On 07/22/2016 03:46 PM, Michael Walle wrote:
Am 2016-07-22 15:07, schrieb Alexander Graf:
On 22 Jul 2016, at 15:00, Michael Walle <mich...@walle.cc> wrote:
64 bit user mode doesn't work for the e5500 core because the MSR_CM
bit is
not set which enables the 64 bit mode for this MMU model. Memory
addresses
are truncated to 32 bit, which results in "Invalid data memory access"
error messages. Fix it by setting the MSR_CM bit for this MMU model.
Signed-off-by: Michael Walle <mich...@walle.cc>
---
target-ppc/translate_init.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
index 5ecafc7..1ebb143 100644
--- a/target-ppc/translate_init.c
+++ b/target-ppc/translate_init.c
@@ -10218,6 +10218,9 @@ static void ppc_cpu_reset(CPUState *s)
if (env->mmu_model & POWERPC_MMU_64) {
msr |= (1ULL << MSR_SF);
}
+ if (env->mmu_model == POWERPC_MMU_BOOKE206) {
Is this check correct? Doesn’t e500mc adhere to 2.06 as well? Running
qemu-system-ppc64 -M ppce500 -cpu e500mc …
is perfectly valid and should just work. With your patch, it would
start in invalid 64bit mode :).
Alex
Mhh, sorry I don't really have any understanding of the PPC state
after reset. Should have flagged this as RFC.
Maybe I should explain my issue. I'm debugging a problem with the 64
bit linux-user variant (qemu-ppc64). There the first instructions
causes an "Invalid data memory access" because the address is
truncated to 32 bit. This is because the msr_is_64bit() returns false
in my case. So first question here, is qemu-ppc64 supposed to set the
MSR to 64bit mode? I guess so, because 32bit mode would be the
qemu-ppc binary. What is the MSR state in full system emulation for a
e5500 core? 64bit or 32bit?
It depends on the target. Usually the reset vector is used for system
emulation. But apparently you're targeting user mode emulation, so the
reset MSR really goes to linux-user/main.c. We already set MSR_SF there
for 64bit binaries, I guess you'd have to check on the cpu flavor and
just set either SF or CM depending on cpu flags (PPC2_BOOKE206 maybe?)
in there.
Alex
If it is 32bit, the simple solution would be to put #ifdef
CONFIG_USER_ONLY around my patch, right?
If the MMU is in 64bit mode after reset, I would have to check for the
e5500, too. Mhh, I don't see that this information is available in
ppc_cpu_reset().
-michael
