e. read only). This prevents accidental alteration of the file. Without this option, BOFF accesses the file for both read and write.

The RUNUnit mode of BOFF lets you examine and patch Native Mode run-units. It is like "BOFF Patch", except in the following ways.

RUNUnit mode only works on Native Mode run-units.
The binary @ construction (A@B) is not supported.
All pointers must be full NSA pointers (with an offset in the upper bits and a SEGID in the lower bits).
A new unary @ construction has been introduced. "A@" or "@A" can be used to refer to a location in the file. "A" is an expression giving an offset in the current hardware segment. "A@" or "@A" is the pointer value computed by shifting the offset to the top of a word and ORing in the SEGID of the current segment. Thus "*@A" refers to the contents of this location.
The current segment is set by assigning a SEGID number to the variable "segid". When the program begins execution, "segid" has the (octal) value 6000.
The ":vx" command displays the name of the file, the name of the run-unit being examined, the entry address, and the octal value of the descriptor that frames the Linkage Segment.

To patch a value in the file, simply assign a new value to the appropriate address. This changes the corresponding location in the run-unit file.