fixed EOS calculation

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

diff --git a/Kernel/lib.c b/Kernel/lib.c
index 35805b5..3399d3d 100644 (file)
--- a/Kernel/lib.c
+++ b/Kernel/lib.c
@@ -6,8 +6,9 @@
 
 // === CONSTANTS ===
 #define        RANDOM_SEED     0xACE55052
-#define        RANDOM_A        0x12231ADE
-#define        RANDOM_C        0x1BADBEEF
+#define        RANDOM_A        0x00731ADE
+#define        RANDOM_C        12345
+#define        RANDOM_SPRUCE   0xf12b02b
 //                          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
@@ -15,6 +16,9 @@ const short DAYS_BEFORE[] = {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 3
 // === PROTOTYPES ===
  int   ReadUTF8(Uint8 *str, Uint32 *Val);
 
+// === GLOBALS ===
+static Uint    giRandomState = RANDOM_SEED;
+
 // === CODE ===
 static const char cUCDIGITS[] = "0123456789ABCDEF";
 /**
@@ -137,7 +141,8 @@ int strcmp(char *str1, char *str2)
  */
 int strncmp(char *Str1, char *Str2, size_t num)
 {
-       while(num-- && *Str1 && *Str1 == *Str2)
+       if(num == 0)    return 0;       // TODO: Check what should officially happen here
+       while(--num && *Str1 && *Str1 == *Str2)
                Str1++, Str2++;
        return *Str1-*Str2;
 }
@@ -315,17 +320,12 @@ Sint64 timestamp(int sec, int mins, int hrs, int day, int month, int year)
  */
 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
+       Uint    old = giRandomState;
+       // Get the next state value
+       giRandomState = (RANDOM_A*giRandomState + RANDOM_C) & 0xFFFFFFFF;
+       // Check if it has changed, and if it hasn't, change it
+       if(giRandomState == old)        giRandomState += RANDOM_SPRUCE;
+       return giRandomState;
 }
 
 EXPORT(timestamp);