bootloader_app_start vs NVIC_SystemReset();

[ToTo]

Hi, i want to jump from my app to the bootloader, i used the function

void bootloader_app_start(void)

{

    vMBt_eStopAdv_Exe() ;// Stoping the BLE ADV 
    sd_power_gpregret_clr(POWER_GPREGRET_GPREGRET_Msk); 
sd_power_gpregret_set(BOOTLOADER_DFU_START); 
sd_softdevice_disable(); 
interrupts_disable(); 
sd_softdevice_vector_table_base_set(NRF_UICR->BOOTLOADERADDR); 
bootloader_util_app_start(NRF_UICR->BOOTLOADERADDR);

}

and it's OK , but when i use NVIC_SystemReset(); instead of bootloader_util_app_start it dosen't work and the bootloader dosen't start. although i added in the script of the bootloader to enter the bootloader program if GPREGRET=BOOTLOADERADDR or GPREGRET=0x00 ( case of a reset is handled )

this the modfication in the bootloader code :

if (dfu_start || (!bootloader_app_is_valid(DFU_BANK_0_REGION_START)) ||NRF_POWER->GPREGRET == 0x00)... this the condition part to enter dfu_mode , i just added the case where GPREGRET=0x00

Remarks:

1- the initialisation of the softdevice is always done in the case of a reset because we have :

-static bool dfu_start = false;

• bool app_reset = (NRF_POWER->GPREGRET == BOOTLOADER_DFU_START);

• ble_stack_init(!app_reset );

2- no button check is included , i commented that part as follow

//dfu_start |= ((nrf_gpio_pin_read(BOOTLOADER_BUTTON_PIN) == 0) ? true: false);

Questions :

1. Why it dosen't work with the nvic reset ?
2. can you explain to me the process of jump ..i have a small idea about assembly code but i don't know what are the registers used there when jumping...(thread mode .. )
3. If i want to use Nvic_Reset() what should i do ? ( i don't care about the bonding service !! )
4. This function ( __asm static void bootloader_util_reset(uint32_t start_addr) , used for the jump) is really confusing me !! in fact it's invoking a parameter that it never uses ..any explanation please

[ToTo]

Hi Hung Bui,

frankly i don't know which SDK used, because i downloaded the project from GitHub ... I remember that i faced some problems, the BLE for example didn't work from the biginning, so i read the s130_nrf51822_0.9.0-1.releasenotes and i added the function sd_ble_enable() to enable the BLE... Any way to know the SKD i'm using from the files it contains ? i have been working on this project for many days, and i tested many app i don't really remember, what i did.. i remember that the bootloader project i downloaded missed some files, so i took two folders ( Source and Include ) from a folder called nrf51822 ( i think this is the SDK you are talking about ) ...I'm sorry for my unprecise replies, this is my first project using nordic.

I want to ask concenrning the BLE re-init : are you talking about this function ?

static void ble_stack_init(bool init_softdevice) { uint32_t err_code; sd_mbr_command_t com = {SD_MBR_COMMAND_INIT_SD, };

if (init_softdevice)
{
    err_code = sd_mbr_command(&com);
    APP_ERROR_CHECK(err_code);
}

err_code = sd_softdevice_vector_table_base_set(BOOTLOADER_REGION_START);
APP_ERROR_CHECK(err_code);

SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_XTAL_20_PPM, true);

// Enable BLE stack 
ble_enable_params_t ble_enable_params;
memset(&ble_enable_params, 0, sizeof(ble_enable_params));
ble_enable_params.gatts_enable_params.service_changed = IS_SRVC_CHANGED_CHARACT_PRESENT;
err_code = sd_ble_enable(&ble_enable_params);
APP_ERROR_CHECK(err_code);

err_code = softdevice_sys_evt_handler_set(sys_evt_dispatch);
APP_ERROR_CHECK(err_code);

}

And the check inside the ble_stack_init() is only about re-initializing the softdevice or not ...so i tested with this way ble_stack_init(!app_reset ||NRF_POWER->GPREGRET ==0) and i have the same issue. i didn't understand your point of view about reinit the stack ? what part of the code in the function ble_stack_init() ?

Something important i forgot to say : the hard reset is working very well, when the bootloader or the app is running if i click reset button the chip jump to bootloader...