Merge pull request 'Typo fixes + update of pico_sdk_import.cmake' (#2) from kratz00/pico-serprog:misc into main

Reviewed-on: https://codeberg.org/Riku_V/pico-serprog/pulls/2

99-serprog.rules

@@ -0,0 +1,6 @@
+# udev rule that creates symlinks like /dev/serprog0
+#
+# only matches standard usb cdc-acm devices (/dev/ttyACM*) since non-standard
+# (ftdi etc) uart converters will probably have a generic descriptor anyway
+
+DRIVERS=="cdc_acm", ATTRS{interface}=="serprog", SYMLINK+="serprog%n"

CMakeLists.txt

@@ -7,5 +7,5 @@ pico_sdk_init()
 
 add_executable(pico_serprog)
 target_sources(pico_serprog PRIVATE main.c usb_descriptors.c)
-target_link_libraries(pico_serprog PRIVATE pico_stdlib hardware_spi tinyusb_device)
+target_link_libraries(pico_serprog PRIVATE pico_stdlib pico_unique_id hardware_spi tinyusb_device)
 pico_add_extra_outputs(pico_serprog)

COPYING.CC-BY-SA

@@ -0,0 +1,428 @@
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main.c

@@ -1,138 +1,40 @@
 /**
  * Copyright (C) 2021, Mate Kukri <km@mkukri.xyz>
+ * Copyright (C) 2023, 2024, Riku Viitanen <riku.viitanen@protonmail.com>
  * Based on "pico-serprog" by Thomas Roth <code@stacksmashing.net>
  * 
  * Licensed under GPLv3
  *
  * Also based on stm32-vserprog:
  *  https://github.com/dword1511/stm32-vserprog
- * 
  */
 
+#define DESCRIPTION "SPI flash chip programmer using Flashprog's serprog protocol"
+#define WEBSITE "https://codeberg.org/Riku_V/pico-serprog/"
+
 #include "pico/stdlib.h"
+#include "pico/binary_info.h"
 #include "hardware/spi.h"
 #include "tusb.h"
 #include "serprog.h"
 
-#define CDC_ITF     0           // USB CDC interface no
+#define CDC_ITF     0           /* USB CDC interface no */
 
-#define SPI_IF      spi0        // Which PL022 to use
-#define SPI_BAUD    12000000    // Default baudrate (12 MHz)
-#define SPI_CS      5
+#define SPI_IF      spi0        /* Which PL022 to use   */
+#define SPI_CS_0    5		/* The default CS pin   */
 #define SPI_MISO    4
 #define SPI_MOSI    3
 #define SPI_SCK     2
 
-static void enable_spi(uint baud)
-{
-    // Setup chip select GPIO
-    gpio_init(SPI_CS);
-    gpio_put(SPI_CS, 1);
-    gpio_set_dir(SPI_CS, GPIO_OUT);
+uint8_t spi_enabled = 0;
+uint cs_pin = SPI_CS_0;
+#define NUM_CS_AVAILABLE 4	/* Number of usable chip selects */
 
-    // Setup PL022
-    spi_init(SPI_IF, baud);
-    gpio_set_function(SPI_MISO, GPIO_FUNC_SPI);
-    gpio_set_function(SPI_MOSI, GPIO_FUNC_SPI);
-    gpio_set_function(SPI_SCK,  GPIO_FUNC_SPI);
-}
+uint baud = 12000000; /* Default to 12MHz */
 
-static void disable_spi()
-{
-    // Set all pins to SIO inputs
-    gpio_init(SPI_CS);
-    gpio_init(SPI_MISO);
-    gpio_init(SPI_MOSI);
-    gpio_init(SPI_SCK);
+static const char progname[16] = "pico-serprog";
 
