diff options
| -rw-r--r-- | kernel/Makefile | 4 | ||||
| -rw-r--r-- | kernel/kernel.c | 107 | ||||
| -rw-r--r-- | kernel/tty.c | 83 | ||||
| -rw-r--r-- | kernel/tty.h | 14 | ||||
| -rw-r--r-- | kernel/types.h | 16 |
5 files changed, 119 insertions, 105 deletions
diff --git a/kernel/Makefile b/kernel/Makefile index 9846422..6c1b3ae 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -3,8 +3,8 @@ all: kernel.elf .c.o : gcc -std=gnu99 -m32 -fno-builtin -ffreestanding -nostdlib -Wall -Wextra -c $< -o $@ -kernel.elf: kernel.o entry.o - ld -Tlinker.ld -melf_i386 entry.o kernel.o -o kernel.elf +kernel.elf: kernel.o tty.o tty.h entry.o + ld -Tlinker.ld -melf_i386 entry.o tty.o kernel.o -o kernel.elf # entry.o: entry.S # as -32 $< -o entry.o diff --git a/kernel/kernel.c b/kernel/kernel.c index 5054231..d65b07d 100644 --- a/kernel/kernel.c +++ b/kernel/kernel.c @@ -1,114 +1,15 @@ -#if !defined(__cplusplus) -#include <stdbool.h> /* C doesn't have booleans by default. */ -#endif -#include <stddef.h> -#include <stdint.h> - -/* Check if the compiler thinks we are targeting the wrong operating system. */ -#if defined(__linux__) -/* TODO how does this check for a cross compiler? It was failing. */ -/*#error "You are not using a cross-compiler, you will most certainly run into trouble"*/ -#endif +#include "tty.h" -/* This tutorial will only work for the 32-bit ix86 targets. */ +/* this 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 { - COLOR_BLACK = 0, - COLOR_BLUE = 1, - COLOR_GREEN = 2, - COLOR_CYAN = 3, - COLOR_RED = 4, - COLOR_MAGENTA = 5, - COLOR_BROWN = 6, - COLOR_LIGHT_GREY = 7, - COLOR_DARK_GREY = 8, - COLOR_LIGHT_BLUE = 9, - COLOR_LIGHT_GREEN = 10, - COLOR_LIGHT_CYAN = 11, - COLOR_LIGHT_RED = 12, - COLOR_LIGHT_MAGENTA = 13, - COLOR_LIGHT_BROWN = 14, - COLOR_WHITE = 15, -}; - -static uint8_t make_color(enum vga_color fg, enum vga_color bg) -{ - return fg | bg << 4; -} - -static uint16_t make_vgaentry(char c, uint8_t color) -{ - uint16_t c16 = c; - uint16_t color16 = color; - return c16 | color16 << 8; -} - -/* static size_t strlen(const char* str) */ -/* { */ -/* size_t ret = 0; */ -/* for (const char* p = str; *p != 0; p++, ret++); */ -/* return ret; */ -/* } */ - -static const size_t VGA_WIDTH = 80; -static const size_t VGA_HEIGHT = 25; - -size_t terminal_row; -size_t terminal_column; -uint8_t terminal_color; -uint16_t* terminal_buffer; - -static void terminal_initialize() -{ - terminal_row = 0; - terminal_column = 0; - terminal_color = make_color(COLOR_LIGHT_GREY, COLOR_BLACK); - terminal_buffer = (uint16_t*) 0xB8000; - 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] = make_vgaentry(' ', terminal_color); - } - } -} - -/* static void terminal_setcolor(uint8_t color) */ -/* { */ -/* terminal_color = color; */ -/* } */ - -static 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] = make_vgaentry(c, color); -} - -static 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; - } - } -} - -static void terminal_writestring(const char* data) -{ - for (const char* p = data; *p != 0; p++) - terminal_putchar(*p); -} - #if defined(__cplusplus) extern "C" /* Use C linkage for kernel_main. */ #endif void kernel_main() { - terminal_initialize(); - terminal_writestring("Hello, kernel World!