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Kernel is not loading after Higher Half
Posted: Sat Oct 28, 2023 7:13 am
by leventkaya
Hello i am triying to move up my kernel as higher half kernel. I have tried this thread
viewtopic.php?f=1&t=28796 and updated my bootloader and linker script as follows:
loader.asm:
Code: Select all
bits 32
KERNEL_CS equ 0x08
KERNEL_DS equ 0x10
USERMODE_CS equ 0x18
USERMODE_DS equ 0x20
STACK_SIZE equ 0x1000 ; 4KB stack
MBOOT_PAGE_ALIGN equ 0x1
MBOOT_MEM_INFO equ 0x2
MBOOT_USE_GFX equ 0x4
MBOOT_HDR_MAGIC equ 0x1BADB002
MBOOT_HDR_FLAGS equ MBOOT_PAGE_ALIGN | MBOOT_MEM_INFO
MBOOT_CHECKSUM equ -(MBOOT_HDR_MAGIC + MBOOT_HDR_FLAGS)
KERNEL_VIRTUAL_BASE equ 0xC0000000
KERNEL_PAGE_NUM equ (KERNEL_VIRTUAL_BASE >> 22)
section .data
align 0x1000
boot_page_directory:
dd 0x00000083 ; First 4MB, which will be unmapped later
times (KERNEL_PAGE_NUM - 1) dd 0 ; Pages before kernel
dd 0x00000083 ; Kernel 4MB at 3GB offset
times (1024 - KERNEL_PAGE_NUM - 1) dd 0 ; Pages after kernel
section .text
align 4
multiboot:
dd MBOOT_HDR_MAGIC
dd MBOOT_HDR_FLAGS
dd MBOOT_CHECKSUM
extern kernel_main
global g_start
g_start:
mov ecx, (boot_page_directory - KERNEL_VIRTUAL_BASE)
mov cr3, ecx ; Load page directory
mov ecx, cr4
or ecx, 0x00000010 ; Set PSE bit in CR4 to enable 4MB pages
mov cr4, ecx
mov ecx, cr0
or ecx, 0x80000000 ; Set PG bit in CR0 to enable paging
mov cr0, ecx
lea ecx, [start_higher_half]
jmp ecx ; Absolute jump!!
start_higher_half:
mov dword [boot_page_directory], 0
invlpg [0]
mov esp, kernel_stack_top
push eax
add ebx, KERNEL_VIRTUAL_BASE
push ebx
cli
call kernel_main
cli
.hang:
hlt
jmp .hang
section .bss
global kernel_stack_bottom
global kernel_stack_top
global main_thread_addr
main_thread_addr:
resb THREAD_CONTEXT_SIZE
kernel_stack_bottom:
resb STACK_SIZE
kernel_stack_top:
linked.ld:
Code: Select all
OUTPUT_FORMAT(elf32-i386)
ENTRY(g_start)
phys = 0x100000;
offset = 0xC0000000;
virt = offset + phys;
SECTIONS
{
. = virt;
.text : AT(ADDR(.text) - offset) {
g_code = .;
*(.text)
*(.rodata)
. = ALIGN(0x1000);
}
.data : AT(ADDR(.data) - offset) {
g_data = .;
*(.data)
. = ALIGN(0x1000);
}
.bss : AT(ADDR(.bss) - offset) {
g_bss = .;
*(COMMON)
*(.bss)
. = ALIGN(0x1000);
}
g_end = .;
/DISCARD/ : {
*(.comment)
*(.eh_frame)
*(.note.gnu.build-id)
}
}
when i try to run my kernel this is the qemu error that i faced:
It quickly returns the os selection screen and a loop starts. This is the error that i get from virtualbox:
I am dealing with this issue for a quite long time. I dont know what is missing or wrong. I will be thankfull for any comments.
Re: Kernel is not loading after Higher Half
Posted: Sat Oct 28, 2023 2:34 pm
by Octocontrabass
That sounds like a triple fault. QEMU's default behavior is to reboot when there's a triple fault, whereas VirtualBox's default behavior is to report an error.
You can use QEMU to examine the problem by adding "-d int" and "-no-reboot" to your QEMU command line. QEMU will log the exceptions that lead up to the triple fault. You can share the log here if you're not sure how to interpret it.
VirtualBox also has logging capabilities that should provide similar information, and you can share that log instead if you prefer. (But not as many people use VirtualBox for debugging, so you may not get as much help.)
