Merge branch 'feature/rewrite'

.gitignore

@@ -1,2 +1,2 @@
-i386-elf-toolchain-aur
-i386-elf-tools-aur-pkgs
+bin/
+obj/

.vscode/c_cpp_properties.json

@@ -3,7 +3,7 @@
         {
             "name": "Linux",
             "includePath": [
-                "${workspaceFolder}/**"
+                "${workspaceFolder}/include/**"
             ],
             "defines": [],
             "compilerPath": "/usr/bin/clang",

.vscode/settings.json

@@ -1,5 +1,5 @@
 {
     "files.associations": {
-        "idt.h": "c"
+        "types.h": "c"
     }
 }

Makefile

@@ -1,56 +1,67 @@
-# $@ = target file
-# $< = first dependency
-# $^ = all dependencies
+ASM := nasm
 
-GDB = gdb
+CC := x86_64-elf-gcc
+CCFLAGS := 
 
-C_FILES = $(shell find src/ -type f -name '*.c')
-CO_FILES = $(patsubst src/%.c, obj/%.o, $(C_FILES))
-ASM_FILES = $(shell find src/kernel/ -type f -name '*.asm')
-AO_FILES = $(patsubst src/kernel/%.asm, obj/kernel/%.o, $(ASM_FILES))
-ABIN_FILES = $(patsubst src/%.asm, bin/%.bin, $(ASM_FILES))
+LD := x86_64-elf-ld
+LDFLAGS := 
 
-os-image.bin: bin/boot.bin bin/kernel.bin
-	cat $^ > $@
+INCLUDE := include/
 
-bin/boot.bin: src/boot/boot.asm bin/kernel.bin .FORCE
-	sed -i.orig "s@CH_REPLACE_BOOTSECTORCOUNT@$(shell ./getinblocks.py $(shell du -b "bin/kernel.bin" | cut -f 1))@g" src/boot/kernel.asm
-	nasm -Isrc/boot/ $< -f bin -o $@
-	mv src/boot/kernel.asm.orig src/boot/kernel.asm
+# Target: kernel, type: C ASM
+kernel_c_source_files = $(shell find src/kernel/ -type f -name *.c)
+kernel_c_object_files = $(patsubst src/%.c,obj/%.o,$(kernel_c_source_files))
+kernel_asm_source_files = $(shell find src/kernel/ -type f -name *.asm)
+kernel_asm_object_files = $(patsubst src/%.asm,obj/%.o,$(kernel_asm_source_files))
+kernel_source_files = $(kernel_c_source_files) $(kernel_asm_object_files)
+kernel_object_files = $(kernel_c_object_files) $(kernel_asm_object_files)
 
-.FORCE:
+# Target: libc, type: C ASM
+libc_c_source_files = $(shell find src/libc/ -type f -name *.c)
+libc_c_object_files = $(patsubst src/%.c,obj/%.o,$(libc_c_source_files))
+libc_asm_source_files = $(shell find src/libc/ -type f -name *.asm)
+libc_asm_object_files = $(patsubst src/%.asm,obj/%.o,$(libc_c_object_files))
+libc_source_files = $(libc_c_source_files) $(libc_asm_source_files)
+libc_object_files = $(libc_c_object_files) $(libc_asm_object_files)
 
-bin/kernel.bin: obj/kernel/entry.o ${CO_FILES} ${AO_FILES}
-	i386-elf-ld -o $@ -Ttext 0x1000 $^ --oformat binary
+# Target: sboot, type: ASM
+# Override: 32-bit
+sboot_asm_source_files = $(shell find src/boot/ -type f -name *.asm)
+sboot_asm_object_files = $(patsubst src/%.asm,obj/%.o,$(sboot_asm_source_files))
+sboot_source_files = $(sboot_asm_source_files)
+sboot_object_files = $(sboot_asm_object_files)
 
-kernel.elf: obj/kernel/entry.o ${CO_FILES} ${AO_FILES}
-	i386-elf-ld -o $@ -Ttext 0x1000 $^
+shade_bin_ldfile = src/linker.ld
 
-run: clean os-image.bin
-	qemu-system-x86_64 -hdd os-image.bin
+default: run
 
-debug: clean os-image.bin kernel.elf
-	qemu-system-x86_64 -s -S -hdd os-image.bin &
-	${GDB} os-image.bin -ex "symbol-file kernel.elf" -ex "target remote localhost:1234"
+bin/shade.iso: bin/shade.bin
+	cp bin/shade.bin src/iso/boot/shade.bin
+	grub-mkrescue src/iso/ -o $@
+	rm src/iso/boot/shade.bin
 
+bin/shade.bin: $(sboot_object_files) $(kernel_object_files) $(libc_object_files)
+	mkdir -p "$(@D)"
+	$(LD) $(LDFLAGS) -n -T $(shade_bin_ldfile) $^ -o $@
+	grub-file --is-x86-multiboot2 $@
 
