Bootloader address flash write

RE: Bootloader address flash write

AP1 — Thu, 08 Aug 2024 05:37:07 GMT

Hi thanks for the reply we are using GPREGRET registers to store the values it is working fine during soft reset

RE: Bootloader address flash write

Vidar Berg — Mon, 15 Jul 2024 07:46:02 GMT

The flash is erased in units of flash pages, which are 4kB each on the nRF52 series.

RE: Bootloader address flash write

AP1 — Sat, 13 Jul 2024 08:32:35 GMT

1. Hi I need to write in flash address but my issue is before writing anything I should erase atleast 4kB data in flash address then only I can write

2. Is there any thing like we can erase only required bytes in flash

RE: Bootloader address flash write

AP1 — Sat, 13 Jul 2024 08:28:51 GMT

Hi I am using s140 soft device ver 7.2.0 will flash address remains same as you have posted above or there is any changes will be there

RE: Bootloader address flash write

AP1 — Fri, 12 Jul 2024 10:58:34 GMT

Hi vidar Berg thanks for your reply

1.I have tried with nrf_power_gpregret api by writing and reading in the register it is working fine in bootloader_ble_debug app

2.but when we tried to read only using nrf_power_gpregret2_get() after power reset the data is 0 is that the register value becoming 0 after power reset or any where it is clearing in the code after reset in booloader_ble_debug sdk

3. Can i verify through any particular flash address or the register address so that the data is written

4. Is there any other registers which will retain its value even after power reset

// nrf_power_gpregret2_set(0x56);
// APP_ERROR_CHECK(err_code);

// Set GPREGRET register to trigger DFU
uint8_t ret = nrf_power_gpregret2_get();
APP_ERROR_CHECK(err_code);

logs:

ret = 0x0
<info> app: Inside main
<debug> app: In nrf_bootloader_init
<debug> nrf_dfu_settings: Calling nrf_dfu_settings_init()...
<debug> nrf_dfu_flash: Initializing nrf_fstorage_nvmc backend.
<debug> nrf_dfu_settings: Using settings page.
<debug> nrf_dfu_settings: Copying forbidden parts from backup page.
<debug> nrf_dfu_settings: Destination settings are identical to source, write not needed. Skipping.
<info> nrf_dfu_settings: Backing up settings page to address 0xFE000.
<debug> nrf_dfu_settings: Destination settings are identical to source, write not needed. Skipping.
<debug> app: Enter nrf_bootloader_fw_activate
<info> app: No firmware to activate.
<info> app: Boot validation failed. No valid app to boot.
<debug> app: DFU mode because app is not valid.
<info> nrf_bootloader_wdt: WDT is not enabled
<debug> app: in weak nrf_dfu_init_user
<debug> app: timer_stop (0x2000599C)
<debug> app: timer_activate (0x2000599C)
<info> app: Entering DFU mode.
<debug> app: Initializing transports (found: 1)
<debug> nrf_dfu_ble: Initializing BLE DFU transport
<debug> nrf_dfu_ble: Setting up vector table: 0x000F1000
<debug> nrf_dfu_ble: Enabling SoftDevice.
<debug> nrf_dfu_ble: Configuring BLE stack.
<debug> nrf_dfu_ble: Enabling the BLE stack.
<debug> nrf_dfu_ble: No advertising name found
<debug> nrf_dfu_ble: Using default advertising name
<debug> nrf_dfu_ble: Advertising...
<debug> nrf_dfu_ble: BLE DFU transport initialized.
<debug> nrf_dfu_flash: Initializing nrf_fstorage_sd backend.
<debug> app: Enter main loop

RE: Bootloader address flash write

Vidar Berg — Fri, 12 Jul 2024 06:33:57 GMT

The GPREGRET registers are included in the POWER peripheral, which the Softdevice reserves access to. Therefore, you need to use the sd_power_gpregret_* APIs to access these registers in the application while the Softdevice is enabled. However, these functions cannot be when the Softdevice is disabled, hence the NRF_ERROR_SVC_HANDLER_MISSING ('1') error.

You can see how the nrf_power_gpregret* functions are used in the bootloader.

