Espresso 0.0.2a

Makefile

@@ -6,10 +6,10 @@ AS           := i686-elf-as
 NASM         := nasm
 QEMU_MKE_IMG := qemu-img create -f raw espresso.img 64M
 MKFS_VFAT    := sudo mkfs.vfat
-MKFS_FLAGS   := -F 32 -S 512
+MKFS_FLAGS   := -F 16 -S 512
 NASMFLAGS    := -f elf32
 WNOFLAGS     := -Wno-discarded-qualifiers
-CFLAGS       := -std=gnu99 -ffreestanding -O2 -Wall -Wextra -msse $(WNOFLAGS) -nostdlib -nostartfiles -include kincl.h
+CFLAGS       := -std=gnu99 -ffreestanding -O2 -Wall -Wextra -msse $(WNOFLAGS) -nostdlib -nostartfiles -include include/kincl.h
 LDFLAGS      := -T linker.ld -ffreestanding -O2 -nostdlib -nostartfiles
 QEMUFLAGS    := -boot d -cdrom $(ISO) -drive file=espresso.img,format=raw,if=ide,readonly=off,rerror=report,werror=report -cpu qemu32,sse4.1
 QEMUFLGS_EXT := -vga std -d int,cpu_reset -D qemu.log -no-reboot #-singlestep
@@ -81,6 +81,7 @@ run: iso
 	@if [ ! -f espresso.img ]; then \
 		$(QEMU_MKE_IMG); \
 	fi
+	sudo mkfs.fat $(MKFS_FLAGS) espresso.img
 	@echo
 	qemu-system-i386 $(QEMUFLAGS) $(QEMUFLGS_EXT) $(MOR_QEMUFLGS)
 

arch/x86/cpuid_asm.asm

@@ -1,44 +1,51 @@
-.global get_cpu_brand_string
+global get_cpu_brand_string
 
-.type get_cpu_brand_string, @function
+section .text
+
+; void get_cpu_brand_string(char* buffer)
 
 get_cpu_brand_string:
-    pushad                      # Save all general-purpose registers
+    pushad                      ; Save registers
 
-    mov ebx, eax                # Save buffer pointer to ebx
+    mov edi, eax               ; EAX = pointer to output buffer
 
     mov eax, 0x80000000
     cpuid
-    cmp eax, 0x80000004         # Check if brand string is supported
+    cmp eax, 0x80000004
     jb .not_supported
 
-    mov esi, ebx                # Copy address to ESI
+    mov esi, edi               ; Buffer pointer → ESI
 
+    ; ---- CPUID leaf 0x80000002 ----
     mov eax, 0x80000002
     cpuid
-    mov [esi], eax
+    mov [esi],     eax
-    mov [esi + 4], ebx
+    mov [esi+4],   ebx
-    mov [esi + 8], ecx
+    mov [esi+8],   ecx
-    mov [esi + 12], edx
+    mov [esi+12],  edx
 
+    ; ---- CPUID leaf 0x80000003 ----
     mov eax, 0x80000003
     cpuid
-    mov [esi + 16], eax
+    mov [esi+16],  eax
-    mov [esi + 20], ebx
+    mov [esi+20],  ebx
-    mov [esi + 24], ecx
+    mov [esi+24],  ecx
-    mov [esi + 28], edx
+    mov [esi+28],  edx
 
+    ; ---- CPUID leaf 0x80000004 ----
     mov eax, 0x80000004
     cpuid
-    mov [esi + 32], eax
+    mov [esi+32],  eax
-    mov [esi + 36], ebx
+    mov [esi+36],  ebx
-    mov [esi + 40], ecx
+    mov [esi+40],  ecx
-    mov [esi + 44], edx
+    mov [esi+44],  edx
+
+    mov byte [esi+48], 0        ; Null terminator
 
     jmp .done
 
 .not_supported:
-    mov byte [ebx], 0           # Null-terminate if not supported
+    mov byte [edi], 0
 
 .done:
     popad

drivers/irq.c

@@ -19,8 +19,8 @@ void irq_init(void)
   {
     func_list[i] = 0x0;
   }
-  set_irq_handler(0, (irq_func_t*)pit_handler);
+  set_irq_handler(0, (irq_func_t*) pit_handler);
-  set_irq_handler(1, (irq_func_t*)keyboard_handler);
+  set_irq_handler(1, (irq_func_t*) keyboard_handler);
 }
 
 void irq_handler(uint8_t irq_number)

drivers/pit.c

@@ -48,4 +48,3 @@ void pit_sleep(uint64_t ms)
     asm volatile ("hlt");
   }
 }
-

drivers/ps2_keyboard.c

@@ -31,6 +31,14 @@
 
 #define RETURN_STI() do { _sti_asm(); return; } while (0)
 
+
+#define GETS_BUFFER_SIZE 256
+
+static char gets_buffer[GETS_BUFFER_SIZE];
+volatile char* gets_string = gets_buffer;
+volatile int32_t gets_capacity = GETS_BUFFER_SIZE;
+volatile int32_t gets_length = 0;
+
 bool ps2keyboard_initialized = false;
 