+# Generics
+# Source file types: C ASM
 
+# C
 obj/%.o: src/%.c
 	mkdir -p "$(@D)"
-	i386-elf-gcc -g -ffreestanding -c $< -o $@
+	$(CC) $(CCFLAGS) -I $(INCLUDE) -ffreestanding -c $< -o $@
 
+# ASM
 obj/%.o: src/%.asm
 	mkdir -p "$(@D)"
-	nasm -f elf $< -o $@
+	$(ASM) -felf64 $< -o $@
 
-bin/%.bin: src/%.asm
-	mkdir -p "$(@D)"
-	nasm -f bin $< -o $@
+# Other
+run: clean bin/shade.iso
+	qemu-system-x86_64 -drive file=bin/shade.iso,index=0,media=disk,format=raw
 
 clean:
-	find obj -type f -name '*.o' -exec rm {} +
-	find obj -type f -name '*.bin' -exec rm {} +
-	find bin -type f -name '*.o' -exec rm {} +
-	find bin -type f -name '*.bin' -exec rm {} +
-	find . -type f -name '*.dis' -exec rm {} +
-	rm -f kernel.elf
+	rm -rf bin/*
+	rm -rf obj/*

bochsrc.txt

@@ -0,0 +1,57 @@
+# configuration file generated by Bochs
+plugin_ctrl: unmapped=true, biosdev=true, speaker=true, extfpuirq=true, parallel=true, serial=true, iodebug=true, pcidev=false, usb_uhci=false
+config_interface: textconfig
+display_library: x
+memory: host=32, guest=32
+romimage: file="/usr/share/bochs/BIOS-bochs-latest", address=0x00000000, options=none
+vgaromimage: file="/usr/share/bochs/VGABIOS-lgpl-latest"
+boot: floppy
+floppy_bootsig_check: disabled=0
+floppya: type=1_44
+# no floppyb
+ata0: enabled=true, ioaddr1=0x1f0, ioaddr2=0x3f0, irq=14
+ata0-master: type=disk, path="bin/shade.iso", mode=flat, cylinders=0, heads=0, spt=0, sect_size=512, model="Generic 1234", biosdetect=auto, translation=auto
+ata0-slave: type=none
+ata1: enabled=true, ioaddr1=0x170, ioaddr2=0x370, irq=15
+ata1-master: type=none
+ata1-slave: type=none
+ata2: enabled=false
+ata3: enabled=false
+optromimage1: file=none
+optromimage2: file=none
+optromimage3: file=none
+optromimage4: file=none
+optramimage1: file=none
+optramimage2: file=none
+optramimage3: file=none
+optramimage4: file=none
+pci: enabled=1, chipset=i440fx, slot1=none, slot2=none, slot3=none, slot4=none, slot5=none
+vga: extension=vbe, update_freq=5, realtime=1, ddc=builtin
+cpu: count=1:1:1, ips=4000000, quantum=16, model=bx_generic, reset_on_triple_fault=1, cpuid_limit_winnt=0, ignore_bad_msrs=1, mwait_is_nop=0
+cpuid: level=6, stepping=3, model=3, family=6, vendor_string="AuthenticAMD", brand_string="AMD Athlon(tm) processor"
+cpuid: mmx=true, apic=xapic, simd=sse2, sse4a=false, misaligned_sse=false, sep=true
+cpuid: movbe=false, adx=false, aes=false, sha=false, xsave=false, xsaveopt=false, avx_f16c=false
+cpuid: avx_fma=false, bmi=0, xop=false, fma4=false, tbm=false, x86_64=true, 1g_pages=false
+cpuid: pcid=false, fsgsbase=false, smep=false, smap=false, mwait=true
+print_timestamps: enabled=0
+debugger_log: -
+magic_break: enabled=0
+port_e9_hack: enabled=0
+private_colormap: enabled=0
+clock: sync=none, time0=local, rtc_sync=0
+# no cmosimage
+log: -
+logprefix: %t%e%d
+debug: action=ignore
+info: action=report
+error: action=report
+panic: action=ask
+keyboard: type=mf, serial_delay=250, paste_delay=100000, user_shortcut=none
+mouse: type=ps2, enabled=false, toggle=ctrl+mbutton
+speaker: enabled=true, mode=system
+parport1: enabled=true, file=none
+parport2: enabled=false
+com1: enabled=true, mode=null
+com2: enabled=false
+com3: enabled=false
+com4: enabled=false