RE: Bootloader address flash write

AP1 — Thu, 11 Jul 2024 14:19:04 GMT

1. Hi after setting the GPREGRET2 register value in which address should i verify that the value is written properly

i have the following code snippet in central uart app before calling ble bootloader is this a correct method ?

// Clear GPREGRET register
err_code = sd_power_gpregret_clr(0, 0xFF);
APP_ERROR_CHECK(err_code);

// Set GPREGRET register to trigger DFU
err_code = sd_power_gpregret_set(0, BOOTLOADER_DFU_START);
APP_ERROR_CHECK(err_code);

// Clear GPREGRET2 register
err_code = sd_power_gpregret_clr(1, 0xFF);
APP_ERROR_CHECK(err_code);

// Set GPREGRET2 register
err_code = sd_power_gpregret_set(1, 0x56);
APP_ERROR_CHECK(err_code);

// Reset the system
NVIC_SystemReset();
}

2. I Tried to write the register in the Bootloader_ble_debug app to verify whether we can able to write and read the data but error code 01 is returned form the func what are the required things to be done before writing into it

code snippet

uint32_t err_code;

err_code = sd_power_gpregret_clr(1, 0xFF);
NRF_LOG_DEBUG("ret 1 = %d\n", err_code);
APP_ERROR_CHECK(err_code);

// Set GPREGRET2 register
err_code = sd_power_gpregret_set(1, 0x56);
NRF_LOG_DEBUG("ret 2 = %d\n", err_code);
APP_ERROR_CHECK(err_code);

uint32_t custom_data = NRF_POWER->GPREGRET2;

NRF_LOG_DEBUG("custom data 0x%04X", custom_data);

logs:

<info> app: Inside main
<debug> app: ret 1 = 1

<error> app: Received an error: 0x00000001!

Note : i have tried to achieve that read and write in both the app for verification of this GPREGRET2 register

RE: Bootloader address flash write

Vidar Berg — Thu, 11 Jul 2024 12:12:26 GMT

I'm trying to understand your goal is. If just want the app to be able to pass a flag/value to the bootloader, you could just use the one of the General purpose retention registers (GPREGRET). These are retained through a Soft reset.

Note that there are two of these registers available, and one is used by the bootloader when NRF_BL_APP_CRC_CHECK_SKIPPED_ON_GPREGRET2 is enabled, and the other when NRF_BL_DFU_ENTER_METHOD_GPREGRET is enabled.

RE: Bootloader address flash write

AP1 — Thu, 11 Jul 2024 08:54:47 GMT

1. So i need to retain the data at least 4 byte even if it enters into bootloader_ble dfu after triggering form the main central UART

2. I have explained requirements in the above post so need to know that for writing at least 4 bytes is possible using fstorage because we need to erase before writing

3. Is it required to erase 4096 bytes before writing the data ?

3. Is there any other method like registers, so that i can write 4 bytes data in the flash and that should be accessible even if it enters in the bootloader_ble dfu mode also

Note : I need only 1 byte if it is not happening 4 bytes is also ok but i need a simple way to write small data in flash or registers so that i can access in bootloader_ble dfu also

RE: Bootloader address flash write

Vidar Berg — Thu, 11 Jul 2024 07:40:49 GMT

Can you please elaborate on what you are trying to achieve? The minimum write size for flash is 4 bytes.

RE: Bootloader address flash write

AP1 — Thu, 11 Jul 2024 07:35:24 GMT

Hi thanks for your reply i need to write only 1 byte data and currently i am using fstorage libraries can we achieve using this or is there any other method for writing small data into flash or any registers that can be used ?

RE: Bootloader address flash write

Vidar Berg — Wed, 10 Jul 2024 17:13:26 GMT

Hi,

You should use the area below the bootloader shown as "Application data" here:

https://docs.nordicsemi.com/bundle/sdk_nrf5_v17.1.0/page/lib_bootloader.html

The size and location of this area is dependent on the start address of the bootloader and the NRF_DFU_APP_DATA_AREA_SIZE value configured in the bootloader project.

Bes regards,

Vidar