Init sources

src/Makefile

@@ -0,0 +1,29 @@
+EXEC := boucane
+CC := gcc -c -fno-pie -fno-builtin -fno-stack-protector -I ./
+LD_SCRIPT := linker.ld
+
+# Note that BOOT_OBJ do not match boot.S
+# Indeed boot.o generated by boot.S should appear
+# first in the kernel binary (thus it must be linked first, cf the $(EXEC) rule)
+BOOT_OBJ := $(addsuffix .o,$(basename $(shell find ./boot -name "*.[c|S]" ! -name "boot.S")))
+DRIVERS_OBJ := $(addsuffix .o,$(basename $(shell find ./drivers -name "*.[c|S]")))
+LIBC_OBJ := $(addsuffix .o,$(basename $(shell find ./libc -name "*.[c|S]")))
+
+all: $(EXEC)
+
+$(EXEC): boot/boot.o $(BOOT_OBJ) $(DRIVERS_OBJ) $(LIBC_OBJ) boucane.o
+	ld -n -T $(LD_SCRIPT) -nostdlib -o $@ $^ 
+
+%.o: %.S
+	as -o $@ $^
+
+%.o: %.c
+	$(CC) -o $@ $<
+	
+clean:
+	rm -f $(EXEC)
+	find ./ -name "*.o" -delete
+
+.PHONY: clean cdrom
+
+

src/boot/boot.S

@@ -0,0 +1,128 @@
+.globl  _start
+.globl MB_INFO
+.extern boucane
+.extern _bss_start
+.extern _bss_end
+.extern boucane
+
+.set STACK_LOCATION, 0x1FFFFF
+
+.section .multiboot
+
+.set MB_MAGIC, 0xE85250D6
+.set MB_ARCH, 0x00000000
+.set MB_HEADER_LENGTH, (mb_header_end-mb_header_start)
+.set MB_CHECKSUM, -(MB_MAGIC+MB_ARCH+MB_HEADER_LENGTH)
+
+mb_header_start:
+.align 8
+.int MB_MAGIC
+.int MB_ARCH
+.int MB_HEADER_LENGTH
+.int MB_CHECKSUM
+# ----------- Address tag
+.align 8
+.short 2
+.short 0 # Not optional
+.int 24  # Size
+.int mb_header_start # header_addr
+.int mb_header_start # load_addr
+.int 0x0 # load_end_addr
+.int 0x0 # bss_end_addr
+# ----------- Addr tag
+.align 8
+.short 0x3
+.short 0
+.int 12
+.int _start
+# ----------- End tag
+.align 8
+.int 0x0
+.int 0x8
+mb_header_end:
+
+.section .text
+.code32 # Require since grub do not enable long mode
+
+MB_INFO:
+ .int 0xABCDEF # Will contains the Multiboot2 information data structure address
+
+_start:
+mov %ebx,(MB_INFO)
+
+# ----- Setup PAE Paging (identity on the first 10MB)
+mov $8192, %ecx # 8*4096/4 (8 tables of 4096 byte each divide by 4 because of movl)
+mov $0, %eax
+zeroing_paging:
+movl $0, (%eax)
+add $4, %eax
+loop zeroing_paging
+# Setup PML4 Table (Address 0x0)
+mov $0x0, %edi
+mov %edi, %cr3 # Setup PML4 location
+movl $0x1003, (%edi) # Setup PDPT location
+# Setup PDPT
+mov $0x1000, %edi
+movl $0x2003, (%edi) # Setup PDPT location
+# Setup PDT (5 PT = 10MB)
+mov $0x2000, %edi
+mov $0x3003, %eax
+mov $5, %ecx
+pdt_fill:
+movl %eax, (%edi) # Setup PDPT location
+add $8, %edi # Goto next entry
+add $0x1000, %eax # Next PT
+loop pdt_fill
+# Setup the 5 PT
+mov $0x3000, %edi
+mov $0x3, %ebx # First map to 0
+mov $2560, %ecx # 512*5
+pt_fill:
+mov %ebx, (%edi)
+add $8, %edi # Next entry
+add $0x1000, %ebx # Next Page
+loop pt_fill
+
+# ----- Switch to compatibility mode
+# Set CR4.PAE
+mov %cr4, %eax
+bts $5, %eax
+mov %eax, %cr4 
+# Set EFER.LME
+mov $0xC0000080, %ecx
+rdmsr
+bts $8, %eax
+wrmsr
+# Set CR0.PG
+mov %cr0, %eax
+bts $31, %eax
+mov %eax, %cr0
+
+# Now we are in Compatibility mode
+# Now we need to set CS.L=1 (setting up a 64 bit GDT)
+lgdt (gdtr)
+jmp $0x08, $new_cs
+new_cs:
+
+# Run boucane
+jmp boucane
+
+# GDT
+gdt64:
+    gdt64_null:
+    .long 0
+    .long 0
+    gdt64_cs:
+    .long 0
+    .byte 0
+    .byte 0b10011100
+    .byte 0b00100000
+    .byte 0
+    gdt64_ds:
+    .long 0
+    .byte 0
+    .byte 0b10000000
+    .word 0
+gdtr:
+    .word . - gdt64 - 1
+    .quad gdt64

