Tag: lscpu

Upgrade OpenBSD from 6.2 to 6.3

Since OpenBSD 6.3 is released, it is time to upgrade 6.2.

The upgrade manual is here. But for newbies like me, I think the most challenge step is booting from ramdisk kernel, bsd.rd: Download and copy it into root file system:

# mv bsd.rd /

Then reboot machine, during prompting boot>, input boot /bsd.rd:

boot> boot /bsd.rd

Then upgrade OpenBSD according to the instructions.

For me, there are 2 important aspects of OpenBSD 6.3:
(1) The vim is upgrade to 8.0.1589, and the strange display issue is fixed when using terminal (Please refer this thread).
(2) My lscpu is included into ports since OpenBSD 6.3, so you can install it on x86 architectures:

# pkg_add lscpu
# lscpu
Architecture:            amd64
Byte Order:              Little Endian
Active CPU(s):           2
Total CPU(s):            2
......

lscpu for OpenBSD/FreeBSD

There is a neat command, lscpu, which is very handy to display CPU information on GNU/Linux OS:

$ lscpu
Architecture:        x86_64
CPU op-mode(s):      32-bit, 64-bit
Byte Order:          Little Endian
CPU(s):              32
On-line CPU(s) list: 0-31
Thread(s) per core:  2
Core(s) per socket:  8
Socket(s):           2
......

But unfortunately, the BSD OSs lack this command, maybe one reason is lscpu relies heavily on /proc file system which BSD don’t provide, :-). TakeOpenBSD as an example, if I want to know CPU information, dmesg should be one choice:

# dmesg | grep -i cpu
cpu0 at mainbus0: apid 0 (boot processor)
cpu0: Intel(R) Core(TM)2 Duo CPU P8700 @ 2.53GHz, 2527.35 MHz
cpu0: FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE,SSE3,DTES64,MWAIT,DS-CPL,VMX,SMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,SSE4.1,XSAVE,NXE,LONG,LAHF,PERF,SENSOR
cpu0: 3MB 64b/line 8-way L2 cache
cpu0: apic clock running at 266MHz
cpu0: mwait min=64, max=64, C-substates=0.2.2.2.2.1.3, IBE
......

But the output makes me feeling messy, not very clear. As for dmidecode, it used to be another option, but now can’t work out-of-box because it will access /dev/mem which for security reason, OpenBSD doesn’t allow by default (You can refer this discussion):

# ./dmidecode
# dmidecode 3.1
Scanning /dev/mem for entry point.
/dev/mem: Operation not permitted

Based on above situation, I want a specified command for showing CPU information for my BSD box. So in the past 2 weeks, I developed a lscpu program for OpenBSD/FreeBSD, or more accurately, OpenBSD/FreeBSD on x86 architecture since I only have some Intel processors at hand. The application getsCPU metrics from 2 sources:

(1) sysctl functions.
The BSD OSs provide sysctl interface which I can use to get general CPU particulars, such as how many CPUs the system contains, the byte-order of CPU, etc.

(2) CPUID instruction. For x86 architecture, CPUID instruction can obtain very detail information of CPU. This coding work is a little tedious and error-prone, not only because I need to reference both Intel and AMD specifications since these 2 vendors have minor distinctions, but also I need to parse the bits of register values.

The code is here, and if you run OpenBSD/FreeBSD on x86 processors, please try it. It will be better you can give some feedback or report the issues, and I appreciate it very much. In the future if I have other CPUs resource, such as ARM or SPARC64, maybe I will enrich this small program.