 /* State for shift key */
@@ -50,11 +58,8 @@ static volatile bool gets_finished = false;
 
 volatile unsigned char current_char;
 volatile char* current_string   = NULL;
-volatile char* gets_string      = NULL;
 volatile int32_t current_length = 0;
-volatile int32_t gets_length    = 0;
 volatile int32_t capacity       = 0;
-volatile int32_t gets_capacity  = 0;
 volatile uint16_t current_key;
 
 volatile ps2_hook_t* hooks = NULL;
@@ -88,7 +93,7 @@ void keyboard_init(void)
 
   outb(0x64, 0xAE); /* Enable keyboard interface (often optional, but here for safety) */
   
-  hooks = (ps2_hook_t*) malloc(sizeof(ps2_hook_t) * hook_count);
+  hooks = NULL;
   
   ps2keyboard_initialized = true;
   
@@ -251,143 +256,95 @@ char* get_string(void)
   return current_string;
 }
 
+static inline void print_(void)
+{
+  static char ch = 'a';
+  
+  int r = 0, c = 0;
+  
+  terminal_get_cursor(&r, &c);
+  terminal_set_cursor((uint16_t) 30, (uint16_t) 0);
+  printf("%c", ch);
+  terminal_set_cursor((uint16_t) r, (uint16_t) c);
+  
+  ch++;
+}
+
 char* kbd_gets(void)
 {
   gets_called = true;
   gets_finished = false;
-  
+  gets_length = 0;
-  while (gets_finished != true)
+  gets_string[0] = '\0';
+
+  while (!gets_finished)
   {
     sleep(1);
   }
-  
+
-  char* result = strdup(gets_string); /* Could be NULL, that is checked below */
+  _cli_asm();
-  
+
-  free(gets_string);
+  char* result = strdup((char*) gets_string);
-  
+
-  gets_string = NULL;
-  gets_capacity = 0;
   gets_length = 0;
+  gets_string[0] = '\0';
   gets_called = false;
-  
+
-  return result == NULL ? "" : result;
+  _sti_asm();
+
+  return result ? result : "";
 }
 
 void gets_append_char(unsigned char c)
 {
-  _cli_asm();
+  if (!gets_called)
-  
-  if (!gets_string && gets_capacity > 0)
   {
-    printf("[keyboard] ERROR: gets_string is NULL but capacity > 0!\n");
+    return;
-    RETURN_STI();
   }
 
-  
   if (c == KEY_ARROW_UP || c == KEY_ARROW_DOWN || c == KEY_ARROW_RIGHT || c == KEY_ARROW_LEFT)
   {
-    gets_string[1] = '\0';
+    if (GETS_BUFFER_SIZE >= 2)
-    
-    char tc = '\0';
-    
-    switch (c)
     {
-      case KEY_ARROW_UP:
+      gets_string[0] = (char)c;
-        tc = KEY_UP;
+      gets_string[1] = '\0';
-        break;
-      case KEY_ARROW_DOWN:
-        tc = KEY_DOWN;
-        break;
-      case KEY_ARROW_RIGHT:
-        tc = KEY_RIGHT;
-        break;
-      case KEY_ARROW_LEFT:
-        tc = KEY_LEFT;
-        break;
-      default:
-        tc = '\0';
-        break;
     }
-    
+
-    gets_string[0] = tc;
-    
     gets_finished = true;
-    
+    return;
-    RETURN_STI();
   }
   else if (c == '\n')
   {
-    /* The returned string must/will not have newlines in it, so we return here after setting gets_finished to 'true'. */
-  
     gets_finished = true;
-    
     printf("\n");
-    
+    return;
-    RETURN_STI();
   }
-  else if (c == 27)  /* ASCII escape, here it's used to cancel input. */
+  else if (c == 27)
   {
-    gets_finished = true;
     gets_string[0] = '\0';
-    
+    gets_finished = true;
-    RETURN_STI();
+    return;
   }
   else if (c == '\b')
   {
-    if (gets_length < 1)
+    if (gets_length > 0)
     {
-      RETURN_STI();
+      gets_length--;
+      gets_string[gets_length] = '\0';
+      printf("\b \b");
     }
+    return;
+  }
 
-    gets_length--;
+  if (gets_length < GETS_BUFFER_SIZE - 1)
+  {
+    gets_string[gets_length++] = (char)c;
     gets_string[gets_length] = '\0';
-    
+    printf("%c", c);
-    printf("\b \b");
-    
-    RETURN_STI();
   }
-
-  if ((gets_length) >= gets_capacity)
-  {
-    int new_capacity = (gets_capacity == 0) ? 64 : gets_capacity * 2;
-
-    char* new_str = (char*) malloc(new_capacity);
-    
-    if (!new_str)
-    {
-      RETURN_STI();
-    }
-    
-    if (gets_string)
-    {
-      for (int i = 0; i < gets_length; i++)
-      {
-        new_str[i] = gets_string[i];
-      }
-      
-      new_str[gets_length] = '\0';
-      
-      free(gets_string);
-    }
-
-    gets_string = new_str;
-    gets_capacity = new_capacity;
-  }
-  
-  if (!gets_string)
-  {
-    RETURN_STI();
-  }
-
-  gets_string[gets_length] = (char) c;
-  gets_length++;
-  gets_string[gets_length] = '\0';
-  
-  printf("%c", c);
-  
-  RETURN_STI();
 }
 
