feat: formatter and oslog()

Kernel/Include/Lib/String.h

@@ -0,0 +1,18 @@
+#pragma once
+#include <types.h>
+#include <Lib/VAArgs.h>
+
+void* StringSet(BytePointer destination, ASCII value, Size count);
+void* MemoryCopy(void* destination, const void* source, Size count);
+
+Int32 StringCompare(const ASCII* firstString, const ASCII* secondString);
+Int32 StringCompareWithLimit(const ASCII* firstString, const ASCII* secondString, Size limit);
+
+ASCII* StringCopy(ASCII* destination, const ASCII* source);
+ASCII* StringCopyWithLimit(ASCII* destination, const ASCII* source, Size limit);
+
+Size StringGetLength(const ASCII* string);
+const ASCII* StringFindLastOccurrenceOfCharacter(const ASCII* string, ASCII separator);
+
+Int32 StringFormatVariadic(ASCII* string, Size size, const ASCII* format, va_list args);
+Int32 StringFormat(ASCII* destination, UInt64 size, const ASCII* format, ...);

Kernel/Include/Lib/VAArgs.h

@@ -0,0 +1,8 @@
+#pragma once
+
+typedef __builtin_va_list va_list;
+
+#define va_start(v, l) __builtin_va_start(v, l)
+#define va_end(v)      __builtin_va_end(v)
+#define va_arg(v, l)   __builtin_va_arg(v, l)
+#define va_copy(d, s)  __builtin_va_copy(d, s)

Kernel/Include/OS/Log.h

@@ -0,0 +1,8 @@
+#pragma once
+#include <types.h>
+
+enum {
+    kOSLogBufferSize = 1024,
+};
+
+void OSLog(const ASCII* format, ...);

Kernel/Source/IO/Serial.c

@@ -4,7 +4,7 @@
 
 Int32 IOSerialPutCharacter(ASCII character) {
     // TXFF -- TRansmit FIFO Full for PL011 is 5 bit of FR reg (0x18)
-    UInt64 uartFR = kUARTBaseAddress + 0x18; 
+    UInt64 uartFR = kUARTBaseAddress + 0x18;
 
     while ((IOAddressRead32(uartFR) & (1 << 5)) != 0)  {
         CPUYield();
@@ -22,4 +22,4 @@ Int32 IOSerialPutString(const ASCII* string) {
     }
 
