chg: changed comment

[proxmark3-svn] / armsrc / BigBuf.c

diff --git a/armsrc/BigBuf.c b/armsrc/BigBuf.c
index da86e9d3ccdbd98c469ffa1b84acebbcdcd9413b..57eb8db1d8c46b14b8d840f18036f98ec1b195e1 100644 (file)
--- a/armsrc/BigBuf.c
+++ b/armsrc/BigBuf.c
@@ -16,10 +16,17 @@
 
 // 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)];
 
+/* BigBuf memory layout:
+Pointer to highest available memory: BigBuf_hi
+
+    high BIGBUF_SIZE
+    reserved = BigBuf_malloc()  subtracts amount from BigBuf_hi,   
+       low  0x00
+*/
+
 // High memory mark
 static uint16_t BigBuf_hi = BIGBUF_SIZE;
 
@@ -36,31 +43,34 @@ uint8_t *BigBuf_get_addr(void)
        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
+       // not yet allocated
+       if (emulator_memory == NULL)
                emulator_memory = BigBuf_malloc(CARD_MEMORY_SIZE);
-       }
        
        return emulator_memory;
 }
 
-
 // clear ALL of BigBuf
 void BigBuf_Clear(void)
 {
        BigBuf_Clear_ext(true);
 }
+
 // clear ALL of BigBuf
 void BigBuf_Clear_ext(bool verbose)
 {
-       memset(BigBuf,0,BIGBUF_SIZE);
+       memset(BigBuf, 0, BIGBUF_SIZE);
        if (verbose) 
-               Dbprintf("Buffer cleared (%i bytes)",BIGBUF_SIZE);
+               Dbprintf("Buffer cleared (%i bytes)", BIGBUF_SIZE);
 }
 
+void BigBuf_Clear_keep_EM(void)
+{
+       memset(BigBuf, 0, BigBuf_hi);
+}
 
 // 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
@@ -75,36 +85,36 @@ uint8_t *BigBuf_malloc(uint16_t chunksize)
        }
 }
 
-
 // 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;
+       
+       // shouldn't this empty BigBuf also?
 }
 
-
 // free allocated chunks EXCEPT the emulator memory
 void BigBuf_free_keep_EM(void)
 {
-       if (emulator_memory != NULL) {
+       if (emulator_memory != NULL)
                BigBuf_hi = emulator_memory - (uint8_t *)BigBuf;
-       } else {
+       else
                BigBuf_hi = BIGBUF_SIZE;
-       }
+       
+       // shouldn't this empty BigBuf also?
 }
 
 void BigBuf_print_status(void)
 {
        Dbprintf("Memory");
        Dbprintf("  BIGBUF_SIZE.............%d", BIGBUF_SIZE);
-       Dbprintf("  BigBuf_hi  .............%d", BigBuf_hi);
+       Dbprintf("  Available memory........%d", BigBuf_hi);
        Dbprintf("Tracing");
        Dbprintf("  tracing ................%d", tracing);
        Dbprintf("  traceLen ...............%d", traceLen);
 }
 
-
 // return the maximum trace length (i.e. the unallocated size of BigBuf)
 uint16_t BigBuf_max_traceLen(void)
 {
@@ -145,9 +155,7 @@ bool RAMFUNC LogTrace(const uint8_t *btBytes, uint16_t iLen, uint32_t timestamp_
        uint16_t duration = timestamp_end - timestamp_start;
 
        // Return when trace is full
-       uint16_t max_traceLen = BigBuf_max_traceLen();
-
-       if (traceLen + sizeof(iLen) + sizeof(timestamp_start) + sizeof(duration) + num_paritybytes + iLen >= max_traceLen) {
+       if (traceLen + sizeof(iLen) + sizeof(timestamp_start) + sizeof(duration) + num_paritybytes + iLen >= BigBuf_max_traceLen()) {
                tracing = FALSE;        // don't trace any more
                return FALSE;
        }
@@ -239,15 +247,14 @@ int LogTraceHitag(const uint8_t * btBytes, int iBits, int iSamples, uint32_t dwP
        return TRUE;
 }
 
+
 // Emulator memory
 uint8_t emlSet(uint8_t *data, uint32_t offset, uint32_t length){
        uint8_t* mem = BigBuf_get_EM_addr();
-       if(offset+length < CARD_MEMORY_SIZE)
-       {
+       if(offset+length < CARD_MEMORY_SIZE) {
                memcpy(mem+offset, data, length);
                return 0;
-       }else
-       {
+       } else {
                Dbprintf("Error, trying to set memory outside of bounds! %d  > %d", (offset+length), CARD_MEMORY_SIZE);
                return 1;
        }