+
 void append_char(char c)
 {
   _cli_asm();

drivers/tty.c

@@ -18,6 +18,12 @@ void terminal_initialize(void)
   terminal_update_cursor();
 }
 
+void terminal_get_cursor(int* row, int* column)
+{
+  *row = (int) terminal_row;
+  *column = (int) terminal_column;
+}
+
 void terminal_initializec(uint8_t color)
 {
   terminal_row = 0;
@@ -170,12 +176,15 @@ void terminal_writeline(const char* data)
 
 void terminal_writechar_r(const char ch)
 {
-  unsigned char uch = ch;
+  size_t saved_row = terminal_row;
+  size_t saved_col = terminal_column;
 
   for (size_t i = 0; i < VGA_WIDTH; i++)
   {
-    terminal_putchar(uch);
+    terminal_putentryat(ch, terminal_color, i, saved_row);
   }
+
+  terminal_set_cursor(saved_row, saved_col);
 }
 
 void terminal_clear(void)
@@ -185,46 +194,49 @@ void terminal_clear(void)
 
 void terminal_clearl(size_t num_lines)
 {
-  if (num_lines == (size_t) -1)
+  if (num_lines == (size_t)-1)
   {
     terminal_initializec(terminal_getcolor());
   }
   else
   {
-    /* XXX note to self: VGA_HEIGHT is 25, and VGA_WIDTH is 80 XXX */
+    if (num_lines > VGA_HEIGHT)
-    /* static size_t terminal_row; static size_t terminal_column; */
-    
-    terminal_row = VGA_HEIGHT;
-    terminal_column = 0;
-    
-    while (terminal_row < num_lines)
     {
-      for (int32_t k = 0; k < (int32_t)VGA_WIDTH; k++)
+      num_lines = VGA_HEIGHT;
-      {
-        terminal_putentryat((unsigned char)' ', terminal_getcolor(), (size_t)terminal_row, (size_t)k);
-      }
-      terminal_row -= 1;
     }
+
+    size_t start = VGA_HEIGHT - num_lines;
+    for (size_t y = start; y < VGA_HEIGHT; y++)
+    {
+      for (size_t x = 0; x < VGA_WIDTH; x++)
+      {
+        terminal_putentryat(' ', terminal_getcolor(), x, y);
+      }
+    }
+
+    terminal_set_cursor(start, 0);
   }
 }
 
 void terminal_scroll(void)
 {
-  
   memmove(
     terminal_buffer,
     terminal_buffer + VGA_WIDTH,
-    sizeof(uint16_t) * VGA_WIDTH * (VGA_HEIGHT/* + 1*/)
+    sizeof(uint16_t) * VGA_WIDTH * (VGA_HEIGHT - 1)
   );
-  
+
   terminal_row = VGA_HEIGHT - 1;
-  
+  for (int32_t x = 0; x < (int32_t)VGA_WIDTH; x++)
-  for (int32_t k = 0; k < (int32_t)VGA_WIDTH; k++)
   {
-    terminal_putentryat((unsigned char)' ', terminal_getcolor(), (size_t)terminal_row, (size_t)k);
+    terminal_putentryat(' ', terminal_getcolor(), (size_t)x, (size_t)terminal_row);
   }
+
+  terminal_column = 0;
+  terminal_update_cursor();
 }
 
+
 unsigned char terminal_get_shifted(unsigned char uc)
 {
   unsigned char lowerc[] = { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '\0' };

drivers/vga/vga.c

@@ -1,10 +1,12 @@
 #include <stddef.h>
 #include <vga/vga.h>
 
-uint8_t vga_entry_color(enum vga_color fg, enum vga_color bg) {
+uint8_t vga_entry_color(enum vga_color fg, enum vga_color bg)
-    return fg | bg << 4;
+{
+  return fg | bg << 4;
 }
 
-uint16_t vga_entry(unsigned char uc, uint8_t color) {
+uint16_t vga_entry(unsigned char uc, uint8_t color)
-    return (uint16_t) uc | (uint16_t) color << 8;
+{
+  return (uint16_t) uc | (uint16_t) color << 8;
 }

include/drivers/ide.h

@@ -32,6 +32,9 @@
 #define ATA_SR_DRQ     0x08
 #define ATA_SR_ERR     0x01
 
+
+#define SECTOR_SIZE 512
+
 void ide_initialize(void);
 
 int32_t ide_identify(uint8_t drive, uint16_t* buffer);

include/kernel/vars.h

@@ -2,6 +2,8 @@
 #define _KERNEL_VARIABLES_H
 
 
+#define KERNEL_VARIABLES_SIZE 4096 /* in bytes (note: it take up a whole page, yes.) */
+
 void init_vars(void);
 
 #endif

include/kincl.h

@@ -1,6 +1,21 @@
 #ifndef _KERNEL_INCLUDES_H
 #define _KERNEL_INCLUDES_H
 
-#define KERNEL_VERSION "0.0.1e"
+#define ESPRESSO_KERNEL_
+
+#define KERNEL_VERSION "0.0.2a"
+
+#define _STATE_NORMAL 0
+#define _STATE_HANDLED 1
+#define _STATE_INTERRUPT -1
+#define _STATE_EXCEPTION -2
+#define _STATE_CRASH -555
+
+
+#define __always_inline inline __attribute__((always_inline))
+#define __hot __attribute__((hot))
+#define __cold __attribute__((cold))
+#define __noreturn __attribute__((noreturn))
+#define __section(x) __attribute__((section(x)))
 
 #endif

include/port_io.h

@@ -10,12 +10,12 @@ static inline uint32_t inl(uint16_t port)
   return rv;
 }
 
-static inline void outl(uint16_t port, uint32_t data)
+static inline __attribute__((always_inline)) void outl(uint16_t port, uint32_t data)
 {
   asm volatile ("outl %%eax, %%dx" : : "dN" (port), "a" (data));
 }
 
-static inline void outb(uint16_t port, uint8_t val)
+static inline __attribute__((always_inline)) void outb(uint16_t port, uint8_t val)
 {
   asm volatile ( "outb %0, %1" : : "a"(val), "Nd"(port) : "memory");
 }
@@ -30,17 +30,19 @@ static inline uint8_t inb(uint16_t port)
   return ret;
 }
 
-static inline void io_wait()
+static inline __attribute__((always_inline)) void io_wait()
 {
   outb(0x80, 0);
 }
 
-static inline void insw(uint16_t port, void* addr, uint32_t count) {
+static inline __attribute__((always_inline)) void insw(uint16_t port, void* addr, uint32_t count)
-    __asm__ volatile ("rep insw" : "+D"(addr), "+c"(count) : "d"(port) : "memory");
+{
+  asm volatile ("rep insw" : "+D"(addr), "+c"(count) : "d"(port) : "memory");
 }
 
-static inline void outsw(uint16_t port, const void* addr, uint32_t count) {
+static inline __attribute__((always_inline)) void outsw(uint16_t port, const void* addr, uint32_t count)
-    __asm__ volatile ("rep outsw" : "+S"(addr), "+c"(count) : "d"(port));
+{
+  asm volatile ("rep outsw" : "+S"(addr), "+c"(count) : "d"(port));
 }
 
 #endif

include/string.h

@@ -17,6 +17,9 @@ char* strdup(const char* s);
 char* strtok(char* str, const char* delim);
 char* strchr(const char* s, int c);
 
+/* this function is NOT in the standard C library */
+int num_strchr(const char* s, int c);
+
 void lowers(char* str);
 void uppers(char* str);
 

include/tty.h

@@ -16,6 +16,9 @@ void terminal_write(const char* data, size_t size);
 void terminal_writestring(const char* data);
 void terminal_debug_writestring(const char* data);
 
+void terminal_writeline(const char* data);
+void terminal_writechar_r(const char ch);
+
 void terminal_setcolor(uint8_t color);
 uint8_t terminal_getcolor(void);
 
@@ -26,6 +29,7 @@ void terminal_scroll(void);
 unsigned char terminal_get_shifted(unsigned char uc);
 
 void terminal_set_cursor(uint16_t row, uint16_t column);
+void terminal_get_cursor(int* row, int* column);
 void terminal_update_cursor(void);
 
 #endif

include/vector_extensions/sse.h

@@ -21,7 +21,7 @@ void *sse2_memcpy(void *dst, const void *src, uint32_t n);
 void double_vector_to_int_vector(const double *src, int32_t *dst);
 void int_vector_to_double_vector(const int32_t *src, double *dst);
 
-void *memclr_sse2(const void *const m_start, const size_t m_count);
+void* memclr_sse2(void *m_start, size_t m_count);
 