\n"); + tty_init(); + tty_writestring("Hello, kernel World!\n"); } diff --git a/kernel/tty.c b/kernel/tty.c new file mode 100644 index 0000000..4cb2cf1 --- /dev/null +++ b/kernel/tty.c @@ -0,0 +1,83 @@ +#include "tty.h" + +/* Hardware text mode color constants. */ +enum vga_color { + COLOR_BLACK = 0, + COLOR_BLUE = 1, + COLOR_GREEN = 2, + COLOR_CYAN = 3, + COLOR_RED = 4, + COLOR_MAGENTA = 5, + COLOR_BROWN = 6, + COLOR_LIGHT_GREY = 7, + COLOR_DARK_GREY = 8, + COLOR_LIGHT_BLUE = 9, + COLOR_LIGHT_GREEN = 10, + COLOR_LIGHT_CYAN = 11, + COLOR_LIGHT_RED = 12, + COLOR_LIGHT_MAGENTA = 13, + COLOR_LIGHT_BROWN = 14, + COLOR_WHITE = 15, +}; + +#define VGA_WIDTH 80 +#define VGA_HEIGHT 25 +#define VGA_TEXT_BUFFER 0xB8000 +#define VGA_COLOR_SHIFT 8 + +static size_t tty_row; +static size_t tty_col; +static uint8_t tty_color; +static uint16_t* tty_buffer; + +static inline uint8_t make_color(enum vga_color fg, enum vga_color bg) +{ + return fg | bg << 4; +} + +static inline uint16_t make_vgaentry(char c, uint8_t color) +{ + return ((uint16_t) c) | (((uint16_t) color) << VGA_COLOR_SHIFT); +} + +static inline void tty_putentryat(char c, uint8_t color, size_t x, size_t y) +{ + const size_t i = y * VGA_WIDTH + x; + tty_buffer[i] = make_vgaentry(c, color); +} + +void tty_setcolor(uint8_t color) +{ + tty_color = color; +} + +void tty_putchar(char c) +{ + tty_putentryat(c, tty_color, tty_col, tty_row); + if (++tty_col == VGA_WIDTH) { + tty_col = 0; + if (++tty_row == VGA_HEIGHT) { + tty_row = 0; + } + } +} + +void tty_writestring(const char* data) +{ + for (const char* p = data; *p != 0; p++) + tty_putchar(*p); +} + +void tty_init() +{ + tty_row = 0; + tty_col = 0; + tty_buffer = (uint16_t*) VGA_TEXT_BUFFER; + tty_setcolor(make_color(COLOR_LIGHT_GREY, COLOR_BLACK)); + for (size_t y = 0; y < VGA_HEIGHT; y++) { + for (size_t x = 0; x < VGA_WIDTH; x++) { + const size_t i = y * VGA_WIDTH + x; + tty_buffer[i] = make_vgaentry(' ', tty_color); + } + } +} diff --git a/kernel/tty.h b/kernel/tty.h new file mode 100644 index 0000000..3c4b09e --- /dev/null +++ b/kernel/tty.h @@ -0,0 +1,14 @@ +#ifndef _TTY_H_ +#define _TTY_H_ + +#include "types.h" + +void tty_init(); + +void tty_setcolor(uint8_t color); + +void tty_putchar(char c); + +void tty_writestring(const char* data); + +#endif diff --git a/kernel/types.h b/kernel/types.h new file mode 100644 index 0000000..5065af7 --- /dev/null +++ b/kernel/types.h @@ -0,0 +1,16 @@ +#ifndef _TYPES_H_ +#define _TYPES_H_ + +#include <stdint.h> +#include <stdbool.h> +#include <stddef.h> + +typedef unsigned char uchar; +typedef unsigned short ushort; +typedef unsigned int uint; +typedef unsigned long ulong; + +/* #define NULL 0 */ + +#endif + |