Move the code to generate the "condition failed" instruction
codepath out of the if (singlestepping) {} else {}. This
will allow adding support for handling a new is_jmp type
which can't be neatly split into "singlestepping case"
versus "not singlestepping case".
Backports commit f021b2c4627890d82fbcc300db3bd782b37b7f8a from qemu
arm: Abstract out "are we singlestepping" test to utility function
We now test for "are we singlestepping" in several places and
it's not a trivial check because we need to care about both
architectural singlestep and QEMU gdbstub singlestep. We're
also about to add another place that needs to make this check,
so pull the condition out into a function.
Backports commit b636649f5a2e108413dd171edaf320f781f57942 from qemu
Move the utility routines gen_set_condexec() and gen_set_pc_im()
up in the file, as we will want to use them from a function
placed earlier in the file than their current location.
Backports commit 4d5e8c969a74c86124fc2284ea603cc6dd3c5dfa from qemu
We currently have two places that do:
if (dc->ss_active) {
gen_step_complete_exception(dc);
} else {
gen_exception_internal(EXCP_DEBUG);
}
Factor this out into its own function, as we're about to add
a third place that needs the same logic.
Backports commit 5425415ebba5fa20558e1ef25e1997a6f5ea4c7c from qemu
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
For M-profile CPUs, the BXJ instruction does not exist at all, and
the encoding should always UNDEF. We were accidentally implementing
it to behave like A-profile BXJ; correct the error.
Backports commit 9d7c59c84d4530d05e8702b1c3a31e6da00a397e from qemu
Our implementation of writes to the APSR for M-profile via the MSR
instruction was badly broken.
First and worst, we had the sense wrong on the test of bit 2 of the
SYSm field -- this is supposed to request an APSR write if bit 2 is 0
but we were doing it if bit 2 was 1. This bug was introduced in
commit 58117c9bb429cd, so hasn't been in a QEMU release.
Secondly, the choice of exactly which parts of APSR should be written
is defined by bits in the 'mask' field. We were not passing these
through from instruction decode, making it impossible to check them
in the helper.
Pass the mask bits through from the instruction decode to the helper
function and process them appropriately; fix the wrong sense of the
SYSm bit 2 check.
Invalid mask values and invalid combinations of mask and register
number are UNPREDICTABLE; we choose to treat them as if the mask
values were valid.
Backports commit b28b3377d7e9ba35611d454d5a63ef50cab1f8c5 from qemu
For v7M attempts to access a nonexistent coprocessor are reported
differently from plain undefined instructions (as UsageFaults of type
NOCP rather than type UNDEFINSTR). Split them out into a new
EXCP_NOCP so we can report the FSR value correctly.
Backports commit 7517748e3f71a3099e57915fba95c4c308e6d842 from qemu
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.
Backports commit 542b3478a00cb7ef51c259255b3ab1e2a7daada2 from qemu
The MRS instruction requires that bits [19..16] are all 1s, and for
A/R profile also that bits [7..0] are all 0s. At this point in the
decode tree we have checked all of the rest of the instruction but
were allowing these to be any value. If these bits are not set then
the result is architecturally UNPREDICTABLE, but choosing to UNDEF is
more helpful to the user and avoids unexpected odd behaviour if the
encodings are used for some purpose in future architecture versions.
Backports commit 3d54026fb06d1aea7ebb4e9825970b06bebcacac from qemu
M profile doesn't have the MSR(banked) and MRS(banked) instructions
and uses the encodings for different kinds of M-profile MRS/MSR.
Guard the relevant bits of the decode logic to make sure we don't
accidentally fall into them by accident on M-profile.
(The bit being checked for this (bit 5) is part of the SYSm field on
M-profile, but since no currently allocated system registers have
encodings with bit 5 of SYSm set, this hasn't been a problem in
practice.)
Backports commit 43ac65742319ef5ac4461daf43316b189cd21e89 from qemu
M profile doesn't have the HVC or SMC encodings, so make them always
UNDEF rather than generating calls to helper functions that assume
A/R profile.
Backports commit 001b3cab51ebfcb13e8dd03ea25bfa3bd0c517a3 from qemu
The WFE and YIELD instructions are really only hints and in TCG's case
they were useful to move the scheduling on from one vCPU to the next. In
the parallel context (MTTCG) this just causes an unnecessary cpu_exit
and contention of the BQL.
Backports commit c22edfebff29f63d793032e4fbd42a035bb73e27 from qemu
Add support for generating the ISS (Instruction Specific Syndrome)
for Data Abort exceptions taken from AArch32. These syndromes are
used by hypervisors for example to trap and emulate memory accesses.
This is the equivalent for AArch32 guests of the work done for AArch64
guests in commit aaa1f954d4cab243.
Backports commit 9bb6558a218bf7e466e5ac1100639517d8a30d33 from qemu
In the ARM ldr/str decode path, rather than directly testing
"insn & (1 << 21)" and "insn & (1 << 24)", abstract these
bits out into wbit and pbit local flags. (We will want to
do more tests against them to determine whether we need to
provide syndrome information.)
Backports commit 63f26fcfda8e19f94ce23336726d14805250a5b6 from qemu
We've currently got 18 architectures in QEMU, and thus 18 target-xxx
folders in the root folder of the QEMU source tree. More architectures
(e.g. RISC-V, AVR) are likely to be included soon, too, so the main
folder of the QEMU sources slowly gets quite overcrowded with the
target-xxx folders.
To disburden the main folder a little bit, let's move the target-xxx
folders into a dedicated target/ folder, so that target-xxx/ simply
becomes target/xxx/ instead.
Backports commit fcf5ef2ab52c621a4617ebbef36bf43b4003f4c0 from qemu
