Simple Bootloader

RE: Simple Bootloader

superpak — Mon, 25 Sep 2017 20:57:52 GMT

Hi Martin, I just wanted no dependence on SD in my bootloader since I want it to provide basic functionality. Thank you for your answers!

RE: Simple Bootloader

MartinBL — Mon, 25 Sep 2017 07:48:54 GMT

It should work. Can you elaborate a bit around your motivation for doing all this?

The MBR might work alone, but is not tested by itself. So proceed at your own discretion.

RE: Simple Bootloader

superpak — Wed, 20 Sep 2017 16:31:40 GMT

Hi Martin. My application works as I wanted. I will let you know that separating the MBR and using it as a standalone does work! I flash the MBR, then the BL and the BL runs correctly. I, then install SD only (no MBR) and then my app. My BL inits the SD, sets the vector table to app and then jumps to the app! Everything works! But I was just curious about those two functions. Whether they have any dependence on the SD?

Also, can I start the application from my BL and use these two functions at the start of my application instead of the BL to correctly set the SD vector table address? Thanks!

RE: Simple Bootloader

MartinBL — Wed, 20 Sep 2017 07:51:07 GMT

Hi, The MBR is not made to work as standalone. Anyway, if you look at the documentation of nrf_dfu_mbr_init_sd() and sd_softdevice_vector_table_base_set(start_addr) you'll see that they probably return NRF_SUCCESS regardless of whether a Softdevice i present. The first one might return NRF_ERROR_INVALID_PARAM, but that probably doesn't depend on the presence of a SD.

Have you tried to change your application's linker script so that it starts at address 0x1000, where the SD would normally start?

RE: Simple Bootloader

superpak — Tue, 19 Sep 2017 22:14:47 GMT

Hi Martin, I accidentally clicked on convert to answer.

Anyway, here is what I am trying to do.

I have seperated the SD into the MBR part and the SD part. I flash the MBR and then flash the Bootloader. At this point, there is no SD present on the device -just the bootloader and the MBR. The MBR jumps to the bootloader correctly and runs the bootloader. In the bootloader, I have calls to nrf_dfu_mbr_init_sd(); and sd_softdevice_vector_table_base_set(start_addr);. I have these 2 calls, but no SD (just the MBR and Bootloader). Why is it that I don't get an error when I make these 2 calls since the Softdevice is not actually present?

RE: Simple Bootloader

MartinBL — Tue, 19 Sep 2017 06:58:42 GMT

I might be misunderstanding your ideas, but there is a Master Boot Record implemented in the Softdevice that is intended to enable updates of both the bootloader and Softdevice.

RE: Simple Bootloader

superpak — Mon, 18 Sep 2017 20:06:23 GMT

Thanks Martin. So let's say I never want to modify my bootloader and I upgrade the Softdevice to a newer version, could it be possible that the new API of the Softdevice will fail to work with my bootloader code? I will only be initializing the SD in the bootloader and setting the base address in the bootloader.

RE: Simple Bootloader

MartinBL — Mon, 18 Sep 2017 11:29:22 GMT

Unfortunately, if your main application uses a softdevice you will have to set the base address in the bootloader using SD calls. The bootloader can run independently of the softdevice though, until you want to start it.

RE: Simple Bootloader

superpak — Fri, 15 Sep 2017 18:44:43 GMT

The problem is that I am not not forwarding the SD vector table to the application in my bootloader and therefore when I try to use any SD calls in my main application, I get the error.

If I initialize the SD using nrf_dfu_mbr_init_sd(); and then set the vector table address using sd_softdevice_vector_table_base_set(start_addr); in my bootloader everything works fine.

I want my bootloader to be completely independent of SD or any SD calls. How do I forward the vector table to the app without using the SD calls?

RE: Simple Bootloader

superpak — Fri, 15 Sep 2017 16:31:53 GMT

Hi Martin, thanks for following up. I have attached a new image that shows where the error is. As I mentioned before, it is when we call nrf_sdh_enable_request().

RE: Simple Bootloader

MartinBL — Fri, 15 Sep 2017 11:39:58 GMT

What is going on around line 449 (hexadecimal 0x1C1) in your main.c file?

RE: Simple Bootloader

superpak — Thu, 14 Sep 2017 16:58:21 GMT

Thanks for pointing that out, Martin. I have attached the error info. Please let me know!

RE: Simple Bootloader

MartinBL — Thu, 14 Sep 2017 06:08:24 GMT

Hi, If you debug like this, you will probably find an error code that might give us a clue about what is wrong.