Message Integrity Checking

[uccvend-snackrom.git] / ROM2 / helpers.c

diff --git a/ROM2/helpers.c b/ROM2/helpers.c
index b66f5ee..f7bb406 100644 (file)
--- a/ROM2/helpers.c
+++ b/ROM2/helpers.c
@@ -9,24 +9,31 @@ void delay(u16 ms) {
         * XXX - how do we know gcc isn't optimising this? it seems to optimise after
         * parsing C -> asm, but before asm -> machine code.
         */
-       asm volatile ("pshx\npsha\npshb\n"); /* save registers */
-       asm volatile ("ldx %0\n" :: "m" (ms));
+       //asm volatile ("pshx\npsha\npshb\n"); /* save registers */
+       asm volatile ("ldx %0\n" :: "m" (ms) : "x");
        asm volatile (
-               "loop:\n"
-               "       dex\n"                  /* 3 */
-               "       beq out\n"              /* 3 */
-               "       ldd #327\n"             /* 3 */
-               "inner_loop:\n" /* 15 cycles each */
-               "       cpd #0x0000\n"          /* 5 */
-               "       beq inner_loop_end\n"   /* 3 */
-               "       subd #0x0001\n"         /* 4 */
-               "       bra inner_loop\n"       /* 3 */
-               "inner_loop_end:\n"
-               "       bra loop\n"             /* 3 */
-               "out:\n"
-               "       pulb\n"
+               "delay_loop:\n"
+               //"     ldd #327\n"                   /* 3 */
+               "       ldd #150\n"                   /* 3 */
+               "delay_inner_loop:\n" /* 15 cycles each */
+               "       cpd #0x0000\n"                /* 5 */
+               "       beq delay_inner_loop_end\n"   /* 3 */
+               "       subd #0x0001\n"               /* 4 */
+               "       bra delay_inner_loop\n"       /* 3 */
+               "delay_inner_loop_end:\n"
+               "       dex\n"                        /* 3 */
+               "       beq delay_out\n"              /* 3 */
+               "       bra delay_loop\n"             /* 3 */
+               "delay_out:\n" ::: "x", "d");
+               /*"     pulb\n"
                "       pula\n"
-               "       pulx\n");
+               "       pulx\n");*/
+}
+
+u8 my_strlen(char* s) {
+       char *p = s;
+       while (*p) p++;
+       return p-s;
 }
 
 void my_strncpy(char* dst, char* src, u8 max_size) {
@@ -35,7 +42,48 @@ void my_strncpy(char* dst, char* src, u8 max_size) {
        if (src[i] == 0 && i < max_size) dst[i] = 0; /* null terminator */
 }
 
+bool my_strncmp(char* a, char* b, u8 len) {
+       u8 i;
+       for (i = 0; i < len; i++) {
+               if (*a != *b) return 0;
+               a++;
+               b++;
+       }
+       return 1;
+}
+
 void my_memcpy(char* dst, char* src, u8 size) {
        u8 i = 0;
        for (i = 0; i < size; i++) dst[i] = src[i];
 }
+
+void my_memset(char* dst, u8 val, u16 count) {
+       char* c;
+       for (c = dst; c < dst+count; c++) *c = val;
+}
+
+u8 hexchar2u8(char b) {
+       if (b >= '0' && b <= '9') return b-'0';
+       if (b >= 'a' && b <= 'f') return b-'a'+0x0a;
+       if (b >= 'A' && b <= 'F') return b-'A'+0x0a;
+       return 0;
+}
+
+char nibble2hexchar(u8 b) {
+       if (b <= 9) return b+'0';
+       if (b >= 10 && b <= 15) return b+'A'-10;
+       return 'X';
+}
+
+u8 hex2u8(char msb, char lsb) {
+       return (hexchar2u8(msb) << 4) + hexchar2u8(lsb);
+}
+
+static char hexconv_buf[3];
+char* u82hex(u8 a) {
+       hexconv_buf[0] = nibble2hexchar((a&0xf0) >> 4);
+       hexconv_buf[1] = nibble2hexchar(a&0x0f);
+       hexconv_buf[2] = '\0';
+       return hexconv_buf;
+}
+