Major Nerdminer code rework

* Rework block header generation
* Fix dual-threaded mining code
* Fix share diff calculation
* Set default difficulty to 1e-4

src/mining.cpp

@@ -259,10 +259,19 @@ void runMiner(void * task_id) {
     // split up odd/even nonces between miner tasks
     nonce += miner_id;
     uint32_t startT = micros();
-    unsigned char *header64 = mMiner.bytearray_blockheader + 64;
+    unsigned char *header64;
+    // each miner thread needs to track its own blockheader template
+    memcpy(mMiner.bytearray_blockheader2, &mMiner.bytearray_blockheader, 80);
+    if (miner_id == 0)
+      header64 = mMiner.bytearray_blockheader + 64;
+    else
+      header64 = mMiner.bytearray_blockheader2 + 64;
     Serial.println(">>> STARTING TO HASH NONCES");
     while(true) {
+      if (miner_id == 0)
         memcpy(mMiner.bytearray_blockheader + 76, &nonce, 4);
+      else
+        memcpy(mMiner.bytearray_blockheader2 + 76, &nonce, 4);
 
       //Con midstate
       // Primer SHA-256
@@ -283,12 +292,15 @@ void runMiner(void * task_id) {
         Serial.println("");  */
       
       hashes++;
-      nonce += 2;
       if (nonce > TARGET_NONCE) break; //exit
       if(!mMiner.inRun) { Serial.println ("MINER WORK ABORTED >> waiting new job"); break;}
 
       // check if 16bit share
-      if(hash[31] !=0 || hash[30] !=0) continue;
+      if(hash[31] !=0 || hash[30] !=0) {
+        // increment nonce
+        nonce += 2;
+        continue;
+      }
       halfshares++;
       
       //Check target to submit
@@ -305,12 +317,24 @@ void runMiner(void * task_id) {
         Serial.print("   - TX SHARE: ");
         for (size_t i = 0; i < 32; i++)
             Serial.printf("%02x", hash[i]);
+        #ifdef DEBUG_MINING
+        Serial.println("");
+        Serial.print("   - Current nonce: "); Serial.println(nonce);
+        Serial.print("   - Current block header: ");
+        for (size_t i = 0; i < 80; i++) {
+            Serial.printf("%02x", mMiner.bytearray_blockheader[i]);
+        }
+        #endif
         Serial.println("");
         mLastTXtoPool = millis();  
       }
       
       // check if 32bit share
-      if(hash[29] !=0 || hash[28] !=0) continue;
+      if(hash[29] !=0 || hash[28] !=0) {
+        // increment nonce
+        nonce += 2;
+        continue;
+      }
       shares++;
 
         // check if valid header
@@ -325,6 +349,8 @@ void runMiner(void * task_id) {
         nonce = MAX_NONCE;
         break;
       }
+      // increment nonce
+      nonce += 2;
     } // exit if found a valid result or nonce > MAX_NONCE
 
     wc_Sha256Free(&sha256);

src/mining.h

@@ -5,7 +5,7 @@
 // Mining
 #define MAX_NONCE       5000000U
 #define TARGET_NONCE    471136297U
-#define DEFAULT_DIFFICULTY  1e-9
+#define DEFAULT_DIFFICULTY  1e-4
 #define KEEPALIVE_TIME_ms       30000
 #define POOLINACTIVITY_TIME_ms  60000
 
@@ -21,6 +21,7 @@ typedef struct{
   uint8_t bytearray_pooltarget[32];
   uint8_t merkle_result[32];
   uint8_t bytearray_blockheader[80];
+  uint8_t bytearray_blockheader2[80];
   double poolDifficulty;
   bool inRun;
   bool newJob;

src/utils.cpp

@@ -83,16 +83,16 @@ double le256todouble(const void *target)
 	double dcut64;
 
 	data64 = (uint64_t *)(target + 24);
-	dcut64 = bswap64(*data64) * 6277101735386680763835789423207666416102355444464034512896.0;
+	dcut64 = *data64 * 6277101735386680763835789423207666416102355444464034512896.0;
 
 	data64 = (uint64_t *)(target + 16);
-	dcut64 += bswap64(*data64) * 340282366920938463463374607431768211456.0;
+	dcut64 += *data64 * 340282366920938463463374607431768211456.0;
 
