System emulation only has a little-endian target; BE32 mode
is implemented by adjusting the low bits of the address
for every byte and halfword load and store. 64-bit accesses
flip the low and high words.
Backports commit e334bd3190f6c4ca12f1d40d316dc471c70009ab from qemu
Since this is not a high-performance path, just use a helper to
flip the E bit and force a lookup in the hash table since the
flags have changed.
Backports commit 9886ecdf31165de2d4b8bccc1a220bd6ac8bc192 from qemu
Introduce a tbflags for endianness, set based upon the CPUs current
endianness. This in turn propagates through to the disas endianness
flag.
Backports commit 91cca2cda9823b1e7a049cb308a05104b5076cba from qemu
Introduce a disas flag for setting the CPU data endianness. This allows
control of the endianness from the CPU state rather than hard-coding it
to TARGET_WORDS_BIGENDIAN.
Backports commit dacf0a2ff7d39ab12bd90f2f5496a3889facd54a from qemu
Implement SCTLR.EE bit which controls data endianess for exceptions
and page table translations. SCTLR.EE is mirrored to the CPSR.E bit
on exception entry.
Backports commit 73462dddf670c32c45c8ea359658092b0365b2d4 from qemu
endian with address manipulations on subword accesses (to give the
illusion of BE). But user-mode cannot tell the difference and is
already implemented as straight BE. So handle the difference in the
endianess query, where USER mode is BE and system is not.
Backports commit b2e62d9a7b9a2eb10e451a57813bad168376e122 from qemu
There is a CPU data endianness test that is used to drive the
virtio_big_endian test.
Move this up to the header so it can be more generally used for endian
tests. The KVM specific cpu_syncronize_state call is left behind in the
virtio specific function.
Rename it arm_cpu-data_is_big_endian() to more accurately capture that
this is for data accesses only.
Backports commit ed50ff7875d61a75517c92deb0444d73fbbca878 from qemu
bswap_code is a CPU property of sorts ("is the iside endianness the
opposite way round to TARGET_WORDS_BIGENDIAN?") but it is not the
actual CPU state involved here which is SCTLR.B (set for BE32
binaries, clear for BE8).
Replace bswap_code with SCTLR.B, and pass that to arm_ld*_code.
The next patches will make data fetches honor both SCTLR.B and
CPSR.E appropriately.
Backports commit f9fd40ebe4f55e0048e002925b8d65e66d56e7a7 from qemu
In helper.c the expression
(env->uncached_cpsr & CPSR_M) != CPSR_USER
is always true; the right hand side was supposed to be ARM_CPU_MODE_USR
(an error in commit cb01d391).
Since the incorrect expression was always true, this just meant that
commit cb01d391 had no effect.
However simply changing the RHS here would reveal a logic error: if
the mode is USR we wish to completely ignore the attempt to set the
mode bits, which means that we must clear the CPSR_M bits from mask
to avoid the uncached_cpsr bits being updated at the end of the
function.
Move the condition into the correct place in the code, fix its RHS
constant, and add a comment about the fact that we must be doing a
gdbstub write if we're in user mode.
Backports commit 8c4f0eb94cc65ee32a12feba88d0b32e3665d5ea from qemu
The v8 ARM ARM defines that unused spaces in the ID_AA64* system
register ranges are Reserved and must RAZ, rather than being UNDEF.
Implement this.
In particular, ARM v8.2 adds a new feature register ID_AA64MMFR2,
and newer versions of the Linux kernel will attempt to read this,
which causes them not to boot up on versions of QEMU missing this fix.
Since the encoding .opc0 = 3, .opc1 = 0, .crn = 0, .crm = 2, .opc2 = 6
is actually defined in ARMv8 (as ID_MMFR4), we give it an entry in
the ARMCPU struct so CPUs can override it, though since none do
this too will just RAZ.
Backports commit e20d84c1407d43d5a2e2ac95dbb46db3b0af8f9f from qemu
Mark CNTHP_TVAL_EL2 as ARM_CP_NO_RAW due to the register not
having any underlying state. This fixes an issue with booting
KVM enabled kernels when EL2 is on.
