How can I compile dfu bootloader examples for PCA10031/other 16K RAM boards/dongles?

[Rifat Mahmud]

Apparently, the dfu bootloader example in nrf51 SDK 8.1 is not working on PCA10031 type(16K RAM devices). In my case, the device is RedBearLab BLE Nano and nrf51822. Can anybody help?

[Einar Thorsrud]

You need to change the linker settings of the bootloader project, taking into account that you have 0x4000 byte less RAM.

If you use Keil you need to go to Project -> Options for Target ... -> Target. Then in the lower right half of the pane you have a section called "Read/Write Memory Areas". There you should update the following:

• IRAM1 size should be 0x5380 - 0x4000 = 0x1380 (leave the start address as is, 0x20002C00)
• IRAM2 start address shall be 0x20007F80 - 0x4000 = 0x20003F80 instead of 0x20007F80 (leave the size as is, 0x80)

If you use GCC you would have to change the linker script (examples/dfu/bootloader/dfu_gcc_nrf51.ld) in the same way:

• Change RAM LENGTH to 0x1380 (line 17)
• Change NOINIT ORIGIN to 0x20003F80 (line 22)

[Tanasis!]

For the SDK12.1, nrf51 and the bootloader_secure example this wont compile.
Can we lower the start address 0x20002C00? How is this derived? Thanks!