 
 #endif

include/vga/vga.h

@@ -5,22 +5,22 @@
 
 /* Hardware text mode color constants. */
 enum vga_color {
-	VGA_COLOR_BLACK = 0,
+  VGA_COLOR_BLACK = 0,
-	VGA_COLOR_BLUE = 1,
+  VGA_COLOR_BLUE = 1,
-	VGA_COLOR_GREEN = 2,
+  VGA_COLOR_GREEN = 2,
-	VGA_COLOR_CYAN = 3,
+  VGA_COLOR_CYAN = 3,
-	VGA_COLOR_RED = 4,
+  VGA_COLOR_RED = 4,
-	VGA_COLOR_MAGENTA = 5,
+  VGA_COLOR_MAGENTA = 5,
-	VGA_COLOR_BROWN = 6,
+  VGA_COLOR_BROWN = 6,
-	VGA_COLOR_LIGHT_GREY = 7,
+  VGA_COLOR_LIGHT_GREY = 7,
-	VGA_COLOR_DARK_GREY = 8,
+  VGA_COLOR_DARK_GREY = 8,
-	VGA_COLOR_LIGHT_BLUE = 9,
+  VGA_COLOR_LIGHT_BLUE = 9,
-	VGA_COLOR_LIGHT_GREEN = 10,
+  VGA_COLOR_LIGHT_GREEN = 10,
-	VGA_COLOR_LIGHT_CYAN = 11,
+  VGA_COLOR_LIGHT_CYAN = 11,
-	VGA_COLOR_LIGHT_RED = 12,
+  VGA_COLOR_LIGHT_RED = 12,
-	VGA_COLOR_LIGHT_MAGENTA = 13,
+  VGA_COLOR_LIGHT_MAGENTA = 13,
-	VGA_COLOR_LIGHT_BROWN = 14,
+  VGA_COLOR_LIGHT_BROWN = 14,
-	VGA_COLOR_WHITE = 15,
+  VGA_COLOR_WHITE = 15,
 };
 
 uint8_t vga_entry_color(enum vga_color fg, enum vga_color bg);

kernel/boot.c

@@ -38,7 +38,7 @@ char* get_cpu_vendor_string(void)
   return strdup(vendor);
 }
 
-char* get_cpu_brand_string(void)
+/*char* get_cpu_brand_string(void)
 {
   unsigned int eax = 0, ebx = 0, ecx = 0, edx = 0;
   
@@ -63,4 +63,4 @@ char* get_cpu_brand_string(void)
 
   brand[48] = '\0';
   return strdup(brand);
-}
+}*/

kernel/kernel.c

@@ -136,10 +136,6 @@ void kernel_main(multiboot_info_t* mbd, uint32_t magic)
 	
   terminal_setcolor(VGA_COLOR_LIGHT_GREEN);
   
-  
-  /*pit_sleep(4000);
-  begin_anim(kernel_version);*/
-  
   printf("Guten tag and welcome to Espresso %s\n", kernel_version);
   
   sleep(1000);

kernel/kshell.c

@@ -4,6 +4,9 @@
 #include <drivers/ps2_keyboard.h>
 #include <tty.h>
 #include <kernel/ksh_debug.h>
+#include <arch/x86/intrin.h>
+
+#include <fs/fat16.h>
 
 #include <kernel/kshell.h>
 
@@ -27,29 +30,20 @@ static void print_intro(void)
 
   printf("\nSSE level: ");
   
-  command = 0;
+  command = 1;
   
   execute();
   
   extern char* get_cpu_vendor_string(void);
   extern char* get_cpu_brand_string(void);
   
+  /* XXX: NOTE: these do not need freeing. */
   char* temp_ = get_cpu_vendor_string();
   char* _temp = get_cpu_brand_string();
   
   printf("CPU: %s\n", _temp == NULL ? "No info" : _temp);
   printf("CPU vendor: %s\n", temp_ == NULL ? "No info" : temp_);
   
-  if (temp_)
-  {
-    free(temp_);
-  }
-  
-  if (_temp)
-  {
-    free(_temp);
-  }
-  
   printf("\nCopyright 2025 David J Goeke\n");
 }
 
@@ -64,6 +58,33 @@ static void parse_opts(int argc, char** argv)
   }
 }
 
+static char* commands[] = {
+  "kinfo",
+  "sseinfo",
+  "kernelmem",
+  "sectionmem",
+  
+  "enable_debug",
+  "disable_debug",
+  "toggle_debug",
+  "get_debug",
+  
+  "dumpregs",
+  "dumpgprs",
+  
+  "testascii",
+  
+  "printrandom",
+  
+  "acm", /* ACcess Memory */
+  
+  "testfat16",
+  
+  NULL,
+};
+
+#define NUM_COMMANDS 15 /* Yes, including the NULL */
+
 int kshell_start(int argc, char** argv)
 {
   (void)argc;
@@ -73,8 +94,6 @@ int kshell_start(int argc, char** argv)
   
   char* i = NULL;
   
-  terminal_setcolor(VGA_COLOR_LIGHT_BLUE);
-  
   print_intro();
   