-    // Disable all pulls
-    gpio_set_pulls(SPI_CS, 0, 0);
-    gpio_set_pulls(SPI_MISO, 0, 0);
-    gpio_set_pulls(SPI_MOSI, 0, 0);
-    gpio_set_pulls(SPI_SCK, 0, 0);
-
-    // Disable SPI peripheral
-    spi_deinit(SPI_IF);
-}
-
-static inline void cs_select(uint cs_pin)
-{
-    asm volatile("nop \n nop \n nop"); // FIXME
-    gpio_put(cs_pin, 0);
-    asm volatile("nop \n nop \n nop"); // FIXME
-}
-
-static inline void cs_deselect(uint cs_pin)
-{
-    asm volatile("nop \n nop \n nop"); // FIXME
-    gpio_put(cs_pin, 1);
-    asm volatile("nop \n nop \n nop"); // FIXME
-}
-
-static void wait_for_read(void)
-{
-    do
-        tud_task();
-    while (!tud_cdc_n_available(CDC_ITF));
-}
-
-static inline void readbytes_blocking(void *b, uint32_t len)
-{
-    while (len) {
-        wait_for_read();
-        uint32_t r = tud_cdc_n_read(CDC_ITF, b, len);
-        b += r;
-        len -= r;
-    }
-}
-
-static inline uint8_t readbyte_blocking(void)
-{
-    wait_for_read();
-    uint8_t b;
-    tud_cdc_n_read(CDC_ITF, &b, 1);
-    return b;
-}
-
-static void wait_for_write(void)
-{
-    do {
-        tud_task();
-    } while (!tud_cdc_n_write_available(CDC_ITF));
-}
-
-static inline void sendbytes_blocking(const void *b, uint32_t len)
-{
-    while (len) {
-        wait_for_write();
-        uint32_t w = tud_cdc_n_write(CDC_ITF, b, len);
-        b += w;
-        len -= w;
-    }
-}
-
-static inline void sendbyte_blocking(uint8_t b)
-{
-    wait_for_write();
-    tud_cdc_n_write(CDC_ITF, &b, 1);
-}
-
-static void command_loop(void)
-{
-    uint baud = spi_get_baudrate(SPI_IF);
-
-    for (;;) {
-        switch (readbyte_blocking()) {
-        case S_CMD_NOP:
-            sendbyte_blocking(S_ACK);
-            break;
-        case S_CMD_Q_IFACE:
-            sendbyte_blocking(S_ACK);
-            sendbyte_blocking(0x01);
-            sendbyte_blocking(0x00);
-            break;
-        case S_CMD_Q_CMDMAP:
-            {
+/* Map of supported serprog commands */
 static const uint32_t cmdmap[8] = {
 	(1 << S_CMD_NOP)         |
 	(1 << S_CMD_Q_IFACE)     |
@@ -144,51 +46,140 @@ static void command_loop(void)
 	(1 << S_CMD_O_SPIOP)     |
 	(1 << S_CMD_S_BUSTYPE)   |
 	(1 << S_CMD_S_SPI_FREQ)  |
-                      (1 << S_CMD_S_PIN_STATE)
+	(1 << S_CMD_S_PIN_STATE) |
+	(1 << S_CMD_S_SPI_CS)
 };
 
-                sendbyte_blocking(S_ACK);
-                sendbytes_blocking((uint8_t *) cmdmap, sizeof cmdmap);
-                break;
-            }
-        case S_CMD_Q_PGMNAME:
-            {
-                static const char progname[16] = "pico-serprog";
 
