Thanks to krw@ I have ddb-enabled i386 kernel. Note that I used amd64 booloader.
Transcribed output: OpenBSD 4.7-current (RAMDISK_CD) #6: Thu Jul 22 20:21:46 EDT 2010 r...@acer.westerback.sa:/usr/src/sys/arch/i386/compile/RAMDISK_CD cpu0: Intel(R) Core(TM)2 Duo CPU T6570 @ 2.10GHz ("GenuineIntel" 686-class) 2.10 Ghz cpu0: FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUS H,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,SBF,SSE3,MWAIT,DS-CPL,VMX,EST,TM2,SSSE3 ,CX16,xTPR,PDCM,SSE4.1,XSAVE real mem B = 2004135936 (1911MB) avail mem = 1964355584 (1873MB) mainbus0 at root bios0 at mainbus0: AT/286+ BIOS, date 06/24/10, BIOS32 rev. 0 @ 0xfdbf0, SMBIOS rev. 2.5 @ 0xe0010 (44 entries) bios0: vendor LENOVO version "6JET81WW (1.39 )" date 06/24/2010 bios0: LENOVO 28477TG acpi at bios0 function 0x0 not configured mpbios at bios0 function 0x0 not configured pcibios0 at bios0: rev 3.0 @ 0xfdbf0/0x410 pcibios0: PCI IRQ Routing Table rev 1.0 @ 0xfdeb0/304 (17 entries) pcibios0: bad IRQ table checksum uvm_fault(0xd07e834c, 0x0, 0, 1) -> e kernel: page fault trap, code=0 Stopped at 0xfde5d: uvm_fault(0xd07e834c, 0xfd000, 0, 1) -> e kernel: page fault trap, code=0 Stopped at db_read_bytes+0xf: movb 0xffffffff(%ebx),%al db_read_bytes(fde5d,1,d0900a8c,d02df9f4,2) at db_read_bytes+0xf db_get_value(fde5d, 1, 0, d0900b1b, 78) at db_get_value+0x18 db_disasm(fde5d, 0, d030404f, 0) at db_disasm+0x16 db_print_loc_and_inst(fde5d, d0900b60, d0900b60, d048fcc3, d048fcc3) at db_print_loc_and_inst+0x2d db_trap(6, 0, 58, f0, d0900b94) at db_trap+0xaf kdb_trap(6, 0, d0900bf4, d07e8444) at kdb_trap+0xae trap() at trap+0x178 --- trap (number 14) --- 0: