This change lets me test OpenOCD's behavior when harts become available.
It only affects how things look to the debugger. Harts that are
"unavailable" still execute code as usual.

Control is implemented through the 2 LSBs of the DMCUSTOM register in
the Debug Module.

Replace ternary operator with std:min

Add support for BF16 extensions

Fix bugs in disassembling code for cm.mva01s/mvsa01 instructions

dscr.ebreakh is now dcsr.ebreakv[su]

This change was made ages ago in the spec.

I did not actually test that the new privilege checks in ebreak and
c.ebreak are correct, but all the existing debug tests still pass.

Minor fixes (mostly related to __int128 support)

decode_macros: move 'is_aligned' from 'v_ext_macros.h'

Calling 'extension_enabled' this early during the constructor of
'processor_t' causes SIGSEGV.

Make sure that the configure decision on 128-bit is consistent during
compilation.

Also move uint128_t definition.

Modify configure.ac to generate a header that expose the support for
128-bit integers.

Implement dcsr.v and make DRET use it

This cleans up the code and avoids bugs like #1365.

So it's right next to set_privilege() which it will be combined with next.

So it's right next to set_privilege() which it will be combined with
next.

Since we're going to move the change to state->v next.

Should already be 1.

Resolves #1365

triggers: Fix etrigger match on exceptions

The etrigger match on exceptions doesn't work properly in cases like
the following:

1) M-mode delegates ECALLs to S-mode
2) A CPU hardware point mechanism is used to place a breakpoint on the
   Umode instruction that executes the ECALL from Umode to Smode. In
   effect, this creates a breakpoint etrigger based on Umode.

In the above, the expectation is that #2 will first cause an exit to
the Smode handler (stvec), and the hardware breakpoint exception will
be triggered following an entry into the handler.

However, since etrigger currently checks the current privilege mode, we
will never get a match on conditions like #2.

The patch attempts to address the issue by using the stashed version of
the previous privilege mode for the etrigger match.

cc: YenHaoChen <howard25336284@gmail.com>
Signed-off-by: Atul Khare <atulkhare@rivosinc.com>

The current version of mode_match() is based on the current privilege
level. This adds an explicit privilege and virtual mode parameters in
anticipation of an upcoming patch for matching trap triggers.

This adds the prev_prv field to track the previous privilege. It will
be used in a forthcoming patch for trigger matching.

This adds the prev_v field to track the previous virtual mode state. We
also assign it unconditionally to handle cases for trigger matching
like the following (pointed out by Scott Johnson):

    1) SRET from HS to VU: prev_v is set to 0
    2) Trap from VU to VS: state.v/prev_v won't be assigned because of
       unchanged v, and remain 0.
    3) An etrigger that's set to break on a VU-mode trap won't match
       properly because prev_v is incorrect

This be used in a forthcoming patch for trigger matching.

Let mstatus.MPP initially be M-mode if unsupporting U-mode

This commit lets the mstatus.MPP be a valid value if unsupporting
U-mode. Without this commit, the mret may result in a corrupted state
without properly setting the MPP to M-mode (if unsupporting U-mode).