old/Makefile

@@ -0,0 +1,56 @@
+# $@ = target file
+# $< = first dependency
+# $^ = all dependencies
+
+GDB = gdb
+
+C_FILES = $(shell find src/ -type f -name '*.c')
+CO_FILES = $(patsubst src/%.c, obj/%.o, $(C_FILES))
+ASM_FILES = $(shell find src/kernel/ -type f -name '*.asm')
+AO_FILES = $(patsubst src/kernel/%.asm, obj/kernel/%.o, $(ASM_FILES))
+ABIN_FILES = $(patsubst src/%.asm, bin/%.bin, $(ASM_FILES))
+
+os-image.bin: bin/boot.bin bin/kernel.bin
+	cat $^ > $@
+
+bin/boot.bin: src/boot/boot.asm bin/kernel.bin .FORCE
+	sed -i.orig "s@CH_REPLACE_BOOTSECTORCOUNT@$(shell ./getinblocks.py $(shell du -b "bin/kernel.bin" | cut -f 1))@g" src/boot/kernel.asm
+	nasm -Isrc/boot/ $< -f bin -o $@
+	mv src/boot/kernel.asm.orig src/boot/kernel.asm
+
+.FORCE:
+
+bin/kernel.bin: obj/kernel/entry.o ${CO_FILES} ${AO_FILES}
+	i386-elf-ld -o $@ -Ttext 0x1000 $^ --oformat binary
+
+kernel.elf: obj/kernel/entry.o ${CO_FILES} ${AO_FILES}
+	i386-elf-ld -o $@ -Ttext 0x1000 $^
+
+run: clean os-image.bin
+	qemu-system-x86_64 -hdd os-image.bin -d int
+
+debug: clean os-image.bin kernel.elf
+	qemu-system-x86_64 -s -S -hdd os-image.bin &
+	${GDB} os-image.bin -ex "symbol-file kernel.elf" -ex "target remote localhost:1234"
+
+
+
+obj/%.o: src/%.c
+	mkdir -p "$(@D)"
+	i386-elf-gcc -g -ffreestanding -c $< -o $@
+
+obj/%.o: src/%.asm
+	mkdir -p "$(@D)"
+	nasm -f elf $< -o $@
+
+bin/%.bin: src/%.asm
+	mkdir -p "$(@D)"
+	nasm -f bin $< -o $@
+
+clean:
+	find obj -type f -name '*.o' -exec rm {} +
+	find obj -type f -name '*.bin' -exec rm {} +
+	find bin -type f -name '*.o' -exec rm {} +
+	find bin -type f -name '*.bin' -exec rm {} +
+	find . -type f -name '*.dis' -exec rm {} +
+	rm -f kernel.elf

old/src/boot/protected/gdt.asm

@@ -1,3 +1,4 @@
+
 gdt_start: ; use labels to compute sizes and jumps
     ; gdt starts with 8 byte null
     dd 0x0
@@ -14,12 +15,12 @@ gdt_code:
 
 ; GDT for data segment
 gdt_data:
-    dw 0xffff
-    dw 0x0
-    db 0x0
-    db 10010010b
-    db 11001111b
-    db 0x0
+    dw 0xffff ; segment length
+    dw 0x0 ; segment base
+    db 0x0 ; segment base
+    db 10010010b ; flags
+    db 11001111b ; flags + segment length
+    db 0x0 ; segment base
 
 gdt_end:
 

old/src/kernel/kernel.c

@@ -0,0 +1,54 @@
+#include "./platform/drivers/ports.h"
+#include "print.h"
+#include "./platform/types.h"
+#include "./platform/interrupts/int.h"
+
+void dummy_test_entrypoint() {}
+
+void kernel_welcome() {
+    print_str("Welcome to ");
+    print_set_color(PRINT_COLOR_CYAN, PRINT_COLOR_BLACK);
+    print_str("Shade");
+	print_set_color(PRINT_COLOR_WHITE, PRINT_COLOR_BLACK);
+    print_str("!\n");
+	
+	print_str("shadeOS kernel version ");
+	
+	print_set_color(PRINT_COLOR_YELLOW, PRINT_COLOR_BLACK);
+	print_str("0.2.2");
+	
+	print_set_color(PRINT_COLOR_WHITE, PRINT_COLOR_BLACK);
+	print_newline();
+	
+	print_str("Running on ");
+	
+	print_set_color(PRINT_COLOR_YELLOW, PRINT_COLOR_BLACK);
+	print_str("shade-development");
+
+    print_set_color(PRINT_COLOR_WHITE, PRINT_COLOR_BLACK);
+	
+	print_newline();
+}
+
+// kMain
+void main() {
+    // Initialize screen buffer
+	struct Char* buffer = (struct Char*) 0xb8000;
+    
+    clear_all(); // Clear screen
+    set_cursor_pos(0, 0); // Set cursor position
+    print_set_color(PRINT_COLOR_WHITE, PRINT_COLOR_BLACK); // Set print color
+
+    // welcome messages
+    kernel_msg_ok("Initialized display successfully\n");
+    kernel_welcome();
+
+    print_str("Copyright (c) e3team 2022. All rights reserved.\n");
+    print_str("This program is provided \"as-is\" and no express or implied warranty is provided.\n");
+    print_str("The full license can be found at /sys/LICENCE on this system or ./LICENCE in the source tree.\n");
+
+    idt_init();
+    kernel_msg_ok("Interrupts initialized");
+
+    __asm__ __volatile__("int $2");
+}

