FreeBSD on Bochs

[jumbler chi]

Hi All:
   I have a question about Freebsd on bochs.
I'm interesting to build owner  Freebsd scratch. 
Due the hardware limited , I want to run this scratch on Bochs. 
Therefore , I refered a article ,
http://sig9.com/articles/freebsd-on-bochs , to build a image  under
5.2R.
when I booted the image file under Bochs-2.0.2 .. it stoped on a
prompt  ,  mountroot > .

The bochs' console screenshot is following
   
lpt0: Interrupt-driven port
ppi0: <Parallel I/O> on ppbus0
sc0: <System console> at flags 0x100 on isa0
sc0: VGA <16 virtual consoles, flags=0x300>
sio0 at port 0x3f8-0x3ff irq 4 flags 0x10 on isa0
sio0: type 16550A
sio1: configured irq 3 not in bitmap of probed irqs 0
sio1: port may not be enabled
vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0
Timecounter "TSC" frequency 500159 Hz quality 800
Timecounters tick every 10.000 msec
ad0: FAILURE - SETFEATURES ENABLE RCACHE status=41<READY,ERROR> error=4<ABORTED>

ad0: FAILURE - SETFEATURES ENABLE WCACHE status=41<READY,ERROR> error=4<ABORTED>

GEOM: create disk ad0 dp=0xc1a81e60
ad0: 511MB <Generic 1234> [1040/16/63] at ata0-master PIO2

Manual root filesystem specification:
  <fstype>:<device>  Mount <device> using filesystem <fstype>
                       eg. ufs:da0s1a
  ?                  List valid disk boot devices
  <empty line>       Abort manual input

----------------------------------------------------------------------------------------------
the bochs' log records 

00505152373i[HD   ] SET FEATURES subcommand 0xaa not supported by disk.
00505289771i[HD   ] SET FEATURES subcommand 0x02 not supported by disk.

What's happen?!  Did I miss something else ?! 


ps. my bochs configuration is as following 

--------------------------------------------------------------------------------------------------------------------------
megs: 64
romimage: file=$BXSHARE/BIOS-bochs-latest, address=0xf0000
vgaromimage: $BXSHARE/VGABIOS-lgpl-latest

floppya: 1_44=/dev/fd0, status=ejected

# hard disk
ata0: enabled=1, ioaddr1=0x1f0, ioaddr2=0x3f0, irq=14
ata0-master: type=disk, path="freebsd.img", mode=flat, cylinders=1040,
heads=16, spt=63

boot: disk
log: out.txt
mouse: enabled=0
keyboard_mapping: enabled=1, map=$BXSHARE/keymaps/sdl-pc-us.map


Regards

Jumbler