Now that MTTCG is here, the comment in the 32-bit Arm decoder that
"Since the emulation does not have barriers, the acquire/release
semantics need no special handling" is no longer true. Emit the
correct barriers for the load-acquire/store-release insns, as
we already do in the A64 decoder.
Backports commit 96c552958dbb63453b5f02bea6e704006d50e39a from qemu
Use "register" TBFLAG_ANY to indicate shared state between
A32 and A64, and "registers" TBFLAG_A32 & TBFLAG_A64 for
fields that are specific to the given cpu state.
Move ARM_TBFLAG_BE_DATA to shared state, instead of its current
placement within "Bit usage when in AArch32 state".
Backports commit aad821ac4faad369fad8941d25e59edf2514246b from qemu
Instead of shifts and masks, use direct loads and stores from
the neon register file.
Backports commit 2d6ac920837f558be214ad2ddd28cad7f3b15e5c from qemu
For a sequence of loads or stores from a single register,
little-endian operations can be promoted to an 8-byte op.
This can reduce the number of operations by a factor of 8.
Backports commit e23f12b3a252352b575908ca7b94587acd004641 from qemu
Instead of shifts and masks, use direct loads and stores from the neon
register file. Mirror the iteration structure of the ARM pseudocode
more closely. Correct the parameters of the VLD2 A2 insn.
Note that this includes a bugfix for handling of the insn
"VLD2 (multiple 2-element structures)" -- we were using an
incorrect stride value.
Backports commit ac55d00709e78cd39dfa298dcaac7aecb58762e8 from qemu
Also introduces neon_element_offset to find the env offset
of a specific element within a neon register.
Backports commit 32f91fb71f4c32113ec8c2af5f74f14abe6c7162 from qemu
For traps of FP/SIMD instructions to AArch32 Hyp mode, the syndrome
provided in HSR has more information than is reported to AArch64.
Specifically, there are extra fields TA and coproc which indicate
whether the trapped instruction was FP or SIMD. Add this extra
information to the syndromes we construct, and mask it out when
taking the exception to AArch64.
Backports commit 4be42f4013fa1a9df47b48aae5148767bed8e80c from qemu
For AArch32, exception return happens through certain kinds
of CPSR write. We don't currently have any CPU_LOG_INT logging
of these events (unlike AArch64, where we log in the ERET
instruction). Add some suitable logging.
This will log exception returns like this:
Exception return from AArch32 hyp to usr PC 0x80100374
paralleling the existing logging in the exception_return
helper for AArch64 exception returns:
Exception return from AArch64 EL2 to AArch64 EL0 PC 0x8003045c
Exception return from AArch64 EL2 to AArch32 EL0 PC 0x8003045c
(Note that an AArch32 exception return can only be
AArch32->AArch32, never to AArch64.)
Backports commit 81e3728407bf4a12f83e14fd410d5f0a7d29b5b4 from qemu
Having V6 alone imply jazelle was wrong for cortex-m0.
Change to an assertion for V6 & !M.
This was harmless, because the only place we tested ARM_FEATURE_JAZELLE
was for 'bxj' in disas_arm(), which is unreachable for M-profile cores.
Backports commit 09cbd50198d5dcac8bea2e47fa5dd641ec505fae from qemu
Both arm and thumb2 division are controlled by the same ISAR field,
which takes care of the arm implies thumb case. Having M imply
thumb2 division was wrong for cortex-m0, which is v6m and does not
have thumb2 at all, much less thumb2 division.
Backports commit 7e0cf8b47f0e67cebbc3dfa73f304e56ad1a090f from qemu
Most of the v8 extensions are self-contained within the ISAR
registers and are not implied by other feature bits, which
makes them the easiest to convert.
Backports commit 962fcbf2efe57231a9f5df0ae0f40c05e35628ba from qemu
Add the v8M stack checks for the VLDM/VSTM
(aka VPUSH/VPOP) instructions. This code is currently
unreachable because we haven't yet implemented M profile
floating point support, but since the change is simple,
we add it now because otherwise we're likely to forget to
do it later.
Backports commit 8a954faf5412d5073d585d85a1da63a09bb5d84e from qemu
Add v8M stack checks for the 16-bit Thumb push/pop
encodings: STMDB, STMFD, LDM, LDMIA, LDMFD.
Backports commit aa369e5c08bbe2748d2be96f13f4ef469a4d3080 from qemu
Add v8M stack checks for the instructions in the T32
"load/store single" encoding class: these are the
"immediate pre-indexed" and "immediate, post-indexed"
LDR and STR instructions.
Backports commit 0bc003bad9752afc61624cb680226c922f34f82c from qemu
Add the v8M stack checks for:
* LDM (T2 encoding)
* STM (T2 encoding)
This includes the 32-bit encodings of the instructions listed
in v8M ARM ARM rule R_YVWT as
* LDM, LDMIA, LDMFD
* LDMDB, LDMEA
* POP (multiple registers)
* PUSH (muliple registers)
* STM, STMIA, STMEA
* STMDB, STMFD
We perform the stack limit before doing any other part
of the load or store.
