I tried the kernel netbsd.quadra on my centris 660 av  when I'm booting
from the
mac os partition  my computer crash this is the result with the bootlog
Logging to bootlog
Booting...MID_M68K executable: entry 0x3382.
794868+58540+95560+152796+139386
Loading 1145622 byte miniroot...Done.
  Bye-bye...
        So I sez to him...  The real way
        that it should be done is to...
Logging to bootlog
Booting...MID_M68K executable: entry 0x3382.
794868+58540+95560+152796+139386
Loading 1145622 byte miniroot...Done.
  Bye-bye...
        So I sez to him...  The real way
        that it should be done is to...
Logging to bootlog
Booting...MID_M68K executable: entry 0x3382.
794868+58540+95560+152796+139386
Loading 1145622 byte miniroot...Done.

Set _boothowto to 0x202.
  Bye-bye...
        So I sez to him...  The real way
        that it should be done is to...
Env: "ROOT_SCSI_ID" set to 0 (0x0).
Env: "SINGLE_USER" set to 2 (0x2).
Env: "VIDEO_ADDR" set to 1343227392 (0x50100600).
Env: "ROW_BYTES" set to 1280 (0x500).
Env: "FLAGS" set to -2147349262 (0x80020cf2).
Env: "SCREEN_DEPTH" set to 16 (0x10).
Env: "DIMENSIONS" set to 31457920 (0x1e00280).
Env: "BOOTTIME" set to -421124524 (0xe6e62654).
Env: "GMTBIAS" set to 0 (0x0).
Env: "BOOTERVER" set to 108 (0x6c).
Env: "MACOS_VIDEO" set to 1343227392 (0x50100600).
Env: "MACOS_SCC" set to 1357922304 (0x50f04000).
Env: "MACHINEID" set to 60 (0x3c).
Env: "MEMSIZE" set to 24 (0x18).
Env: "GRAYBARS" set to 1 (0x1).
Env: "SERIALECHO" set to 0 (0x0).
Env: "SERIALCONSOLE" set to 0 (0x0).
Env: "SERIAL_MODEM_FLAGS" set to 0 (0x0).
Env: "SERIAL_MODEM_HSKICLK" set to 0 (0x0).
Env: "SERIAL_MODEM_GPICLK" set to 0 (0x0).
Env: "SERIAL_PRINT_FLAGS" set to 0 (0x0).
Env: "SERIAL_PRINT_HSKICLK" set to 0 (0x0).
Env: "SERIAL_PRINT_GPICLK" set to 0 (0x0).
Env: "PROCESSOR" set to 2 (0x2).
Env: "END_SYM" set to 1249102 (0x130f4e).
Env: "ROMBASE" set to 1082130432 (0x40800000).
Env: "TIMEDBRA" set to 6255 (0x186f).
Env: "ADBDELAY" set to 510 (0x1fe).
Env: "HWCFGFLAGS" set to -1024 (0xfffffc00).
Env: "HWCFGFLAG2" set to 1224738847 (0x4900081f).
Env: "HWCFGFLAG3" set to 587251494 (0x2300bf26).
Env: "ADBREINIT_JTBL" set to 1082213304 (0x408143b8).

Set _mac68k_vrsrc_cnt to 0.