Tossing or sharing data after entering bootloader DFU

RE: Tossing or sharing data after entering bootloader DFU

Hung Bui — Wed, 23 Mar 2016 13:46:47 GMT

Yes you are correct, it's the no_init section. Note that you only configure that for bootloader, you don't have to configure that for the application.

RE: Tossing or sharing data after entering bootloader DFU

MANGO — Wed, 23 Mar 2016 13:36:39 GMT

@Hung Bui: Hmm, I forgot how I got that number. I referenced from one of the answers in the devzone's question.

Sorry I cannot find the referenced link. I will edit this comment if I find it.

Surprisingly, I haven't failed BLE OTA with that settings.

So, I have to change the linker script (in IAR ,.icf file) to 0x20002C00-0x20003FFF.

IAR is different from Keil uVision so I think the iRAM2 is meaning the __no_init section in IAR.

Anyways, 128 (128 = 0x20004000 - 0x20003F80, top of 16KB Ram ~ __no_init section)

-46 (size of two global variables)

= 82 bytes for my extra data, is this correct?

Thanks for your help.

RE: Tossing or sharing data after entering bootloader DFU

Hung Bui — Wed, 23 Mar 2016 08:49:25 GMT

@Mango: Could you let me know where you got the 3FAF from ? The default configuration is IRAM1 from 0x20002C00-0x3F7F, IRAM2: 0x3F80-0x3FFF. This mean you have 0x80 (128) byte for noinit RAM (IRAM2). The m_peer_data and m_peer_data_crc occupied 46 bytes, you have 82 bytes left for your application data.

RE: Tossing or sharing data after entering bootloader DFU

MANGO — Tue, 22 Mar 2016 14:42:41 GMT

Great, what about the size? How much I can insert my own data? In case of SDK 7.2,

typedef struct{ // sizeof(dfu_ble_peer_data_t) == 44 at SDK 7.2
ble_gap_enc_info_t enc_info;
ble_gap_irk_t      irk;
ble_gap_addr_t     addr;
} dfu_ble_peer_data_t;

Since the bootloader at SDK 7.2 occupies small size of RAM of nRF518922-QFAA (16KB RAM),

(0x20002C00 ~ 0x20003FAF) how much data am I allowed to add?

RE: Tossing or sharing data after entering bootloader DFU

Hung Bui — Tue, 22 Mar 2016 13:51:02 GMT

@Mango: Yes, you can modify the dfu_ble_peer_data_t struct to add your own data in.