Add versions and capabilities to BOS descriptor

Adds versions and capabilities to the BOS Descriptor by
appending dynamically-generated platform descriptors that
use the same UUIDs that are used with BLE and contain the
following values:

 * Firmware version
 * Software (protocol) version
 * Hub capabilities

lib/pbio/drv/usb/stm32_usbd/usbd_desc.c

@@ -43,10 +43,19 @@
   ******************************************************************************
   */
 /* Includes ------------------------------------------------------------------*/
+#include <string.h>
+
 #include "usbd_core.h"
 #include "usbd_conf.h"
 #include "usbd_pybricks.h"
 
+#include "pbio/protocol.h"
+#include "pbio/version.h"
+#include "pbsys/app.h"
+#include "pbsys/program_load.h"
+#include "pbdrvconfig.h"
+#include "sys/config.h"
+
 /* Private typedef -----------------------------------------------------------*/
 /* Private define ------------------------------------------------------------*/
 #define USBD_VID                      0x0483
@@ -57,12 +66,21 @@
 #define USBD_CONFIGURATION_FS_STRING  "Pybricks Config"
 #define USBD_INTERFACE_FS_STRING      "Pybricks Interface"
 
+static const char firmware_version[] = PBIO_VERSION_STR;
+static const char software_version[] = PBIO_PROTOCOL_VERSION_STR;
+
 #define         DEVICE_ID1          (0x1FFF7A10)
 #define         DEVICE_ID2          (0x1FFF7A14)
 #define         DEVICE_ID3          (0x1FFF7A18)
 
 #define  USB_SIZ_STRING_SERIAL       0x1A
-#define  USB_SIZ_BOS_DESC            33
+#define  USB_SIZ_BOS_DESC_CONST      (5 + 28)
+#define  USB_SIZ_UUID                (128 / 8)
+#define  USB_SIZ_PLATFORM_HDR        (4 + USB_SIZ_UUID)
+#define  USB_SIZ_BOS_DESC            (USB_SIZ_BOS_DESC_CONST + \
+                                      USB_SIZ_PLATFORM_HDR + sizeof(firmware_version) + \
+                                      USB_SIZ_PLATFORM_HDR + sizeof(software_version) + \
+                                      USB_SIZ_PLATFORM_HDR + PBIO_PYBRICKS_HUB_CAPABILITIES_VALUE_SIZE)
 
 /* USB Standard Device Descriptor */
 __ALIGN_BEGIN uint8_t USBD_DeviceDesc[USB_LEN_DEV_DESC] __ALIGN_END = {
@@ -378,6 +396,54 @@ static uint8_t *USBD_Pybricks_BOSDescriptor(USBD_SpeedTypeDef speed, uint16_t *l
   /* Prevent unused argument(s) compilation warning */
   UNUSED(speed);
 
+  static uint8_t created = 0;
+  uint8_t *ptr;
+
+  /* Generate BOS Descriptor on first attempt */
+  if (!created) {
+    created = 1;
+    ptr = &USBD_BOSDesc[USB_SIZ_BOS_DESC_CONST];
+
+    /* Add firmware version */
+    *ptr++ = USB_SIZ_PLATFORM_HDR + sizeof(firmware_version);
+    *ptr++ = USB_DEVICE_CAPABITY_TYPE;
+    *ptr++ = 0x05;
+    *ptr++ = 0x00;
+
+    pbio_uuid128_le_copy(ptr, pbio_gatt_firmware_version_char_uuid_128);
+    ptr += USB_SIZ_UUID;
+
+    memcpy(ptr, firmware_version, sizeof(firmware_version));
+    ptr += sizeof(firmware_version);
+
+    /* Add software (protocol) version */
+    *ptr++ = USB_SIZ_PLATFORM_HDR + sizeof(software_version);
+    *ptr++ = USB_DEVICE_CAPABITY_TYPE;
+    *ptr++ = 0x05;
+    *ptr++ = 0x00;
+
+    pbio_uuid128_le_copy(ptr, pbio_gatt_software_version_char_uuid_128);
+    ptr += USB_SIZ_UUID;
+
+    memcpy(ptr, software_version, sizeof(software_version));
+    ptr += sizeof(software_version);
+
+    /* Add hub capabilities */
+    *ptr++ = USB_SIZ_PLATFORM_HDR + PBIO_PYBRICKS_HUB_CAPABILITIES_VALUE_SIZE;
+    *ptr++ = USB_DEVICE_CAPABITY_TYPE;
+    *ptr++ = 0x05;
+    *ptr++ = 0x00;
+
+    pbio_uuid128_le_copy(ptr, pbio_pybricks_hub_capabilities_char_uuid);
+    ptr += USB_SIZ_UUID;
+
+    pbio_pybricks_hub_capabilities(ptr, 0, PBSYS_APP_HUB_FEATURE_FLAGS, PBSYS_PROGRAM_LOAD_MAX_PROGRAM_SIZE);
+    ptr += PBIO_PYBRICKS_HUB_CAPABILITIES_VALUE_SIZE;
+
+    /* Update bNumDeviceCaps field in BOS Descriptor */
+    USBD_BOSDesc[4] += 3;
+  }
+
   *length = sizeof(USBD_BOSDesc);
   return (uint8_t *)USBD_BOSDesc;
 }