-                sendbyte_blocking(S_ACK);
-                sendbytes_blocking(progname, sizeof progname);
-                break;
+static void use_cs(uint pin) {
+	gpio_put(pin, 1);
+	gpio_set_dir(pin, GPIO_OUT);
+	gpio_set_drive_strength(pin, GPIO_DRIVE_STRENGTH_12MA);
 }
-        case S_CMD_Q_SERBUF:
-            sendbyte_blocking(S_ACK);
-            sendbyte_blocking(0xFF);
-            sendbyte_blocking(0xFF);
-            break;
-        case S_CMD_Q_BUSTYPE:
-            sendbyte_blocking(S_ACK);
-            sendbyte_blocking((1 << 3)); // BUS_SPI
-            break;
-        case S_CMD_SYNCNOP:
-            sendbyte_blocking(S_NAK);
-            sendbyte_blocking(S_ACK);
-            break;
-        case S_CMD_S_BUSTYPE:
-            // If SPI is among the requsted bus types we succeed, fail otherwise
+
+static void pullup_cs(uint pin) {
+	gpio_set_dir(pin, GPIO_IN);
+	gpio_pull_up(pin);
+}
+
+static void enable_spi() {
+#ifdef PICO_DEFAULT_LED_PIN
+	/* Setup status LED */
+	gpio_init(PICO_DEFAULT_LED_PIN);
+	gpio_set_dir(PICO_DEFAULT_LED_PIN, GPIO_OUT);
+#endif
+
+	/* Setup default CS as output, others as inputs with pull-ups */
+	for (uint8_t i = SPI_CS_0+1; i<SPI_CS_0+NUM_CS_AVAILABLE; i++) {
+	    gpio_init(i);
+	    pullup_cs(i);
+	}
+	gpio_init(cs_pin);
+	use_cs(cs_pin);
+
+	/* Setup PL022 */
+	spi_init(SPI_IF, baud);
+	gpio_set_function(SPI_MISO, GPIO_FUNC_SPI);
+	gpio_set_function(SPI_MOSI, GPIO_FUNC_SPI);
+	gpio_set_function(SPI_SCK,  GPIO_FUNC_SPI);
+
+	gpio_set_drive_strength(SPI_MISO, GPIO_DRIVE_STRENGTH_12MA);
+	gpio_set_drive_strength(SPI_MOSI, GPIO_DRIVE_STRENGTH_12MA);
+	gpio_set_drive_strength(SPI_SCK,  GPIO_DRIVE_STRENGTH_12MA);
+
+	spi_enabled = 1;
+}
+
+static void disable_pin(uint pin) {
+	gpio_init(pin);            /* Set pin to SIO input */
+	gpio_set_pulls(pin, 0, 0); /* Disable all pulls */
+}
+
+static void disable_spi() {
+	for (uint8_t i=0; i<NUM_CS_AVAILABLE; i++)
+		disable_pin(SPI_CS_0 + i);
+	disable_pin(SPI_MISO);
+	disable_pin(SPI_MOSI);
+	disable_pin(SPI_SCK);
+
+	/* Disable SPI peripheral */
+	spi_deinit(SPI_IF);
+
+	spi_enabled = 0;
+}
+
+
+static inline void cs_select(uint cs_pin) {
+	asm volatile("nop \n nop \n nop"); /* FIXME */
+	gpio_put(cs_pin, 0);
+	asm volatile("nop \n nop \n nop"); /* FIXME */
+}
+
+static inline void cs_deselect(uint cs_pin) {
+	asm volatile("nop \n nop \n nop"); /* FIXME */
+	gpio_put(cs_pin, 1);
+	asm volatile("nop \n nop \n nop"); /* FIXME */
+}
+
+static void wait_for_read(void) {
+	do
+	    tud_task();
+	while (!tud_cdc_n_available(CDC_ITF));
+}
+
+static inline void readbytes_blocking(void *b, uint32_t len) {
+	while (len) {
+		wait_for_read();
+		uint32_t r = tud_cdc_n_read(CDC_ITF, b, len);
+		b += r;
+		len -= r;
+	}
+}
+
+static inline uint8_t readbyte_blocking(void) {
+	wait_for_read();
+	uint8_t b;
+	tud_cdc_n_read(CDC_ITF, &b, 1);
+	return b;
+}
+
+static void wait_for_write(void) {
+	do {
+		tud_task();
+	} while (!tud_cdc_n_write_available(CDC_ITF));
+}
+
+static inline void sendbytes_blocking(const void *b, uint32_t len) {
+	while (len) {
+		wait_for_write();
+		uint32_t w = tud_cdc_n_write(CDC_ITF, b, len);
+		b += w;
+		len -= w;
+	}
+}
+
+static inline void sendbyte_blocking(uint8_t b) {
+	wait_for_write();
+	tud_cdc_n_write(CDC_ITF, &b, 1);
+}
+
+void s_cmd_s_bustype() {
+	/* If SPI is among the requested bus types we succeed,
+	 * fail otherwise */
 	if ((uint8_t) readbyte_blocking() & (1 << 3))
 		sendbyte_blocking(S_ACK);
 	else
 		sendbyte_blocking(S_NAK);
-            break;
-        case S_CMD_O_SPIOP:
-            {
-                static uint8_t buf[4096];
+}
 
+void s_cmd_o_spiop() {
+	static uint8_t buf[4096];
 	uint32_t wlen = 0;
-                readbytes_blocking(&wlen, 3);
 	uint32_t rlen = 0;
+	readbytes_blocking(&wlen, 3);
 	readbytes_blocking(&rlen, 3);
 
-                cs_select(SPI_CS);
+	cs_select(cs_pin);
 
 	while (wlen) {
 		uint32_t cur = MIN(wlen, sizeof buf);
@@ -206,47 +197,133 @@ static void command_loop(void)
 		rlen -= cur;
 	}
 
