Nigel
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BarinkOS
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Page faults and protetion faults will now hang with a helpful message 

to explain what is going on.

I removed previously set barriers from the code to load
the kernel further.
dev
Nigel Barink 2022-08-19 00:44:52 +02:00
parent 7d6c823d79
commit d280aa0584
7 changed files with 145 additions and 30 deletions
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1
Makefile
View File

@ -37,6 +37,7 @@ run: all
$(EMULATOR) -cdrom build/barinkOS.iso -serial stdio -vga std -display gtk -m 2G -cpu core2duo
debug: all
objcopy --only-keep-debug build/myos.bin kernel.sym
$(EMULATOR) -cdrom build/barinkOS.iso -serial stdio -vga std -display gtk -m 2G -cpu core2duo -s -d int
build_kernel: $(OBJ_LINK_LIST)

80
src/kernel/Interrupts/idt/idt.cpp
View File

@ -1,10 +1,11 @@
#include "idt.h"
#include "../../Drivers/PIT/pit.h"
#include "../../Drivers/PS-2/keyboard.h"
#include "../../cpu.h"
IDT_entry idt_table[256];
IDT_ptr idt_ptr;
void set_id_entry (uint8_t num , uint32_t base, uint16_t sel, uint8_t flags){
idt_table[num].offset_1 = base & 0xFFFF;
idt_table[num].selector = sel;
@ -15,7 +16,7 @@ void set_id_entry (uint8_t num , uint32_t base, uint16_t sel, uint8_t flags){
};
void irs_handler (registers regs) {
uint32_t FaultingAddress;
//printf("(IRS) Interrupt number: %d \r", regs.int_no);
switch (regs.int_no)
{
@ -120,28 +121,83 @@ void irs_handler (registers regs) {
case 13:
// General Protection Exception #GP
printf("#GP\n");
printf("EIP: 0x%x\n", regs.eip);
printf("EAX: 0x%x\n", regs.eax);
printf("EBP: 0x%x\n", regs.ebp);
printf("ERR_CODE: 0x%x", regs.err_code);
if( regs.err_code & 0x1)
{
printf("Originated externally!");
}
if(regs.err_code & 0x3 >> 1 == 0 ){
printf("Index references GDT");
}
if(regs.err_code & 0x3 >> 1 == 1 ){
printf("Index references IDT");
}
if(regs.err_code & 0x3 >> 1 == 2 ){
printf("Index references LDT");
}
if(regs.err_code & 0x3 >> 1 == 4 ){
printf("Index references IDT");
}
printf("Index: ", (regs.err_code >> 3 & 0xFFF ) );
__asm__("cli;" "1: hlt;" "jmp 1b;");
break;
case 14:
// Page Fault Exception #PF
printf("#PF\n");
printf("EIP: 0x%x\n", regs.eip); // Points to faulting instruction ???
printf("EAX: 0x%x\n", regs.eax);
printf("EBP: 0x%x\n", regs.ebp); // Base pointer pointing to the bottom of the stack
FaultingAddress = GetCR2();
printf("Faulting instruction adddress: 0x%x\n", FaultingAddress);
// Error code of 32 bits are on the stack
// CR2 register contains the 32-bit linear address that generated the exception
// CR2 register contains the 32-bit linear virtual address that generated the exception
// See Intel Software Developers manual Volume 3A Part 1 page 236 for more info
#define PF_ERR_PRESENT_BIT 0x1
#define PF_ERR_WRITE_BIT 0x2
#define PF_ERR_USER_BIT 0x3
#define PF_ERR_RESERVERD_WRITE_BIT 0x4
#define PF_ERR_INSTRUCTION_FETCH_BIT 0x5
#define PF_ERR_PROTECTION_KEY_BIT 0x6
#define PF_ERR_SHADOW_STACK_BIT 0x7
#define PF_ERR_SOFTWARE_GUARD_EXTENSION_BIT 0xE
printf("Determining cause of fault...\n");
if (regs.err_code & PF_ERR_PRESENT_BIT ){
printf("Page protection violation!\n");
} else{
printf("page not-present!\n");
}
if(regs.err_code & PF_ERR_WRITE_BIT){
printf("Write access violation!\n");
} else{
printf("Read access violation!\n");
}
if(regs.err_code & PF_ERR_USER_BIT){
printf("Violation from user-space (CPL=3)\n");
}
if(regs.err_code & PF_ERR_INSTRUCTION_FETCH_BIT){
printf("Caused by an instruction fetch. \n");
}
/*
Check the error code to figure out what happened here
*/
__asm__("cli;" "1: hlt;" "jmp 1b;");

