unicorn/qemu/target/arm
Peter Maydell ddfe550411
arm: Thumb shift operations should not permit interworking branches
In Thumb mode, the only instructions which can cause an interworking
branch by writing the PC are BLX, BX, BXJ, LDR, POP and LDM. Unlike
ARM mode, data processing instructions which target the PC do not
cause interworking branches.

When we added support for doing interworking branches on writes to
PC from data processing instructions in commit 21aeb3430ce7ba, we
accidentally changed a Thumb instruction to have interworking
branch behaviour for writes to PC. (MOV, MOVS register-shifted
register, encoding T2; this is the standard encoding for
LSL/LSR/ASR/ROR (register).)

For this encoding, behaviour with Rd == R15 is specified as
UNPREDICTABLE, so allowing an interworking branch is within
spec, but it's confusing and differs from our handling of this
class of UNPREDICTABLE for other Thumb ALU operations. Make
it perform a simple (non-interworking) branch like the others.

Backports commit bedb8a6b09c1754c3b9f155750c62dc087706698 from qemu
2018-03-02 14:42:40 -05:00
..
arm-powerctl.c ARM: Factor out ARM on/off PSCI control functions 2018-03-01 23:31:47 -05:00
arm-powerctl.h ARM: Factor out ARM on/off PSCI control functions 2018-03-01 23:31:47 -05:00
arm_ldst.h Fix Thumb-1 BE32 execution and disassembly. 2018-03-02 00:20:11 -05:00
cpu-qom.h Move target-* CPU file into a target/ folder 2018-03-01 22:50:58 -05:00
cpu.c armv7m: R14 should reset to 0xffffffff 2018-03-02 13:56:36 -05:00
cpu.h arm: Move excnames[] array into arm_log_exceptions() 2018-03-02 14:39:37 -05:00
cpu64.c target-arm: Enable EL2 feature bit on A53 and A57 2018-03-01 23:36:44 -05:00
crypto_helper.c Move target-* CPU file into a target/ folder 2018-03-01 22:50:58 -05:00
helper-a64.c Move target-* CPU file into a target/ folder 2018-03-01 22:50:58 -05:00
helper-a64.h Move target-* CPU file into a target/ folder 2018-03-01 22:50:58 -05:00
helper.c arm: Move excnames[] array into arm_log_exceptions() 2018-03-02 14:39:37 -05:00
helper.h Move target-* CPU file into a target/ folder 2018-03-01 22:50:58 -05:00
internals.h arm: Move excnames[] array into arm_log_exceptions() 2018-03-02 14:39:37 -05:00
iwmmxt_helper.c Move target-* CPU file into a target/ folder 2018-03-01 22:50:58 -05:00
kvm-consts.h arm: better stub version for MISMATCH_CHECK 2018-03-02 00:13:45 -05:00
Makefile.objs ARM: Factor out ARM on/off PSCI control functions 2018-03-01 23:31:47 -05:00
neon_helper.c Move target-* CPU file into a target/ folder 2018-03-01 22:50:58 -05:00
op_addsub.h Move target-* CPU file into a target/ folder 2018-03-01 22:50:58 -05:00
op_helper.c target/arm: Add assertion about FSC format for syndrome registers 2018-03-02 14:41:07 -05:00
psci.c target/arm/psci.c: If EL2 implemented, start CPUs in EL2 2018-03-01 23:34:57 -05:00
translate-a64.c target/arm: Fix aa64 ldp register writeback 2018-03-02 14:35:46 -05:00
translate.c arm: Thumb shift operations should not permit interworking branches 2018-03-02 14:42:40 -05:00
translate.h target/arm: A32, T32: Create Instruction Syndromes for Data Aborts 2018-03-02 00:37:06 -05:00
unicorn.h Move target-* CPU file into a target/ folder 2018-03-01 22:50:58 -05:00
unicorn_aarch64.c Move target-* CPU file into a target/ folder 2018-03-01 22:50:58 -05:00
unicorn_arm.c Move target-* CPU file into a target/ folder 2018-03-01 22:50:58 -05:00