Draw directly to framebuffer in stivale2?

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kspatlas
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Draw directly to framebuffer in stivale2?

Post by kspatlas »

So, I'm writing a kernel that uses stivale2. I want to draw drectly to the framebuffer, so i tried using the method described in the stivale1 part (replacing stivale_struct with STIVALE2_STRUCT_TAG_FRAMEBUFFER). This just caused my kernel to bootloop. Help?

The wiki article I used: Stivale_Bare_Bones
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Octocontrabass
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Re: Draw directly to framebuffer in stivale2?

Post by Octocontrabass »

Have you tried using a debugger to track down what's causing the triple fault?

Have you tried configuring your virtual machine to dump the CPU state when it triple faults so you can see what it's doing when that happens?

You'll have to share your code if you want more specific suggestions than those. (But it's a good idea to learn how to debug now, while the problems are easy to find.)
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kspatlas
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Re: Draw directly to framebuffer in stivale2?

Post by kspatlas »

So i removed all the terminal code (prevent collisions) and it's not an issue with getting the address, it only crashes when writing to it.
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nexos
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Re: Draw directly to framebuffer in stivale2?

Post by nexos »

If you are using QEMU, try passing

Code: Select all

-d int -no-reboot
and it will give you the exception that caused the triple fault. That will help you and us debug. If you are in Bochs, look at the log it gives you for this.
"How did you do this?"
"It's very simple — you read the protocol and write the code." - Bill Joy
Projects: NexNix | libnex | nnpkg
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kspatlas
Posts: 7
Joined: Mon Aug 16, 2021 12:53 pm
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Re: Draw directly to framebuffer in stivale2?

Post by kspatlas »

