I can't set hardware breakpoint, only software.
FreeBSD 8.1-RELEASE-p1 Thu Oct 7 18:29:43 MSD 2010 amd64 custom kernel
GNU gdb 6.6 [GDB v6.6 for FreeBSD]
or
GNU gdb 6.1.1 [FreeBSD]
Code:
(gdb) hb *0x400d70
No hardware breakpoint support in the target.
CPU: Intel(R) Xeon(R) CPU 5120 @ 1.86GHz (1862.06-MHz K8-class CPU)
Features=<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
Features2=<SSE3,DTES64,MON,DS_CPL,VMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,DCA>
AMD Features=0x20000800<SYSCALL,LM>
AMD Features2=0x1<LAHF>
FreeBSD 8.1-RELEASE-p1 Thu Oct 7 18:29:43 MSD 2010 amd64 custom kernel
GNU gdb 6.6 [GDB v6.6 for FreeBSD]
or
GNU gdb 6.1.1 [FreeBSD]