Re: Kernel is not loading after Higher Half
Posted: Sun Oct 29, 2023 7:37 am
by leventkaya
Hi Octocontrabass for your reply. this is my log output with your given advice:
Code: Select all
SMM: enter
EAX=00000001 EBX=00000000 ECX=02000000 EDX=02000628
ESI=0000000b EDI=02000000 EBP=00014900 ESP=00006c5c
EIP=000e9bb1 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= 000f6180 00000037
IDT= 000f61be 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=00014900 ESP=00006c5c
EIP=000e9bb1 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= 000f6180 00000037
IDT= 000f61be 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=000f7d2a ECX=00001234 EDX=00006cff
ESI=00006cb8 EDI=07fbec71 EBP=00006c78 ESP=00006c78
EIP=00007d29 EFL=00000006 [-----P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =d980 000d9800 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=00000004 CCD=00006c78 CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=000f7d2a ECX=00001234 EDX=00006cff
ESI=00006cb8 EDI=07fbec71 EBP=00006c78 ESP=00006c78
EIP=000f7d2a 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= 000f6180 00000037
IDT= 000f61be 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=00007d44 ECX=00005678 EDX=07fa91c0
ESI=000e8d00 EDI=07fbec71 EBP=00006c78 ESP=00006c78
EIP=000f7d43 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= 000f6180 00000037
IDT= 000f61be 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000010 CCD=00006c64 CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=00007d44 ECX=00005678 EDX=07fa91c0
ESI=000e8d00 EDI=07fbec71 EBP=00006c78 ESP=00006c78
EIP=00007d44 EFL=00000006 [-----P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =d980 000d9800 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=00000004 CCD=00000001 CCO=EFLAGS
EFER=0000000000000000
SMM: enter
EAX=000000b5 EBX=000f7d2a ECX=00001234 EDX=000069ff
ESI=0000699e EDI=07fbec71 EBP=0000695e ESP=0000695e
EIP=00007d29 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =d980 000d9800 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=0000695e CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=000f7d2a ECX=00001234 EDX=000069ff
ESI=0000699e EDI=07fbec71 EBP=0000695e ESP=0000695e
EIP=000f7d2a 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= 000f6180 00000037
IDT= 000f61be 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=00007d44 ECX=00005678 EDX=00000005
ESI=00000000 EDI=07fbec71 EBP=0000695e ESP=0000695e
EIP=000f7d43 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= 000f6180 00000037
IDT= 000f61be 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000010 CCD=0000694a CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=00007d44 ECX=00005678 EDX=00000005
ESI=00000000 EDI=07fbec71 EBP=0000695e ESP=0000695e
EIP=00007d44 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =d980 000d9800 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=000f7d2a ECX=00001234 EDX=000069ff
ESI=00006998 EDI=07fbec71 EBP=00006958 ESP=00006958
EIP=00007d29 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =d980 000d9800 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=00006958 CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=000f7d2a ECX=00001234 EDX=000069ff
ESI=00006998 EDI=07fbec71 EBP=00006958 ESP=00006958
EIP=000f7d2a 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= 000f6180 00000037
IDT= 000f61be 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=00007d44 ECX=00005678 EDX=00000003
ESI=07f8b590 EDI=07fbec71 EBP=00006958 ESP=00006958
EIP=000f7d43 EFL=00000016 [----AP-] 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= 000f6180 00000037
IDT= 000f61be 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000014 CCD=00006944 CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=00007d44 ECX=00005678 EDX=00000003
ESI=07f8b590 EDI=07fbec71 EBP=00006958 ESP=00006958
EIP=00007d44 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =d980 000d9800 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=000f7d2a ECX=00001234 EDX=000069ff
ESI=0000699e EDI=07fbec71 EBP=0000695e ESP=0000695e
EIP=00007d29 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =d980 000d9800 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=0000695e CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=000f7d2a ECX=00001234 EDX=000069ff
ESI=0000699e EDI=07fbec71 EBP=0000695e ESP=0000695e
EIP=000f7d2a 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= 000f6180 00000037
IDT= 000f61be 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=00007d44 ECX=00005678 EDX=00000005
ESI=00000000 EDI=07fbec71 EBP=0000695e ESP=0000695e