it is a bit big but here is the output of those qemu options

Code: Select all

SMM: enter
EAX=00000001 EBX=00000000 ECX=02000000 EDX=02000628
ESI=0000000b EDI=02000000 EBP=000f254b ESP=00006ce0
EIP=000eaee6 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=     000f62c0 00000037
IDT=     000f62fe 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000080 CCD=00000001 CCO=LOGICB
EFER=0000000000000000
SMM: after RSM
EAX=00000001 EBX=00000000 ECX=02000000 EDX=02000628
ESI=0000000b EDI=02000000 EBP=000f254b ESP=00006ce0
EIP=000eaee6 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
CS =0008 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]
SS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
FS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
GS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT=     000f62c0 00000037
IDT=     000f62fe 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000000 CCD=00000000 CCO=EFLAGS
EFER=0000000000000000
SMM: enter
EAX=000000b5 EBX=000f7dc9 ECX=00001234 EDX=00006cff
ESI=00006c80 EDI=07fbec8f EBP=00006c40 ESP=00006c40
EIP=00007dc8 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =db00 000db000 ffffffff 008f9300
CS =f000 000f0000 ffffffff 008f9b00
SS =0000 00000000 ffffffff 008f9300
DS =0000 00000000 ffffffff 008f9300
FS =0000 00000000 ffffffff 008f9300
GS =0000 00000000 ffffffff 008f9300
LDT=0000 00000000 0000ffff 00008200
TR =0000 00000000 0000ffff 00008b00
GDT=     00000000 00000000
IDT=     00000000 000003ff
CR0=00000010 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000000 CCD=00006c40 CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=000f7dc9 ECX=00001234 EDX=00006cff
ESI=00006c80 EDI=07fbec8f EBP=00006c40 ESP=00006c40
EIP=000f7dc9 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
CS =0008 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]
SS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
FS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
GS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT=     000f62c0 00000037
IDT=     000f62fe 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000000 CCD=00000000 CCO=EFLAGS
EFER=0000000000000000
SMM: enter
EAX=000000b5 EBX=00007de3 ECX=00005678 EDX=07fa9220
ESI=000ea060 EDI=07fbec8f EBP=00006c40 ESP=00006c40
EIP=000f7de2 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
CS =0008 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]
SS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
FS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
GS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT=     000f62c0 00000037
IDT=     000f62fe 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000000 CCD=00006c2c CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=00007de3 ECX=00005678 EDX=07fa9220
ESI=000ea060 EDI=07fbec8f EBP=00006c40 ESP=00006c40
EIP=00007de3 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =db00 000db000 ffffffff 00809300
CS =f000 000f0000 ffffffff 00809b00
SS =0000 00000000 ffffffff 00809300
DS =0000 00000000 ffffffff 00809300
FS =0000 00000000 ffffffff 00809300
GS =0000 00000000 ffffffff 00809300
LDT=0000 00000000 0000ffff 00008200
TR =0000 00000000 0000ffff 00008b00
GDT=     00000000 00000000
IDT=     00000000 000003ff
CR0=00000010 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000000 CCD=00000001 CCO=EFLAGS
EFER=0000000000000000
SMM: enter
EAX=000000b5 EBX=000f7dc9 ECX=00001234 EDX=000069ff
ESI=0000696a EDI=07fbec8f EBP=0000692a ESP=0000692a
EIP=00007dc8 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =db00 000db000 ffffffff 008f9300
CS =f000 000f0000 ffffffff 008f9b00
SS =0000 00000000 ffffffff 008f9300
DS =0000 00000000 ffffffff 008f9300
FS =0000 00000000 ffffffff 008f9300
GS =ca00 000ca000 ffffffff 008f9300
LDT=0000 00000000 0000ffff 00008200
TR =0000 00000000 0000ffff 00008b00
GDT=     00000000 00000000
IDT=     00000000 000003ff
CR0=00000010 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000000 CCD=0000692a CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=000f7dc9 ECX=00001234 EDX=000069ff
ESI=0000696a EDI=07fbec8f EBP=0000692a ESP=0000692a
EIP=000f7dc9 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
CS =0008 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]
SS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
FS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
GS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT=     000f62c0 00000037
IDT=     000f62fe 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000000 CCD=00000000 CCO=EFLAGS
EFER=0000000000000000
SMM: enter
EAX=000000b5 EBX=00007de3 ECX=00005678 EDX=00000005
ESI=00000000 EDI=07fbec8f EBP=0000692a ESP=0000692a
EIP=000f7de2 EFL=00000012 [----A--] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
CS =0008 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]
SS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
FS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
GS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT=     000f62c0 00000037
IDT=     000f62fe 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000010 CCD=00006916 CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=00007de3 ECX=00005678 EDX=00000005
ESI=00000000 EDI=07fbec8f EBP=0000692a ESP=0000692a
EIP=00007de3 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =db00 000db000 ffffffff 00809300
CS =f000 000f0000 ffffffff 00809b00
SS =0000 00000000 ffffffff 00809300
DS =0000 00000000 ffffffff 00809300
FS =0000 00000000 ffffffff 00809300
GS =ca00 000ca000 ffffffff 00809300
LDT=0000 00000000 0000ffff 00008200
TR =0000 00000000 0000ffff 00008b00
GDT=     00000000 00000000
IDT=     00000000 000003ff
CR0=00000010 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000000 CCD=00000001 CCO=EFLAGS
