why did memory_pool_internal default buffer change from sdk 8 to 9

[Zhou]

#define TX_BUF_SIZE       32u    /**< TX buffer size in bytes. */
#define RX_BUF_SIZE       600u   /**< RX buffer size in bytes. */

#define RX_BUF_QUEUE_SIZE 2u     /**< RX buffer element size. */

These value changed from sdk 8 to 9.

What are the reasons?

I find dfu have a higher success rate in sdk9 than sdk8, is this the reason for the change?

[bjorn-spockeli]

The following values are the default buffer sizes in both the SDK 8 and 9 release

#define TX_BUF_SIZE       4u    /**< TX buffer size in bytes. */
#define RX_BUF_SIZE       32u   /**< RX buffer size in bytes. */

#define RX_BUF_QUEUE_SIZE 8u    /**< RX buffer element size. */

i.e. there has not been any change in buffer sizes in the internal memory pool from SKD 8 to 9.

As to why you see a higher success rate, it's likely due to improvements and fixes in the SDK and the DFU libraries.

[bjorn-spockeli]

Are you referring to serial or OTA DFU? The hci_mem_pool_internal.h file will differ depending on if you're using a serial or BLE connection to update the firmware of your device.

In components/libraries/bootloader_dfu you'll find the two different header files in the following folders:

• ble_transport/hci_mem_pool_internal.h - OTA DFU
• hci_transport/hci_mem_pool_internal.h - Serial DFU

These header files are identical in SDK v8.0 and SDK v9.0.