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/openbmc/qemu/hw/arm/
H A Darmv7m.cdiff 542b3478a00cb7ef51c259255b3ab1e2a7daada2 Fri Jan 27 09:20:21 CST 2017 Michael Davidsaver <mdavidsaver@gmail.com> armv7m: Replace armv7m.hack with unassigned_access handler

For v7m we need to catch attempts to execute from special
addresses at 0xfffffff0 and above. Previously we did this
with the aid of a hacky special purpose lump of memory
in the address space and a check in translate.c for whether
we were translating code at those addresses.

We can implement this more cleanly using a CPU
unassigned access handler which throws the exception
if the unassigned access is for one of the special addresses.

Signed-off-by: Michael Davidsaver <mdavidsaver@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 1484937883-1068-3-git-send-email-peter.maydell@linaro.org
[PMM:
* drop the deletion of the "don't interrupt if PC is magic"
code in arm_v7m_cpu_exec_interrupt() -- this is still
required
* don't generate an exception for unassigned accesses
which aren't to the magic address -- although doing
this is in theory correct in practice it will break
currently working guests which rely on the RAZ/WI
behaviour when they touch devices which we haven't
modelled.
* trigger EXCP_EXCEPTION_EXIT on is_exec, not !is_write
]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
/openbmc/qemu/target/arm/
H A Dcpu.cdiff 542b3478a00cb7ef51c259255b3ab1e2a7daada2 Fri Jan 27 09:20:21 CST 2017 Michael Davidsaver <mdavidsaver@gmail.com> armv7m: Replace armv7m.hack with unassigned_access handler

For v7m we need to catch attempts to execute from special
addresses at 0xfffffff0 and above. Previously we did this
with the aid of a hacky special purpose lump of memory
in the address space and a check in translate.c for whether
we were translating code at those addresses.

We can implement this more cleanly using a CPU
unassigned access handler which throws the exception
if the unassigned access is for one of the special addresses.

Signed-off-by: Michael Davidsaver <mdavidsaver@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 1484937883-1068-3-git-send-email-peter.maydell@linaro.org
[PMM:
* drop the deletion of the "don't interrupt if PC is magic"
code in arm_v7m_cpu_exec_interrupt() -- this is still
required
* don't generate an exception for unassigned accesses
which aren't to the magic address -- although doing
this is in theory correct in practice it will break
currently working guests which rely on the RAZ/WI
behaviour when they touch devices which we haven't
modelled.
* trigger EXCP_EXCEPTION_EXIT on is_exec, not !is_write
]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>