Correct these issues with the handling of CP0.Status for MIPSr6:
* only ignore the bit pattern of 0b11 on writes to CP0.Status.KSU, that
is for processors that do implement Supervisor Mode, let the bit
pattern be written to CP0.Status.UM:R0 freely (of course the value
written to read-only CP0.Status.R0 will be discarded anyway); this is
in accordance to the relevant architecture specification[1],
* check the newly written pattern rather than the current contents of
CP0.Status for the KSU bits being 0b11,
* use meaningful macro names to refer to CP0.Status bits rather than
magic numbers.
References:
[1] "MIPS Architecture For Programmers, Volume III: MIPS64 / microMIPS64
Privileged Resource Architecture", MIPS Technologies, Inc., Document
Number: MD00091, Revision 6.00, March 31, 2014, Table 9.45 "Status
Register Field Descriptions", pp. 210-211.
Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
uint32_t mask = env->CP0_Status_rw_bitmask;
if (env->insn_flags & ISA_MIPS32R6) {
- if (extract32(env->CP0_Status, CP0St_KSU, 2) == 0x3) {
+ bool has_supervisor = extract32(mask, CP0St_KSU, 2) == 0x3;
+
+ if (has_supervisor && extract32(arg1, CP0St_KSU, 2) == 0x3) {
mask &= ~(3 << CP0St_KSU);
}
- mask &= ~(0x00180000 & arg1);
+ mask &= ~(((1 << CP0St_SR) | (1 << CP0St_NMI)) & arg1);
}
val = arg1 & mask;