ba command

The ba command adds a breakpoint.

Syntax

ba{.}fid[.|,]disp
bao{.}offset
ba+{.}offset
b{n}

The effective address can be specified in several different ways:

  • The first line of the syntax is computed by adding the argument FID to the FID breakpoint offset, and the specified displacement to the displacement breakpoint offset defined by the bo command.

  • The second line of the syntax is specified by the FID, defined by the breakpoint offset and offset added to the breakpoint offset displacement set by the bo command.

  • The third line of the syntax is defined by the current value of R1to which the offset is added.

  • The fourth line of the syntax is defined by the current value of R1 to which the n * 4 is added. If n is not specified, 1 is assumed. This syntax is used for architectures having a fixed 4-byte instruction size (RISC).

The address must be at a virtual address boundary. Breakpoints are global for the whole virtual machine. Once the breakpoint is set, any process which triggers it, stops. Breakpoints are removed once they are encountered. A breakpoint should not be set into an ABS frame that has been write required (mloaded into). Up to three breakpoints can be set simultaneously. Once a setting is set successfully, a plus sign and breakpoint displays.

Breakpoints remain in action until they are explicitly removed or until the virtual machine is shut down.