Restructuration part 2: libc, programs

src/libc/stdint.h

@@ -0,0 +1,20 @@
+#ifndef INCLUDE_STDINT_H
+#define INCLUDE_STDINT_H
+
+typedef signed char int8_t;
+typedef unsigned char uint8_t;
+
+typedef signed short int16_t;
+typedef unsigned short uint16_t;
+
+typedef signed long int int32_t;
+typedef unsigned long int uint32_t;
+
+typedef signed long long int int64_t;
+typedef unsigned long long int uint64_t;
+
+typedef uint8_t bool;
+#define true 1
+#define false 0
+
+#endif

src/libc/stdio.c

@@ -0,0 +1,337 @@
+#include "../kernel/io.h"
+#include "stdio.h"
+#include "string.h"
+#include "stdint.h"
+
+char* fb = (char *) 0x000B8000;
+const unsigned VGA_WIDTH = 80;
+const unsigned VGA_HEIGHT = 25;
+const unsigned int COLOR = 0x7;
+unsigned int VGA_X = 0, VGA_Y = 0;
+
+void move_cursor(int x, int y)
+{
+  unsigned short pos = y*VGA_WIDTH+x; 
+
+  outb(FB_CMD_PORT, FB_HIGH_BYTE_CMD);
+  outb(FB_DATA_PORT, ((pos >> 8) & 0x00FF));
+  outb(FB_CMD_PORT, FB_LOW_BYTE_CMD);
+  outb(FB_DATA_PORT, pos & 0x00FF);
+}
+
+void putchar(int x, int y, char c) 
+{
+  fb[2*(y*VGA_WIDTH+x)] = c;
+}
+
+void putcolor(int x, int y, unsigned int color)
+{
+  fb[2*(y*VGA_WIDTH+x)+1] = color;
+}
+
+void clear(void)
+{
+  for (unsigned int y=0; y<VGA_HEIGHT; y++)
+  {
+    for (unsigned int x=0; x<VGA_WIDTH; x++)
+    {
+      putchar(x, y, '\0');
+      putcolor(x, y, COLOR);
+    }
+  }
+  VGA_X = 0;
+  VGA_Y = 0;
+  move_cursor(VGA_X, VGA_Y);
+}
+
+char getchar(int x, int y)
+{
+  return fb[2*(y*VGA_WIDTH+x)];
+}
+
+unsigned int getcolor(int x, int y)
+{
+  return fb[2*(y*VGA_WIDTH+x)+1];
+}
+
+void scroll(int lines)
+{
+  for (unsigned int y = lines; y < VGA_HEIGHT; y++)
+  {
+    for (unsigned int x = 0; x < VGA_WIDTH; x++)
+    {
+      putchar(x, y-lines, getchar(x, y));
+      putcolor(x, y-lines, getcolor(x, y));
+    }
+  }
+
+  for (unsigned int y = VGA_HEIGHT-lines; y<VGA_HEIGHT; y++)
+  {
+    for (unsigned int x = 0; x < VGA_WIDTH; x++)
+    {
+      putchar(x, y, '\0');
+      putcolor(x, y, COLOR);
+    }
+  }
+}
+
+void putc(char c)
+{
+  switch(c)
+  {
+    case '\n':
+      VGA_X = 0;
+      VGA_Y++;
+      break;
+    case '\r':
+      VGA_X = 0;
+      break;
+    default:
+      putchar(VGA_X, VGA_Y, c);
+      VGA_X++;
+      break;
+  }
+
+  if (VGA_X >= VGA_WIDTH)
+  {
+    VGA_Y++;
+    VGA_X = 0;
+  }
+  if (VGA_Y >= VGA_HEIGHT) scroll(1);
+
+  move_cursor(VGA_X, VGA_Y);
+}
+
+void colorputc(char c, unsigned int color)
+{
+  switch(c)
+  {
+    case '\n':
+      VGA_X = 0;
+      VGA_Y++;
+      break;
+    case '\r':
+      VGA_X = 0;
+      break;
+    default:
+      putchar(VGA_X, VGA_Y, c);
+      putcolor(VGA_X, VGA_Y, color);
+      VGA_X++;
+      break;
+  }
+
+  if (VGA_X >= VGA_WIDTH)
+  {
+    VGA_Y++;
+    VGA_X = 0;
+  }
+  if (VGA_Y >= VGA_HEIGHT) scroll(1);
+  move_cursor(VGA_X, VGA_Y);
+}
+
+void puts(const char* str)
+{
+  while (*str)
+  {
+    putc(*str);
+    str++;
+  }
+}
+
+void colorputs(const char* str, unsigned int color)
+{
+  while (*str)
+  {
+    colorputc(*str, color);
+    str++;
+  }
+}
+
+void printf(const char* fmt, ...)
+{
+  int* argp = (int*) &fmt;
+  int state = PRINTF_STATE_START;
+  int length = PRINTF_LENGTH_START;
+  int radix = 10;
+  bool sign = false;
+
+  argp++;
+  while (*fmt)
+  {
+    switch(state) {
+    case PRINTF_STATE_START:
+      if (*fmt == '%')
+      {
+        state = PRINTF_STATE_LENGTH;
+      }
+      else {
+        putc(*fmt);
+      }
+      break;
+    case PRINTF_STATE_LENGTH:
+      if (*fmt == 'h')
+      {
+        length = PRINTF_LENGTH_SHORT;
+        state = PRINTF_STATE_SHORT;
+      }
+      else if (*fmt == 'l')
+      {
+        length = PRINTF_LENGTH_LONG;
+        state = PRINTF_STATE_LONG;
+      }
+      else {
+        goto PRINTF_STATE_SPEC_;
+      }
+      break;
+    case PRINTF_STATE_SHORT:
+      if (*fmt == 'h')
+      {
+        length = PRINTF_LENGTH_SHORT_SHORT;
+        state = PRINTF_STATE_SPEC;
+      }
+      else {
+        goto PRINTF_STATE_SPEC_;
+      }
+      break;
+    case PRINTF_STATE_LONG:
+      if (*fmt == 'l')
+      {
+        length = PRINTF_LENGTH_LONG_LONG;
+        state = PRINTF_STATE_SPEC;
+      }
+      else {
+        goto PRINTF_STATE_SPEC_;
+      }
+      break;
+    case PRINTF_STATE_SPEC:
+      PRINTF_STATE_SPEC_:
+        switch(*fmt)
+        {
+          case 'c':
+            putc((char)*argp);
+            argp++;
+            break;
+          case 's':
+            puts(*(const char **)argp);
+            argp++;
+            break;
+          case '%':
+            putc('%');
+            break;
+          case 'd':
+          case 'i':
+            radix = 10;
+            sign = true;
+            argp = printf_number(argp, length, sign, radix);
+            break;
+          case 'u':
+            radix = 10;
+            sign = false;
+            argp = printf_number(argp, length, sign, radix);
+            break;
+          case 'X':
+          case 'x':
+          case 'p':
+            radix = 16;
+            sign = false;
+            argp = printf_number(argp, length, sign, radix);
+            break;
+          case 'o':
+            radix = 8;
+            sign = false;
+            argp = printf_number(argp, length, sign, radix);
+            break;
+          default:
+            break;
+        }
+      state = PRINTF_STATE_START;
+      length = PRINTF_LENGTH_START;
+      radix = 10;
+      sign = false;
+      break;
+    }
+    fmt++;
+  }
+}
+
+const char charset[] = "0123456789abcdef";
+
+int* printf_number(int* argp, int length, bool sign, int radix)
+{
+  char buffer[32];
+  unsigned long long number;
+  int number_sign = 1;
+  int pos = 0;
+
+  switch(length)
+  {
+    case PRINTF_LENGTH_SHORT_SHORT:
+    case PRINTF_LENGTH_SHORT:
+    case PRINTF_LENGTH_START:
+      if (sign)
+      {
+        int n = *argp;
+        if (n < 0)
+        {
+          n = -n;
+          number_sign = -1;
+        }
+        number = (unsigned long long) n;
+      }
+      else {
+        number = *(unsigned int*) argp;
+      }
+      argp++;
+      break;
+    case PRINTF_LENGTH_LONG:
+      if (sign)
+      {
+        long int n = *(long int*)argp;
+        if (n < 0)
+        {
+          n = -n;
+          number_sign = -1;
+        }
+        number = (unsigned long long) n;
+      }
+      else {
+        number = *(unsigned long int*) argp;
+      }
+      argp += 2;
+      break;
+    case PRINTF_LENGTH_LONG_LONG:
+      if (sign)
+      {
+        long long int n = *(long long int*)argp;
+        if (n < 0)
+        {
+          n = -n;
+          number_sign = -1;
+        }
+        number = (unsigned long long) n;
+      }
+      else {
+        number = *(unsigned long long int*) argp;
+      }
+      argp += 4;
+      break;
+  }
+
+  do {
+    uint32_t rem;
+    x86_div64_32(number, radix, &number, &rem);
+    buffer[pos++] = charset[rem];
+  } while (number > 0);
+
+  if (sign && number_sign < 0)
+  {
+    buffer[pos++] = '-';
+  }
+
+  while (--pos >= 0)
+  {
+    putc(buffer[pos]);
+  }
+
+  return argp;
+}

