The test is supposed to terminate TB if the end of the page is reached.
However, with current implementation it may never succeed for microMIPS or
mips16.
Backports commit fe2372910a09034591fd2cfc2d70cca43fccaa95 from qemu
Commit fecd264 added a number of fall-throughs, but neglected to
properly document them as intentional. Commit d922445 cleaned that up
for many, but not all cases. Take care of the remaining ones.
Backports commit b6f3b233eabb4df5d65ae9fbfb3d3c8befea0de7 from qemu
Add missing calls to synchronise the SoftFloat status with the CP1.FSCR:
+ for the rounding and flush-to-zero modes upon processor reset,
+ for the flush-to-zero mode on FSCR updates through the GDB stub.
Refactor code accordingly and remove the redundant RESTORE_ROUNDING_MODE
macro.
Backports commit bb962386b82c1b0e9e12fdb6b9bb62106bf1f822 from qemu
Make sure the address space is unconditionally wrapped on 32-bit
processors, that is ones that do not implement at least the MIPS III
ISA.
Also make MIPS16 SAVE and RESTORE instructions use address calculation
rather than plain arithmetic operations for stack pointer manipulation
so that their semantics for stack accesses follows the architecture
specification. That in particular applies to user software run on
64-bit processors with the CP0.Status.UX bit clear where the address
space is wrapped to 32 bits.
Backports commit c48245f0c62405f27266fcf08722d8c290520418 from qemu
Tighten ISA level checks down to MIPS II that many of our instructions
are missing. Also make sure any 64-bit instruction enables are only
applied to 64-bit processors, that is ones that implement at least the
MIPS III ISA.
Backports commit d9224450208e0de62323b64ace91f98bc31d6e2c from qemu
Fix CP0.Config3.ISAOnExc write accesses on microMIPS processors. This
bit is mandatory for any processor that implements the microMIPS
instruction set. This bit is r/w for processors that implement both the
standard MIPS and the microMIPS instruction set. This bit is r/o and
hardwired to 1 if only the microMIPS instruction set is implemented.
There is no other bit ever writable in CP0.Config3 so defining a
corresponding `CP0_Config3_rw_bitmask' member in `CPUMIPSState' is I
think an overkill. Therefore make the ability to write the bit rely on
the presence of ASE_MICROMIPS set in the instruction flags.
The read-only case of the microMIPS instruction set being implemented
only can be added when we add support for such a configuration. We do
not currently have such support, we have no instruction flag that would
control the presence of the standard MIPS instruction set nor any
associated code in instruction decoding.
This change is needed to boot a microMIPS Linux kernel successfully,
otherwise it hangs early on as interrupts are enabled and then the
exception handler invoked loops as its first instruction is interpreted
in the wrong execution mode and triggers another exception right away.
And then over and over again.
We already check the current setting of the CP0.Config3.ISAOnExc in
`set_hflags_for_handler' to set the ISA bit correctly on the exception
handler entry so it is the ability to set it that is missing only.
Backports commit 90f12d735d66ac1196d9a2bced039a432eefc03d from qemu
Fix microMIPS MOVE16 and MOVEP instructions on 64-bit processors by
using register addition operations.
This copies the approach taken with MIPS16 MOVE instructions (I8_MOV32R
and I8_MOVR32 opcodes) and follows the observation that OPC_ADDU expands
to tcg_gen_mov_tl whenever `rt' is 0 and `rs' is not, therefore copying
`rs' to `rd' verbatim. This is not the case with OPC_ADDIU where a
sign-extension from bit #31 is made, unless in the uninteresting case of
`rs' being 0, losing the upper 32 bits of the value copied for any
proper 64-bit values.
This also serves as an optimization as one op is produced in generated
code rather than two (again, unless `rs' is 0, where it doesn't change
anything).
Backports commit 7215d7e7aea85699bf516c3e8d84f6a22584da35 from qemu
Correct MIPS16/microMIPS branch size calculation in PC adjustment
needed:
- to set the value of CP0.ErrorEPC at the entry to the reset exception,
- for the purpose of branch reexecution in the context of device I/O.
Follow the approach taken in `exception_resume_pc' for ordinary, Debug
and NMI exceptions.
MIPS16 and microMIPS branches can be 2 or 4 bytes in size and that has
to be reflected in calculation. Original MIPS ISA branches, which is
where this code originates from, are always 4 bytes long, just as all
original MIPS ISA instructions.
Backports commit c3577479815f5bcf9d38993967bca2115af245d8 from qemu
Backports commits d75de74967f631a7d0b538d4b88f96f9c426bfe2, 6225a4a0e39cb24e7b9e1d4d2c1a3e6eaee18e85, and d2bfa6e6222baa0218bd0658499d38bac56ac34c from qemu
Add the 5KEc and 5KEf processors from MIPS Technologies that are the
original implementation of the MIPS64r2 ISA.
Silicon for these processors has never been taped out and no soft cores
were released even. They do exist though, a CP0.PRId value has been
assigned and experimental RTLs produced at the time the MIPS64r2 ISA has
been finalized. The settings introduced here faithfully reproduce that
hardware.
As far the implementation goes these processors are the same as the 5Kc
and the 5Kf CPUs respectively, except implementing the MIPS64r2 rather
than the original MIPS64 instruction set. There must have been some
updates to the CP0 architecture as mandated by the ISA, such as the
addition of the EBase register, although I am not sure about the exact
details, no documentation has ever been produced for these processors.
The remaining parts of the microarchitecture, in particular the
pipeline, stayed unchanged. Or to put it another way, the difference
between a 5K and a 5KE CPU corresponds to one between a 4K and a 4KE
CPU, except for the 64-bit rather than 32-bit ISA.
Backports commit 36b86e0dc2be93fc538fe7e11e0fda1a198f0135 from qemu
While we're at it, emit the opcode adjacent to where we currently
record data for search_pc. This puts gen_io_start et al on the
"correct" side of the marker.
Backports commit 667b8e29c5b1d8c5b4e6ad5f780ca60914eb6e96 from qemu
The checks in dins is required to avoid triggering an assertion
in tcg_gen_deposit_tl. The check in dext is just for completeness.
Fold the other D cases in via fallthru.
Backports commit b7f26e523914b982a1c1bfa8295f77ff9787c33c from qemu
This is improved type checking for the translators -- it's no longer
possible to accidentally swap arguments to the branch functions.
Note that the code generating backends still manipulate labels as int.
With notable exceptions, the scope of the change is just a few lines
for each target, so it's not worth building extra machinery to do this
change in per-target increments.
Backports commit 42a268c241183877192c376d03bd9b6d527407c7 from qemu
The method by which we count the number of ops emitted
is going to change. Abstract that away into some inlines.
Backports commit fe700adb3db5b028b504423b946d4ee5200a8f2f from qemu.
Thus, use cpu_env as the parameter, not TCG_AREG0 directly.
Update all uses in the translators.
Backports commit e1ccc05444676b92c63708096e36582be27fbee1 from qemu