src/boucane.c

@@ -0,0 +1,9 @@
+#include "libc/stdio.h"
+
+
+
+void boucane(){
+    clear();
+    print("Boucane is booting...");
+    while(1);
+}

src/core/types.h

@@ -0,0 +1,9 @@
+#ifndef TYPES_H
+#define TYPES_H
+
+typedef unsigned char u8;
+typedef unsigned short u16;
+typedef unsigned int u32;
+typedef unsigned long long u64;
+
+#endif

src/drivers/framebuffer.c

@@ -0,0 +1,58 @@
+#include "framebuffer.h"
+
+#define MAX_COL 80
+#define MAX_LINE 25
+
+VIDEO_STATE VS={
+  (u8 *)0xB8000,
+  0,
+  0,
+  BLACK,
+  GRAY,
+};
+
+void putchar(char c){
+  // Handle newline here
+  if(c=='\n'){
+    VS.col=0;
+    VS.line+=1;
+    if(VS.line>=MAX_LINE){
+      VS.line=MAX_LINE-1;
+      scrollup();
+    }
+    return;
+  }
+  
+  // Print char
+  VS.mem[VS.col*2+MAX_COL*VS.line*2]=c;
+  VS.mem[VS.col*2+MAX_COL*VS.line*2+1]=VS.fg|VS.bg<<4;
+  
+  // Refresh location
+  VS.col+=1;
+  if(VS.col>= MAX_COL){
+    VS.col=0;
+    VS.line+=1;
+    if(VS.line>=MAX_LINE){
+      VS.line=MAX_LINE-1;
+      scrollup();
+    }
+  }
+}
+
+void clear(){
+  for(char i=0;i<MAX_LINE;i++){
+    scrollup();
+  }
+}
+
+void scrollup(){
+  // Move VS.line up
+  for(char i=1;i<=MAX_LINE;i++){
+    for(char j=0;j<=MAX_COL;j++)
+      VS.mem[j*2+MAX_COL*(i-1)*2]=VS.mem[j*2+MAX_COL*i*2];
+  }
+  // Clear last VS.line
+  for(char i=0;i<=MAX_COL;i++){
+    VS.mem[i*2+MAX_COL*(MAX_LINE-1)*2]='\0';
+  }
+}

src/drivers/framebuffer.h

@@ -0,0 +1,35 @@
+#ifndef FRAMEBUFFER_H
+#define FRAMEBUFFER_H
+
+#include "core/types.h"
+
+typedef enum VIDEO_COLORS {
+  BLACK=0, BLUE=1, GREEN=2,CYAN=3, RED=4,PURPLE=5,BROWN=6,GRAY=7,
+  DARK_GRAY=8,LIGHT_BLUE=9,LIGHT_GREEN=10,LIGHT_CYAN=11,LIGHT_RED=12,LIGHT_PURPLE=13,YELLOW=14,WHITE=15
+  
+} VIDEO_COLORS;
+
+typedef struct VIDEO_STATE {
+  u8 *mem;
+  u8 col;
+  u8 line;
+  u8 bg;
+  u8 fg;
+} VIDEO_STATE;
+
+/**
+ * Print char
+ */
+void putchar(char);
+
+/**
+ * Scroll the framebuffer from one line
+ */
+void scrollup();
+
+/**
+ * Clear all char from the framebuffer
+ */
+void clear();
+
+#endif