EFER=0000000000000000
SMM: enter
EAX=000000b5 EBX=000f7dc9 ECX=00001234 EDX=000069ff
ESI=00006964 EDI=07fbec8f EBP=00006924 ESP=00006924
EIP=00007dc8 EFL=00000006 [-----P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =db00 000db000 ffffffff 00809300
CS =f000 000f0000 ffffffff 00809b00
SS =0000 00000000 ffffffff 00809300
DS =0000 00000000 ffffffff 00809300
FS =0000 00000000 ffffffff 00809300
GS =ca00 000ca000 ffffffff 00809300
LDT=0000 00000000 0000ffff 00008200
TR =0000 00000000 0000ffff 00008b00
GDT=     00000000 00000000
IDT=     00000000 000003ff
CR0=00000010 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000004 CCD=00006924 CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=000f7dc9 ECX=00001234 EDX=000069ff
ESI=00006964 EDI=07fbec8f EBP=00006924 ESP=00006924
EIP=000f7dc9 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
CS =0008 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]
SS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
FS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
GS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT=     000f62c0 00000037
IDT=     000f62fe 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000000 CCD=00000000 CCO=EFLAGS
EFER=0000000000000000
SMM: enter
EAX=000000b5 EBX=00007de3 ECX=00005678 EDX=00000003
ESI=07f915f0 EDI=07fbec8f EBP=00006924 ESP=00006924
EIP=000f7de2 EFL=00000012 [----A--] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
CS =0008 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]
SS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
FS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
GS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT=     000f62c0 00000037
IDT=     000f62fe 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000010 CCD=00006910 CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=00007de3 ECX=00005678 EDX=00000003
ESI=07f915f0 EDI=07fbec8f EBP=00006924 ESP=00006924
EIP=00007de3 EFL=00000006 [-----P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =db00 000db000 ffffffff 00809300
CS =f000 000f0000 ffffffff 00809b00
SS =0000 00000000 ffffffff 00809300
DS =0000 00000000 ffffffff 00809300
FS =0000 00000000 ffffffff 00809300
GS =ca00 000ca000 ffffffff 00809300
LDT=0000 00000000 0000ffff 00008200
TR =0000 00000000 0000ffff 00008b00
GDT=     00000000 00000000
IDT=     00000000 000003ff
CR0=00000010 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000004 CCD=00000001 CCO=EFLAGS
EFER=0000000000000000
SMM: enter
EAX=000000b5 EBX=000f7dc9 ECX=00001234 EDX=000069ff
ESI=0000696a EDI=07fbec8f EBP=0000692a ESP=0000692a
EIP=00007dc8 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =db00 000db000 ffffffff 00809300
CS =f000 000f0000 ffffffff 00809b00
SS =0000 00000000 ffffffff 00809300
DS =0000 00000000 ffffffff 00809300
FS =0000 00000000 ffffffff 00809300
GS =ca00 000ca000 ffffffff 00809300
LDT=0000 00000000 0000ffff 00008200
TR =0000 00000000 0000ffff 00008b00
GDT=     00000000 00000000
IDT=     00000000 000003ff
CR0=00000010 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000000 CCD=0000692a CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=000f7dc9 ECX=00001234 EDX=000069ff
ESI=0000696a EDI=07fbec8f EBP=0000692a ESP=0000692a
EIP=000f7dc9 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
CS =0008 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]
SS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
FS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
GS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT=     000f62c0 00000037
IDT=     000f62fe 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000000 CCD=00000000 CCO=EFLAGS
EFER=0000000000000000
SMM: enter
EAX=000000b5 EBX=00007de3 ECX=00005678 EDX=00000005
ESI=00000000 EDI=07fbec8f EBP=0000692a ESP=0000692a
EIP=000f7de2 EFL=00000012 [----A--] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
CS =0008 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]
SS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
FS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
GS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT=     000f62c0 00000037
IDT=     000f62fe 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000010 CCD=00006916 CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=00007de3 ECX=00005678 EDX=00000005
ESI=00000000 EDI=07fbec8f EBP=0000692a ESP=0000692a
EIP=00007de3 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =db00 000db000 ffffffff 00809300
CS =f000 000f0000 ffffffff 00809b00
SS =0000 00000000 ffffffff 00809300
DS =0000 00000000 ffffffff 00809300
FS =0000 00000000 ffffffff 00809300
GS =ca00 000ca000 ffffffff 00809300
LDT=0000 00000000 0000ffff 00008200
TR =0000 00000000 0000ffff 00008b00
GDT=     00000000 00000000
IDT=     00000000 000003ff
CR0=00000010 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000000 CCD=00000001 CCO=EFLAGS
EFER=0000000000000000
SMM: enter
EAX=000000b5 EBX=000f7dc9 ECX=00001234 EDX=000069ff
ESI=00006964 EDI=07fbec8f EBP=00006924 ESP=00006924
EIP=00007dc8 EFL=00000006 [-----P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =db00 000db000 ffffffff 00809300
CS =f000 000f0000 ffffffff 00809b00
SS =0000 00000000 ffffffff 00809300
DS =0000 00000000 ffffffff 00809300
FS =0000 00000000 ffffffff 00809300
GS =ca00 000ca000 ffffffff 00809300
LDT=0000 00000000 0000ffff 00008200
TR =0000 00000000 0000ffff 00008b00
GDT=     00000000 00000000
IDT=     00000000 000003ff
CR0=00000010 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000004 CCD=00006924 CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=000f7dc9 ECX=00001234 EDX=000069ff
ESI=00006964 EDI=07fbec8f EBP=00006924 ESP=00006924
