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-rw-r--r--Makefile6
-rw-r--r--boot.obin17252 -> 0 bytes
-rw-r--r--boot/grub.cfg3
-rw-r--r--kernel.c0
-rw-r--r--linker.ld28
-rw-r--r--src/boot.s (renamed from boot.s)0
-rw-r--r--src/kernel.c118
7 files changed, 152 insertions, 3 deletions
diff --git a/Makefile b/Makefile
index dee9099..5920b1b 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
CC = i686-elf-gcc
-AS = nasm
+AS = i686-elf-as
CFLAGS = -std=gnu99 -ffreestanding -O2 -Wall -Wextra
SRCS = src/kernel.c
@@ -7,8 +7,8 @@ OBJS = src/boot.o src/kernel.o
all: FrenchToastOS.iso
-src/boot.o: src/boot.asm
- $(AS) -f elf32 src/boot.asm -o src/boot.o
+src/boot.o: src/boot.s
+ $(AS) src/boot.s -o src/boot.o
src/kernel.o: src/kernel.c
$(CC) $(CFLAGS) -c src/kernel.c -o src/kernel.o
diff --git a/boot.o b/boot.o
deleted file mode 100644
index dc86509..0000000
--- a/boot.o
+++ /dev/null
Binary files differ
diff --git a/boot/grub.cfg b/boot/grub.cfg
new file mode 100644
index 0000000..206459c
--- /dev/null
+++ b/boot/grub.cfg
@@ -0,0 +1,3 @@
+menuentry "FrenchToastOS" {
+ multiboot /boot/FrenchToastOS.bin
+}
diff --git a/kernel.c b/kernel.c
deleted file mode 100644
index e69de29..0000000
--- a/kernel.c
+++ /dev/null
diff --git a/linker.ld b/linker.ld
new file mode 100644
index 0000000..e56537d
--- /dev/null
+++ b/linker.ld
@@ -0,0 +1,28 @@
+ENTRY(_start)
+
+SECTIONS
+{
+ . = 2M;
+
+ .text BLOCK(4K) : ALIGN(4K)
+ {
+ *(.multiboot)
+ *(.text)
+ }
+
+ .rodata BLOCK(4K) : ALIGN(4K)
+ {
+ *(.rodata)
+ }
+
+ .data BLOCK(4K) : ALIGN(4K)
+ {
+ *(.data)
+ }
+
+ .bss BLOCK(4K) : ALIGN(4K)
+ {
+ *(COMMON)
+ *(.bss)
+ }
+}
diff --git a/boot.s b/src/boot.s
index 592ba46..592ba46 100644
--- a/boot.s
+++ b/src/boot.s
diff --git a/src/kernel.c b/src/kernel.c
new file mode 100644
index 0000000..eb5ac45
--- /dev/null
+++ b/src/kernel.c
@@ -0,0 +1,118 @@
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+/* Check if the compiler thinks you are targeting the wrong operating system. */
+#if defined(__linux__)
+#error "you are not using a cross-compiler, this is bad. use an elf cross-compiler for ix86 targets, for example, i686-elf-gcc"
+#endif
+
+/* This operating system will only work for the 32-bit ix86 targets. */
+#if !defined(__i386__)
+#error "This tutorial needs to be compiled with a ix86-elf compiler"
+#endif
+
+/* Hardware text mode color constants. */
+enum vga_color {
+ VGA_COLOR_BLACK = 0,
+ VGA_COLOR_BLUE = 1,
+ VGA_COLOR_GREEN = 2,
+ VGA_COLOR_CYAN = 3,
+ VGA_COLOR_RED = 4,
+ VGA_COLOR_MAGENTA = 5,
+ VGA_COLOR_BROWN = 6,
+ VGA_COLOR_LIGHT_GREY = 7,
+ VGA_COLOR_DARK_GREY = 8,
+ VGA_COLOR_LIGHT_BLUE = 9,
+ VGA_COLOR_LIGHT_GREEN = 10,
+ VGA_COLOR_LIGHT_CYAN = 11,
+ VGA_COLOR_LIGHT_RED = 12,
+ VGA_COLOR_LIGHT_MAGENTA = 13,
+ VGA_COLOR_LIGHT_BROWN = 14,
+ VGA_COLOR_WHITE = 15,
+};
+
+static inline uint8_t vga_entry_color(enum vga_color fg, enum vga_color bg)
+{
+ return fg | bg << 4;
+}
+
+static inline uint16_t vga_entry(unsigned char uc, uint8_t color)
+{
+ return (uint16_t) uc | (uint16_t) color << 8;
+}
+
+size_t strlen(const char* str)
+{
+ size_t len = 0;
+ while (str[len])
+ len++;
+ return len;
+}
+
+#define VGA_WIDTH 80
+#define VGA_HEIGHT 25
+#define VGA_MEMORY 0xB8000
+
+size_t terminal_row;
+size_t terminal_column;
+uint8_t terminal_color;
+uint16_t* terminal_buffer = (uint16_t*)VGA_MEMORY;
+
+void terminal_initialize(void)
+{
+ terminal_row = 0;
+ terminal_column = 0;
+ terminal_color = vga_entry_color(VGA_COLOR_LIGHT_GREY, VGA_COLOR_BLACK);
+
+ for (size_t y = 0; y < VGA_HEIGHT; y++) {
+ for (size_t x = 0; x < VGA_WIDTH; x++) {
+ const size_t index = y * VGA_WIDTH + x;
+ terminal_buffer[index] = vga_entry(' ', terminal_color);
+ }
+ }
+}
+
+void terminal_setcolor(uint8_t color)
+{
+ terminal_color = color;
+}
+
+void terminal_putentryat(char c, uint8_t color, size_t x, size_t y)
+{
+ const size_t index = y * VGA_WIDTH + x;
+ terminal_buffer[index] = vga_entry(c, color);
+}
+
+void terminal_putchar(char c)
+{
+ terminal_putentryat(c, terminal_color, terminal_column, terminal_row);
+ if (++terminal_column == VGA_WIDTH) {
+ terminal_column = 0;
+ if (++terminal_row == VGA_HEIGHT)
+ terminal_row = 0;
+ }
+}
+
+void terminal_write(const char* data, size_t size)
+{
+ for (size_t i = 0; i < size; i++)
+ terminal_putchar(data[i]);
+}
+
+void terminal_writestring(const char* data)
+{
+ terminal_write(data, strlen(data));
+}
+
+void kernel_main(void)
+{
+ /* Initialize terminal interface */
+ terminal_initialize();
+
+ terminal_writestring("Hello, kernel World!\n");
+
+ while (1) {
+ __asm__ __volatile__ ("hlt");
+ }
+}