[ipxe-devel] Unable to boot Linux kernel for arm64 architecture

[Michael Brown]

On 20/03/17 20:57, Mark Rutland wrote:
> On Mon, Mar 20, 2017 at 08:27:13PM +0200, Michael Brown wrote:
>> You can add "EXTRA_CFLAGS=-mstrict-align" to your build command
>> line. That will build a (much bigger and slower) iPXE binary in
>> which all potentially unaligned accesses will be handled using byte
>> loads/stores and shifts as needed; this should work around the buggy
>> platform firmware.
>
> Sorry to be the bearer of bad news, but the above might not be
> sufficient. :(
>
> When the MMU is off, LDXR/STXR sequences are not guaranteed to function
> as they do with the MMU+caches on, and are permitted to behave in a
> number of surprising ways. AFAICT that would affect the ipxe bitops.

Thanks for the heads-up.  Fortunately the only current user of 
test_and_{set,clear}_bit() is xenevent_pending(), so any non-Xen uses 
should survive.  Are there any other instructions that might be affected?

Thanks,

Michael