Update USB Serial Number from SPI flash's uniqueID

Also allow flash to be separately enabled via PLATFORM_EXTRAS.

NOTE: this does *NOT* enable the serial number
in the bootrom.  Still investigating options there.

Makefile.platform.sample

@@ -5,6 +5,8 @@ PLATFORM=PM3RDV4
 #PLATFORM=PM3GENERIC
 # If you want more than one PLATFORM_EXTRAS option, separate them by spaces:
 #PLATFORM_EXTRAS=BTADDON
+#PLATFORM_EXTRAS=FLASH
+#PLATFORM_EXTRAS=BTADDON FLASH
 #STANDALONE=LF_SAMYRUN
 
 # Uncomment the lines below in order to make a 256KB image

armsrc/appmain.c

@@ -2471,8 +2471,11 @@ static void PacketReceived(PacketCommandNG *packet) {
                 LED_B_OFF();
                 break;
             }
-            if (page < 3)
+            if (page < 3) {
                 isok = Flash_WipeMemoryPage(page);
+                // let spiffs check and update its info post flash erase
+                rdv40_spiffs_check();
+            }
 
             reply_mix(CMD_ACK, isok, 0, 0, 0, 0);
             LED_B_OFF();
@@ -2677,6 +2680,17 @@ void  __attribute__((noreturn)) AppMain(void) {
     I2C_init(false);
 #endif
 
+#ifdef WITH_FLASH
+    if (FlashInit()) {
+        uint64_t flash_uniqueID = 0;
+        if (!Flash_CheckBusy(BUSY_TIMEOUT)) { // OK because firmware was built for devices with flash
+            Flash_UniqueID((uint8_t*)&(flash_uniqueID));
+        }
+        FlashStop();
+        usb_update_serial(flash_uniqueID);
+    }
+#endif
+
 #ifdef WITH_FPC_USART
     usart_init(USART_BAUD_RATE, USART_PARITY);
 #endif

armsrc/flashmem.c

@@ -22,7 +22,7 @@
 #include "ticks.h"
 #include "dbprint.h"
 #include "string.h"
-#include "spiffs.h"
+#include "usb_cdc.h"
 
 /* here: use NCPS2 @ PA10: */
 #define SPI_CSR_NUM      2
@@ -436,7 +436,9 @@ out:
     return len;
 }
 
-
+// WARNING -- if callers are using a file system (such as SPIFFS),
+//            they should inform the file system of this change
+//            e.g., rdv40_spiffs_check()
 bool Flash_WipeMemoryPage(uint8_t page) {
     if (!FlashInit()) {
         if (g_dbglevel > 3) Dbprintf("Flash_WriteData init fail");
@@ -451,8 +453,6 @@ bool Flash_WipeMemoryPage(uint8_t page) {
 
     FlashStop();
 
-    // let spiffs check and update its info post flash erase
-    rdv40_spiffs_check();
     return true;
 }
 // Wipes flash memory completely, fills with 0xFF

common_arm/Makefile.hal

@@ -114,6 +114,10 @@ endif
 
 # parsing additional PLATFORM_EXTRAS tokens
 PLATFORM_EXTRAS_TMP:=$(PLATFORM_EXTRAS)
+ifneq (,$(findstring FLASH,$(PLATFORM_EXTRAS_TMP)))
+    PLATFORM_DEFS += -DWITH_FLASH
+    PLATFORM_EXTRAS_TMP := $(strip $(filter-out FLASH,$(PLATFORM_EXTRAS_TMP)))
+endif
 ifneq (,$(findstring BTADDON,$(PLATFORM_EXTRAS_TMP)))
     PLATFORM_DEFS += -DWITH_FPC_USART_HOST
     PLATFORM_EXTRAS_TMP := $(strip $(filter-out BTADDON,$(PLATFORM_EXTRAS_TMP)))

common_arm/usb_cdc.c

@@ -366,11 +366,56 @@ static const char StrProduct[] = {
     'p', 0, 'r', 0, 'o', 0, 'x', 0, 'm', 0, 'a', 0, 'r', 0, 'k', 0, '3', 0
 };
 
+#ifndef WITH_FLASH
 static const char StrSerialNumber[] = {
     14,         // Length
     0x03,       // Type is string
     'i', 0, 'c', 0, 'e', 0, 'm', 0, 'a', 0, 'n', 0
 };
+#else // WITH_FLASH is defined
+
+// Manually calculated size of descriptor with unique ID:
+// offset  0, lengt h 1: total length field
+// offset  1, length  1: descriptor type field
+// offset  2, length 12: 6x unicode chars (original string)
+// offset 14, length  4: 2x unicode chars (underscores)      [[ to avoid descriptor being (size % 8) == 0, OS bug workaround ]]
+// offset 18, length 32: 16x unicode chars (8-byte serial as hex characters)
+// ============================
+// total: 50 bytes
+
+#define USB_STRING_DESCRIPTOR_SERIAL_NUMBER_LENGTH  50
+char StrSerialNumber[] = {
+    14,         // Length is initially identical to non-unique version ... The length updated at boot, if unique serial is available
+    0x03,       // Type is string
+    'i', 0, 'c', 0, 'e', 0, 'm', 0, 'a', 0, 'n', 0,
+    '_', 0, '_', 0,
+    'x', 0, 'x', 0, 'x', 0, 'x', 0, 'x', 0, 'x', 0, 'x', 0, 'x', 0,
+    'x', 0, 'x', 0, 'x', 0, 'x', 0, 'x', 0, 'x', 0, 'x', 0, 'x', 0,
+};
+void usb_update_serial(uint64_t newSerialNumber) {
+    static bool configured = false; // TODO: enable by setting to false here...
+    if (configured) {
+        return;
+    }
+    // run this only once per boot... even if it fails to find serial number
+    configured = true;
+    if ((newSerialNumber == 0x0000000000000000) || (newSerialNumber == 0xFFFFFFFFFFFFFFFF)) {
+        return;
+    }
+    // Descriptor is, effectively, initially identical to non-unique serial
+    // number because it reports the shorter length in the first byte.
+    // Convert uniqueID's eight bytes to 16 unicode characters in the
+    // descriptor and, finally, update the descriptor's length, which 
+    // causes the serial number to become visible.
+    for (uint8_t i = 0; i < 16; i++) {
+        uint8_t nibble = (uint8_t)((newSerialNumber >> (60 - (4*i))) & 0xFu);
+        char c = nibble < 10 ? '0' + nibble : 'A' + (nibble-10);
+        StrSerialNumber[18+(2*i)] = c; // [ 18, 20, 22, .., 46, 48 ]
+    }
+    StrSerialNumber[0] = USB_STRING_DESCRIPTOR_SERIAL_NUMBER_LENGTH;
+}
+#endif
+
 
 // size includes their own field.
 static const char StrMS_OSDescriptor[] = {

common_arm/usb_cdc.h

@@ -31,6 +31,7 @@ bool usb_poll_validate_length(void);
 uint32_t usb_read(uint8_t *data, size_t len);
 int usb_write(const uint8_t *data, const size_t len);
 uint32_t usb_read_ng(uint8_t *data, size_t len);
+void usb_update_serial(uint64_t newSerialNumber);
 
 void SetUSBreconnect(int value);
 int GetUSBreconnect(void);