fix STM32_UID string corruption

Marlin/src/feature/tmc_util.cpp

@@ -763,7 +763,7 @@
         SERIAL_CHAR('\t');
         st.printLabel();
         SERIAL_CHAR('\t');
-        print_hex_long(drv_status, ':');
+        print_hex_long(drv_status, ':', true);
         if (drv_status == 0xFFFFFFFF || drv_status == 0) SERIAL_ECHOPGM("\t Bad response!");
         SERIAL_EOL();
         break;

Marlin/src/gcode/host/M115.cpp

@@ -88,14 +88,15 @@ void GcodeSuite::M115() {
      * This code should work on all STM32-based boards.
      */
     #if ENABLED(STM32_UID_SHORT_FORM)
-      uint32_t * const UID = (uint32_t*)UID_BASE;
-      SERIAL_ECHO(hex_long(UID[0]), hex_long(UID[1]), hex_long(UID[2]));
+      const uint32_t * const UID = (uint32_t*)UID_BASE;
+      for (uint8_t i = 0; i < 3; i++) print_hex_long(UID[i]);
     #else
-      uint16_t * const UID = (uint16_t*)UID_BASE;
-      SERIAL_ECHO(
-        F("CEDE2A2F-"), hex_word(UID[0]), C('-'), hex_word(UID[1]), C('-'), hex_word(UID[2]), C('-'),
-        hex_word(UID[3]), hex_word(UID[4]), hex_word(UID[5])
-      );
+      const uint16_t * const UID = (uint16_t*)UID_BASE; // Little-endian!
+      SERIAL_ECHO(F("CEDE2A2F-"));
+      for (uint8_t i = 1; i <= 6; i++) {
+        print_hex_word(UID[(i % 2) ? i : i - 2]);       // 1111-0000-3333-222255554444
+        if (i <= 3) SERIAL_ECHO(C('-'));
+      }
     #endif
   #endif
 

Marlin/src/libs/hex_print.cpp

@@ -27,57 +27,43 @@
 #include "hex_print.h"
 #include "../core/serial.h"
 
-#ifdef CPU_32_BIT
-  constexpr int byte_start = 4;
-  static char _hex[] = "0x00000000";
-#else
-  constexpr int byte_start = 0;
-  static char _hex[] = "0x0000";
-#endif
+static char _hex[] = "0x00000000"; // 0:adr32 2:long 4:adr16 6:word 8:byte
 
-char* hex_byte(const uint8_t b) {
-  _hex[byte_start + 4] = hex_nybble(b >> 4);
-  _hex[byte_start + 5] = hex_nybble(b);
-  return &_hex[byte_start + 4];
+inline void __hex_byte(const uint8_t b, const uint8_t o=8) {
+  _hex[o + 0] = hex_nybble(b >> 4);
+  _hex[o + 1] = hex_nybble(b);
 }
-
-inline void __hex_word(const uint16_t w) {
-  _hex[byte_start + 2] = hex_nybble(w >> 12);
-  _hex[byte_start + 3] = hex_nybble(w >> 8);
-  _hex[byte_start + 4] = hex_nybble(w >> 4);
-  _hex[byte_start + 5] = hex_nybble(w);
+inline void __hex_word(const uint16_t w, const uint8_t o=6) {
+  __hex_byte(w >> 8, o + 0);
+  __hex_byte(w     , o + 2);
 }
-
-char* _hex_word(const uint16_t w) {
-  __hex_word(w);
-  return &_hex[byte_start + 2];
+inline void __hex_long(const uint32_t w) {
+  __hex_word(w >> 16, 2);
+  __hex_word(w      , 6);
 }
 
-char* _hex_long(const uintptr_t l) {
-  _hex[2] = hex_nybble(l >> 28);
-  _hex[3] = hex_nybble(l >> 24);
-  _hex[4] = hex_nybble(l >> 20);
-  _hex[5] = hex_nybble(l >> 16);
-  __hex_word((uint16_t)(l & 0xFFFF));
-  return &_hex[2];
-}
+char*  hex_byte(const uint8_t b)  { __hex_byte(b); return &_hex[8]; }
+char* _hex_word(const uint16_t w) { __hex_word(w); return &_hex[6]; }
+char* _hex_long(const uint32_t l) { __hex_long(l); return &_hex[2]; }
 
-char* hex_address(const void * const w) {
+char* hex_address(const void * const a) {
   #ifdef CPU_32_BIT
-    (void)hex_long((uintptr_t)w);
+    (void)_hex_long((uintptr_t)a);
+    return _hex;
   #else
-    (void)hex_word((uintptr_t)w);
+    _hex[4] = '0'; _hex[5] = 'x';
+    (void)_hex_word((uintptr_t)a);
+    return &_hex[4];
   #endif
-  return _hex;
 }
 
 void print_hex_nybble(const uint8_t n)       { SERIAL_CHAR(hex_nybble(n));  }
 void print_hex_byte(const uint8_t b)         { SERIAL_ECHO(hex_byte(b));    }
-void print_hex_word(const uint16_t w)        { SERIAL_ECHO(hex_word(w));    }
+void print_hex_word(const uint16_t w)        { SERIAL_ECHO(_hex_word(w));    }
 void print_hex_address(const void * const w) { SERIAL_ECHO(hex_address(w)); }
 
-void print_hex_long(const uint32_t w, const char delimiter/*='\0'*/) {
-  SERIAL_ECHOPGM("0x");
+void print_hex_long(const uint32_t w, const char delimiter/*='\0'*/, const bool prefix/*=false*/) {
+  if (prefix) SERIAL_ECHOPGM("0x");
   for (int B = 24; B >= 8; B -= 8) {
     print_hex_byte(w >> B);
     if (delimiter) SERIAL_CHAR(delimiter);

Marlin/src/libs/hex_print.h

@@ -30,16 +30,17 @@
 constexpr char hex_nybble(const uint8_t n) {
   return (n & 0xF) + ((n & 0xF) < 10 ? '0' : 'A' - 10);
 }
-char* hex_byte(const uint8_t b);
 char* _hex_word(const uint16_t w);
-char* hex_address(const void * const w);
-char* _hex_long(const uintptr_t l);
+char* _hex_long(const uint32_t l);
 
+char* hex_byte(const uint8_t b);
 template<typename T> char* hex_word(T w) { return _hex_word((uint16_t)w); }
 template<typename T> char* hex_long(T w) { return _hex_long((uint32_t)w); }
 
+char* hex_address(const void * const w);
+
 void print_hex_nybble(const uint8_t n);
 void print_hex_byte(const uint8_t b);
 void print_hex_word(const uint16_t w);
 void print_hex_address(const void * const w);
-void print_hex_long(const uint32_t w, const char delimiter='\0');
+void print_hex_long(const uint32_t w, const char delimiter='\0', const bool prefix=false);