Backports commit d44ec156300a149b386a14d3ab349d3b83b66b8c from qemu
Implement the performance monitor register traps controlled
by MDCR_EL3.TPM and MDCR_EL2.TPM. Most of the performance
registers already have an access function to deal with the
user-enable bit, and the TPM checks can be added there. We
also need a new access function which only implements the
TPM checks for use by the few not-EL0-accessible registers
and by PMUSERENR_EL0 (which is always EL0-readable).
Backports commit 1fce1ba985d9c5c96e5b9709e1356d1814b8fa9e from qemu
Fix two issues with our implementation of the SDCR:
* it is only present from ARMv8 onwards
* it does not contain several of the trap bits present in its 64-bit
counterpart the MDCR_EL3
Put the register description in the right place so that it does not
get enabled for ARMv7 and earlier, and give it a write function so that
we can mask out the bits which should not be allowed to have an effect
if EL3 is 32-bit.
Backports commit a8d64e735182cbbb5dcc98f41656b118c45e57cc from qemu
If HCR.TGE is 1 then mode changes via CPS and MSR from Monitor to
NonSecure PL1 modes are illegal mode changes. Implement this check
in bad_mode_switch().
(We don't currently implement HCR.TGE, but this is the only missing
check from the v8 ARM ARM G1.9.3 and so it's worth adding now; the
rest of the HCR.TGE checks can be added later as necessary.)
Backports commit 10eacda787ac9990dc22d4437b289200c819712c from qemu
Mode switches from Hyp to any other mode via the CPS and MRS
instructions are illegal mode switches (though obviously switching
via exception return is valid). Add this check to bad_mode_switch().
Backports commit af393ffc6da116b9dd4c70901bad1f4cafb1773d from qemu
In v8, the illegal mode changes which are UNPREDICTABLE in v7 are
given architected behaviour:
* the mode field is unchanged
* PSTATE.IL is set (so any subsequent instructions will UNDEF)
* any other CPSR fields are written to as normal
This is pretty much the same behaviour we picked for our
UNPREDICTABLE handling, with the exception that for v8 we
need to set the IL bit.
Backports commit 81907a582901671c15be36a63b5063f88f3487e2 from qemu
In v8 trying to switch mode to Mon from Secure EL1 is an
illegal mode switch. (In v7 this is impossible as all secure
modes except User are at EL3.) We can handle this case by
making a switch to Mon valid only if the current EL is 3,
which then gives the correct answer whether EL3 is AArch32
or AArch64.
Backports commit 58ae2d1f037fae1d90eed4522053a85d79edfbec from qemu
We don't actually support Hyp mode yet, but add the correct
checks for it to the bad_mode_switch() function for completeness.
Backports commit e6c8fc07b4fce0729bb747770756835f4b0ca7f4 from qemu
QEMU doesn't implement the NSACR.RFR bit, which is a permitted
IMPDEF in choice in ARMv7 and the only permitted choice in ARMv8.
Add a comment to bad_mode_switch() to note that this is why
FIQ is always a valid mode regardless of the CPU's Secure state.
Backports commit 52ff951b4f63a29593650a15efdf82f63d6d962d from qemu
The only case where we can attempt a cpsr_write() mode switch from
User is from the gdbstub; all other cases are handled in the
calling code (notably translate.c). Architecturally attempts to
alter the mode bits from user mode are simply ignored (and not
treated as a bad mode switch, which in v8 sets CPSR.IL). Make
mode switches from User ignored in cpsr_write() as well, for
consistency.
Backports commit cb01d3912c8b000ed26d5fe95f6c194b3e3ba7a6 from qemu
Raw CPSR writes should skip the architectural checks for whether
we're allowed to set the A or F bits and should also not do
the switching of register banks if the mode changes. Handle
this inside cpsr_write(), which allows us to drop the "manually
set the mode bits to avoid the bank switch" code from all the
callsites which are using CPSRWriteRaw.
This fixes a bug in 32-bit KVM handling where we had forgotten
the "manually set the mode bits" part and could thus potentially
trash the register state if the mode from the last exit to userspace
differed from the mode on this exit.
