Changed kernel magic combo prefix to Ctrl-Alt-...

[tpg/acess2.git] / Kernel / lib.c

diff --git a/Kernel/lib.c b/Kernel/lib.c
index ee9f24e..35805b5 100644 (file)
--- a/Kernel/lib.c
+++ b/Kernel/lib.c
@@ -5,6 +5,9 @@
 #include <common.h>
 
 // === CONSTANTS ===
+#define        RANDOM_SEED     0xACE55052
+#define        RANDOM_A        0x12231ADE
+#define        RANDOM_C        0x1BADBEEF
 //                          Jan Feb Mar Apr May  Jun  Jul  Aug  Sept Oct  Nov  Dec
 const short DAYS_BEFORE[] = {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334};
 #define UNIX_TO_2K     ((30*365*3600*24) + (7*3600*24))        //Normal years + leap years
@@ -139,6 +142,18 @@ int strncmp(char *Str1, char *Str2, size_t num)
        return *Str1-*Str2;
 }
 
+/**
+ * \fn char *strdup(char *str)
+ * \brief Duplicates a string
+ */
+char *strdup(char *str)
+{
+       char    *ret;
+       ret = malloc(strlen(str)+1);
+       strcpy(ret, str);
+       return ret;
+}
+
 /**
  * \fn int strpos8(char *str, Uint32 search)
  * \brief Search a string for a UTF-8 character
@@ -168,6 +183,8 @@ int strpos8(char *str, Uint32 Search)
  */
 int ReadUTF8(Uint8 *str, Uint32 *Val)
 {
+       *Val = 0xFFFD;  // Assume invalid character
+       
        // ASCII
        if( !(*str & 0x80) ) {
                *Val = *str;
@@ -176,7 +193,6 @@ int ReadUTF8(Uint8 *str, Uint32 *Val)
        
        // Middle of a sequence
        if( (*str & 0xC0) == 0x80 ) {
-               *Val = -1;
                return 1;
        }
        
@@ -217,10 +233,55 @@ int ReadUTF8(Uint8 *str, Uint32 *Val)
        }
        
        // UTF-8 Doesn't support more than four bytes
-       *Val = -1;
        return 4;
 }
 
+/**
+ * \fn int WriteUTF8(Uint8 *str, Uint32 Val)
+ * \brief Write a UTF-8 character sequence to a string
+ */
+int WriteUTF8(Uint8 *str, Uint32 Val)
+{
+       // ASCII
+       if( Val < 128 ) {
+               *str = Val;
+               return 1;
+       }
+       
+       // Two Byte
+       if( Val < 0x8000 ) {
+               *str = 0xC0 | (Val >> 6);
+               str ++;
+               *str = 0x80 | (Val & 0x3F);
+               return 2;
+       }
+       
+       // Three Byte
+       if( Val < 0x10000 ) {
+               *str = 0xE0 | (Val >> 12);
+               str ++;
+               *str = 0x80 | ((Val >> 6) & 0x3F);
+               str ++;
+               *str = 0x80 | (Val & 0x3F);
+               return 3;
+       }
+       
+       // Four Byte
+       if( Val < 0x110000 ) {
+               *str = 0xF0 | (Val >> 18);
+               str ++;
+               *str = 0x80 | ((Val >> 12) & 0x3F);
+               str ++;
+               *str = 0x80 | ((Val >> 6) & 0x3F);
+               str ++;
+               *str = 0x80 | (Val & 0x3F);
+               return 4;
+       }
+       
+       // UTF-8 Doesn't support more than four bytes
+       return 0;
+}
+
 /**
  * \fn Uint64 timestamp(int sec, int mins, int hrs, int day, int month, int year)
  * \brief Converts a date into an Acess Timestamp
@@ -247,5 +308,25 @@ Sint64 timestamp(int sec, int mins, int hrs, int day, int month, int year)
        return stamp * 1000;
 }
 
+/**
+ * \fn Uint rand()
+ * \brief Pseudo random number generator
+ * \note Unknown effectiveness (made up on the spot)
+ */
+Uint rand()
+{
+       #if 0
+       static Uint     randomState = RANDOM_SEED;
+       Uint    ret = randomState;
+        int    roll = randomState & 31;
+       randomState = (randomState << roll) | (randomState >> (32-roll));
+       randomState ^= 0x9A3C5E78;
+       return ret;
+       #else
+       static Uint     randomState = RANDOM_SEED;
+       return randomState = (RANDOM_A*randomState + RANDOM_C) & 0xFFFFFFFF;
+       #endif
+}
+
 EXPORT(timestamp);
 EXPORT(ReadUTF8);