Re: [XenARM] Linking errors of Mini-OS for ARM32

[Julien Grall <julien.grall@linaro.org>]

On 06/10/2013 01:13 AM, Chen Baozi wrote:

> On Sun, Jun 09, 2013 at 02:48:42PM +0100, Julien Grall wrote:
>> On Sun, Jun 9, 2013 at 1:42 PM, Chen Baozi <baozich@gmail.com> wrote:
>>> Since finishing the very beginning setup assembly, I was turning to adding
>>> necessary headers and empty functions to build the binary. After introducing
>>> those bit operations, spinlocks etc., I thought I have a basic framework to
>>> pass the first build. However, when comming to the final linking stage,
>>> there are errors:
>>>
>>> arm-linux-gnueabihf-ld   -T arch/arm/minios-arm32.lds
>>> /home/cbz/src/xen/extras/mini-os/mini-os.o  -o
>>> //home/cbz/src/xen/extras/mini-os/mini-os
>>> /home/cbz/src/xen/extras/mini-os/mini-os.o: In function `init_blkfront':
>>> /home/cbz/src/xen/extras/mini-os/blkfront.c:122: undefined reference to `__aeabi_uldivmod'
>>> /home/cbz/src/xen/extras/mini-os/blkfront.c:122: undefined reference to `__aeabi_uldivmod'
>>> /home/cbz/src/xen/extras/mini-os/blkfront.c:122: undefined reference to `__aeabi_uldivmod'
>>> /home/cbz/src/xen/extras/mini-os/blkfront.c:122: undefined reference to `__aeabi_uldivmod'
>>> /home/cbz/src/xen/extras/mini-os/blkfront.c:122: undefined reference to `__aeabi_uldivmod'
>>> /home/cbz/src/xen/extras/mini-os/mini-os.o:/home/cbz/src/xen/extras/mini-os/blkfront.c:122: more undefined references to `__aeabi_uldivmod' follow
>>> /home/cbz/src/xen/extras/mini-os/mini-os.o:(.ARM.exidx+0x0): undefined reference to `__aeabi_unwind_cpp_pr0'
>>> /home/cbz/src/xen/extras/mini-os/mini-os.o:(.ARM.exidx+0x50): undefined reference to `__aeabi_unwind_cpp_pr0'
>>> make: *** [/home/cbz/src/xen/extras/mini-os/mini-os] Error 1
>>>
>>> I googled that error message. Some has mentioned that add "-fno-exceptions
>>>  -fno-unwind tables" could sovle the problem. I tried, but got the same
>>> errors.
>>>
>>> Any ideas?
>>
>> You need to provide an implementation for __aeabi_uldivmod.
>> For this purpose, you can re-use xen/arch/arm/arm32/lib/lib1func.S
> 
> Thanks a lot.
> 
> A further question. I'm a litte curious that whether __aeabi_uldivmod is missing 
> because of a toolchain bug or some other reasons? 

__aeabi_uldivmod and co. are provided by libgcc.{so,a}. Mini-OS is not
linked against this library.

-- 
Julien