Hi Bin,
On 29.11.2017 13:31, Bin Meng wrote:
Hi Stefan,
On Wed, Nov 29, 2017 at 6:01 PM, Stefan Roese <s...@denx.de> wrote:
Hi Bin,
On 29.11.2017 10:23, Bin Meng wrote:
On Wed, Nov 29, 2017 at 4:42 PM, Stefan Roese <s...@denx.de> wrote:
Hi Bin,
On 29.11.2017 09:30, Bin Meng wrote:
<snip>
I wrote some codes soemthing like:
s64 a, b, c;
c = a/b;
The compiler will generate codes to call __divdi3. This works before
your
patch.
Yes, I understand this. But right now, we don't have any code
generating this error. And if this will happen at some time, I would
prefer to investigate this code sequence introducing this division, to
use the division functions / macros available in U-Boot (as mentioned
above) and in the kernel instead.
Here a short explanation, why this new version is preferred to the
currently available functions pulled from libgcc: We are fixing an
"ugly" Yocto build problem with this patch, related to 32bit binaries
with 64bit toolchains (multilib) building by not relying on anything
from libgcc. Please see this thread for some more details:
https://www.mail-archive.com/yocto@yoctoproject.org/msg36721.html
I hope this helps a bit to understand the motivation behind this patch.
Thanks for the background. I am not familiar with yocto project, but
is the build broken due to the gcc on the build host does not ship
with multilib?
Please take a look at the email thread mentioned above for a detailed
explanation. Especially this post should answer your questions:
https://www.mail-archive.com/yocto@yoctoproject.org/msg36748.html
Now I see. Thank you.
I am using a 64-bit host with gcc multilib, and there is no such build
error observed.
Right. This issue is only seen on Yocto builds (AFAIK). But again,
I would really like to see U-Boot x86 being self-contained without
any host libgcc dependencies as on other architectures as well.
So to completely resolve such issue to make U-Boot self-contained, we
should remove the reference to the host libgcc.a in
arch/x86/lib/Makefile, and use CONFIG_USE_PRIVATE_GCC to include the
build for div64.o. Thoughts?
I was under the impression, that I already removed the host libgcc
reference completely for x86 with my patch. But you are correct - there
still is a reference in this Makefile which is used by the standalone
code, AFAICT.
Any quick idea on how to rid of this one as well?
I believe we need change
obj-y += div64.o
to
lib-$(CONFIG_USE_PRIVATE_LIBGCC) += div64.o
To remove the libgcc dependency completely.
Yep. Thanks.
I've posted v3 with this additional removal.
Thanks,
Stefan
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