Some news about this issue:
Since the 4.4 Release, there's a kernel driver named vmt (only i386 at the moment) that seems to be the solution to the problem, it is not compiled in the kernel so you have to build a new kernel. By the way here's how i did:
# cd /usr/src
# wget ftp://your.mirror/pub/OpenBSD/4.5/sys.tar.gz
# tar -xzvpf sys.tar.gz
# cp /bsd /bsd.backup
# cp /usr/src/sys/arch/i386/conf/GENERIC /usr/src/sys/arch/i386/conf/GENERIC.vmt
# vi /usr/src/sys/arch/i386/conf/GENERIC.vmt
-> uncomment the line: vmt0 at mainbus? # VMware Tools
# cd /usr/src/sys/arch/i386/conf
# config GENERIC.vmt
# cd ..
# make clean && make depend && make
# make install
here's the relevant part of the dmesg after installed the new kernel:
bios0 at mainbus0: AT/286+ BIOS, date 07/29/08, BIOS32 rev. 0 @ 0xfd780, SMBIOS rev. 2.4 @ 0xe4010 (45 entries)
bios0: vendor Phoenix Technologies LTD version "6.00" date 07/29/2008
bios0: VMware, Inc. VMware Virtual Platform
From now the driver is loaded and sysctl | grep hw give me:
hw.cpuspeed=2305
hw.vendor=VMware, Inc.
hw.product=VMware Virtual Platform
hw.version=None
hw.serialno=VMware-56 4d 34 64 c4 5a 29 ce-ad 63 c1 d5 2f 8c 49 35
hw.uuid=564d3464-c45a-29ce-ad63-c1d52f8c4935
hw.physmem=267939840
hw.usermem=267927552
But the VmWare tools are not detected by VmWare Server, can someone provide me some hints or feedback about this setup, is it needed to use sensorsd?