motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-08-03 15:53:54 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

armv7m: Fix reads of CONTROL register bit 1

Browse source 
The v7m CONTROL register bit 1 is SPSEL, which indicates
the stack being used. We were storing this information
not in v7m.control but in the separate v7m.other_sp
structure field. Unfortunately, the code handling reads
of the CONTROL register didn't take account of this, and
so if SPSEL was updated by an exception entry or exit then
a subsequent guest read of CONTROL would get the wrong value.

Using a separate structure field doesn't really gain us
anything in efficiency, so drop this unnecessary complexity
in favour of simply storing all the bits in v7m.control.

This is a migration compatibility break for M profile
CPUs only.

Signed-off-by: Michael Davidsaver <mdavidsaver@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 1484937883-1068-6-git-send-email-peter.maydell@linaro.org
[PMM: rewrote commit message;
 use deposit32(); use FIELD to define constants for
 masking and shifting of CONTROL register fields
]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Michael Davidsaver 2017-01-27 15:20:21 +00:00 • committed by Peter Maydell
parent afb3141c66
commit abc24d86cc
4 changed files with 32 additions and 17 deletions
Download patch file Download diff file Expand all files Collapse all files

7
target/arm/internals.h
View file

@ -25,6 +25,8 @@
#ifndef TARGET_ARM_INTERNALS_H
#define TARGET_ARM_INTERNALS_H
#include "hw/registerfields.h"
/* register banks for CPU modes */
#define BANK_USRSYS 0
#define BANK_SVC 1
@ -75,6 +77,11 @@ static const char * const excnames[] = {
*/
#define GTIMER_SCALE 16
/* Bit definitions for the v7M CONTROL register */
FIELD(V7M_CONTROL, NPRIV, 0, 1)
FIELD(V7M_CONTROL, SPSEL, 1, 1)
FIELD(V7M_CONTROL, FPCA, 2, 1)
/*
* For AArch64, map a given EL to an index in the banked_spsr array.
* Note that this mapping and the AArch32 mapping defined in bank_number()