old/src/kernel/platform/drivers/ports.h

@@ -0,0 +1,4 @@
+unsigned char port_byte_in(unsigned short port);
+void port_byte_out(unsigned short port, unsigned char data);
+unsigned short port_word_in(unsigned short port);
+void port_word_out(unsigned short port, unsigned short data);

old/src/kernel/platform/gdt.h

@@ -0,0 +1,28 @@
+#ifndef GDT_H
+#define GDT_H
+
+#include <stdint.h>
+
+// the GDT descriptor format makes literally no sense, who came up with this
+typedef struct {
+    uint16_t limit_low16; // Low 16 bits of limit
+    uint16_t base_low16;  // Low 16 bits of base
+    uint8_t  base_mid8;   // Middle 8 bits of base
+    uint8_t  access;      // 7: present, 6-5: priv level, 4: type, 3: executable, 2: dc, 1: rw, 0: accessed (zero)
+    uint8_t  limit_flags; // High 4 bits of limit AND flags (?? why). flags: 3: granularity, 2: size, 1: long, 0: reserved
+    uint8_t  base_high8;  // High 8 bits of base
+} __attribute__((packed)) gdt_entry_t;
+
+typedef struct {
+    uint16_t size;   // GDT size (bytes) - 1
+    uint32_t offset; // Address of element 0 of the GDT
+} __attribute__((packed)) gdt_ptr_t;
+
+static gdt_entry_t gdt[8192];
+static gdt_ptr_t gdtr;
+
+void init_gdt();
+void gdt_set_segment(int limit, int base, int access);
+void load_gdt();
+
+#endif

old/src/kernel/platform/interrupts/int.c

@@ -1,8 +1,14 @@
 #include "int.h"
 #include "../../print.h"
 
-void exception_handler() {
+int count = 0;
+
+void exception_handler(registers_t r) {
     print_str("I");
+    count++;
+    if (count > 4) {
+        __asm__ __volatile__("cli; hlt");
+    }  
 }
 
 void idt_set_descriptor(u8 vector, void* isr, u8 flags) {

old/src/kernel/platform/interrupts/int.h

@@ -21,8 +21,15 @@ typedef struct {
 
 static idtr_t idtr;
 
+typedef struct {
+   u32 ds; /* Data segment selector */
+   u32 edi, esi, ebp, esp, ebx, edx, ecx, eax; /* Pushed by pusha. */
+   u32 int_no, err_code; /* Interrupt number and error code (if applicable) */
+   u32 eip, cs, eflags, useresp, ss; /* Pushed by the processor automatically */
+} registers_t;
+
 __attribute__((noreturn))
-void exception_handler(void);
+void exception_handler(registers_t r);
 
 void idt_set_descriptor(u8 vector, void* isr, u8 flags);
 

old/src/kernel/platform/interrupts/int_lowlevel.asm

@@ -0,0 +1,102 @@
+%macro isr_err_stub 1
+isr_stub_%+%1:
+    push byte %1 ; Push interrupt no to stack
+
+    ; 1. Save CPU state
+	pusha ; Pushes edi,esi,ebp,esp,ebx,edx,ecx,eax
+	mov ax, ds ; Lower 16-bits of eax = ds.
+	push eax ; save the data segment descriptor
+	mov ax, 0x10  ; kernel data segment descriptor
+	mov ds, ax
+	mov es, ax
+	mov fs, ax
+	mov gs, ax
+	
+    ; 2. Call C handler
+	call exception_handler
+	
+    ; 3. Restore state
+	pop eax 
+	mov ds, ax
+	mov es, ax
+	mov fs, ax
+	mov gs, ax
+	popa
+	add esp, 8 ; Cleans up the pushed error code and pushed ISR number
+	sti
+	iret ; pops 5 things at once: CS, EIP, EFLAGS, SS, and ESP
+%endmacro
+; if writing for 64-bit, use iretq instead
+%macro isr_no_err_stub 1
+isr_stub_%+%1:
+    push byte 0  ; No error occured
+    push byte %1 ; Push interrupt no to stack
+    
+    ; 1. Save CPU state
+	pusha ; Pushes edi,esi,ebp,esp,ebx,edx,ecx,eax
+	mov ax, ds ; Lower 16-bits of eax = ds.
+	push eax ; save the data segment descriptor
+	mov ax, 0x10  ; kernel data segment descriptor
+	mov ds, ax
+	mov es, ax
+	mov fs, ax
+	mov gs, ax
+	
+    ; 2. Call C handler
+	call exception_handler
+	
+    ; 3. Restore state
+	pop eax 
+	mov ds, ax
+	mov es, ax
+	mov fs, ax
+	mov gs, ax
+	popa
+	add esp, 8 ; Cleans up the pushed error code and pushed ISR number
+	sti
+	iret ; pops 5 things at once: CS, EIP, EFLAGS, SS, and ESP
+%endmacro
+
+extern exception_handler
+
+isr_no_err_stub 0
+isr_no_err_stub 1
+isr_no_err_stub 2
+isr_no_err_stub 3
+isr_no_err_stub 4
+isr_no_err_stub 5
+isr_no_err_stub 6
+isr_no_err_stub 7
+isr_err_stub    8
+isr_no_err_stub 9
+isr_err_stub    10
+isr_err_stub    11
+isr_err_stub    12
+isr_err_stub    13
+isr_err_stub    14
+isr_no_err_stub 15
+isr_no_err_stub 16
+isr_err_stub    17
+isr_no_err_stub 18
+isr_no_err_stub 19
+isr_no_err_stub 20
+isr_no_err_stub 21
+isr_no_err_stub 22
+isr_no_err_stub 23
+isr_no_err_stub 24
+isr_no_err_stub 25
+isr_no_err_stub 26
+isr_no_err_stub 27
+isr_no_err_stub 28
+isr_no_err_stub 29
+isr_err_stub    30
+isr_no_err_stub 31
+
+global isr_stub_table
+isr_stub_table:
+%assign i 0 
+%rep    32 
+    dd isr_stub_%+i ; use DQ instead if targeting 64-bit
+%assign i i+1 
+%endrep
+