   command = -1;
@@ -95,59 +114,36 @@ int kshell_start(int argc, char** argv)
     {
       break;
     }
-    else if (strcmp(i, "sseinfo") == 0)
+    
+    for (int j = 0; j < NUM_COMMANDS; j++)
     {
-      command = 0;
+      if (strcmp(i, commands[j]) == 0)
+      {
+        command = j;
+        break;
+      }
     }
-    else if (strcmp(i, "kinfo") == 0)
+    
-    {
+    if (command == -1)
-      command = 1;
-    }
-    else if (strcmp(i, "enable_debug") == 0)
-    {
-      _debug = true;
-    }
-    else if (strcmp(i, "disable_debug") == 0)
-    {
-      _debug = false;
-    }
-    else if (strcmp(i, "toggle_debug") == 0)
-    {
-      _debug = !_debug;
-    }
-    else if (strcmp(i, "get_debug") == 0)
-    {
-      printf("Debugging: %s\n", _debug == true ? "On" : "Off");
-    }
-    else if (strcmp(i, "dumpregs") == 0)
-    {
-      command = 2;
-    }
-    else if (strcmp(i, "dumpgprs") == 0)
-    {
-      command = 3;
-    }
-    else if (strcmp(i, "kernelmem") == 0)
-    {
-      command = 4;
-    }
-    else if (strcmp(i, "sectionmem") == 0)
-    {
-      command = 5;
-    }
-    else if (strcmp(i, "testascii") == 0)
-    {
-      command = 6;
-    }
-    else if (strcmp(i, "asciitype") == 0)
-    {
-      command = 7;
-    }
-    else
     {
       printf("Unknown command %s len %i\n", i, strlen(i));
     }
-    
+    else if (command == 4)
+    {
+      _debug = true;
+    }
+    else if (command == 5)
+    {
+      _debug = false;
+    }
+    else if (command == 6)
+    {
+      _debug = !_debug;
+    }
+    else if (command == 7)
+    {
+      printf("Debugging: %s\n", _debug == true ? "On" : "Off");
+    }
     
     if (_debug)
     {
@@ -163,23 +159,63 @@ int kshell_start(int argc, char** argv)
       printf("\n");
     }
     
+    printf("C: %s; %i\n", commands[command], command);
+    
     execute();
     
   } while (1);
   
-  free(i);
+  if (i != NULL)
+  {
+    free(i);
+  }
   
-  printf("Goodbye\n");
+  printf("Goodbye!\n");
   
   return 0;
 }
 
+/*
+  static char* commands[] = {
+  "kinfo",
+  "sseinfo",
+  "kernelmem",
+  "sectionmem",
+  
+  "enable_debug",
+  "disable_debug",
+  "toggle_debug",
+  "get_debug",
+  
+  "dumpregs",
+  "dumpgprs",
+  
+  "testascii",
+  
+  "printrandom",
+  
+  "acm",
+  
+  NULL,
+};
+*/
+
 int execute(void)
 {
-
   switch (command)
   {
     case 0: {
+      printf("Espresso %s ", KERNEL_VERSION);
+      
+#ifdef _DEBUG
+      printf("DEBUG BUILD");
+#endif
+      
+      printf("\n");
+      
+      break;
+    }
+    case 1: {
       extern int sse_initialized;
       
       switch (sse_initialized)
@@ -214,20 +250,7 @@ int execute(void)
       
       break;
     }
-    case 1: {
-      printf("Espresso %s\n", KERNEL_VERSION);
-      
-      break;
-    }
     case 2: {
-      print_all_regs();
-      break;
-    }
-    case 3: {
-      print_gprs();
-      break;
-    }
-    case 4: {
       extern uint8_t __kernel_start;
       extern uint8_t __kernel_end;
       size_t kernel_size = (size_t)&__kernel_end - (size_t)&__kernel_start;
@@ -240,7 +263,7 @@ int execute(void)
       
       break;
     }
-    case 5: {
+    case 3: {
       extern uint8_t __kernel_text_start;
       extern uint8_t __kernel_text_end;
       extern uint8_t __kernel_rodata_start;
@@ -255,7 +278,15 @@ int execute(void)
                                                                     
       break;
     }
-    case 6: {
+    case 8: {
+      print_all_regs();
+      break;
+    }
+    case 9: {
+      print_gprs();
+      break;
+    }
+    case 10: {
       /*extern void terminal_clear(void);*/
     
       terminal_clear();
@@ -271,14 +302,106 @@ int execute(void)
         printf("%c", (char) i);
       }
       
-      printf("\nCool ASCII art\n%c%c\n%c%c\n", 0xDA, 0xBF, 0xC0, 0xD9);
+      printf("\n\n\\/ Cool ASCII art \\/\n%c%c\n%c%c\n", 0xDA, 0xBF, 0xC0, 0xD9);
       
       gets();
       
       break;
     }
-    case 7: {
+    case 11: {
+      extern void seed_rand(uint32_t seed);
+      extern uint32_t ulrand(void);
+      
+      uint64_t v = rdtsc();
+      
+      seed_rand((uint32_t) v);
+      
+      printf("%ull\n", ulrand());
     
