Run armv7 32 bit userspace on aarch64
arnd at arndb.de
Sat Oct 10 14:25:25 PDT 2015
On Friday 09 October 2015 17:28:08 Shi, Yang wrote:
> On 10/9/2015 3:32 PM, Shi, Yang wrote:
> > On 10/8/2015 4:12 AM, Will Deacon wrote:
> >> On Wed, Oct 07, 2015 at 03:46:57PM -0700, Shi, Yang wrote:
> >>> I'm trying to run armv7 little endian userspace on qemu aarch64 with
> >>> 4.1.x
> >>> kernel. I was told by someone such usecase is valid and I have
> >>> CONFIG_COMPAT
> >>> enabled in my kernel.
> >>> But, I ran into the below error. It looks the userspace application is
> >>> trying to write a readonly page. I got the similar failure on arm vfp
> >>> with
> >>> Linaro images (4.1 kernel) too.
> >>> Did anyone have tried it recently?
> >> -rc4 seems to be working fine with Debian Jessie armhf on my Juno boards.
> >> Do you have a good way of reproducing this with a mainline kernel?
> > It seems a qemu's bug. I can get both ubuntu and openembedded userspace
> > bootup on my LS2085 board with 4.1 kernel.
> Some new findings pointed me to another direction.
> I just tried to build OE userspace with gcc 5.2 (default toolchain in OE
> now), it fails to boot up with the same error.
> Then I tried the below test on 4.1 kernel:
> Linaro OE userspace image (4.9 toolchain) Failed
> My OE build with 4.9.3 toolchain Success
> My OE build with 5.2 toolchain Failed
> Ubuntu image Success
Does your kernel have 64KB pages enabled? If it does, most 32-bit user space
won't run, except when building it with relatively new toolchains.
Try running with the default 4KB page size if that is the problem.
More information about the linux-arm-kernel