Creating a "system" static lib

RE: Creating a "system" static lib

Zoptune — Mon, 01 Jul 2019 12:34:00 GMT

Ok so I finally succeed to get the output using the static lib I generated.

In my last comment I said that all object files in the static lib were not linked.

To force gcc to link every file in the lib I added the flag -Wl,--whole-archive before libnrf52.a. Now we can see that the linker links all objects from the static lib :

attempt to open libnrf52.a succeeded
(libnrf52.a)app_error.c.o
(libnrf52.a)app_error_weak.c.o
(libnrf52.a)app_fifo.c.o
(libnrf52.a)app_uart_fifo.c.o
(libnrf52.a)app_util_platform.c.o
(libnrf52.a)boards.c.o
(libnrf52.a)gcc_startup_nrf52840.S.o
(libnrf52.a)nrf_assert.c.o
(libnrf52.a)nrf_balloc.c.o
(libnrf52.a)nrf_drv_common.c.o
(libnrf52.a)nrf_drv_uart.c.o
(libnrf52.a)nrf_log_frontend.c.o
(libnrf52.a)nrf_memobj.c.o
(libnrf52.a)nrf_strerror.c.o
(libnrf52.a)retarget.c.o
(libnrf52.a)system_nrf52840.c.o

I also added the -Wl,--no-whole-archive after the library that other libraries won't be affected. The final gcc command is the following :

arm-none-eabi-gcc -O3 -mthumb -mabi=aapcs -L ../../../../../../components/toolchain/gcc -Tuart_gcc_nrf52.ld -mcpu=cortex-m4 -mfloat-abi=hard -mfpu=fpv4-sp-d16 --specs=nano.specs main.c.o -Wl,--whole-archive libnrf52.a -Wl,--no-whole-archive -o nrf52840_xxaa.out

RE: Creating a "system" static lib

Zoptune — Mon, 01 Jul 2019 11:24:14 GMT

In order to get more debug information, I added the -Wl,--verbose flag to the linking step for both Makefile and manual linking with static lib.

Then I compared the outputs and I found that when I use the static lib, not all the object files in the archive are used for linking.

Here are the files loaded during linking with the Makefile :

_build/nrf52840_xxaa/nrf_log_frontend.c.o
_build/nrf52840_xxaa/boards.c.o
_build/nrf52840_xxaa/app_error.c.o
_build/nrf52840_xxaa/app_error_weak.c.o
_build/nrf52840_xxaa/app_fifo.c.o
_build/nrf52840_xxaa/app_uart_fifo.c.o
_build/nrf52840_xxaa/app_util_platform.c.o
_build/nrf52840_xxaa/nrf_assert.c.o
_build/nrf52840_xxaa/nrf_balloc.c.o
_build/nrf52840_xxaa/nrf_memobj.c.o
_build/nrf52840_xxaa/nrf_strerror.c.o
_build/nrf52840_xxaa/retarget.c.o
_build/nrf52840_xxaa/nrf_drv_common.c.o
_build/nrf52840_xxaa/nrf_drv_uart.c.o
_build/nrf52840_xxaa/main.c.o
_build/nrf52840_xxaa/gcc_startup_nrf52840.S.o
_build/nrf52840_xxaa/system_nrf52840.c.o

And here are the files loaded during manual linking with the static lib :

attempt to open main.c.o succeeded
main.c.o
attempt to open libnrf52.a succeeded
(libnrf52.a)app_error.c.o
(libnrf52.a)app_error_weak.c.o
(libnrf52.a)app_uart_fifo.c.o
(libnrf52.a)boards.c.o
(libnrf52.a)gcc_startup_nrf52840.S.o
(libnrf52.a)nrf_drv_uart.c.o
(libnrf52.a)system_nrf52840.c.o
(libnrf52.a)app_fifo.c.o
(libnrf52.a)nrf_drv_common.c.o

I don't understand why not every files are loaded.

Does someone has any idea ?

Thanks

RE: Creating a "system" static lib

awneil — Mon, 01 Jul 2019 10:22:52 GMT

Yes, I'd have thought it should be possible - you're just going to have to search out how to actually do it.

RE: Creating a "system" static lib

Zoptune — Mon, 01 Jul 2019 10:20:02 GMT

Hi and thanks for your answer.

I don't think that's a problem because a static lib is just a bunch of object files right ?

RE: Creating a "system" static lib

awneil — Fri, 28 Jun 2019 12:55:12 GMT

can you debug into a GCC static library?

you'll need to do some googling to find out ...