src/libc/math.c

@@ -0,0 +1,32 @@
+#include "math.h"
+
+int pow(int x,int n){
+    if(n<0)
+        return -1;
+    else if(n==0)
+        return 1;
+    else if(n==1)
+        return x;
+    int ret=x;
+    for(int i=0;i<(n-1);i++)
+        ret*=x;
+    return ret;
+}
+
+int max(int x,int y){
+    if(x>y)
+        return x;
+    return y;
+}
+
+int min(int x,int y){
+    if(x<y)
+        return x;
+    return y;
+}
+
+int abs(int x){
+    if(x<0)
+        return -x;
+    return x;
+}

src/libc/math.h

@@ -0,0 +1,9 @@
+#ifndef MATH_H
+#define MATH_H
+
+int pow(int x,int n);
+int max(int x,int y);
+int min(int x,int y);
+int abs(int x);
+
+#endif

src/libc/stdio.c

@@ -0,0 +1,25 @@
+#include "stdio.h"
+#include "string.h"
+
+extern VIDEO_STATE VS;
+
+void print(char *str){
+  int i=0;
+  while(str[i]!='\0'){
+    putchar(str[i]);
+    i++;
+  }
+}
+
+void printc(char* str,VIDEO_COLORS c){
+  VIDEO_COLORS backup=VS.fg;
+  VS.fg=c;
+  print(str);
+  VS.fg=backup;
+}
+
+void printi(int i){
+    char str[12];
+    itoa(i,str);
+    print(str);
+}

src/libc/stdio.h

@@ -0,0 +1,21 @@
+#ifndef STDIO_H
+#define STDIO_H
+
+#include "drivers/framebuffer.h"
+
+/**
+ * Print a char* in the framebuffer
+ */
+void print(char*);
+
+/**
+ * Print a char in the framebuffer
+ */
+void printc(char*,VIDEO_COLORS c);
+
+/**
+ * Print an integer using itoa()
+ */
+void printi(int i);
+
+#endif

src/libc/string.c

@@ -0,0 +1,29 @@
+#include "string.h"
+#include "math.h"
+
+void itoa(int i, char *a){
+    // Check if lower than 0
+    char neg=0;
+    if(i<0){
+        neg=1;
+        i=-i;
+        a[0]='-';
+    }
+
+    // Count number of digits
+    int len=1;
+    while(i/pow(10,len)>=1)
+    {
+        len++;
+    }
+
+    // Build string
+    int max_pow=len-1;
+    for(int j=0;j<=max_pow;j++){
+        int cur_pow=pow(10,max_pow-j);
+        char digit=i/cur_pow;
+        a[j+neg]='0'+digit;
+        i=i-digit*cur_pow; // Remove first digits (most significant)
+    }
+    a[len+neg]='\0';
+}

src/libc/string.h

@@ -0,0 +1,9 @@
+#ifndef STRING_H
+#define STRING_H
+
+/**
+ * Convert int to char
+ */
+void itoa(int i, char *a);
+
+#endif

src/linker.ld

@@ -0,0 +1,29 @@
+ENTRY(_start)
+OUTPUT_FORMAT(elf64-x86-64)
+
+SECTIONS {
+
+    . = 1M;
+
+    .text : ALIGN(4)
+    {
+        *(.multiboot)
+        *(.text)
+    }
+    .rodata : ALIGN(4)
+    {
+        *(.rodata)
+    }
+    .data : ALIGN(4)
+    {
+        *(.data)
+    }
+    .bss : ALIGN(4)
+    {
+        _bss_start = .;
+        *(.bss);
+        _bss_end = .;
+        *(COMMON);
+    }
+
+}