old/src/kernel/print.c

@@ -0,0 +1,110 @@
+#include "print.h"
+#include "./platform/drivers/ports.h"
+
+int row = 0;
+int col = 0;
+char color = PRINT_COLOR_WHITE | PRINT_COLOR_BLACK << 4;
+
+void clear_row(int row) {
+    struct Char* buffer = (struct Char*) 0xb8000;
+
+    struct Char empty = (struct Char) {
+        character: ' ',
+        color: color,
+    };
+
+    for (int x = 0; x < NUM_COLS; x++) {
+        buffer[x + NUM_COLS * row] = empty;
+    }
+    set_cursor_pos(col, row);
+}
+
+void clear_all() {
+    for (int i = 0; i < NUM_ROWS; i++) {
+        clear_row(i);
+    }
+    set_cursor_pos(col, row);
+}
+
+void print_newline() {
+    struct Char* buffer = (struct Char*) 0xb8000;
+
+    col = 0;
+
+    if (row < NUM_ROWS - 1) {
+        row++;
+        return;
+    }
+
+    for (int row = 1; row < NUM_ROWS; row++) {
+        for (int col = 0; col < NUM_COLS; col++) {
+            struct Char character = buffer[col + NUM_COLS * row];
+            buffer[col + NUM_COLS * (row - 1)] = character;
+        }
+    }
+
+    clear_row(NUM_COLS - 1);
+    set_cursor_pos(col, row);
+}
+
+void print_char(char character) {
+    struct Char* buffer = (struct Char*) 0xb8000;
+
+    if (character == '\n') {
+        print_newline();
+        return;
+    }
+
+    if (col > NUM_COLS) {
+        print_newline();
+    }
+
+    struct Char cr = (struct Char) {
+        character: character,
+        color: color,
+    };
+    buffer[col + NUM_COLS * row] = cr;
+
+    col++;
+    set_cursor_pos(col, row);
+}
+
+void print_str(char* str) {
+    for (int i = 0; 1; i++) {
+        char character = (char) str[i];
+
+        if (character == '\0') {
+            return;
+        }
+
+        print_char(character);
+    }
+}
+
+void print_set_color(char foreground, char background) {
+    color = foreground + (background << 4);
+}
+
+void set_cursor_pos(int col, int row) {
+   int offset = col + NUM_COLS * row;
+   port_byte_out(REG_SCREEN_CTRL, 14);
+   port_byte_out(REG_SCREEN_DATA, (unsigned char)(offset >> 8));
+   port_byte_out(REG_SCREEN_CTRL, 15);
+   port_byte_out(REG_SCREEN_DATA, (unsigned char)(offset & 0xff)); 
+}
+
+void kernel_msg_ok(char* msg) {
+	char ok_p1[] = "[ ";
+	char ok_p2[] = "OK ";
+	char ok_p3[] = "] ";
+	
+	print_set_color(PRINT_COLOR_WHITE, PRINT_COLOR_BLACK);
+	print_str(ok_p1);
+	
+	print_set_color(PRINT_COLOR_GREEN, PRINT_COLOR_BLACK);
+	print_str(ok_p2);
+	
+	print_set_color(PRINT_COLOR_WHITE, PRINT_COLOR_BLACK);
+	print_str(ok_p3);
+	print_str(msg);
+}