EIP=000f7d43 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= 000f6180 00000037
IDT= 000f61be 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000010 CCD=0000694a CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=00007d44 ECX=00005678 EDX=00000005
ESI=00000000 EDI=07fbec71 EBP=0000695e ESP=0000695e
EIP=00007d44 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =d980 000d9800 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=000f7d2a ECX=00001234 EDX=000069ff
ESI=00006998 EDI=07fbec71 EBP=00006958 ESP=00006958
EIP=00007d29 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =d980 000d9800 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=00006958 CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=000f7d2a ECX=00001234 EDX=000069ff
ESI=00006998 EDI=07fbec71 EBP=00006958 ESP=00006958
EIP=000f7d2a 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= 000f6180 00000037
IDT= 000f61be 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=00007d44 ECX=00005678 EDX=00000003
ESI=07ecb590 EDI=07fbec71 EBP=00006958 ESP=00006958
EIP=000f7d43 EFL=00000016 [----AP-] 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= 000f6180 00000037
IDT= 000f61be 00000000
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000014 CCD=00006944 CCO=EFLAGS
EFER=0000000000000000
SMM: after RSM
EAX=000000b5 EBX=00007d44 ECX=00005678 EDX=00000003
ESI=07ecb590 EDI=07fbec71 EBP=00006958 ESP=00006958
EIP=00007d44 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =d980 000d9800 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
check_exception old: 0xffffffff new 0xe
0: v=0e e=0002 i=0 cpl=0 IP=0008:00000000c0100250 pc=00000000c0100250 SP=0010:00000000c0106f04 CR2=00000000000b8000
EAX=0000075b EBX=000b8000 ECX=00000000 EDX=00000700
ESI=00000000 EDI=00000000 EBP=00000000 ESP=c0106f04
EIP=c0100250 EFL=00000092 [--S-A--] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0010 00000000 ffffffff 00cf9300 DPL=0 DS [-WA]
CS =0008 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= c0107008 00000017
IDT= 00000000 00000000
CR0=80000011 CR2=000b8000 CR3=00104000 CR4=00000010
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000008 CCD=c0106f04 CCO=ADDL
EFER=0000000000000000
check_exception old: 0xe new 0xd
1: v=08 e=0000 i=0 cpl=0 IP=0008:00000000c0100250 pc=00000000c0100250 SP=0010:00000000c0106f04 env->regs[R_EAX]=000000000000075b
EAX=0000075b EBX=000b8000 ECX=00000000 EDX=00000700
ESI=00000000 EDI=00000000 EBP=00000000 ESP=c0106f04
EIP=c0100250 EFL=00000092 [--S-A--] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0010 00000000 ffffffff 00cf9300 DPL=0 DS [-WA]
CS =0008 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= c0107008 00000017
IDT= 00000000 00000000
CR0=80000011 CR2=000b8000 CR3=00104000 CR4=00000010
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400
CCS=00000008 CCD=c0106f04 CCO=ADDL
EFER=0000000000000000
check_exception old: 0x8 new 0xd
i think the issue with GDT but im not sure
Re: Kernel is not loading after Higher Half
Posted: Sun Oct 29, 2023 12:58 pm
by nullplan
Ignoring the SMM output, the last three exceptions are causing the problems. You see where it says "check_exception old: 0xffffffff new 0xe"? That means it has a new page fault. The fault address (CR2) is 0xb8000, so that means you are not mapping it. The error code is 2, which means you tried to write to a nonexistent page in supervisor mode.
You then immediately get a GPF with error code 0. No clue what this means. The IDT entry seemed correct in the entry above that. But I do see that GPF and PF use the same exception handler (at 0xc0100250). That cannot possibly work, since the handler address itself is the only way to tell the exceptions apart. And then of course it tries for a double fault.
Re: Kernel is not loading after Higher Half
Posted: Sun Oct 29, 2023 1:54 pm
by Octocontrabass
Code: Select all
check_exception old: 0xffffffff new 0xe
0: v=0e
It's a page fault.
It's a page fault caused by a supervisor write to an unmapped page.
It's a page fault caused by a supervisor write to an unmapped page at virtual address 0xB8000. I think that's enough information to find the problem...
(Afterwards there's a double fault because the bootloader's IDT is also in an unmapped page, and then a triple fault for the same reason. You can ignore those because you haven't set up your IDT yet.)
Re: Kernel is not loading after Higher Half
Posted: Mon Oct 30, 2023 5:14 am
by leventkaya
hi nullplan and Octocontrabass i dont know how to thank you guys, thank you for this great explanation omw to fix it thanks