lib/pbio/include/pbio/protocol.h

@@ -301,7 +301,9 @@ extern const uint8_t pbio_pybricks_hub_capabilities_char_uuid[];
 
 extern const uint16_t pbio_gatt_device_info_service_uuid;
 extern const uint16_t pbio_gatt_firmware_version_char_uuid;
+extern const uint8_t  pbio_gatt_firmware_version_char_uuid_128[];
 extern const uint16_t pbio_gatt_software_version_char_uuid;
+extern const uint8_t  pbio_gatt_software_version_char_uuid_128[];
 extern const uint16_t pbio_gatt_pnp_id_char_uuid;
 
 extern const uint8_t pbio_lwp3_hub_service_uuid[];

lib/pbio/include/pbio/util.h

@@ -118,6 +118,7 @@ void pbio_set_uint32_be(uint8_t *buf, uint32_t value) {
     buf[3] = value;
 }
 
+void pbio_uuid128_le_copy(uint8_t *dst, const uint8_t *src);
 bool pbio_uuid128_reverse_compare(const uint8_t *uuid1, const uint8_t *uuid2);
 void pbio_uuid128_reverse_copy(uint8_t *dst, const uint8_t *src);
 

lib/pbio/src/protocol/pybricks.c

@@ -87,9 +87,17 @@ const uint16_t pbio_gatt_device_info_service_uuid = 0x180A;
 
 /** Bluetooth Firmware Version Characteristic UUID. */
 const uint16_t pbio_gatt_firmware_version_char_uuid = 0x2A26;
+const uint8_t pbio_gatt_firmware_version_char_uuid_128[] = {
+    0x00, 0x00, 0x2A, 0x26, 0x00, 0x00, 0x10, 0x00,
+    0x80, 0x00, 0x00, 0x80, 0x5F, 0x9B, 0x34, 0xFB,
+};
 
 /** Bluetooth Software Version Characteristic UUID (Pybricks protocol version). */
 const uint16_t pbio_gatt_software_version_char_uuid = 0x2A28;
+const uint8_t pbio_gatt_software_version_char_uuid_128[] = {
+    0x00, 0x00, 0x2A, 0x28, 0x00, 0x00, 0x10, 0x00,
+    0x80, 0x00, 0x00, 0x80, 0x5F, 0x9B, 0x34, 0xFB,
+};
 
 /** Bluetooth PnP ID Characteristic UUID. */
 const uint16_t pbio_gatt_pnp_id_char_uuid = 0x2A50;

lib/pbio/src/util.c

@@ -3,6 +3,34 @@
 
 #include <stdbool.h>
 #include <stdint.h>
+#include <string.h>
+
+/**
+ * Copies a 128-bit UUID from @p src to a buffer @p dst,
+ * which is a buffer used by a little endian medium.
+ * 
+ * According to RFC 4122, the UUID is grouped into the following:
+ * 1) One 32-bit
+ * 2) Two 16-bit
+ * 3) Eight 8-bit
+ *
+ * @param [in]  dst     The destination array.
+ * @param [in]  src     The UUID to reverse and copy.
+ */
+void pbio_uuid128_le_copy(uint8_t *dst, const uint8_t *src) {
+    dst[0] = src[3];
+    dst[1] = src[2];
+    dst[2] = src[1];
+    dst[3] = src[0];
+
+    dst[4] = src[5];
+    dst[5] = src[4];
+
+    dst[6] = src[7];
+    dst[7] = src[6];
+
+    memcpy(&dst[8], &src[8], 8);
+}
 
 /**
  * Compares two 128-bit UUIDs with opposite byte ordering for equality.