nub31/nub-os
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

remove 64 bit for now

Browse Source
This commit is contained in:
nub31
2025-08-23 22:50:44 +02:00
parent 751a182122
commit 3cc9ab2174
9 changed files with 8 additions and 424 deletions
Download Patch File Download Diff File Expand all files Collapse all files

24
makefile
View File

@@ -1,7 +1,7 @@
CC = x86_64-elf-gcc
LD = x86_64-elf-ld
CC = i386-elf-gcc
LD = i386-elf-ld
CFLAGS = -ffreestanding -m64
CFLAGS = -ffreestanding -m32
all: .build/nub-os.iso
@@ -17,8 +17,8 @@ build-dir:
cp .build/kernel.bin .build/iso/boot/
grub-mkrescue -o .build/nub-os.iso .build/iso/
.build/kernel.bin: build-dir .build/boot.o .build/kernel.o .build/print.o .build/idt.o .build/keyboard.o .build/exceptions.o .build/interrupts.o
$(LD) -Ttext 0x100000 -o .build/kernel.bin .build/boot.o .build/kernel.o .build/print.o .build/idt.o .build/keyboard.o .build/exceptions.o .build/interrupts.o
.build/kernel.bin: build-dir .build/boot.o .build/kernel.o .build/print.o
$(LD) -Ttext 0x100000 -o .build/kernel.bin .build/boot.o .build/kernel.o .build/print.o
.build/kernel.o: build-dir src/kernel.c
$(CC) $(CFLAGS) -c -o .build/kernel.o src/kernel.c
@@ -26,17 +26,5 @@ build-dir:
.build/print.o: build-dir src/print.c
$(CC) $(CFLAGS) -c -o .build/print.o src/print.c
.build/idt.o: build-dir src/idt.c
$(CC) $(CFLAGS) -c -o .build/idt.o src/idt.c
.build/keyboard.o: build-dir src/keyboard.c
$(CC) $(CFLAGS) -c -o .build/keyboard.o src/keyboard.c
.build/exceptions.o: build-dir src/exceptions.c
$(CC) $(CFLAGS) -c -o .build/exceptions.o src/exceptions.c
.build/interrupts.o: build-dir src/interrupts.asm
nasm -f elf64 -o .build/interrupts.o src/interrupts.asm
.build/boot.o: build-dir src/boot.asm
nasm -f elf64 -o .build/boot.o src/boot.asm
nasm -f elf32 -o .build/boot.o src/boot.asm

130
src/boot.asm
View File

@@ -14,14 +14,6 @@ align 4
header_end:
section .bss
align 4096
page_table_l4:
resb 4096
page_table_l3:
resb 4096
page_table_l2:
resb 4096
align 16
resb 16384
stack_top:
@@ -29,129 +21,11 @@ stack_top:
extern kernel_main
section .text
bits 32
global _start
_start:
mov esp, stack_top
call check_cpuid
call check_long_mode
call setup_page_tables
call enable_paging
lgdt [gdt64.pointer]
jmp gdt64.kernel_code:long_mode_start
check_cpuid:
pushfd
pop eax
mov ecx, eax
xor eax, 1 << 21
push eax
popfd
pushfd
pop eax
push ecx
popfd
xor eax, ecx
jz .no_cpuid
ret
.no_cpuid:
mov al, 'I'
jmp error
check_long_mode:
mov eax, 0x80000000
cpuid
cmp eax, 0x80000001
jb .no_long_mode
mov eax, 0x80000001
cpuid
test edx, 1 << 29
jz .no_long_mode
ret
.no_long_mode:
mov al, 'L'
jmp error
setup_page_tables:
mov edi, page_table_l4
mov ecx, 4096 * 3 / 4
xor eax, eax
rep stosd
mov eax, page_table_l3
or eax, 0b11
mov [page_table_l4], eax
mov eax, page_table_l2
or eax, 0b11
mov [page_table_l3], eax
mov ecx, 0
.map_p2_table:
mov eax, 0x200000
mul ecx
or eax, 0b10000011
mov [page_table_l2 + ecx * 8], eax
inc ecx
cmp ecx, 512
jne .map_p2_table
ret
enable_paging:
mov eax, page_table_l4
mov cr3, eax
mov eax, cr4
or eax, 1 << 5
mov cr4, eax
mov ecx, 0xC0000080
rdmsr
or eax, 1 << 8
wrmsr
mov eax, cr0
or eax, 1 << 31
mov cr0, eax
ret
bits 64
long_mode_start:
mov ax, gdt64.kernel_data
mov ss, ax
mov ds, ax
mov es, ax
mov fs, ax
mov gs, ax
mov rsp, stack_top
call kernel_main
cli
hang:
cli
hlt
jmp hang
error:
mov dword [0xb8000], 0x4f524f45
mov dword [0xb8004], 0x4f3a4f52
mov dword [0xb8008], 0x4f204f20
mov byte [0xb800a], al
hlt
section .rodata
gdt64:
dq 0
.kernel_code: equ $ - gdt64
dq (1<<44) | (1<<47) | (1<<41) | (1<<43) | (1<<53)
.kernel_data: equ $ - gdt64
dq (1<<44) | (1<<47) | (1<<41)
.pointer:
dw $ - gdt64 - 1
dq gdt64
jmp hang

30
src/exceptions.c
View File

@@ -1,30 +0,0 @@
#include "print.h"
#include <stdint.h>
void exception_handler(uint64_t* stack)
{
uint64_t interrupt_num = stack[0];
uint64_t error_code = stack[1];
print("EXCEPTION: ");
if (interrupt_num == 0)
{
print("Division by zero");
}
else if (interrupt_num == 13)
{
print("General protection fault");
}
else
{
print("Unknown exception");
}
print("\nError code: ");
// You'd need to implement number printing here
print("\nSystem halted.\n");
while (1)
{
__asm__ volatile("hlt");
}
}