-                cs_deselect(SPI_CS);
+	cs_deselect(cs_pin);
 }
-            break;
-        case S_CMD_S_SPI_FREQ:
-            {
+
+void s_cmd_s_spi_freq() {
 	uint32_t want_baud;
 	readbytes_blocking(&want_baud, 4);
 	if (want_baud) {
-                    // Set frequence
+		/* Set frequency */
 		baud = spi_set_baudrate(SPI_IF, want_baud);
-                    // Send back actual value
+		/* Send back actual value */
 		sendbyte_blocking(S_ACK);
 		sendbytes_blocking(&baud, 4);
 	} else {
-                    // 0 Hz is reserved
+		/* 0 Hz is reserved */
 		sendbyte_blocking(S_NAK);
 	}
-                break;
 }
-        case S_CMD_S_PIN_STATE:
+
+void s_cmd_s_pin_state() {
 	if (readbyte_blocking())
-                enable_spi(baud);
+		enable_spi();
 	else
 		disable_spi();
 	sendbyte_blocking(S_ACK);
+}
+
+void s_cmd_s_spi_cs() {
+	uint8_t cs = readbyte_blocking();
+	if (cs >= NUM_CS_AVAILABLE)
+		sendbyte_blocking(S_NAK);
+	return;
+
+	cs += SPI_CS_0;
+	if (spi_enabled) {
+		if (cs_pin != cs) {
+			pullup_cs(cs_pin);
+			use_cs(cs);
+		}
+	}
+	cs_pin = cs;
+	sendbyte_blocking(S_ACK);
+}
+
+
+static void command_loop() {
+	while (1) {
+		uint8_t cmd = readbyte_blocking();
+#ifdef PICO_DEFAULT_LED_PIN
+		gpio_put(PICO_DEFAULT_LED_PIN, 1);
+#endif
+		switch (cmd) {
+		case S_CMD_NOP:
+			sendbyte_blocking(S_ACK);
+			break;
+		case S_CMD_Q_IFACE:
+			sendbyte_blocking(S_ACK);
+			sendbyte_blocking(0x01);
+			sendbyte_blocking(0x00);
+			break;
+		case S_CMD_Q_CMDMAP:
+			sendbyte_blocking(S_ACK);
+			sendbytes_blocking((uint8_t *)cmdmap, sizeof(cmdmap));
+			break;
+		case S_CMD_Q_PGMNAME:
+			sendbyte_blocking(S_ACK);
+			sendbytes_blocking(progname, sizeof(progname));
+			break;
+		case S_CMD_Q_SERBUF:
+			sendbyte_blocking(S_ACK);
+			sendbyte_blocking(0xFF);
+			sendbyte_blocking(0xFF);
+			break;
+		case S_CMD_Q_BUSTYPE:
+			sendbyte_blocking(S_ACK);
+			sendbyte_blocking((1 << 3)); /* SPI */
+			break;
+		case S_CMD_SYNCNOP:
+			sendbyte_blocking(S_NAK);
+			sendbyte_blocking(S_ACK);
+			break;
+		case S_CMD_S_BUSTYPE:
+			s_cmd_s_bustype();
+			break;
+		case S_CMD_O_SPIOP:
+			s_cmd_o_spiop();
+			break;
+		case S_CMD_S_SPI_FREQ:
+			s_cmd_s_spi_freq();
+			break;
+		case S_CMD_S_PIN_STATE:
+			s_cmd_s_pin_state();
+			break;
+		case S_CMD_S_SPI_CS:
+			s_cmd_s_spi_cs();
 			break;
 		default:
 			sendbyte_blocking(S_NAK);
-            break;
 		}
 
 		tud_cdc_n_write_flush(CDC_ITF);
+
+#ifdef PICO_DEFAULT_LED_PIN
+		gpio_put(PICO_DEFAULT_LED_PIN, 0);
+#endif
 	}
 }
 
