User`s guide

4–86 User Commands
User Commands
mcheck
mcheck
The mcheck command controls the reporting of hardware error conditions
(machine checks).
Format
mcheck state
Parameters
state = on
Enables all machine check reporting.
state = off
Disables all machine check reporting.
state = system
Enables machine check reporting for hardware errors detected external to the CPU.
state = cpu
Enables machine check reporting for hardware errors detected by the CPU.
Description
The mcheck command controls the reporting of hardware error conditions. A
machine check indicates that a hardware error condition was detected. Different
error conditions are detected by the CPU or system logic external to the CPU. To
help to ensure the availability of the Debug Monitor for hardware debug, machine
check reporting is disabled when the Debug Monitor starts up. This condition makes
the Debug Monitor firmware more fail-safe than conventional firmware when
hardware integrity is questionable. Therefore, when using the Debug Monitor,
machine checks can be enabled on demand by the mcheck command to facilitate
low-level hardware debug.
Because some machine checks are reported through interrupt requests at interrupt
priority level (IPL) 6, the mcheck command could change the current IPL. If the
current IPL is lower than 7, the current IPL will not be affected. See the description
of the swpipl command for more information about the IPL.