Backports commit 7c0ed88e7d6bee3e55c3d8935c46226cb544191a from qemu
Add the v8M stack checks for:
* LDRD (immediate)
* STRD (immediate)
Loads and stores are more complicated than ADD/SUB/MOV, because we
must ensure that memory accesses below the stack limit are not
performed, so we can't simply do the check when we actually update
SP.
For these instructions, if the stack limit check triggers
we must not:
* perform any memory access below the SP limit
* update PC, SP or the load/store base register
but it is IMPDEF whether we:
* perform any accesses above or equal to the SP limit
* update destination registers for loads
For QEMU we choose to always check the limit before doing any other
part of the load or store, so we won't update any registers or
perform any memory accesses.
It is UNKNOWN whether the limit check triggers for a load or store
where the initial SP value is below the limit and one of the stores
would be below the limit, but the writeback moves SP to above the
limit. For QEMU we choose to trigger the check in this situation.
Note that limit checks happen only for loads and stores which update
SP via writeback; they do not happen for loads and stores which
simply use SP as a base register.
Backports commit 910d7692e5b60f2c2d08cc3d6d36076e85b6a69d from qemu
Add some comments to the Thumb decoder indicating what bits
of the instruction have been decoded at various points in
the code.
This is not an exhaustive set of comments; we're gradually
adding comments as we work with particular bits of the code.
Backports commit a2d12f0f34e9c5ef8a193556fde983aa186fa73a from qemu
Add code to insert calls to a helper function to do the stack
limit checking when we handle these forms of instruction
that write to SP:
* ADD (SP plus immediate)
* ADD (SP plus register)
* SUB (SP minus immediate)
* SUB (SP minus register)
* MOV (register)
Backports commit 5520318939fea5d659bf808157cd726cb967b761 from qemu
The Arm v8M architecture includes hardware stack limit checking.
When certain instructions update the stack pointer, if the new
value of SP is below the limit set in the associated limit register
then an exception is taken. Add a TB flag that tracks whether
the limit-checking code needs to be emitted.
Backports commit 4730fb85035e99c909db7d14ef76cd17f28f4423 from qemu
ARMv7VE introduced the ERET instruction, which is necessary to
return from an exception taken to Hyp mode. Implement this.
In A32 encoding it is a completely new encoding; in T32 it
is an adjustment of the behaviour of the existing
"SUBS PC, LR, #<imm8>" instruction.
Backports commit 55c544ed2709bd202e71e77ddfe3ea0327852211 from qemu
The MSR (banked) and MRS (banked) instructions allow accesses to ELR_Hyp
from either Monitor or Hyp mode. Our translate time check
was overly strict and only permitted access from Monitor mode.
The runtime check we do in msr_mrs_banked_exc_checks() had the
correct code in it, but never got there because of the earlier
"currmode == tgtmode" check. Special case ELR_Hyp.
Backports commit aec4dd09f172ee64c19222b78269d5952fd9c1dc from qemu
If an instruction is conditional (like CBZ) and it is executed
conditionally (using the ITx instruction), a jump to an undefined
label is generated, and QEMU crashes.
CBZ in IT block is an UNPREDICTABLE behavior, but we should not
crash. Honouring the condition code is allowed by the spec in this
case (constrained unpredictable, ARMv8, section K1.1.7), and matches
what we do for other "UNPREDICTABLE inside an IT block" instructions.
Fix the 'skip on condition' code to create a new label only if it
does not already exist. Previously multiple labels were created, but
only the last one of them was set.
Backports commit c2d9644e6d517170bf6520f633628259a8460d48 from qemu
We've already added the helpers with an SVE patch, all that remains
is to wire up the aa64 and aa32 translators. Enable the feature
within -cpu max for CONFIG_USER_ONLY.
Backports commit 26c470a7bb4233454137de1062341ad48947f252 from qemu
For aa64 advsimd, we had been passing the pre-indexed vector.
However, sve applies the index to each 128-bit segment, so we
need to pass in the index separately.
For aa32 advsimd, the fp32 operation always has index 0, but
we failed to interpret the fp16 index correctly.
Backports commit 2cc99919a81a62589a4a6b0f365eabfead1db1a7 from qemu
Unlike ARMv7-M, ARMv6-M and ARMv8-M Baseline only supports naturally
aligned memory accesses for load/store instructions.
Backports commit 2aeba0d007d33efa12a6339bb140aa634e0d52eb from qemu
The arrays were made static, "if" was simplified because V7M and V8M
define V6 feature.
Backports commit 8297cb13e407db8a96cc7ed6b6a6c318a150759a from qemu
ARMv6-M supports 6 Thumb2 instructions. This patch checks for these
instructions and allows their execution.
Like Thumb2 cores, ARMv6-M always interprets BL instruction as 32-bit.
This patch is required for future Cortex-M0 support.
Backports commit 14120108f87b3f9e1beacdf0a6096e464e62bb65 from qemu
Do the cast to uintptr_t within the helper, so that the compiler
can type check the pointer argument. We can also do some more
sanity checking of the index argument.
Backports commit 07ea28b41830f946de3841b0ac61a3413679feb9 from qemu