+      break;
+    }
+    case 12: {
+      printf("Enter hexadecimal address to access: ");
+      char* g = gets();
+      
+      int val = atoi(g);
+      
+      if (val == 0)
+      {
+        printf("Improper/Malformed string entered\n");
+        
+        break;
+      }
+      else if (val < 0x100000)
+      {
+        printf("Invalid address, must be higher than 0x100000\n");
+        
+        break;
+      }
+      
+      int val_ = *((int*) val);
+      
+      printf("value at %u: %i\n", val, val_);
+      
+      break;
+    }
+    case 13: {
+      int retv = fat16_mount(0);
+      
+      if (retv != 0)
+      {
+        printf("There was an error while mounting volume 0.\n");
+        
+        break;
+      }
+      
+      printf("Volume 0 mounted successfully.\n");
+      
+      char fat_name[12];
+      fat16_file_t file;
+      
+      filename_to_83("test.txt", fat_name);
+      
+      retv = fat16_create_file(fat_name, &file);
+      
+      if (retv != 0)
+      {
+        printf("There was an error while creating a file on volume 0.\n");
+        
+        break;
+      }
+      
+      uint8_t buf[512];
+      memset(buf, 0, sizeof(buf));
+      strcpy((char*) buf, "fg");
+      
+      retv = fat16_write_file(&file, buf, (strlen((char*) buf)));
+      
+      if (retv != 0)
+      {
+        printf("There was an error while writing to a file on volume 0.\n");
+        
+        break;
+      }
+      
+      uint8_t rbuf[512];
+      memset(rbuf, 0, sizeof(rbuf));
+      
+      retv = fat16_read_file(&file, rbuf);
+      
+      if (retv != 0)
+      {
+        printf("There was an error while reading from a file on volume 0.\n");
+        
+        break;
+      }
+      
+      printf("The data read should be: %s\n", (char*) buf);
+      printf("Read data: %s\n", (char*) rbuf);
+      printf("Deleting test file\n");
+      
+      fat16_delete_file(fat_name);
+      
       break;
     }
   }

kernel/vars.c

@@ -4,13 +4,22 @@
 
 #include <kernel/vars.h>
 
+/*
+  Number of bytes in kernel variable space: 4096  (4KiB)
+  Number of bits in kernel variable space:  32768 (32Mib)
+*/
 
-static uint8_t* vars_start = NULL;
+uint8_t vars[KERNEL_VARIABLES_SIZE];
-
-static int num_bytes_used = 0;
 
 void init_vars(void)
 {
-  vars_start = (uint8_t*) malloc(8 * 1024); /* 1 KiB */
+  memset(vars, 0, KERNEL_VARIABLES_SIZE);
-  memclr(vars_start, (size_t) 1024);
+}
+
+/* bo = bit offset */
+void set_bit_bo(uint32_t offset, uint8_t val)
+{
+  /* First, extract the byte offset. (round down to a multiple of 8, and divide by 8. */
+  (void) offset;
+  (void) val;
 }

lib/printf.c

@@ -301,14 +301,14 @@ void print_lint(int64_t value)
 void print_hex(uint32_t value, int width, bool uppercase)
 {
   const char* hex_chars = uppercase ? "0123456789ABCDEF" : "0123456789abcdef";
-  char buffer[9]; // 8 hex digits max for 32-bit
+  char buffer[9]; /* 8 hex digits max for 32-bit */
   int i = 0;
 
   do
   {
     buffer[i++] = hex_chars[value & 0xF];
     value >>= 4;
-  } while (value || i < width); // ensure at least 'width' digits
+  } while (value || i < width); /* ensure at least 'width' digits */
 
   while (i--)
   {

lib/string.c

@@ -172,9 +172,9 @@ char* strchr(const char* s, int c)
 {
   while (*s)
   {
-    if (*s == (char)c)
+    if (*s == (char) c)
     {
-      return (char*)s;
+      return (char*) s;
     }
     s++;
   }
@@ -182,6 +182,22 @@ char* strchr(const char* s, int c)
   return NULL;
 }
 
+int num_strchr(const char* s, int c)
+{
+  int rv = 0;
+
+  while (*s)
+  {
+    if (*s == (char) c)
+    {
+      rv++;
+    }
+    s++;
+  }
+
+  return rv;
+}
+
 
 void* memset(void* dst, int c, size_t n)
 {
@@ -201,10 +217,10 @@ void* memset(void* dst, int c, size_t n)
 
 void* memcpy(void *dst, const void *src, uint32_t n)
 {
-  /*if (sse_initialized > 1)
+  if (sse_initialized > 1)
   {
     return sse2_memcpy(dst, src, n);
-  }*/
+  }
 
   char *d = dst;
   const char *s = src;

lib/vector_extensions/sse.c

@@ -1,6 +1,8 @@
 #include <types.h>
 #include <stdio.h>
 
+#include <emmintrin.h> /* SSE2 intrinsics, TODO: use these in all functions, currently only used in memclr_sse2 */
+
 #include <vector_extensions/sse.h>
 
 
@@ -20,7 +22,7 @@ void enable_sse(void)
 }
 
 /* Basic SSE test: add two arrays of 4 floats using xmm registers */
-__attribute__((force_align_arg_pointer))
+__attribute__((force_align_arg_pointer, target("sse2")))
 int32_t test_sse(void)
 {
   float a[4] __attribute__((aligned(16))) = {1.0f, 2.0f, 3.0f, 4.0f};
@@ -45,7 +47,7 @@ int32_t test_sse(void)
   return 0;
 }
 