     return i;
-}
+}

Kernel/Source/KernelMain.c

@@ -1,6 +1,4 @@
-#include <types.h>
-#include <IO/Serial.h>
+#include <OS/Log.h>
 
 void KernelMain(void) {
-    IOSerialPutString("Meow nya!!\n");
 }

Kernel/Source/Lib/String.c

@@ -0,0 +1,179 @@
+#include <Lib/String.h>
+#include <Lib/VAArgs.h>
+
+static void BufferAdd(ASCII* buffer, Size bufferSize, Size* written, ASCII character) {
+    if (*written + 1 < bufferSize) {
+        buffer[*written] = character;
+    }
+    (*written)++;
+}
+
+void* StringSet(BytePointer destination, ASCII value, Size count) {
+    BytePointer savedDestination = destination;
+    while (count--) {
+        *destination++ = (UInt8) value;
+    }
+    return savedDestination;
+}
+
+void* MemoryCopy(void* destination, const void* source, Size count) {
+    BytePointer destinationBuffer = (BytePointer) destination;
+    const UInt8* sourceBuffer = (const UInt8*) source;
+
+    while (count >= 8) {
+        *(UInt64*) destinationBuffer = *(const UInt64*) sourceBuffer;
+        destinationBuffer += 8;
+        sourceBuffer += 8;
+        count -= 8;
+    }
+
+    while (count > 0) {
+        *destinationBuffer++ = *sourceBuffer++;
+        count--;
+    }
+
+    return destination;
+}
+
+Int32 StringCompare(const ASCII* firstString, const ASCII* secondString) {
+    while (*firstString && (*firstString == *secondString)) {
+        firstString++;
+        secondString++;
+    }
+    return *(const UInt8*) firstString - *(const UInt8*) secondString;
+}
+
+Int32 StringCompareWithLimit(const ASCII* firstString, const ASCII* secondString, Size limit) {
+    while (limit > 0) {
+        if (*firstString != *secondString) return *(const UInt8*) firstString - *(const UInt8*) secondString;
+        if (*firstString == '\0') return 0;
+        firstString++;
+        secondString++;
+        limit--;
+    }
+    
+    return 0;
+}
+
+ASCII* StringCopy(ASCII* destination, const ASCII* source) {
+    ASCII* saved = destination;
+    while (*source) *destination++ = *source++;
+    *destination = 0;
+    return saved;
+}
+
+ASCII* StringCopyWithLimit(ASCII* destination, const ASCII* source, Size limit) {
+    ASCII* saved = destination;
+    while (*source && limit > 0) {
+        *destination++ = *source++;
+        limit--;
+    }
+    while (limit > 0) {
+        *destination++ = 0;
+        limit--;
+    }
+    return saved;
+}
+
+Size StringGetLength(const ASCII* string) {
+    Size result = 0;
+    for (result = 0; string[result]; result++);
+    return result;
+}
+
+const ASCII* StringFindLastOccurrenceOfCharacter(const ASCII* string, ASCII separator) {
+    const ASCII* lastSeparator = 0;
+    do {
+        if (*string == separator) lastSeparator = string;
+    } while (*string++);
+
+    return lastSeparator;
+}
+
+Int32 StringFormatVariadic(ASCII* string, Size size, const ASCII* format, va_list args) {
+    Size written = 0;
+    for (Size i = 0; format[i] != '\0'; i++) {
+        if (format[i] == '%') {
+            i++;
+            if (format[i] == '\0') break;
+            switch (format[i]) {
+                case 's': {
+                    const ASCII* vaArgString = va_arg(args, const ASCII*);
+                    if (!vaArgString) vaArgString = "(null)";
+                    while (*vaArgString) BufferAdd(string, size, &written, *vaArgString++);
+                    break;
+                }
+                case 'c': {
+                    ASCII character = (ASCII)va_arg(args, Int);
+                    BufferAdd(string, size, &written, character);
+                    break;
+                }
+                case 'd': {
+                    Int64 number = va_arg(args, Int);
+                    if (number < 0) {
+                        BufferAdd(string, size, &written, '-');
+                        number = -number;
+                    }
+
+                    UInt64 unsignedNumber = (UInt64)number;
+                    ASCII tempBuffer[32];
+                    Size position = 0;
+
+                    if (unsignedNumber == 0) tempBuffer[position++] = '0';
+                    while (unsignedNumber > 0) {
+                        tempBuffer[position++] = (ASCII)((unsignedNumber % 10) + '0');
+                        unsignedNumber /= 10;
+                    }
+
+                    while (position > 0) BufferAdd(string, size, &written, tempBuffer[--position]);
+                    break;
+                }
+                case 'x':
+                case 'X': {
+                    UInt64 unsignedNumber = va_arg(args, UInt64);
+                    UInt8 padding = (format[i] == 'X') ? 16 : 0;
+
+                    ASCII tempBuffer[32];
+                    Size position = 0;
+                    static const ASCII kHexDigits[] = "0123456789ABCDEF";
+
+                    if (unsignedNumber == 0 && padding == 0) tempBuffer[position++] = '0';
+                    while (unsignedNumber > 0) {
+                        tempBuffer[position++] = kHexDigits[unsignedNumber % 16];
+                        unsignedNumber /= 16;
+                    }
+
+                    while (position < (Size)padding) tempBuffer[position++] = '0';
+                    while (position > 0) BufferAdd(string, size, &written, tempBuffer[--position]);
+                    break;
+                }
+                case '%': {
+                    BufferAdd(string, size, &written, '%');
+                    break;
+                }
+                default: {
+                    BufferAdd(string, size, &written, '%');
+                    BufferAdd(string, size, &written, format[i]);
+                    break;
+                }
+            }
+        } else {
+            BufferAdd(string, size, &written, format[i]);
+        }
+    }
+
+    if (size > 0) {
+        if (written < size) string[written] = '\0';
+        else string[size - 1] = '\0';
+    }
+
+    return (Int32)written;
+}
+
+Int32 StringFormat(ASCII* destination, UInt64 size, const ASCII* format, ...) {
+    va_list args;
+    va_start(args, format);
+    Int32 returnValue = StringFormatVariadic(destination, size, format, args);
+    va_end(args);
+    return returnValue;
+}

Kernel/Source/OS/Log.c

@@ -0,0 +1,15 @@
+#include <OS/Log.h>
+#include <Lib/String.h>
+#include <Lib/VAArgs.h>
+#include <IO/Serial.h>
+
+void OSLog(const ASCII* format, ...) {
+    ASCII buffer[kOSLogBufferSize];
+   
+    va_list args;
+    va_start(args, format);
+    StringFormatVariadic(buffer, kOSLogBufferSize, format, args);
+    va_end(args);
+
+    IOSerialPutString(buffer);
+}