2
src/kernel/Memory/memory.cpp
View File

@ -10,7 +10,7 @@ void PhysicalMemory::setup( MemoryInfo* memory) {
used_blocks = 0;
memoryBitMap = (uint32_t*) 0x00a00000;
memoryBitMap = (uint32_t*) 0xCCA00000;
printf("Maximum Number of blocks: 0x%x, Number of bytes for memMap: 0x%x\n", max_blocks , (max_blocks/8));

12
src/kernel/cpu.h
View File

@ -60,3 +60,15 @@ extern "C" uint32_t GetCR4();
#define GET_PSE_BIT(CONTROL_REGISTER_4) (CONTROL_REGISTER_4&0x4)
#define GET_PAE_BIT(CONTROL_REGISTER_4) (CONTROL_REGISTER_4&0x5)
/*
* CONTROL_REGISTER_2 FUNCTIONS
*/
extern "C" uint32_t GetCR2();
/*
* CONTROL_REGISTER_3 FUNCTIONS
*/
extern "C" uint32_t GetCR3();

26
src/kernel/cpu.s
View File

@ -36,4 +36,28 @@ GetEFLAGS:
mov %ebp, %esp
pop %ebp
ret
ret
.globl GetCR2
GetCR2:
push %ebp
mov %esp, %ebp
xor %eax, %eax
mov %cr2, %eax
mov %ebp, %esp
pop %ebp
ret
.globl GetCR3
GetCR3:
push %ebp
mov %esp, %ebp
xor %eax, %eax
mov %cr3, %eax
mov %ebp, %esp
pop %ebp
ret

52
src/kernel/kernel.cpp
View File

@ -2,8 +2,7 @@
extern "C" void kernel_main (BootInfo* bootinfo) {
init_serial();
//pit_initialise();
pit_initialise();
startSuperVisorTerminal(bootinfo);
}
@ -17,9 +16,38 @@ extern "C" void early_main(unsigned long magic, unsigned long addr){
initGDT();
kterm_init();
init_serial();
print_serial("Hello Higher half kernel!");
printf("DDDDDDDDDDDDDDDD");
return;
print_serial("Hello Higher half kernel!\n");
init_idt();
// Enable interrupts
asm volatile("STI");
// map the multiboot structure into virtual memory
// so we can gather the necessary data from it.
/* const uint32_t KERNEL_BASE_ADDR = 0xC0000000;
uint32_t pageDirectoryIndex = (addr + KERNEL_BASE_ADDR) >> 22;
printf("pageDirectoryIndex: %d\n", pageDirectoryIndex);
uint32_t pageTableIndex = (addr + KERNEL_BASE_ADDR >> 12) & 0x1FFF;
printf("PagTableIndex: %d\n", pageTableIndex);
printf("boot_page_directory addr: 0x%x\n", &boot_page_directory);
printf("boot_page_table addr: 0x%x\n", &boot_page_table);
uint32_t* pageDirectoryEntry = (uint32_t*) ((uint32_t) &boot_page_directory) + (pageDirectoryIndex * 4);
printf("page_directory_entry addr: 0x%x\n", pageDirectoryEntry);
*pageDirectoryEntry = ( addr & 0xFFFFF000 ) | 0x003;
uint32_t* page_table_entry = (uint32_t*) ((uint32_t) &boot_page_table) + ( pageTableIndex * 4);
printf("page_table_entry addr: 0x%x\n" , page_table_entry);
*page_table_entry = addr | 0x003;
// Reload CR3 to force a flush
asm("movl %cr3, %ecx;" "movl %ecx, %cr3" );
*/
/**
* Check Multiboot magic number
* NOTE: Printf call should not be a thing this early on ...
@ -33,8 +61,7 @@ extern "C" void early_main(unsigned long magic, unsigned long addr){
* Show a little banner for cuteness
*/
printf("|=== BarinkOS ===|\n");
printf("Kernel Begin AT(0x%x)", kernel_begin);
/**
* Use the address given as an argument as the pointer
* to a Multiboot information structure.
@ -111,16 +138,11 @@ extern "C" void early_main(unsigned long magic, unsigned long addr){
//InitializePaging();
//IdentityMap();
//Enable();
} else{
printf("memory flag not set!");
}
//initGDT();
//init_idt();
// Enable interrupts
//asm volatile("STI");
//CheckMBT( (multiboot_info_t *) addr);
CheckMBT( (multiboot_info_t *) addr);
kernel_main(&bootinfo);

2
src/kernel/kernel.h
View File

@ -28,7 +28,7 @@ extern "C"
#include "time.h"
#include "SuperVisorTerminal/superVisorTerminal.h"
#define CHECK_FLAG(flags, bit) ((flags) & (1 <<(bit)))
#define CHECK_FLAG(flag, bit) ( flag & (1 << bit ))
#define PANIC(message) {return;}