old/src/kernel/print.h

@@ -0,0 +1,44 @@
+#ifndef PRINT_H
+#define PRINT_H
+#define REG_SCREEN_CTRL 0x3d4
+#define REG_SCREEN_DATA 0x3d5
+
+enum {
+    PRINT_COLOR_BLACK = 0,
+	PRINT_COLOR_BLUE = 1,
+	PRINT_COLOR_GREEN = 2,
+	PRINT_COLOR_CYAN = 3,
+	PRINT_COLOR_RED = 4,
+	PRINT_COLOR_MAGENTA = 5,
+	PRINT_COLOR_BROWN = 6,
+	PRINT_COLOR_LIGHT_GRAY = 7,
+	PRINT_COLOR_DARK_GRAY = 8,
+	PRINT_COLOR_LIGHT_BLUE = 9,
+	PRINT_COLOR_LIGHT_GREEN = 10,
+	PRINT_COLOR_LIGHT_CYAN = 11,
+	PRINT_COLOR_LIGHT_RED = 12,
+	PRINT_COLOR_PINK = 13,
+	PRINT_COLOR_YELLOW = 14,
+	PRINT_COLOR_WHITE = 15,
+};
+
+const static int NUM_COLS = 80;
+const static int NUM_ROWS = 25;
+
+struct Char {
+    char character;
+    char color;
+};
+
+void clear_row(int row);
+void clear_all();
+
+void print_newline();
+void print_char(char character);
+void print_set_color(char foreground, char background);
+void print_str(char* str);
+
+void set_cursor_pos(int col, int row);
+
+void kernel_msg_ok(char* msg);
+#endif

old/src/kernel/strings.h

@@ -0,0 +1,10 @@
+#ifndef STRINGS_H
+#define STRINGS_H
+
+void itoa(int n, char str[]);
+void strrev(char s[]);
+int strlen(char s[]);
+char* strcpy(char* strDest, const char* strSrc);
+char* strcnc(char* str1, char* str2);
+
+#endif

old/src/kernel/util.c

@@ -0,0 +1,25 @@
+#include "util.h"
+
+void memcpy(char *source, char *dest, int nbytes) {
+    int i;
+    for (i = 0; i < nbytes; i++) {
+        *(dest + i) = *(source + i);
+    }
+}
+
+void memset(char *dest, char val, int len) {
+    char *temp = (char *)dest;
+    for(; len !=0; len--) *temp++ = val;
+}
+
+void int_to_ascii(int n, char str[]) {
+    int i, sign;
+    if ((sign = n) < 0) n = -n;
+    i = 0;
+    do {
+        str[i++] = n % 10 + '0';
+    } while ((n /= 10) > 0);
+
+    if (sign < 0) str[i++] = '-';
+    str[i] = '\0';
+}

old/src/kernel/util.h

@@ -0,0 +1,8 @@
+#ifndef UTIL_H
+#define UTIL_H
+
+void memcpy(char *source, char *dest, int nbytes);
+void memset(char *dest, char val, int len);
+void int_to_ascii(int n, char str[]);
+
+#endif

src/boot/entry.asm

@@ -0,0 +1,141 @@
+
+  
+global entry_x86
+extern entry_x64
+
+section .text
+bits 32
+entry_x86:
+    mov esp, stack_top
+    
+    call check_mb2_boot
+    call check_cpuid
+    call check_x64_supported
+    
+    call setup_page_tables
+    call enable_paging
+    
+    lgdt [gdt64.pointer]
+    jmp gdt64.code_segment:entry_x64 ; Jump into 64 bit entry
+    
+    hlt
+
+check_mb2_boot:
+    cmp eax, 0x36d76289 ; compare eax to mb2 magic number
+    jne .mb2_not_booted
+    ret
+.mb2_not_booted:
+    mov al, "B" ; err code B - boot error
+    jmp error
+
+check_cpuid:
+    pushfd ; Put flags on stack so we can mess with them
+    pop eax ; then put the stack into EAX so we can easily modify it
+    mov ecx, eax ; Make a copy of eax in ecx for comparison
+    xor eax, 1 << 21 ; Attempt to flip the CPUID bit which is bit 21
+    push eax ; Put eax back onto stack
+    popfd ; Write flags back
+    pushfd ; Copy flags onto stack so we can check if the bit did flip
+    pop eax ; Put stack into EAX for comparison
+    push ecx ; Put original flags into stack so we can make sure they remain unchanged
+    popfd; Push original flags back onto the flags register
+    cmp eax, ecx ; Compare the modifided? flags to the original flags
+    je .cpuid_unsupported ; Flags were not changed, cpuid not supported
+    ret
+    
+.cpuid_unsupported:
+    mov al, "C" ; err code C - cpuid unsupported
+    jmp error
+    
+check_x64_supported:
+    mov eax, 0x80000000 ; Magic code that i dont understand
+	cpuid ; Magic code that i dont understand
+	cmp eax, 0x80000001 ; Magic code that i dont undetstand
+	jb .x64_unsupported ; Something went wrong so x64 isnt supported
+
+	mov eax, 0x80000001 ; Set magic value 0x80000001 into EAX for cpuid
+	cpuid ; Get "extended features list" from CPU info
+	test edx, 1 << 29 ; Check if x64 is supported by checking bit 29
+	jz .x64_unsupported ; If zero, x64 unsupported so jump to no x64
+    
+    ret
+.x64_unsupported:
+    mov al, "L" ; err code L, long mode/x64 unsupported
+    jmp error
+
+; Magic paging code that I don't understand
+setup_page_tables:
+	mov eax, page_table_l3
+	or eax, 0b11 ; present, writable
+	mov [page_table_l4], eax
+	
+	mov eax, page_table_l2
+	or eax, 0b11 ; present, writable
+	mov [page_table_l3], eax
+
+	mov ecx, 0 ; counter
+.loop:
+
+	mov eax, 0x200000 ; 2MiB
+	mul ecx
+	or eax, 0b10000011 ; present, writable, huge page
+	mov [page_table_l2 + ecx * 8], eax
+
+	inc ecx ; increment counter
+	cmp ecx, 512 ; checks if the whole table is mapped
+	jne .loop ; if not, continue
+
+	ret
+
+enable_paging:
+	; pass page table location to cpu
+	mov eax, page_table_l4
+	mov cr3, eax
+
+	; enable PAE
+	mov eax, cr4
+	or eax, 1 << 5
+	mov cr4, eax
+
+	; enable long mode
+	mov ecx, 0xC0000080
+	rdmsr
+	or eax, 1 << 8
+	wrmsr
+
+	; enable paging
+	mov eax, cr0
+	or eax, 1 << 31
+	mov cr0, eax
+
+	ret
+
+error:
+	; print "ERR: X" where X is the error code
+	mov dword [0xb8000], 0x4f524f45
+	mov dword [0xb8004], 0x4f3a4f52
+	mov dword [0xb8008], 0x4f204f20
+	mov byte  [0xb800a], al
+	hlt
+
+section .bss
+align 4096
+page_table_l4:
+	resb 4096
+page_table_l3:
+	resb 4096
+page_table_l2:
+	resb 4096
+stack_bottom:
+	resb 4096 * 4
+stack_top:
+
+section .rodata
+gdt64:
+	dd 0 ; zero entry
+	dd 0
+.code_segment: equ $ - gdt64
+	dq (1 << 43) | (1 << 44) | (1 << 47) | (1 << 53) ; code segment
+.pointer:
+	dw $ - gdt64 - 1 ; length
+	dq gdt64 ; address

