GCC changes for Fedora + riscv64

[Jeff Law]

On 04/10/2018 12:27 AM, Richard W.M. Jones wrote:
> On Mon, Apr 09, 2018 at 04:37:30PM -0600, Jeff Law wrote:
>> Are you guys using qemu user mode emulation for testing purposes?  When
>> I've set up a suitable riscv64 rootfs and try to do anything nontrivial
>> in it with qemu user mode emulation it immediately complains that my
>> kernel is too old -- which is quite odd as I've got a dozen or so of
>> these kinds of environments set up for testing which don't issue that
>> complaint.
>>
>> I'd like to avoid full system emulation just from a cost standpoint..
> 
> We're using full system emulation with upstream qemu.  It's
> surprisingly simple to set up, it supports multiple virtual CPUs up to
> ‘-smp 8’, and provided you have a fast enough host hardware isn't too
> bad for development.  Of course compiling GCC with bootstrapping is
> still going to take a long time.  For instructions see the readme
> here:
It's actually a continuous testing system rather than development :-)  A
typical target using user mode emulation takes 6-10 hours to to run
through its paces on one of our 56 processor build machines.  I'd hazard
a guess if we do full system emulation then we're likely looking at
doubling that or worse, which I'd like to avoid given the number of
targets I'm trying to get tested in a 24hr cycle.


> 
>   https://fedorapeople.org/groups/risc-v/disk-images/
Yea.  I actually looked at those briefly to confirm that kernel too old
issue triggered there too.  For my tester I actually use mini roots that
I cross build for the various targets.  The advantage is the contents of
the mini roots is consistent across the targets.


Thanks,

Jeff