Unique serial numbers for picoprobe (#8)

Co-authored-by: newbrain <newbrain@tiscali.it>
Co-authored-by: Liam Fraser <liam@raspberrypi.com>

CMakeLists.txt

@@ -12,6 +12,7 @@ add_executable(picoprobe
         src/usb_descriptors.c
         src/probe.c
         src/cdc_uart.c
+        src/get_serial.c
 )
 
 if (DEFINED ENV{PICOPROBE_LED})
@@ -25,6 +26,6 @@ pico_generate_pio_header(picoprobe ${CMAKE_CURRENT_LIST_DIR}/src/probe.pio)
 
 target_include_directories(picoprobe PRIVATE src)
 
-target_link_libraries(picoprobe PRIVATE pico_stdlib tinyusb_device tinyusb_board hardware_pio)
+target_link_libraries(picoprobe PRIVATE pico_stdlib pico_unique_id tinyusb_device tinyusb_board hardware_pio)
 
 pico_add_extra_outputs(picoprobe)

src/get_serial.c

@@ -0,0 +1,50 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Federico Zuccardi Merli
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#include <stdint.h>
+#include "pico/unique_id.h"
+#include "get_serial.h"
+
+/* C string for iSerialNumber in USB Device Descriptor, two chars per byte + terminating NUL */
+char usb_serial[PICO_UNIQUE_BOARD_ID_SIZE_BYTES * 2 + 1];
+
+/* Why a uint8_t[8] array inside a struct instead of an uint64_t an inquiring mind might wonder */
+static pico_unique_board_id_t uID;
+
+void usb_serial_init(void)
+{
+    pico_get_unique_board_id(&uID);
+
+    for (int i = 0; i < PICO_UNIQUE_BOARD_ID_SIZE_BYTES * 2; i++)
+    {
+        /* Byte index inside the uid array */
+        int bi = i / 2;
+        /* Use high nibble first to keep memory order (just cosmetics) */
+        uint8_t nibble = (uID.id[bi] >> 4) & 0x0F;
+        uID.id[bi] <<= 4;
+        /* Binary to hex digit */
+        usb_serial[i] = nibble < 10 ? nibble + '0' : nibble + 'A' - 10;
+    }
+}

src/get_serial.h

@@ -0,0 +1,35 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Federico Zuccardi Merli
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#ifndef GET_SERIAL_H_
+#define GET_SERIAL_H_
+
+/* Contains unique serial number string (NUL terminated) after call to init_usb_serial */
+extern char usb_serial[];
+
+/* Fills unique_serial with the flash unique id */
+extern void usb_serial_init(void);
+
+#endif

src/main.c

@@ -33,6 +33,7 @@
 #include "picoprobe_config.h"
 #include "probe.h"
 #include "cdc_uart.h"
+#include "get_serial.h"
 #include "led.h"
 
 // UART0 for Picoprobe debug
@@ -41,6 +42,7 @@
 int main(void) {
 
     board_init();
+    usb_serial_init();
     cdc_uart_init();
     tusb_init();
     probe_init();

src/usb_descriptors.c

@@ -24,6 +24,7 @@
  */
 
 #include "tusb.h"
+#include "get_serial.h"
 
 
 //--------------------------------------------------------------------+
@@ -106,7 +107,7 @@ char const* string_desc_arr [] =
   (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
   "Raspberry Pi", // 1: Manufacturer
   "Picoprobe",    // 2: Product
-  "123456",       // 3: Serials, should use chip ID
+  usb_serial,     // 3: Serial, uses flash unique ID
 };
 
 static uint16_t _desc_str[32];