src/boot/entry64.asm

@@ -0,0 +1,17 @@
+global entry_x64
+extern kmain
+
+section .text
+bits 64
+entry_x64:
+    ; Nullify all data registers
+    mov ax, 0
+    mov ss, ax
+    mov ds, ax
+    mov es, ax
+    mov fs, ax
+    mov gs, ax
+    
+    call kmain ; Jump into C kernel entry
+    
+    hlt

src/boot/mb2_header.asm

@@ -0,0 +1,16 @@
+section .mb2_header
+header_start:
+    ; https://www.gnu.org/software/grub/manual/multiboot2/multiboot.html for more information, section 3.1.1
+    dd 0xe85250d6 ; multiboot2 magic number
+    
+    dd 0 ; i386 protected 32 bit mode
+    
+    dd header_end - header_start ; Header length
+    
+    dd 0x100000000 - (0xe85250d6 + 0 + (header_end - header_start)) ; Checksum, total is 0
+    
+    ; Ending tag
+	  dw 0
+	  dw 0
+	  dd 8
+header_end:

src/iso/boot/grub/grub.cfg

@@ -0,0 +1,7 @@
+set timeout=5
+set default=0
+
+menuentry "shadeOS Development Build" {
+    multiboot2 /boot/shade.bin
+    boot
+}

src/kernel/kernel.c

@@ -1,9 +1,5 @@
-#include "./platform/drivers/ports.h"
-#include "print.h"
-#include "./platform/types.h"
-#include "./platform/interrupts/int.h"
-
-void dummy_test_entrypoint() {}
+#include <shade/platform/ports.h>
+#include <shade/print.h>
 
 void kernel_welcome() {
     print_str("Welcome to ");
@@ -31,7 +27,7 @@ void kernel_welcome() {
 }
 
 // kMain
-void main() {
+void kmain() {
     // Initialize screen buffer
 	struct Char* buffer = (struct Char*) 0xb8000;
     
@@ -47,8 +43,4 @@ void main() {
     print_str("This program is provided \"as-is\" and no express or implied warranty is provided.\n");
     print_str("The full license can be found at /sys/LICENCE on this system or ./LICENCE in the source tree.\n");
 
