SDK 8.0.0 DFU bootloader code size too large, gcc

RE: SDK 8.0.0 DFU bootloader code size too large, gcc

Vidar Berg — Mon, 13 Apr 2015 07:51:40 GMT

My suggestion would be to just modify the original dfu_types.h. This file is only used by the bootloader, and it should not be a problem unless you plan to have several versions of the bootloader in the same SDK. In that case you can always make a config file for each bootlaoder project.

RE: SDK 8.0.0 DFU bootloader code size too large, gcc

Eliot Stock — Mon, 13 Apr 2015 00:36:58 GMT

@Vidar I need to change BOOTLOADER_REGION_START but SDK 8.0.0 makes this very messy. I don't want to edit a header file in the SDK, but if I copy dfu_types.h over to my project instead, my build system now has two directories with that header in it to include. Is there a better way? Can this be done more cleanly in the next SDK release?

RE: SDK 8.0.0 DFU bootloader code size too large, gcc

Mike F — Wed, 08 Apr 2015 23:36:13 GMT

I wonder why it is so much larger when you compile it. I just added my map file so you can compare.

$ grep '__Vectors\|__exidx_end' bootloader_s110v8_xxaa.map 
            0x000000000003c000                __Vectors
            0x000000000003f3d8                __exidx_end = .

RE: SDK 8.0.0 DFU bootloader code size too large, gcc

Eliot Stock — Wed, 08 Apr 2015 22:04:09 GMT

Thank you very much indeed! This builds on my machine and weighs in at about 18KB. I'm now playing spot the difference with my own Makefile and sources and these ones to see how mine is getting so big. I haven't run it as a bootloader yet.

RE: SDK 8.0.0 DFU bootloader code size too large, gcc

Mike F — Wed, 08 Apr 2015 21:02:44 GMT

GCC can do it, here's an example. The bootloader_util_gcc.c file in the SDK is fairly close. This works with both single and dual bank updates. It would be nice if a GCC version, like this, was included in future versions of the SDK.

First, if you set m_uicr_bootloader_start_address as a volatile, BOOTLOADER_REGION_START will be written to flash when you program the hex file. If not, it will be optimized out so you'll have to program BOOTLOADER_REGION_START into the UICR later.

Next, you have to pass the argument start_addr to the assembly template so you get the expected application reset vector. If you don't do this the DFU will upload successfully but the application will not start. The code above address this start_addr issue.

I left out isr_abort because it isn't working for whatever reason. I only get to the bootloader after a restart so I don't need this code or this code (or the bond sharing feature) but it does makes sense to get a gcc version of this working.

bltest.tgz

bootloader_s110v8_xxaa.map

RE: SDK 8.0.0 DFU bootloader code size too large, gcc

Vidar Berg — Wed, 08 Apr 2015 13:24:23 GMT

Hi, from your map file it seems like your bootloader is actually 32K . I am not sure if GCC is able to compile it to 16K, but you can try to optimize for size as Mike suggested.

Here are some files that I have modified to use the bootloader with GCC and SDK 8.0.0. The linker file here allocates 21K in flash for the bootloader allowing -O3 optimization. Remember to change dfu_types.h-->BOOTLOADER_REGION_START according to the linker settings.

Note that the modifications are not necessary correct, and may have unexpected side effects due to little testing. Also, did not add the bond sharing feature mentioned here.

EDIT 13.4.2015 Added missing linker file.

RE: SDK 8.0.0 DFU bootloader code size too large, gcc

Mike F — Sun, 05 Apr 2015 22:22:30 GMT

I'm trying to do the same thing. I don't have everything working yet, but ran into this issue. I suspect that if you optimize for size -Os rather than speed -O3, you will be able to load it at 0x3c000.