Backports commit f8c88bbcda76d5674e4bb125471371b41d330df8 from qemu
Add an argument to cpsr_write() to indicate what kind of CPSR
write is being requested, since the exact behaviour should
differ for the different cases.
Backports commit 50866ba5a2cfe922aaf3edb79f6eac5b0653477a from qemu
The rules for setting the CPSR on a 32-bit exception return are
subtly different from those for setting the CPSR via an instruction
like MSR or CPS. (In particular, in Hyp mode changing the mode bits
is not valid via MSR or CPS.) Split the exception-return case into
its own helper for setting CPSR, so we can eventually handle them
differently in the helper function.
Backports commit 235ea1f5c89abf30e452539b973b0dbe43d3fe2b from qemu
Make get_r13_banked() raise an exception at runtime for the
corner case of SRS from System mode, so that we can UNDEF it;
this brings us in to line with the ARM ARM's set of permitted
CONSTRAINED UNPREDICTABLE choices.
Backports commit f01377f591fe15c652f947646c4a69a7d4a71ad9 from qemu
The user-mode versions of get/set_r13_banked() exist just to assert
if they're ever called -- the translate time code should never
emit calls to them because SRS from user mode always UNDEF.
There's no code in the softmmu versions that can't compile in
CONFIG_USER_ONLY, and the assertion is not particularly useful,
so combine the two functions rather than having completely split
versions under ifdefs.
Backports commit d86d57d4fe683c99823f625f941eff26c07c72c3 from qemu
Move get/set_r13_banked() from helper.c to op_helper.c. This will
let us add exception-raising code to them, and also puts them
in the same file as get/set_user_reg(), which makes some conceptual
sense.
(The original reason for the helper.c/op_helper.c split was that
only op_helper.c had access to the CPU env pointer; this distinction
has not been true for a long time, though, and so the split is
now rather arbitrary.)
Backports commit 72309cee482868d6c4711931c3f7e02ab9dec229 from qemu
target-arm: Move bank_number() into internals.h
Move bank_number()'s implementation into internals.h, so
it's available in the user-mode-only compile as well.
Backports commit c766568d3604082c6fd45cbabe42c48e4861a13f from qemu
The SRS instruction is:
* UNDEFINED in Hyp mode
* UNPREDICTABLE in User or System mode
* UNPREDICTABLE if the specified mode isn't accessible
* trapped to EL3 if EL3 is AArch64 and we are at Secure EL1
Clean up the code to handle all these cases cleanly, including
picking UNDEF as our choice of UNPREDICTABLE behaviour rather
blindly trusting the mode field passed in the instruction.
As part of this, move the check for IS_USER into gen_srs()
itself rather than having it done by the caller.
The exception is that we don't UNDEF for calls from System
mode, which need a runtime check. This will be dealt with in
the following commits.
Backports commit cbc0326b6fb905f80b7cef85b24571f7ebb62077 from qemu
If access to FPEXC32_EL2 is trapped by CPTR_EL2.TFP or CPTR_EL3.TFP,
this should be reported with a syndrome register indicating an
FP access trap, not one indicating a system register access trap.
Backports commit f2cae6092767aaf418778eada15be444c23883be from qemu
Implement trapping of the "debug ROM" registers, which are controlled
by MDCR_EL2.TDRA for EL2 but by the more general MDCR_EL3.TDA for EL3.
Backports commit 91b0a23865558e2ce9c2e7042d404e8bf2e4b817 from qemu
Implement the traps to EL2 and EL3 controlled by the bits
MDCR_EL2.TDOSA MDCR_EL3.TDOSA. These can configurably trap
accesses to the "powerdown debug" registers.
Backports commit 187f678d5c28251dba2b44127e59966b14518ef7 from qemu
We weren't quite implementing the handling of SCR.SMD correctly.
The condition governing whether the SMD bit should apply only
for NS state is "is EL3 is AArch32", not "is the current EL AArch32".
Fix the condition, and clarify the comment both to reflect this and
to expand slightly on what's going on for the v7-no-Virtualization case.