EIP=000f7dc9 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
CS =0008 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]
SS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
FS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
GS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT=     000f62c0 00000037
IDT=     000f62fe 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000000 CCD=00000000 CCO=EFLAGS
EFER=0000000000000000
SMM: enter
EAX=000000b5 EBX=00007de3 ECX=00005678 EDX=00000003
ESI=07ef15f0 EDI=07fbec8f EBP=00006924 ESP=00006924
EIP=000f7de2 EFL=00000012 [----A--] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
CS =0008 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]
SS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
FS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
GS =0010 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT=     000f62c0 00000037
IDT=     000f62fe 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000010 CCD=00006910 CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=00007de3 ECX=00005678 EDX=00000003
ESI=07ef15f0 EDI=07fbec8f EBP=00006924 ESP=00006924
EIP=00007de3 EFL=00000006 [-----P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =db00 000db000 ffffffff 00809300
CS =f000 000f0000 ffffffff 00809b00
SS =0000 00000000 ffffffff 00809300
DS =0000 00000000 ffffffff 00809300
FS =0000 00000000 ffffffff 00809300
GS =ca00 000ca000 ffffffff 00809300
LDT=0000 00000000 0000ffff 00008200
TR =0000 00000000 0000ffff 00008b00
GDT=     00000000 00000000
IDT=     00000000 000003ff
CR0=00000010 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000004 CCD=00000001 CCO=EFLAGS
EFER=0000000000000000
check_exception old: 0xffffffff new 0xd
     0: v=0d e=0000 i=0 cpl=0 IP=0028:ffffffff802000f0 pc=ffffffff802000f0 SP=0030:ffffffff802033d8 env->regs[R_EAX]=f000ff54f000ff53
RAX=f000ff54f000ff53 RBX=0000000000000000 RCX=0000000000000000 RDX=f000ff54f000ffd3
RSI=0000000000000000 RDI=ffff8000000238e0 RBP=0000000000000000 RSP=ffffffff802033d8
R8 =0000000000000000 R9 =0000000000000000 R10=0000000000000000 R11=0000000000000000
R12=0000000000000000 R13=0000000000000000 R14=0000000000000000 R15=0000000000000000
RIP=ffffffff802000f0 RFL=00000096 [--S-AP-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0030 0000000000000000 00000000 00009300 DPL=0 DS   [-WA]
CS =0028 0000000000000000 00000000 00209a00 DPL=0 CS64 [-R-]
SS =0030 0000000000000000 00000000 00009300 DPL=0 DS   [-WA]
DS =0030 0000000000000000 00000000 00009300 DPL=0 DS   [-WA]
FS =0030 0000000000000000 00000000 00009300 DPL=0 DS   [-WA]
GS =0030 0000000000000000 00000000 00009300 DPL=0 DS   [-WA]
LDT=0000 0000000000000000 00000000 00008200 DPL=0 LDT
TR =0000 0000000000000000 0000ffff 00008b00 DPL=0 TSS64-busy
GDT=     000000000000d7e0 00000037
IDT=     0000000000000000 00000000
CR0=80000011 CR2=0000000000000000 CR3=0000000007f7e000 CR4=00000020
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=0000000000000094 CCD=ffffffff802033d8 CCO=EFLAGS
EFER=0000000000000d00
check_exception old: 0xd new 0xd
     1: v=08 e=0000 i=0 cpl=0 IP=0028:ffffffff802000f0 pc=ffffffff802000f0 SP=0030:ffffffff802033d8 env->regs[R_EAX]=f000ff54f000ff53
RAX=f000ff54f000ff53 RBX=0000000000000000 RCX=0000000000000000 RDX=f000ff54f000ffd3
RSI=0000000000000000 RDI=ffff8000000238e0 RBP=0000000000000000 RSP=ffffffff802033d8
R8 =0000000000000000 R9 =0000000000000000 R10=0000000000000000 R11=0000000000000000
R12=0000000000000000 R13=0000000000000000 R14=0000000000000000 R15=0000000000000000
RIP=ffffffff802000f0 RFL=00000096 [--S-AP-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0030 0000000000000000 00000000 00009300 DPL=0 DS   [-WA]
CS =0028 0000000000000000 00000000 00209a00 DPL=0 CS64 [-R-]
SS =0030 0000000000000000 00000000 00009300 DPL=0 DS   [-WA]
DS =0030 0000000000000000 00000000 00009300 DPL=0 DS   [-WA]
FS =0030 0000000000000000 00000000 00009300 DPL=0 DS   [-WA]
GS =0030 0000000000000000 00000000 00009300 DPL=0 DS   [-WA]
LDT=0000 0000000000000000 00000000 00008200 DPL=0 LDT
TR =0000 0000000000000000 0000ffff 00008b00 DPL=0 TSS64-busy
GDT=     000000000000d7e0 00000037
IDT=     0000000000000000 00000000
CR0=80000011 CR2=0000000000000000 CR3=0000000007f7e000 CR4=00000020
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=0000000000000094 CCD=ffffffff802033d8 CCO=EFLAGS
EFER=0000000000000d00
check_exception old: 0x8 new 0xd
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nexos
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Re: Draw directly to framebuffer in stivale2?

Post by nexos »

That is a general protection fault. After looking at the Stivale code, nothing jumps out at me that would cause a #GP. Try running under Bochs using its ASM level debugger. This way, you can see the assembly instructions as the execute. That provides a lot of incite into these kind of bugs.
"How did you do this?"
"It's very simple — you read the protocol and write the code." - Bill Joy
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kspatlas
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Re: Draw directly to framebuffer in stivale2?

Post by kspatlas »

I think what is going on is that attempting to write to the memory overwrites the kernel. Is there any way to load the kernel a bit later in memory?
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Octocontrabass
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Posts: 5563
Joined: Mon Mar 25, 2013 7:01 pm

Re: Draw directly to framebuffer in stivale2?

Post by Octocontrabass »

kspatlas wrote:

Code: Select all

RAX=f000ff54f000ff53 [...] RDX=f000ff54f000ffd3
That's the BIOS IVT. You have a null pointer dereference somewhere.
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