Operating instructions

5.20.3 cpu_enabled
The cpu_enabled environment variable sets a bit mask that enables or
disables specific CPUs in a multiprocessor system.
Disabling a CPU may be necessary if a number of errors are reported on a spe-
cific CPU. These errors might be displayed during power-up or might be dis-
played with the show config command.
Disabled CPUs are prevented from running the console or the operating system.
Bit 0 of the mask corresponds to CPU 0 and bit 1 to CPU 1. A zero (0) in the bit
mask prevents the corresponding CPU from running; a one (1) allows it to run.
The bit mask is expressed as a hexadecimal value.
The value of cpu_enabled takes effect only after you reset the system by press-
ing the Reset button or by issuing the init command.
The cpu_enabled environment variable is typically used in benchmark testing.
NOTE: The primary CPU cannot be disabled. The primary CPU is the lowest
numbered working CPU.
The syntax is:
set cpu_enabled hex_digit
The hex_digit values are shown in the table.
Binary Equivalent
Hex_Digit Value CPU enable 3210 (bit) Enabled CPUs
0 0000 No CPUs (CPU 0 still comes up)
1 0001 CPU 0
2 0010 CPU 1
3 0011 CPU 0,1
Example
In the following example, CPU 0 and CPU 1 are enabled.
P00>>> set cpu_enabled 3
5-52 DS25 Owner’s Guide