-int main()
-{
-    // Setup USB
+int main() {
+	/* Metadata for picotool */
+	bi_decl(bi_program_description(DESCRIPTION));
+	bi_decl(bi_program_url(WEBSITE));
+#ifdef PICO_DEFAULT_LED_PIN
+	bi_decl(bi_1pin_with_name(PICO_DEFAULT_LED_PIN, "Activity LED"));
+#endif
+	bi_decl(bi_1pin_with_name(SPI_MISO, "MISO"));
+	bi_decl(bi_1pin_with_name(SPI_MOSI, "MOSI"));
+	bi_decl(bi_1pin_with_name(SPI_SCK, "SCK"));
+	bi_decl(bi_1pin_with_name(SPI_CS_0,   "CS_0 (default)"));
+	bi_decl(bi_1pin_with_name(SPI_CS_0+1, "CS_1"));
+	bi_decl(bi_1pin_with_name(SPI_CS_0+2, "CS_2"));
+	bi_decl(bi_1pin_with_name(SPI_CS_0+3, "CS_3"));
+
+	/* Setup USB */
 	tusb_init();
-    // Setup PL022 SPI
-    enable_spi(SPI_BAUD);
+	/* Setup PL022 SPI */
+	enable_spi(baud);
 
 	command_loop();
 }
+

pico_sdk_import.cmake

@@ -18,9 +18,20 @@ if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT_PATH} AND (NOT PICO_SDK_FETCH_FROM_GIT_P
     message("Using PICO_SDK_FETCH_FROM_GIT_PATH from environment ('${PICO_SDK_FETCH_FROM_GIT_PATH}')")
 endif ()
 
+if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT_TAG} AND (NOT PICO_SDK_FETCH_FROM_GIT_TAG))
+    set(PICO_SDK_FETCH_FROM_GIT_TAG $ENV{PICO_SDK_FETCH_FROM_GIT_TAG})
+    message("Using PICO_SDK_FETCH_FROM_GIT_TAG from environment ('${PICO_SDK_FETCH_FROM_GIT_TAG}')")
+endif ()
+
+if (PICO_SDK_FETCH_FROM_GIT AND NOT PICO_SDK_FETCH_FROM_GIT_TAG)
+  set(PICO_SDK_FETCH_FROM_GIT_TAG "master")
+  message("Using master as default value for PICO_SDK_FETCH_FROM_GIT_TAG")
+endif()
+
 set(PICO_SDK_PATH "${PICO_SDK_PATH}" CACHE PATH "Path to the Raspberry Pi Pico SDK")
 set(PICO_SDK_FETCH_FROM_GIT "${PICO_SDK_FETCH_FROM_GIT}" CACHE BOOL "Set to ON to fetch copy of SDK from git if not otherwise locatable")
 set(PICO_SDK_FETCH_FROM_GIT_PATH "${PICO_SDK_FETCH_FROM_GIT_PATH}" CACHE FILEPATH "location to download SDK")
+set(PICO_SDK_FETCH_FROM_GIT_TAG "${PICO_SDK_FETCH_FROM_GIT_TAG}" CACHE FILEPATH "release tag for SDK")
 
 if (NOT PICO_SDK_PATH)
     if (PICO_SDK_FETCH_FROM_GIT)
@@ -29,11 +40,22 @@ if (NOT PICO_SDK_PATH)
         if (PICO_SDK_FETCH_FROM_GIT_PATH)
             get_filename_component(FETCHCONTENT_BASE_DIR "${PICO_SDK_FETCH_FROM_GIT_PATH}" REALPATH BASE_DIR "${CMAKE_SOURCE_DIR}")
         endif ()
+        # GIT_SUBMODULES_RECURSE was added in 3.17
+        if (${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.17.0")
             FetchContent_Declare(
                     pico_sdk
                     GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
-                GIT_TAG master
+                    GIT_TAG ${PICO_SDK_FETCH_FROM_GIT_TAG}
+                    GIT_SUBMODULES_RECURSE FALSE
             )
+        else ()
+            FetchContent_Declare(
+                    pico_sdk
+                    GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
+                    GIT_TAG ${PICO_SDK_FETCH_FROM_GIT_TAG}
+            )
+        endif ()
+
         if (NOT pico_sdk)
             message("Downloading Raspberry Pi Pico SDK")
             FetchContent_Populate(pico_sdk)

readme.md

@@ -1,16 +1,28 @@
 # pico-serprog
 
 Slightly less terrible serprog implementation for the Raspberry Pi Pico and
-possibly other RP2040 based boards. Based on pico-serprog by GitHub user
-"stacksmashing". Further improved by "kukrimate".
+other RP2040 based boards. Based on
+![pico-serprog by stacksmashing](https://github.com/stacksmashing/pico-serprog/).
+Further improved by kukrimate ![here](https://github.com/kukrimate/pico-serprog).
+And me (Riku\_V) here.
+
+Pre-compiled binaries can be downloaded from the
+![Libreboot project](https://libreboot.org/download.html#https).
+
+For a guide on how to flash a chip see
+![this page](https://libreboot.org/docs/install/spi.html#raspberry-pi-pico).
+
+This takes about 17 seconds to read the 8MiB BIOS chip of an X200.
 
