Memory layout for secure dfu bootloader + main application + softdevice 332 (SDK17.1.0)

Question

Hi, 
 Memory layout for secure dfu bootloader + main application + softdevice 332 (SDK17.1.0) 
 We are currently migrating from SDK 14.2.0 to SDK 17.1.0 it also affects to soft device version which we want to upload it to 7.0.1. 
 We are facing some problems related to memory layout, in order to not introduce more complexity, we are trying to update the following examples of the SDK 17: 
 
 Bootloader: pca10040_s132_ble_debug 
 Main application: ble_app_uart_c_pca10040_s132 
 Softdevice: ANT_s332_nrf52_7.0.1 
 
 We have managed to work with s132, but when we upload to s332 it throws the following error: 
 
 The current memory layout that we are using is (starting address and size): 
 
 Bootloader: [ROM]0x72000 - 0xC000 [RAM] 0x20005968 - 0xA698 
 Main application: [ROM]0x30000 - 0x5A000 [RAM] 0x20002A28 - 0xD5D8 
 
 You can find see it here: 
 
 Which is the correct memory layout for s332? Including the three applications? Do we have to include some missing configuration in the project? 
 We do not find information about that, only for s132: 
 
 Best regards and may thanks, 
 Javier

Einar Thorsrud · Accepted Answer

Hi Javier, 
 jfpastrana said: Now it is working, but I am not sure if it is the best solution. As you can see it is some RAM memory shared between Boot and Main application, I tried to change the Main app RAM before to Boot reserved RAM but it did not work. 
 The bootloader and application are not active at the same time, so there is no problem using the same RAM region for both. (this is different form the SoftDevice, which is used at the same time as the application, and at the same time as the bootloader). 
 jfpastrana said: Which are the RAM addresses used by s332? I have only found the following information, but it is not completely clear: 
 The important point here is that APP_RAM_BASE is not a constant, but is dependent on configuration. From the S332 SDS: " The value of APP_RAM_BASE is obtained by calling sd_softdevice_enable, which will always return the required minimum start address of the application RAM region for the given configuration ". As long as you reserve enough RAM for the SoftDevice and you still have enough for your application there is no problem. If you need to optimize in order to get more RAM for your application (or bootloader), you can do that. See Adjustment of RAM and Flash memory for details. 
 Einar

Memory layout for secure dfu bootloader + main application + softdevice 332 (SDK17.1.0)

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