Linking errors when redirecting stdout to uart on stm32f2

[kevinhuang]

Posted on April 17, 2014 at 22:50

Greetings,

I'm working with an stm32f215rg mcu and I'm attempting to redirect stdout/in to uart4. I seem to be getting linking errors when attempting to link all the objects/libs together. The line I use is below:

arm-none-eabi-gcc    -mthumb -mcpu=cortex-m3  -g -gdwarf-2 -T/home/leela/lib/scripts/stm32_flash.ld -Xlinker --gc-sections -Wl,-Map=uart.map -lm -lc -o uart.elf CMakeFiles/uart.elf.dir/src/main.c.o  -o ../../bin/uart.elf  ../lib/misc/libmisc.a ../lib/std/libleela_std.a

The error message that I receive is:

/usr/bin/../lib/gcc/arm-none-eabi/4.7.3/../../../../arm-none-eabi/lib/thumb2/libc.a(lib_a-sbrkr.o): In function `_sbrk_r':

sbrkr.c:(.text+0x12): undefined reference to `_sbrk'

/usr/bin/../lib/gcc/arm-none-eabi/4.7.3/../../../../arm-none-eabi/lib/thumb2/libc.a(lib_a-writer.o): In function `_write_r':

writer.c:(.text+0x16): undefined reference to `_write'

/usr/bin/../lib/gcc/arm-none-eabi/4.7.3/../../../../arm-none-eabi/lib/thumb2/libc.a(lib_a-closer.o): In function `_close_r':

closer.c:(.text+0x12): undefined reference to `_close'

/usr/bin/../lib/gcc/arm-none-eabi/4.7.3/../../../../arm-none-eabi/lib/thumb2/libc.a(lib_a-lseekr.o): In function `_lseek_r':

lseekr.c:(.text+0x16): undefined reference to `_lseek'

/usr/bin/../lib/gcc/arm-none-eabi/4.7.3/../../../../arm-none-eabi/lib/thumb2/libc.a(lib_a-readr.o): In function `_read_r':

readr.c:(.text+0x16): undefined reference to `_read'

/usr/bin/../lib/gcc/arm-none-eabi/4.7.3/../../../../arm-none-eabi/lib/thumb2/libc.a(lib_a-fstatr.o): In function `_fstat_r':

fstatr.c:(.text+0x14): undefined reference to `_fstat'

/usr/bin/../lib/gcc/arm-none-eabi/4.7.3/../../../../arm-none-eabi/lib/thumb2/libc.a(lib_a-isattyr.o): In function `_isatty_r':

isattyr.c:(.text+0x12): undefined reference to `_isatty'

However, I have all of them symbols defined in libmisc.a, and I've confirmed that by checking the output of arm-none-eabi-nm and objdump. I have no idea what is causing this issue and I'm not sure how to approach this, any help or suggestions on what to do would be appreciated. Thanks. 

#stm32f2

[Tesla DeLorean]

Posted on April 17, 2014 at 22:59

Yes, so you haven't provided the required SYSCALL/NEWLIB support

https://my.st.com/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Flat.aspx?RootFolder=https%3a//my.st.com/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/USART_printf%20not%20working%20on%20STM323221G_eval%20via%20GNU_ARM_GCC&FolderCTID=0x01200200770978C69A1141439FE559EB459D7580009C4E14902C3CDE46A77F0FFD06506F5B&currentviews=166

[kevinhuang]

Posted on April 18, 2014 at 00:18

Hi Clive,

Thank you for your response, but I'm not sure what you mean? In the static library libmisc.a I compiled newlib_stubs.c, which seems to be very similar to the file that you provided from the thread that you linked to. I have pasted the contents of my file 

http://pastebin.com/6CAABeWx

 Is this what you are talking about? 

Beyond the newlib_stubs.c file, I don't see anything that seems to be relevant to newlib/syscall. 

[Tesla DeLorean]

Posted on April 18, 2014 at 01:21

Except my example links.

Your command line seems a bit tortured, two output files? Libraries without -l

Why don't you try just specifying the newlib_stubs as an object, on it's own, and not in a library, or let the compiler build it and link it from the source.