Reset Scenarios

The standard system reset protocol bypasses firmware diagnostics completely unless the NVRAM variable diag-switch? is set to true. The default setting for this variable is false.

To support ASR in Enterprise 250 servers, it is desirable to be able to run firmware diagnostics (POST/OBDiag) on any or all reset events. Rather than simply changing the default setting of diag-switch? to true, which carries with it other side effects (see the OpenBoot 3.x Command Reference Manual), the Enterprise 250 OBP provides a new NVRAM variable called diag-trigger that lets you choose which reset events, if any, will automatically engage POST/OBDiag. The diag-trigger variable, and its various settings are described in the following table.

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Note -

diag-trigger has no effect unless diag-switch? is set to true.

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Table 1-4 Reset Diagnostic Trigger Settings and Effects

Setting	Function
power-reset (default)	Runs diagnostics only on power-on resets.
error-reset	Runs diagnostics only on power-on resets, fatal hardware errors, and watchdog reset events.
soft-reset	Runs diagnostics on all resets (except XIR), including resets triggered by UNIX init 6 or reboot commands.
none	Disables the automatic triggering of diagnostics by any reset event. Users can still invoke diagnostics manually by holding down the Stop and d keys when powering on the system, or by turning the front panel keyswitch to the Diagnostics position when powering on the system.

In the following example, the diag-trigger variable is used to trigger POST and OpenBoot diagnostics on all resets except XIR resets.

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ok setenv diag-switch? true
ok setenv diag-trigger soft-reset

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