-__attribute__((force_align_arg_pointer))
+__attribute__((force_align_arg_pointer, target("sse2")))
 void sse2_add_double_arrays(double *dst, const double *a, const double *b, size_t count)
 {
   for (size_t i = 0; i < count; i += 2)
@@ -62,7 +64,7 @@ void sse2_add_double_arrays(double *dst, const double *a, const double *b, size_
   }
 }
 
-__attribute__((force_align_arg_pointer))
+__attribute__((force_align_arg_pointer, target("sse2")))
 void sse2_add_int64_arrays(int64_t *dst, const int64_t *a, const int64_t *b, size_t count)
 {
   for (size_t i = 0; i < count; i += 2)
@@ -79,7 +81,7 @@ void sse2_add_int64_arrays(int64_t *dst, const int64_t *a, const int64_t *b, siz
   }
 }
 
-__attribute__((force_align_arg_pointer))
+__attribute__((force_align_arg_pointer, target("sse2")))
 void sse2_add_int32_arrays(int32_t *dst, const int32_t *a, const int32_t *b, size_t count)
 {
   for (size_t i = 0; i < count; i += 4)
@@ -96,7 +98,7 @@ void sse2_add_int32_arrays(int32_t *dst, const int32_t *a, const int32_t *b, siz
   }
 }
 
-__attribute__((force_align_arg_pointer))
+__attribute__((force_align_arg_pointer, target("sse2")))
 void *sse2_memcpy(void *dst, const void *src, uint32_t n)
 {
   uint8_t *d = (uint8_t *)dst;
@@ -136,7 +138,7 @@ void *sse2_memcpy(void *dst, const void *src, uint32_t n)
 }
 
 
-__attribute__((force_align_arg_pointer))
+__attribute__((force_align_arg_pointer, target("sse2")))
 char *sse2_strncpy(char *dest, const char *src, uint32_t n)
 {
   uint32_t i = 0;
@@ -218,48 +220,31 @@ void int_vector_to_double_vector(const int32_t *src, double *dst)
   );
 }
 
-void * memclr_sse2(const void * const m_start, const size_t m_count)
+__attribute__((force_align_arg_pointer, target("sse2")))
+void* memclr_sse2(void *m_start, size_t m_count)
 {
-	
+  unsigned char *dst = m_start;
-  /* "i" is our counter of how many bytes we've cleared */
+  size_t i = 0;
-  size_t i;
 
-  /* find out if "m_start" is aligned on a SSE_XMM_SIZE boundary */
+  while ((uintptr_t)(dst + i) & 15 && i < m_count)
-  if ((size_t)m_start & (SSE_XMM_SIZE - 1))
   {
-    i = 0;
+    dst[i++] = 0;
-
-    /* we need to clear byte-by-byte until "m_start" is aligned on an SSE_XMM_SIZE boundary */
-    /* ... and lets make sure we don't copy 'too' many bytes (i < m_count) */
-    while (((size_t)m_start + i) & (SSE_XMM_SIZE - 1) && i < m_count)
-    {
-      asm volatile ("stosb;" :: "D"((size_t)m_start + i), "a"(0));
-      i++;
-    }
   }
-  else
+
+  __m128i zero = _mm_setzero_si128();
+  
+  for (; i + 64 <= m_count; i += 64)
   {
-    /* if "m_start" was aligned, set our count to 0 */
+    _mm_store_si128((__m128i *)(dst + i + 0), zero);
-    i = 0;
+    _mm_store_si128((__m128i *)(dst + i + 16), zero);
+    _mm_store_si128((__m128i *)(dst + i + 32), zero);
+    _mm_store_si128((__m128i *)(dst + i + 48), zero);
   }
- 
+
-  asm volatile ("pxor %%xmm0,%%xmm0"::); /* zero out XMM0 */
+  for (; i < m_count; ++i)
-  /* clear 64-byte chunks of memory (4 16-byte operations) */
-  for(; i + 64 <= m_count; i += 64)
   {
-    asm volatile (" movdqa %%xmm0, 0(%0);	"    /* move 16 bytes from XMM0 to %0 + 0 */
+    dst[i] = 0;
-                  " movdqa %%xmm0, 16(%0);	"
-                  " movdqa %%xmm0, 32(%0);	"
-                  " movdqa %%xmm0, 48(%0);	"
-                  :: "r"((size_t)m_start + i));
   }
- 
+  
-  /* copy the remaining bytes (if any) */
+  return m_start;
-  asm volatile (" rep stosb; " :: "a"((size_t)(0)), "D"(((size_t)m_start) + i), "c"(m_count - i));
-
-  /* "i" will contain the total amount of bytes that were actually transfered */
-  i += m_count - i;
-
-  /* we return "m_start" + the amount of bytes that were transfered */
-  return (void *)(((size_t)m_start) + i);
 }

serial.log

@@ -1,5 +0,0 @@
-Loading Espresso 0.0.2a... 
-[ DEBUG ] Testing SSE...
-[ DEBUG ] SSE test passed
-Disk model: QEMU HARDDISK                           
-Guten tag and welcome to Espresso 0.0.2a