Honour the commandline -semihosting-config userspace=on option,
instead of always permitting userspace semihosting calls in system
emulation mode, by passing the correct value to the is_userspace
argument of semihosting_enabled().
Note that this is a behaviour change: if the user wants to
do semihosting calls from userspace they must now specifically
enable them on the command line.
nios2 semihosting is not implemented for linux-user builds.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220822141230.3658237-6-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Currently our semihosting implementations generally prohibit use of
semihosting calls in system emulation from the guest userspace. This
is a very long standing behaviour justified originally "to provide
some semblance of security" (since code with access to the
semihosting ABI can do things like read and write arbitrary files on
the host system). However, it is sometimes useful to be able to run
trusted guest code which performs semihosting calls from guest
userspace, notably for test code. Add a command line suboption to
the existing semihosting-config option group so that you can
explicitly opt in to semihosting from guest userspace with
-semihosting-config userspace=on
(There is no equivalent option for the user-mode emulator, because
there by definition all code runs in userspace and has access to
semihosting already.)
This commit adds the infrastructure for the command line option and
adds a bool 'is_user' parameter to the function
semihosting_userspace_enabled() that target code can use to check
whether it should be permitting the semihosting call for userspace.
It mechanically makes all the callsites pass 'false', so they
continue checking "is semihosting enabled in general". Subsequent
commits will make each target that implements semihosting honour the
userspace=on option by passing the correct value and removing
whatever "don't do this for userspace" checking they were doing by
hand.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220822141230.3658237-2-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Pass these along to translator_loop -- pc may be used instead
of tb->pc, and host_pc is currently unused. Adjust all targets
at one time.
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The exception return address for nios2 is the instruction
after the one that was executing at the time of the exception.
We have so far implemented this by advancing the pc during the
process of raising the exception. It is perhaps a little less
confusing to do this advance in the translator (and helpers)
when raising the exception in the first place, so that we may
more closely match kernel sources.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220421151735.31996-58-richard.henderson@linaro.org>
When CRS = 0, we restore from estatus; otherwise from sstatus.
Update for the new CRS.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-56-richard.henderson@linaro.org>
Implement these out of line, so that tcg global temps
(aka the architectural registers) are synced back to
tcg storage as required. This makes sure that we get
the proper results when status.PRS == status.CRS.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-55-richard.henderson@linaro.org>
Do not actually enable them so far, in terms of being able
to change the current register set, but add all of the
plumbing to address them. Do not enable them for user-only.
Add an env->regs pointer that handles the indirection to
the current register set. The naming of the pointer hides
the difference between old and new, user-only and sysemu.
From the notes on wrprs, which states that r0 must be initialized
before use in shadow register sets, infer that R_ZERO is *not*
hardwired to zero in shadow register sets, but that it is still
read-only. Introduce tbflags bit R0_0 to track that it has been
properly set to zero. Adjust load_gpr to reflect this.
At the same time we might as well special case crs == 0 to avoid
the indirection through env->regs during translation as well; this
is intended to be the most common case for non-interrupt handlers.
Init env->regs at reset.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220421151735.31996-54-richard.henderson@linaro.org>
Indirect branches, plus eret and bret optionally raise
an exception when branching to a misaligned address.
The exception is required when an mmu is enabled, but
enable it always because the fallback behaviour is not
documented (though presumably it discards low bits).
For the purposes of the linux-user cpu loop, if EXCP_UNALIGN
(misaligned data) were to arrive, it would be treated the
same as EXCP_UNALIGND (misaligned destination). See the
!defined(CONFIG_NIOS2_ALIGNMENT_TRAP) block in kernel/traps.c.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-53-richard.henderson@linaro.org>
Use lookup_and_goto_ptr for indirect chaining between TBs.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-52-richard.henderson@linaro.org>
Depending on the reason for ending the TB, we can chain
to the next TB because the PC is constant.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-51-richard.henderson@linaro.org>
Rather than force all callers to set this, do it
within the subroutine.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-50-richard.henderson@linaro.org>
Split out a function to perform an indirect branch.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-49-richard.henderson@linaro.org>
Constrain all references to cpu_R[] to load_gpr and dest_gpr.
This will be required for supporting shadow register sets.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-46-richard.henderson@linaro.org>
Do as little work as possible within the macro.
Split out helper functions and pass in arguments instead.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Rename the macro from gen_r_mul, because these are the multiply
variants that produce a high-part result. Do as little work as
possible within the macro; split out helper functions and pass
in arguments instead.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split the macro in two, one for reg/imm and one for reg/reg.
Do as little work as possible within the macros; split out
helper functions and pass in arguments instead.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Do as little work as possible within the macro.
Split out helper functions and pass in arguments instead.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Do as little work as possible within the macro.