59
src/idt.c
View File

@@ -1,59 +0,0 @@
#include "idt.h"
#include "print.h"
#define IDT_ENTRIES 256
struct idt_entry
{
uint16_t offset_low;
uint16_t selector;
uint8_t ist;
uint8_t type_attr;
uint16_t offset_mid;
uint32_t offset_high;
uint32_t zero;
} __attribute__((packed));
struct idt_ptr
{
uint16_t limit;
uint64_t base;
} __attribute__((packed));
static struct idt_entry idt[IDT_ENTRIES];
static struct idt_ptr idt_pointer;
extern void isr0(void);
extern void isr13(void);
extern void keyboard_handler_asm(void);
static void idt_set_gate(uint8_t num, uint64_t handler, uint16_t sel, uint8_t flags)
{
idt[num].offset_low = handler & 0xFFFF;
idt[num].selector = sel;
idt[num].ist = 0;
idt[num].type_attr = flags;
idt[num].offset_mid = (handler >> 16) & 0xFFFF;
idt[num].offset_high = (handler >> 32) & 0xFFFFFFFF;
idt[num].zero = 0;
}
void idt_init(void)
{
idt_pointer.limit = (sizeof(struct idt_entry) * IDT_ENTRIES) - 1;
idt_pointer.base = (uint64_t)&idt;
for (int i = 0; i < IDT_ENTRIES; i++)
{
idt_set_gate(i, 0, 0, 0);
}
idt_set_gate(0, (uint64_t)isr0, 0x08, 0x8E);
idt_set_gate(13, (uint64_t)isr13, 0x08, 0x8E);
idt_set_gate(33, (uint64_t)keyboard_handler_asm, 0x08, 0x8E);
__asm__ volatile("lidt %0" : : "m"(idt_pointer));
print_clr("[success]", FG_GREEN, BG_BLACK);
print(" idt initialized\n");
}

3
src/idt.h
View File

@@ -1,3 +0,0 @@
#pragma once
void idt_init(void);

96
src/interrupts.asm
View File

@@ -1,96 +0,0 @@
section .text
global isr0
global isr13
global keyboard_handler_asm
extern exception_handler
extern keyboard_handler
isr0:
push 0
push 0
jmp exception_common
isr13:
push 13
jmp exception_common
exception_common:
push rax
push rbx
push rcx
push rdx
push rsi
push rdi
push rbp
push r8
push r9
push r10
push r11
push r12
push r13
push r14
push r15
mov rdi, rsp
call exception_handler
pop r15
pop r14
pop r13
pop r12
pop r11
pop r10
pop r9
pop r8
pop rbp
pop rdi
pop rsi
pop rdx
pop rcx
pop rbx
pop rax
add rsp, 16
iretq
keyboard_handler_asm:
push rax
push rbx
push rcx
push rdx
push rsi
push rdi
push rbp
push r8
push r9
push r10
push r11
push r12
push r13
push r14
push r15
call keyboard_handler
mov al, 0x20
out 0x20, al
pop r15
pop r14
pop r13
pop r12
pop r11
pop r10
pop r9
pop r8
pop rbp
pop rdi
pop rsi
pop rdx
pop rcx
pop rbx
pop rax
iretq

6
src/kernel.c
View File

@@ -1,12 +1,6 @@
#include "idt.h"
#include "keyboard.h"
#include "print.h"
void kernel_main(void)
{
idt_init();
keyboard_init();
print("Welcome to nub OS\n");
print("> ");
}

80
src/keyboard.c
View File

@@ -1,80 +0,0 @@
#include "print.h"
#include <stdbool.h>
#include <stdint.h>
#define KEYBOARD_DATA_PORT 0x60
#define KEYBOARD_STATUS_PORT 0x64
static char scancode_to_ascii[] = { 0, 0, '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '-', '=', '\b',
'\t', 'q', 'w', 'e', 'r', 't', 'y', 'u', 'i', 'o', 'p', '[', ']', '\n', 0,
'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', ';', '\'', '`', 0, '\\', 'z',
'x', 'c', 'v', 'b', 'n', 'm', ',', '.', '/', 0, '*', 0, ' ' };
static char input_buffer[256];
static int buffer_index = 0;
static bool key_available = false;
static uint8_t inb(uint16_t port)
{
uint8_t result;
__asm__ volatile("inb %1, %0" : "=a"(result) : "Nd"(port));
return result;
}
void keyboard_handler(void)
{
uint8_t scancode = inb(KEYBOARD_DATA_PORT);
if (scancode & 0x80)
{
return;
}
if (scancode < sizeof(scancode_to_ascii))
{
char ascii = scancode_to_ascii[scancode];
if (ascii)
{
if (ascii == '\b')
{
if (buffer_index > 0)
{
buffer_index--;
print("\b \b");
}
}
else if (ascii == '\n')
{
input_buffer[buffer_index] = '\0';
print("\n");
key_available = true;
}
else if (buffer_index < 255)
{
input_buffer[buffer_index++] = ascii;
char str[2] = { ascii, '\0' };
print(str);
}
}
}
}
char* keyboard_get_line(void)
{
buffer_index = 0;
key_available = false;
while (!key_available)
{
__asm__ volatile("hlt");
}
return input_buffer;
}
void keyboard_init(void)
{
__asm__ volatile("sti");
print_clr("[success]", FG_GREEN, BG_BLACK);
print(" keyboard initialized\n");
}

4
src/keyboard.h
View File

@@ -1,4 +0,0 @@
#pragma once
void keyboard_init(void);
char* keyboard_get_line(void);