 	data64 = (uint64_t *)(target + 8);
-	dcut64 += bswap64(*data64) * 18446744073709551616.0;
+	dcut64 += *data64 * 18446744073709551616.0;
 
 	data64 = (uint64_t *)(target);
-	dcut64 += bswap64(*data64);
+	dcut64 += *data64;
 
 	return dcut64;
 }
@@ -100,7 +100,6 @@ double le256todouble(const void *target)
 double diff_from_target(void *target)
 {
 	double d64, dcut64;
-    //reverse_bytes((uint8_t *) target, 32);
 
 	d64 = truediffone;
 	dcut64 = le256todouble(target);
@@ -295,12 +294,13 @@ miner_data calculateMiningData(mining_subscribe& mWorker, mining_job mJob){
     res = to_byte_array(blockheader.c_str(), str_len*2, mMiner.bytearray_blockheader);
 
     #ifdef DEBUG_MINING
+    Serial.println("    blockheader: "); Serial.print(blockheader);
     Serial.println("    blockheader bytes "); Serial.print(str_len); Serial.print(" -> ");
     #endif
 
     // reverse version
     uint8_t buff;
-    size_t bsize, boffset;
+    size_t bword, bsize, boffset;
     boffset = 0;
     bsize = 4;
     for (size_t j = boffset; j < boffset + (bsize/2); j++) {
@@ -309,14 +309,42 @@ miner_data calculateMiningData(mining_subscribe& mWorker, mining_job mJob){
         mMiner.bytearray_blockheader[2 * boffset + bsize - 1 - j] = buff;
     }
 
-    // reverse merkle 
+    // reverse prev hash (4-byte word swap)
-    boffset = 36;
+    boffset = 4;
+    bword = 4;
     bsize = 32;
+    for (size_t i = 1; i <= bsize / bword; i++) {
+        for (size_t j = boffset; j < boffset + bword / 2; j++) {
+            buff = mMiner.bytearray_blockheader[j];
+            mMiner.bytearray_blockheader[j] = mMiner.bytearray_blockheader[2 * boffset + bword - 1 - j];
+            mMiner.bytearray_blockheader[2 * boffset + bword - 1 - j] = buff;
+        }
+        boffset += bword;
+    }
+
+/*
+    // reverse merkle (4-byte word swap)
+    boffset = 36;
+    bword = 4;
+    bsize = 32;
+    for (size_t i = 1; i <= bsize / bword; i++) {
+        for (size_t j = boffset; j < boffset + bword / 2; j++) {
+            buff = mMiner.bytearray_blockheader[j];
+            mMiner.bytearray_blockheader[j] = mMiner.bytearray_blockheader[2 * boffset + bword - 1 - j];
+            mMiner.bytearray_blockheader[2 * boffset + bword - 1 - j] = buff;
+        }
+        boffset += bword;
+    }
+*/
+    // reverse ntime
+    boffset = 68;
+    bsize = 4;
     for (size_t j = boffset; j < boffset + (bsize/2); j++) {
         buff = mMiner.bytearray_blockheader[j];
         mMiner.bytearray_blockheader[j] = mMiner.bytearray_blockheader[2 * boffset + bsize - 1 - j];
         mMiner.bytearray_blockheader[2 * boffset + bsize - 1 - j] = buff;
     }
+
     // reverse difficulty
     boffset = 72;
     bsize = 4;
@@ -344,11 +372,11 @@ miner_data calculateMiningData(mining_subscribe& mWorker, mining_job mJob){
     for (size_t i = 36; i < 36+32; i++)
         Serial.printf("%02x", mMiner.bytearray_blockheader[i]);
     Serial.println("");
-    Serial.print("nbits       ");
+    Serial.print("ntime       ");
     for (size_t i = 68; i < 68+4; i++)
         Serial.printf("%02x", mMiner.bytearray_blockheader[i]);
     Serial.println("");
-    Serial.print("difficulty  ");
+    Serial.print("nbits       ");
     for (size_t i = 72; i < 72+4; i++)
         Serial.printf("%02x", mMiner.bytearray_blockheader[i]);
     Serial.println("");