 Pinout for the SPI lines:
 | Pin | Function |
 |-----|----------|
-| GP5 | CS       |
-| GP4 | MISO     |
-| GP3 | MOSI     |
-| GP2 | SCK      |
+|  7  | CS       |
+|  6  | MISO     |
+|  5  | MOSI     |
+|  4  | SCK      |
+
+![Pico pinout](pinout.png)
 
 ## Compiling
 
@@ -21,7 +33,7 @@ make
 
 Plug in your Pico. Mount it as you would any other USB flash drive.
 Copy `pico_serprog.uf2` into it. Your programmer is now ready.
-If you want to change the firwmare, you need to press the button
+If you want to change the firmware, you need to press the button
 on the board while you plug it in.
 
 ## Usage
@@ -38,12 +50,19 @@ containing something like this will appear:
 Read chip:
 
 ```
-flashrom -p serprog:dev=/dev/ttyACMx,spispeed=32M -r flash.bin
+flashprog -p serprog:dev=/dev/ttyACMx,spispeed=32M -r flash.bin
 ```
 
 Write chip:
 ```
-flashrom -p serprog:dev=/dev/ttyACMx,spispeed=32M -w flash.bin
+flashprog -p serprog:dev=/dev/ttyACMx,spispeed=32M -w flash.bin
+```
+
+Multiple chips can be connected at the same time. Pins GP5-GP8 are Chip
+Selects 0-3, respectively. The firmware defaults to using Chip Select 0.
+```
+flashprog -p serprog:dev=/dev/ttyACMx,cs=0 -r chip0.bin
+flashprog -p serprog:dev=/dev/ttyACMx,cs=1 -r chip1.bin
 ```
 
 ## License
@@ -51,3 +70,9 @@ flashrom -p serprog:dev=/dev/ttyACMx,spispeed=32M -w flash.bin
 As a lot of the code itself was heavily inspired/influenced by `stm32-vserprog`
 this code is licensed under GPLv3.
 
+pinout.png is based on
+[pico-pinout.svg](https://www.raspberrypi.com/documentation/microcontrollers/images/pico-pinout.svg)
+by Raspberry Pi Ltd, under the
+[Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/)
+license.
+

serprog.h

@@ -28,4 +28,6 @@
 #define S_CMD_S_SPI_FREQ	0x14	/* Set SPI clock frequency			*/
 #define S_CMD_S_PIN_STATE	0x15	/* Enable/disable output drivers		*/
 
+#define S_CMD_S_SPI_CS		0x16	/* Select Chip Select to use			*/
+
 #endif

usb_descriptors.c

@@ -24,6 +24,7 @@
  */
 
 #include "tusb.h"
+#include "pico/unique_id.h"
 
 /* A combination of interfaces must have a unique product id, since PC will save device driver after the first plug.
  * Same VID/PID with different interface e.g MSC (first), then CDC (later) will possibly cause system error on PC.
@@ -152,14 +153,16 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+char board_serial[2 * PICO_UNIQUE_BOARD_ID_SIZE_BYTES + 1];
+
 // array of pointer to string descriptors
-char const* string_desc_arr [] =
+const char* const string_desc_arr [] =
 {
-  (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
-  "TinyUSB",                     // 1: Manufacturer
-  "TinyUSB Device",              // 2: Product
-  "123456",                      // 3: Serials, should use chip ID
-  "TinyUSB CDC",                 // 4: CDC Interface
+  (const char[]) { 0x09, 0x04 },      // 0: is English language
+  "libreboot.org",                    // 1: Manufacturer
+  "pico-serprog (" PICO_BOARD ")",    // 2: Product
+  board_serial,                       // 3: Serial number filled later
+  "serprog",                          // 4: CDC Interface
 };
 
 static uint16_t _desc_str[32];
@@ -172,6 +175,8 @@ uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
 
   uint8_t chr_count;
 
+  pico_get_unique_board_id_string(board_serial, sizeof(board_serial));
+
   if ( index == 0)
   {
     memcpy(&_desc_str[1], string_desc_arr[0], 2);