[movitz-devel] Bochs trouble

Tue Jan 20 06:49:41 UTC 2004

Hello to all!

Let me start of by saying that I'm very impressed by Movitz.

When I copy the image onto a 3.5" disk, go find a PC, and boot it, all 
is fine. When I try to run it on my little Macintosh under bochs, 
however, the (virtual) system reboots as soon as it's done loading.

My bochsrc file looks like this:

+---
romimage: file=$BXSHARE/BIOS-bochs-latest,address=0xf0000
megs: 2
vgaromimage: $BXSHARE/VGABIOS-elpin-2.40
floppya: 720k="los0.img", status=inserted
boot: a
log: bochsout.txt
panic: action=ask
error: action=report
info: action=report
debug: action=ignore
ips: 3000000
mouse: enabled=0
+---

I have also tried allowing 64 rather than 2 MB of memory.

The bochs screen does this:

+---
VGA BIOS - Version 2.40
[...]
Bochs BIOS
[...]

Booting from Floppy...
Loading Movitz 1875..
()()()()()()()()()()()()()() [...]
Enter..Ok
+---

at which point it restarts and happily does the same thing again.

The log file looks like this:

+---
00000000000i[     ] Bochs x86 Emulator 2.1
00000000000i[     ]   January 11, 2004
00000000000i[     ] System configuration
00000000000i[     ]   processors: 1
00000000000i[     ]   A20 line support: yes
00000000000i[     ]   APIC support: no
00000000000i[     ] CPU configuration
00000000000i[     ]   level: 5
00000000000i[     ]   fpu support: yes
00000000000i[     ]   paging support: yes, tlb enabled: yes
00000000000i[     ]   mmx support: yes
00000000000i[     ]   sse support: no
00000000000i[     ]   v8086 mode support: yes
00000000000i[     ]   3dnow! support: no
00000000000i[     ]   PAE support: no
00000000000i[     ]   PGE support: no
00000000000i[     ]   PSE support: no
00000000000i[     ]   x86-64 support: no
00000000000i[     ]   SEP support: no
00000000000i[     ] Optimization configuration
00000000000i[     ]   Guest2HostTLB support: no
00000000000i[     ]   RepeatSpeedups support: no
00000000000i[     ]   Icache support: no
00000000000i[     ]   Host Asm support: yes
00000000000i[MEM0 ] allocated memory at 0x505000. after alignment, 
vector=0x505000
00000000000i[MEM0 ] 2.00MB
00000000000i[MEM0 ] rom at 0xf0000/65536 ('./BIOS-bochs-latest')
00000000000i[MEM0 ] rom at 0xc0000/32769 ('./VGABIOS-elpin-2.40')
00000000000i[CMOS ] Using local time for initial clock
00000000000i[CMOS ] Setting initial clock to: Mon Jan 19 13:25:15 2004 
(time0=1074547515)
00000000000i[DMA  ] channel 4 used by cascade
00000000000i[DMA  ] channel 2 used by Floppy Drive
00000000000i[FDD  ] fd0: 'los0.img' ro=0, h=2,t=80,spt=9
00000000000i[XGUI ] test_alloc_colors: 16 colors available out of 16 
colors tried
00000000000i[XGUI ] font 8 wide x 16 high, display depth = 24
00000000000i[VGA  ] interval=30000
00000000000i[     ] init_mem of 'harddrv' plugin device by virtual 
method
00000000000i[     ] init_mem of 'keyboard' plugin device by virtual 
method
00000000000i[     ] init_mem of 'serial' plugin device by virtual method
00000000000i[     ] init_mem of 'parallel' plugin device by virtual 
method
00000000000i[     ] init_mem of 'extfpuirq' plugin device by virtual 
method
00000000000i[     ] init_dev of 'harddrv' plugin device by virtual 
method
00000000000i[HD   ] Boot device will be 'a'
00000000000i[HD   ] Floppy boot signature check is enabled
00000000000i[     ] init_dev of 'keyboard' plugin device by virtual 
method
00000000000i[KBD  ] will paste characters every 1000 keyboard ticks
00000000000i[     ] init_dev of 'serial' plugin device by virtual method
00000000000i[SER  ] com1 at 0x03f8 irq 4
00000000000i[     ] init_dev of 'parallel' plugin device by virtual 
method
00000000000i[PAR  ] parallel port 1 at 0x378 irq 7
00000000000i[     ] init_dev of 'extfpuirq' plugin device by virtual 
method
00000000000i[     ] reset of 'harddrv' plugin device by virtual method
00000000000i[     ] reset of 'keyboard' plugin device by virtual method
00000000000i[     ] reset of 'serial' plugin device by virtual method
00000000000i[     ] reset of 'parallel' plugin device by virtual method
00000000000i[     ] reset of 'extfpuirq' plugin device by virtual method
00000000000i[XGUI ] [x] Mouse off
00000003980i[BIOS ]  rombios.c,v 1.85 2002/12/13 16:26:17 cbothamy Exp $
00000090000e[VGA  ] character height = 1, skipping text update
00000180000e[VGA  ] character height = 1, skipping text update
00000270000e[VGA  ] character height = 1, skipping text update
00000360000e[VGA  ] character height = 1, skipping text update
00000450000e[VGA  ] character height = 1, skipping text update
00000540000e[VGA  ] character height = 1, skipping text update
00000540051i[KBD  ] reset-disable command received
00000630000e[VGA  ] character height = 1, skipping text update
00000720000i[XGUI ] charmap update. Font Height is 16
00012351354e[HD   ] device set to 0 which does not exist
00012351647e[HD   ] device set to 1 which does not exist
00013907541i[CPU  ] WBINVD: (ignoring)
00013907590e[CPU  ] load_seg_reg: LDT invalid
00013907590e[CPU  ] exception(): 3rd (13) exception with no resolution, 
shutdown status is 00h, resetting
00013911570i[BIOS ]  rombios.c,v 1.85 2002/12/13 16:26:17 cbothamy Exp $
00014340071i[KBD  ] reset-disable command received
00014490000i[XGUI ] charmap update. Font Height is 16
00026183802e[HD   ] device set to 0 which does not exist
00026184095e[HD   ] device set to 1 which does not exist
00027739971i[CPU  ] WBINVD: (ignoring)
00027740020e[CPU  ] load_seg_reg: LDT invalid
[repeats itself many times from here onwards]
+---

It boots up a FreeDOS floppy image just fine. Does anyone have an idea 
about what the problem might be?

I gather it must probably be contained in
"00013907541i[CPU  ] WBINVD: (ignoring)
00013907590e[CPU  ] load_seg_reg: LDT invalid
00013907590e[CPU  ] exception(): 3rd (13) exception with no resolution, 
shutdown status is 00h, resetting",
but I don't really now what WBINVD and LDT mean.

Also, when I get this running, I think I should post a sample bochsrc 
file to og along with the floppy image. As you see, they are short, but 
they can be quite tricky at times. I've previously spent many 
potentially productive hours getting some of the incantations right for 
more complicated virtual systems with hard drives, CDROMs and the like.

	/jaap

========================================================================
Jaap Weel                   Campus address:        | dorm (626) 795-9748
Caltech, Blacker '05        Caltech MSC #874, Pasadena, CA 91126, U.S.A.
www.its.caltech.edu/~weel   Permanent address:     | home +31-46-4337033
E-mail: weel at caltech.edu    Kelderstraat 2-4, 6171 GB Stein, Netherlands
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