src/libc/stdio.h

@@ -0,0 +1,41 @@
+#ifndef INCLUDE_STDIO_H
+#define INCLUDE_STDIO_H
+
+#include "stdint.h"
+
+#define FB_GREEN      2
+#define FB_DARK_GREY  8
+
+#define FB_CMD_PORT       0x3D4
+#define FB_DATA_PORT      0x3D5
+#define FB_HIGH_BYTE_CMD  14
+#define FB_LOW_BYTE_CMD   15
+
+void move_cursor(int x, int y);
+void putchar(int x, int y, char c);
+void puts(const char* str);
+void colorputs(const char* str, unsigned int color);
+void clear(void);
+void putcolor(int x, int y, unsigned int color);
+char getchar(int x, int y);
+unsigned int getcolor(int x, int y);
+void scroll(int lines);
+void putc(char c);
+void colorputc(char c, unsigned int color);
+
+#define PRINTF_STATE_START 0
+#define PRINTF_STATE_LENGTH 1
+#define PRINTF_STATE_SHORT 2
+#define PRINTF_STATE_LONG 3
+#define PRINTF_STATE_SPEC 4
+
+#define PRINTF_LENGTH_START 0
+#define PRINTF_LENGTH_SHORT_SHORT 1
+#define PRINTF_LENGTH_SHORT 2
+#define PRINTF_LENGTH_LONG 3
+#define PRINTF_LENGTH_LONG_LONG 4
+
+void printf(const char* fmt, ...);
+int* printf_number(int* argp, int length, bool sign, int radix);
+
+#endif

src/libc/string.c

@@ -0,0 +1,9 @@
+int strlen(char* str)
+{
+  int len = 0;
+  while (*str++)
+  {
+    len++;
+  }
+  return len;
+}

src/libc/string.h

@@ -0,0 +1,6 @@
+#ifndef INCLUDE_STRING_H
+#define INCLUDE_STRING_H
+
+int strlen(char* str);
+
+#endif