On 15/03/2016 19:44, Alexander Graf wrote: > > > On 15.03.16 19:43, Thomas Huth wrote: >> On 15.03.2016 14:15, Laurent Vivier wrote: >>> When they are started, processors are in 32-bit mode, >>> as we are testing ppc64 processors, enable the 64bit mode >>> on starting. >>> >>> Signed-off-by: Laurent Vivier <lvivier@xxxxxxxxxx> >>> --- >>> powerpc/cstart64.S | 9 +++++++++ >>> 1 file changed, 9 insertions(+) >>> >>> diff --git a/powerpc/cstart64.S b/powerpc/cstart64.S >>> index c87e3d6..634b854 100644 >>> --- a/powerpc/cstart64.S >>> +++ b/powerpc/cstart64.S >>> @@ -18,6 +18,15 @@ >>> .globl start >>> start: >>> FIXUP_ENDIAN >>> + >>> + /* enable 64-bit mode */ >>> + mfmsr r11 >>> + li r12,-1 >>> + rldicr r12,r12,0,0 >> >> Nice idea to set the highest bit, I didn't know that one yet :-) >> >>> + or r11,r11,r12 >>> + mtmsrd r11 >>> + isync >> >> Looks good! >> >> Reviewed-by: Thomas Huth <thuth@xxxxxxxxxx> >> >> >> PS: As far as I can see, the C code has already been compiled for 64 >> bits ... how did that work if it has been run in 32-bit mode so far?? > > And why would we enter a 64bit CPU without MSR_SF set? I don't know, but: When I start "qemu-system-ppc64 -machine pseries -s -S" and check the MSR with gdb, the MSR is always set to 0 (or "info registers" in monitor). It's why I've added this initialization. So, perhaps there is a bug in QEMU? [Perhaps "env->msr |= (1ULL << MSR_SF)" is overwritten by the following hreg_store_msr(env, msr, 1);"?] Laurent -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