Split out helper functions and pass in arguments instead.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Currently the structures are anonymous within the macro.
Pull them out to standalone types.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220421151735.31996-44-richard.henderson@linaro.org>
Replace current uses of tcg_const_tl, and remove the frees.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-43-richard.henderson@linaro.org>
Division may (optionally) raise a division exception.
Since the linux kernel has been prepared for this for
some time, enable it by default.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-42-richard.henderson@linaro.org>
Create an array of masks which detail the writable and readonly
bits for each control register. Apply them when writing to
control registers, including the write to status during eret.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220421151735.31996-38-richard.henderson@linaro.org>
Decode 'break 1' during translation, rather than doing
it again during exception processing.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-32-richard.henderson@linaro.org>
Use FIELD_EX32 and FIELD_DP32 instead of managing the
masking by hand.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-30-richard.henderson@linaro.org>
Use FIELD_EX32 and FIELD_DP32 instead of manual manipulation
of the fields.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-27-richard.henderson@linaro.org>
Do not print control registers for user-only mode.
Rename reserved control registers to "resN", where
N is the control register index.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-24-richard.henderson@linaro.org>
Place the control registers into their own array, env->ctrl[].
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-23-richard.henderson@linaro.org>
We don't need to reference them often, and when we do it
is just as easy to load/store from cpu_env directly.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-20-richard.henderson@linaro.org>
We had failed to copy BSTATUS back to STATUS, and diagnose
supervisor-only. The spec is light on the specifics of the
implementation of bret, but it is an easy assumption that
the restore into STATUS should work the same as eret.
Therefore, reuse the existing helper_eret.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-19-richard.henderson@linaro.org>
The implementation of eret will become much more complex
with the introduction of shadow registers.
[rth: Split out of a larger patch for shadow register sets.
Directly exit to the cpu loop from the helper.]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Amir Gonnen <amir.gonnen@neuroblade.ai>
Message-Id: <20220303153906.2024748-3-amir.gonnen@neuroblade.ai>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-18-richard.henderson@linaro.org>
It is cleaner to have a separate name for this variable.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-17-richard.henderson@linaro.org>
Whether the cpu is in user-mode or not is something that we
know at translation-time. We do not need to generate code
after having raised an exception.
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-15-richard.henderson@linaro.org>
eret instruction is only allowed in supervisor mode.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Amir Gonnen <amir.gonnen@neuroblade.ai>
Message-Id: <20220303153906.2024748-2-amir.gonnen@neuroblade.ai>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-14-richard.henderson@linaro.org>
We have fetched and locked the logfile in translator_loop.
Pass the filepointer down to the disas_log hook so that it
need not be fetched and locked again.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-13-richard.henderson@linaro.org>
Previously, we would avoid setting CPU_INTERRUPT_HARD when interrupts
are disabled at a particular point in time, instead queuing the value
into cpu->irq_pending. This is more complicated than required.
Instead, set CPU_INTERRUPT_HARD any time there is a pending interrupt,
and exclusively check for interrupts disabled in nios2_cpu_exec_interrupt.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
It was never correct to be able to write to ipending.
Until the rest of the irq code is tidied, the read of
ipending will generate an "unnecessary" mask.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Create three separate functions for the three separate registers.
Avoid extra dispatch through op_helper.c.
Dispatch to the correct function in translation.
Clean up the ifdefs in wrctl.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This will avoid having to replicate the check to additional cases.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This functionality can be had via plugins, if desired.
In the meantime, it is unused code.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The first word of page1 is data, so the whole thing
can't be implemented with emulation of addresses.
Use init_guest_commpage for the allocation.
Hijack trap number 16 to implement cmpxchg.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20211221025012.1057923-5-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
The real kernel has to load the instruction and extract
the imm5 field; for qemu, modify the translator to do this.
The use of R_AT for this in cpu_loop was a bug. Handle
the other trap numbers as per the kernel's trap_table.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20211221025012.1057923-2-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
The hook is now unused, with breakpoints checked outside translation.
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Just use translator_use_goto_tb directly at the one call site,
rather than maintaining a local wrapper.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We have pre-computed the next instruction address into
dc->base.pc_next, so we might as well use it.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Move handle_instruction into nios2_tr_translate_insn
as the only caller.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Direct assignments to env during translation do not work.
As it happens, the only way we can get here is if env->pc
is already set to dc->pc. We will trap on the first insn
we execute anywhere on the page.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Migrate the is_jmp, tb and singlestep_enabled fields from
DisasContext into the base. Use pc_first instead of tb->pc.
Increment pc_next prior to decode, leaving the address of
the current insn in dc->pc.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We do not need to copy this into DisasContext.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