-    idt_init();
-    kernel_msg_ok("Interrupts initialized");
-
-    __asm__ __volatile__("int $2");
 }

src/kernel/platform/interrupts/int_lowlevel.asm

@@ -1,54 +0,0 @@
-%macro isr_err_stub 1
-isr_stub_%+%1:
-    call exception_handler
-    iret 
-%endmacro
-; if writing for 64-bit, use iretq instead
-%macro isr_no_err_stub 1
-isr_stub_%+%1:
-    call exception_handler
-    iret
-%endmacro
-
-extern exception_handler
-isr_no_err_stub 0
-isr_no_err_stub 1
-isr_no_err_stub 2
-isr_no_err_stub 3
-isr_no_err_stub 4
-isr_no_err_stub 5
-isr_no_err_stub 6
-isr_no_err_stub 7
-isr_err_stub    8
-isr_no_err_stub 9
-isr_err_stub    10
-isr_err_stub    11
-isr_err_stub    12
-isr_err_stub    13
-isr_err_stub    14
-isr_no_err_stub 15
-isr_no_err_stub 16
-isr_err_stub    17
-isr_no_err_stub 18
-isr_no_err_stub 19
-isr_no_err_stub 20
-isr_no_err_stub 21
-isr_no_err_stub 22
-isr_no_err_stub 23
-isr_no_err_stub 24
-isr_no_err_stub 25
-isr_no_err_stub 26
-isr_no_err_stub 27
-isr_no_err_stub 28
-isr_no_err_stub 29
-isr_err_stub    30
-isr_no_err_stub 31
-
-global isr_stub_table
-isr_stub_table:
-%assign i 0 
-%rep    32 
-    dd isr_stub_%+i ; use DQ instead if targeting 64-bit
-%assign i i+1 
-%endrep
-

src/kernel/platform/ports.c

@@ -0,0 +1,26 @@
+/*
+ * Read 1 byte from specified port
+ */
+unsigned char port_byte_in(unsigned short port) {
+    unsigned char result;
+    // source and dest are backwards.
+    // "=a (result)" set the C variable to the value of register e'a'x
+    // '"d" (port) map the C variable port into e'd'x register
+    __asm__("in %%dx, %%al" : "=a" (result) : "d" (port));
+}
+
+void port_byte_out(unsigned short port, unsigned char data) {
+    // both regs are C vars, nothing is returned, so no '=' in asm syntax
+    // comma because two vars in input area and none in return area
+    __asm__("out %%al, %%dx" : : "a" (data), "d" (port));
+}
+
+unsigned short port_word_in(unsigned short port) {
+    unsigned short result;
+    __asm__("in %%dx, %%ax" : "=a" (result) : "d" (port));
+    return result;
+}
+
+void port_word_out(unsigned short port, unsigned short data) {
+    __asm__("out %%ax, %%dx" : : "a" (data), "d" (port));
+}

src/kernel/print.c

@@ -1,5 +1,5 @@
-#include "print.h"
-#include "./platform/drivers/ports.h"
+#include <shade/print.h>
+#include <shade/platform/ports.h>
 
 int row = 0;
 int col = 0;

src/kernel/util.c

@@ -1,4 +1,4 @@
-#include "util.h"
+#include <shade/util.h>
 
 void memcpy(char *source, char *dest, int nbytes) {
     int i;

src/libc/strings.c

@@ -0,0 +1,48 @@
+#include <strings.h>
+#include <stddef.h>
+
+void itoa(int n, char str[]) {
+    int i, sign;
+    if ((sign = n) < 0) n = -n;
+    i = 0;
+    do {
+        str[i++] = n % 10 + '0';
+    } while ((n /= 10) > 0);
+
+    if (sign < 0) str[i++] = '-';
+    str[i] = '\0';
+
+    strrev(str);
+}
+
+/* K&R */
+void strrev(char s[]) {
+    int c, i, j;
+    for (i = 0, j = strlen(s)-1; i < j; i++, j--) {
+        c = s[i];
+        s[i] = s[j];
+        s[j] = c;
+    }
+}
+
+/* K&R */
+int strlen(char s[]) {
+    int i = 0;
+    while (s[i] != '\0') ++i;
+    return i;
+}
+
+char* strcpy(char* strDest, const char* strSrc) {
+    if ( (strDest == NULL) || (strSrc == NULL) ) {
+        return NULL;
+    }
+    char* strDestCopy = strDest;
+    while ((*strDest++=*strSrc++)!='\0');
+    return strDestCopy;
+}
+
+char* strcnc(char* str1, char* str2) {
+    char* str_dest;
+    strcpy(str_dest, str1);
+    strcpy(str_dest, str2);
+}

src/linker.ld

@@ -0,0 +1,30 @@
+ENTRY(entry_x86)
+
+SECTIONS {
+    . = 1M;
+
+    .text BLOCK(4K) : ALIGN(4K)
+    {
+        *(.mb2_header)
+        *(.text)
+    }
+
+    /* Read-only data. */
+	.rodata BLOCK(4K) : ALIGN(4K)
+	{
+		*(.rodata)
+	}
+ 
+	/* Read-write data (initialized) */
+	.data BLOCK(4K) : ALIGN(4K)
+	{
+		*(.data)
+	}
+ 
+	/* Read-write data (uninitialized) and stack */
+	.bss BLOCK(4K) : ALIGN(4K)
+	{
+		*(COMMON)
+		*(.bss)
+	}
+}