BigBuf and tracing rework: allow much longer traces in in hf commands

- provided a BigBuf_malloc() function to dynamically allocate parts of BigBuf
  e.g. for DMA-Buffers, Frame-Buffers, Emulator-Memory
- the whole rest of BigBuf is now available for traces (instead of a small fixed amount)
- send actual traceLen together with trace data
- changed client side to cope with varying traceLen
- changed small buffers to automatic variables instead of parts of BigBuf

armsrc/BigBuf.c

@@ -14,22 +14,38 @@
 #include "apps.h"
 #include "string.h"
 
-// The large multi-purpose buffer, typically used to hold A/D samples or traces,
-// may be processed in some way. Also used to hold various smaller buffers.
-static uint8_t BigBuf[BIGBUF_SIZE];
+// BigBuf is the large multi-purpose buffer, typically used to hold A/D samples or traces.
+// Also used to hold various smaller buffers and the Mifare Emulator Memory.
+
+// declare it as uint32_t to achieve alignment to 4 Byte boundary
+static uint32_t BigBuf[BIGBUF_SIZE/sizeof(uint32_t)];
 
 // High memory mark
 static uint16_t BigBuf_hi = BIGBUF_SIZE;
 
-// trace related global variables. Change to function calls?
-//uint8_t *trace = BigBuf;
-uint16_t traceLen;
+// pointer to the emulator memory.
+static uint8_t *emulator_memory = NULL;
+
+// trace related global variables
+// (only one left). ToDo: make this static as well?
+uint16_t traceLen = 0;
 
 
 // get the address of BigBuf
 uint8_t *BigBuf_get_addr(void)
 {
-	return BigBuf;
+	return (uint8_t *)BigBuf;
+}
+
+
+// get the address of the emulator memory. Allocate part of Bigbuf for it, if not yet done
+uint8_t *BigBuf_get_EM_addr(void)
+{
+	if (emulator_memory == NULL) {		// not yet allocated
+		emulator_memory = BigBuf_malloc(CARD_MEMORY_SIZE);
+	}
+	
+	return emulator_memory;
 }
 
 
@@ -41,28 +57,41 @@ void BigBuf_Clear(void)
 }
 
 
-// allocate a chunk of memory from BigBuf. We allocate high memory first. Low memory
-// is always for traces/samples
+// allocate a chunk of memory from BigBuf. We allocate high memory first. The unallocated memory
+// at the beginning of BigBuf is always for traces/samples
 uint8_t *BigBuf_malloc(uint16_t chunksize)
 {
 	if (BigBuf_hi - chunksize < 0) { 
-		return NULL;						// no memory left
+		return NULL;							// no memory left
 	} else {
-		BigBuf_hi -= chunksize; 		  	// aligned to 4 Byte boundary 
-		return BigBuf + BigBuf_hi;
+		chunksize = (chunksize + 3) & 0xfffc;	// round to next multiple of 4
+		BigBuf_hi -= chunksize; 		  		// aligned to 4 Byte boundary 
+		return (uint8_t *)BigBuf + BigBuf_hi;
 	}
 }
 
 
-// free ALL allocated chunks. The whole BigBuf is available for traces again.
+// free ALL allocated chunks. The whole BigBuf is available for traces or samples again.
 void BigBuf_free(void)
 {
 	BigBuf_hi = BIGBUF_SIZE;
+	emulator_memory = NULL;
+}
+
+
+// free allocated chunks EXCEPT the emulator memory
+void BigBuf_free_keep_EM(void)
+{
+	if (emulator_memory != NULL) {
+		BigBuf_hi = emulator_memory - (uint8_t *)BigBuf;
+	} else {
+		BigBuf_hi = BIGBUF_SIZE;
+	}
 }
 
 
 // return the maximum trace length (i.e. the unallocated size of BigBuf)
-uint16_t BigBuf_max_trace_len(void)
+uint16_t BigBuf_max_traceLen(void)
 {
 	return BigBuf_hi;
-}
+}