There was one genuine issue introduced by PPA changes in 78a5cb98e which
affected instruction injection on multiple harts from the DM (indicating
SMP debug testing needs to be part of regular automated regressions,
instead of semi-manual...). The rest are cosmetic.
default case to DM acmd state machine. Also remove unnecessary clear
of JTAG DR shifter on TAP reset state, which saves a bit of logic. Two
width mismatches are left unfixed in the DTM (the ones with shifts)
because they bizarrely increase area by 100 LUT4s when fixed.
Extend umode_wfi testcase to cover this, and in particular to check
that when entering U-mode with IRQs pending, the IRQs execute before any
exceptions occurring as a result of the U-mode instructions.
None of upstream tests used for Hazard3 seem to cover X != R. The
Hazard3 tests covered this case, but the header file for the tests has
the same mistake. Fix the header.
Interrupting the PC-setting step of a cm.popret (only) can sample the return target
as the exception return PC, which will cause the stack pointer adjust to be skipped
when returning from the IRQ. Fix this by making the PC-setting step uninterruptible
(note the PC-setting step is the instruction we execute first out of the group
of instructions specified in the Zc spec as being atomic wrt interrupts. This
does not itself imply that the PC-setting step is uninterruptible, it just
requires that when the PC-setting step retires, all following steps also retire.
However this is not sufficient given the special case logic that allows the jr
ra PC-setting step to execute before the final stack adjust as an optimisation.)
- sbdata0 should ignore writes when sbbusyerror or sberror is set
- All sbaddress0 writes and sbdata0 accesses should set
sbbusyerror if sbbusy is set
- sbaddress should not increment if access gets bus error
in calculating the privilege of load/stores. This is safe because it
is only the *current* debug mode state which affects load/stores,
and some new properties have been added to ensure load/stores can
not be in aphase at the point debug mode is entered/exited (which
is achieved by delaying the trap). Therefore there is no way for
debug entry to inadvertently boost the privilege of an executing
U-mode load/store.
Also rename a confusingly-named signal for an unsquashable bus
transfer in stage 2 that delays IRQ entry.
Luke Wren