OSDev.org

Posted: **Sat Feb 07, 2015 6:46 am**

So yeah, the title should explain it quite bit even if it is not descriptive. I am having triple faults for some reason and I cannot figure out why. People in the IRC have told me to use Bochs but I just can't do it because it crashes saying that "Message: dlopen failed for module 'usb_uhci': /usr/lib64/bochs/plugins/libbx_usb_uhci.so: undefined symbol: _ZTV12usb_device_c".

So can any of you gurus guide me to the right direction in this?

The crash dump of QEMU:

Code: Select all

Triple fault
CPU Reset (CPU 0)
EAX=00100010 EBX=00010000 ECX=ffffffff EDX=00000000
ESI=00000000 EDI=00000000 EBP=00000000 ESP=0010687c
EIP=001002fd EFL=00200046 [---Z-P-] CPL=0 II=1 A20=1 SMM=0 HLT=0
ES =0010 00000000 ffffffff 00cf9300 DPL=0 DS   [-WA]
CS =0010 00000000 ffffffff 00cf9a00 DPL=0 CS32 [-R-]
SS =0010 00000000 ffffffff 00cf9300 DPL=0 DS   [-WA]
DS =0010 00000000 ffffffff 00cf9300 DPL=0 DS   [-WA]
FS =0010 00000000 ffffffff 00cf9300 DPL=0 DS   [-WA]
GS =0010 00000000 ffffffff 00cf9300 DPL=0 DS   [-WA]
LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT=     00102040 00000027
IDT=     00000000 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=00000000 DR1=00000000 DR2=00000000 DR3=00000000 
DR6=ffff0ff0 DR7=00000400
CCS=0000001c CCD=00106880 CCO=CLR     
EFER=0000000000000000
FCW=037f FSW=0000 [ST=0] FTW=00 MXCSR=00001f80
FPR0=0000000000000000 0000 FPR1=0000000000000000 0000
FPR2=0000000000000000 0000 FPR3=0000000000000000 0000
FPR4=0000000000000000 0000 FPR5=0000000000000000 0000
FPR6=0000000000000000 0000 FPR7=0000000000000000 0000
XMM00=00000000000000000000000000000000 XMM01=00000000000000000000000000000000
XMM02=00000000000000000000000000000000 XMM03=00000000000000000000000000000000
XMM04=00000000000000000000000000000000 XMM05=00000000000000000000000000000000
XMM06=00000000000000000000000000000000 XMM07=00000000000000000000000000000000

CPU Reset (CPU 0)
EAX=00000032 EBX=00000000 ECX=00000000 EDX=0000002f
ESI=0000000a EDI=00100000 EBP=00000000 ESP=00000fc8
EIP=000f1a3a EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0010 00000000 ffffffff 00cf9300 DPL=0 DS   [-WA]
CS =0008 00000000 ffffffff 00cf9b00 DPL=0 CS32 [-RA]
SS =0010 00000000 ffffffff 00cf9300 DPL=0 DS   [-WA]
DS =0010 00000000 ffffffff 00cf9300 DPL=0 DS   [-WA]
FS =0010 00000000 ffffffff 00cf9300 DPL=0 DS   [-WA]
GS =0010 00000000 ffffffff 00cf9300 DPL=0 DS   [-WA]
LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT=     000f6c58 00000037
IDT=     000f6c96 00000000
CR0=60000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=00000000 DR1=00000000 DR2=00000000 DR3=00000000 
DR6=ffff0ff0 DR7=00000400
CCS=00000004 CCD=00000001 CCO=LOGICL  
EFER=0000000000000000
FCW=037f FSW=0000 [ST=0] FTW=00 MXCSR=00001f80
FPR0=0000000000000000 0000 FPR1=0000000000000000 0000
FPR2=0000000000000000 0000 FPR3=0000000000000000 0000
FPR4=0000000000000000 0000 FPR5=0000000000000000 0000
FPR6=0000000000000000 0000 FPR7=0000000000000000 0000
XMM00=00000000000000000000000000000000 XMM01=00000000000000000000000000000000
XMM02=00000000000000000000000000000000 XMM03=00000000000000000000000000000000
XMM04=00000000000000000000000000000000 XMM05=00000000000000000000000000000000
XMM06=00000000000000000000000000000000 XMM07=00000000000000000000000000000000

My flush_idt function,
My flush_gdt,
Primary GDT code and
My IDT code.

Posted: **Sat Feb 07, 2015 6:54 am**

Jiias wrote:People in the IRC have told me to use Bochs but I just can't do it because it crashes saying that "Message: dlopen failed for module 'usb_uhci': /usr/lib64/bochs/plugins/libbx_usb_uhci.so: undefined symbol: _ZTV12usb_device_c".

Did you try building Bochs from source? It isn't difficult and Bochs helps a lot during OS debugging.

Posted: **Sat Feb 07, 2015 6:57 am**

For starters, have a look at the code at that EIP location. That should give you a hint as to where the exception is happening. The stack, which you can examine from the qemu monitor, should also tell you how you got there.

This failure is a good thing; it gives you a chance to learn how to debug.

OSDev.org

A question about a triple fault

A question about a triple fault

Re: A question about a triple fault

Re: A question about a triple fault