Backports commit f096e92b6385fd87e8ea948ad3af70faf752c13a from qemu
Correct some corner cases we were getting wrong for
CNTFRQ access rights:
* should UNDEF from 32-bit Secure EL1
* only writable from the highest implemented exception level,
which might not be EL1 now
To clarify the code, provide a new utility function
arm_highest_el() which returns the highest implemented
exception level.
Backports commit 755026728abb19fba70e6b4396a27fa2e7550d74 from qemu
ARM stops before access to a location covered by watchpoint. Also, QEMU
watchpoint fire is not necessarily an architectural watchpoint match.
Unfortunately, that is hardly possible to ignore a fired watchpoint in
debug exception handler. So move watchpoint check from debug exception
handler to the dedicated watchpoint checking callback.
Backports commit 3826121d9298cde1d29ead05910e1f40125ee9b0 from qemu
All Thumb Neon and VFP instructions are 32 bits, so the IL
bit in the syndrome register should be set. Pass false to the
syn_* function's is_16bit argument rather than s->thumb
so we report the correct IL bit.
Backports commit 7d197d2db5e99e4c8b20f6771ddc7303acaa1c89 from qemu
All Thumb coprocessor instructions are 32 bits, so the IL
bit in the syndrome register should be set. Pass false to the
syn_* function's is_16bit argument rather than s->thumb
so we report the correct IL bit.
Backports commit 4df322593037d2700f72dfdfb967300b7ad2e696 from qemu
In syndrome register values, the IL bit indicates the instruction
length, and is 1 for 4-byte instructions and 0 for 2-byte
instructions. All A64 and A32 instructions are 4-byte, but
Thumb instructions may be either 2 or 4 bytes long. Unfortunately
we named the parameter to the syn_* functions for constructing
syndromes "is_thumb", which falsely implies that it should be
set for all Thumb instructions, rather than only the 16-bit ones.
Fix the functions to name the parameter 'is_16bit' instead.
Backports commit fc05f4a62c568b607ec3fe428a419bb38205b570 from qemu
Enable EL3 support for our Cortex-A53 and Cortex-A57 CPU models.
We have enough implemented now to be able to run real world code
at least to some extent (I can boot ARM Trusted Firmware to the
point where it pulls in OP-TEE and then falls over because it
doesn't have a UEFI image it can chain to).
Backports commit 3ad901bc2b98f5539af9a7d4aef140a6d8fa6442 from qemu
Implement some corner cases of the behaviour of the NSACR
register on ARMv8:
* if EL3 is AArch64 then accessing the NSACR from Secure EL1
with AArch32 should trap to EL3
* if EL3 is not present or is AArch64 then reads from NS EL1 and
NS EL2 return constant 0xc00
It would in theory be possible to implement all these with
a single reginfo definition, but for clarity we use three
separate definitions for the three cases and install the
right one based on the CPU feature flags.
Backports commit 2f027fc52d4b444a47cb05a9c96697372a6b57d2 from qemu
System registers might have access requirements which need to
be described via a CPAccessFn and which differ for reads and
writes. For this to be possible we need to pass the access
function a parameter to tell it whether the access being checked
is a read or a write.
Backports commit 3f208fd76bcc91a8506681bb8472f2398fe6f487 from qemu
The arm_generate_debug_exceptions() function as originally implemented
assumes no EL2 or EL3. Since we now have much more of an implementation
of those now, fix this assumption.
Backports commit 533e93f1cf12c570aab45f14663dab6fb8ea3ffc from qemu
The registers MVBAR and SCR should have the behaviour of trapping to
EL3 if accessed from Secure EL1, but we were incorrectly implementing
them to UNDEF (which would trap to EL1). Fix this by using the new
access_trap_aa32s_el1() access function.
Backports commit efe4a274083f61484a8f1478d93f229d43aa8095 from qemu
Implement the MDCR_EL3 register (which is SDCR for AArch32).
For the moment we implement it as reads-as-written.
Backports commit 5513c3abed8e5fabe116830c63f0d3fe1f94bd21 from qemu
