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.
MIPS semihosting is not implemented for linux-user builds.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220822141230.3658237-5-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Delay generating the exception until after we know the
insn length, and record that length in env->error_code.
Fixes: 8ec7e3c53d ("target/mips: Use an exception for semihosting")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1126
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Within do_interrupt, we hold the iothread lock, which
is required for Chardev access for the console, and for
the round trip for use_gdb_syscalls().
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Switch statements for the code segments that handle nanoMIPS
instruction pools P.LL, P.SC, P.SHIFT, P.LS.S1, P.LS.E0, PP.LSXS
do not have proper default case, resulting in not generating
reserved instruction exception for certain illegal opcodes.
Fix this by adding default cases for these switch statements that
trigger reserved instruction exception.
Signed-off-by: Stefan Pejic <stefan.pejic@syrmia.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220504110403.613168-7-stefan.pejic@syrmia.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
If both rs and rt are the same register, the nanoMIPS instruction
BNEC[32] rs, rt, address is equivalent to NOP (branch is not taken and
there is no delay slot). This commit provides such behavior. Without
this commit, this scenario results in an incorrect behavior.
Signed-off-by: Dragan Mladjenovic <dragan.mladjenovic@syrmia.com>
Signed-off-by: Stefan Pejic <stefan.pejic@syrmia.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220504110403.613168-5-stefan.pejic@syrmia.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
There are currently two problems related to the emulation of the
instruction BPOSGE32C.
The nanoMIPS instruction BPOSGE32C belongs to DSP R3 instructions
(actually, as of now, it is the only instruction of DSP R3). The
presence of DSP R3 instructions in QEMU is indicated by the flag
MIPS_HFLAG_DSP_R3 (0x20000000). This flag is currently being properly
set in CPUMIPSState's hflags (for example, for I7200 nanoMIPS CPU).
However, it is not propagated to DisasContext's hflags, since the flag
MIPS_HFLAG_DSP_R3 is not set in MIPS_HFLAG_TMASK (while similar flags
MIPS_HFLAG_DSP_R2 and MIPS_HFLAG_DSP are set in this mask, and there
is no problem in functioning check_dsp_r2(), check_dsp()). This means
the function check_dsp_r3() currently does not work properly, and the
emulation of BPOSGE32C can not work properly as well.
Change MIPS_HFLAG_TMASK from 0x1F5807FF to 0x3F5807FF (logical OR
with 0x20000000) to fix this.
Additionally, check_cp1_enabled() is currently incorrectly called
while emulating BPOSGE32C. BPOSGE32C is in the same pool (P.BR1) as
FPU branch instruction BC1EQZC and BC1NEZC, but it not a part of FPU
(CP1) instructions, and check_cp1_enabled() should not be involved
while emulating BPOSGE32C.
Rearrange invocations of check_cp1_enabled() within P.BR1 pool
handling to affect only BC1EQZC and BC1NEZC emulation, and not
BPOSGE32C emulation.
Signed-off-by: Dragan Mladjenovic <dragan.mladjenovic@syrmia.com>
Signed-off-by: Stefan Pejic <stefan.pejic@syrmia.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220504110403.613168-4-stefan.pejic@syrmia.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
The field rs in the instruction EXTRV_S.H rt, ac, rs is specified in
nanoMIPS documentation as opcode[20..16]. It is, however, erroneously
considered as opcode[25..21] in the current QEMU implementation. In
function gen_pool32axf_2_nanomips_insn(), the variable v0_t corresponds
to rt/opcode[25..21], and v1_t corresponds to rs/opcode[20..16]), and
v0_t is by mistake passed to the helper gen_helper_extr_s_h().
Use v1_t rather than v0_t in the invocation of gen_helper_extr_s_h()
to fix this.
Signed-off-by: Dragan Mladjenovic <dragan.mladjenovic@syrmia.com>
Signed-off-by: Stefan Pejic <stefan.pejic@syrmia.com>
Fixes: 8b3698b294 ("target/mips: Add emulation of DSP ASE for nanoMIPS")
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220504110403.613168-3-stefan.pejic@syrmia.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
The field ac in nanoMIPS instruction MTHLIP rs, ac is specified in
nanoMIPS documentation as opcode[15..14] (2 bits). However, in the
current QEMU code, the corresponding argument passed to the helper
gen_helper_mthlip() has the value of opcode[15..11] (5 bits). Right
shift the value of this argument by three bits to fix this.
Signed-off-by: Stefan Pejic <stefan.pejic@syrmia.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220504110403.613168-2-stefan.pejic@syrmia.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Simplify cpu_loop by doing all of the decode in translate.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220107213243.212806-18-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Per the "MIPS Architecture Extension: nanoMIPS32 DSP TRM" rev 0.04,
MULT and MULTU opcodes:
The value of ac selects an accumulator numbered from 0 to 3.
When ac=0, this refers to the original HI/LO register pair of the
MIPS32 architecture.
In Release 6 of the MIPS Architecture, accumulators are eliminated
from MIPS32.
Ensure pre-Release 6 is restricted to HI/LO registers pair.
Fixes: 8b3698b294 ("target/mips: Add emulation of DSP ASE for nanoMIPS - part 4")
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
[rth: Split out of a larger patch.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Add the inlined cpu_is_bigendian() function in "translate.h".
Replace the TARGET_WORDS_BIGENDIAN #ifdef'ry by calls to
cpu_is_bigendian().
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210818164321.2474534-6-f4bug@amsat.org>
Extract 4900 lines from the huge translate.c to a new file,
'nanomips_translate.c.inc'. As there are too many inter-
dependencies we don't compile it as another object, but
keep including it in the big translate.o. We gain in code
maintainability.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20201120210844.2625602-13-f4bug@amsat.org>
