GLx Runner: four-CPU TXM debugging
Recorded from a real LLDB session.

Start the runner:
  ./runner --version duo --txm-only --max-cpus 4 --gdb 1234 --gdb-wait --break-after-cpu-boot --no-banner --disable-coredump

Start LLDB in another terminal:
  lldb --no-lldbinit

(lldb) gdb-remote 127.0.0.1:1234
Unable to find file with UUID 7A43864A-8C5F-3892-8578-1A5334A0D41A at address 0x4d68000
Unable to find file at address 0xfffff8001fbd0000
(lldb) (lldb) Process 1 stopped
* thread #1, stop reason = signal SIGTRAP
       frame #0: 0xfffffff017084000 
->  0xfffffff017084000: tbz    x18, #0x3f, 0xfffffff017084008
    0xfffffff017084004: b      0xfffffff01703dabc
    0xfffffff017084008: mov    x20, x0
    0xfffffff01708400c: ldr    x1, [x0]
Target 0: (No executable module.) stopped.
(lldb)  breakpoint set --address 0xfffffff01703da24
Breakpoint 1: address = 0xfffffff01703da24
(lldb) (lldb) continue
Process 1 resuming
(lldb) (lldb) Process 1 stopped
* thread #2, stop reason = breakpoint 1.1
       frame #0: 0xfffffff01703da24 
->  0xfffffff01703da24: mov    sp, x0
    0xfffffff01703da28: and    x0, x16, #0xffffffff
    0xfffffff01703da2c: cmp    x0, #0x0
    0xfffffff01703da30: b.eq   0xfffffff01703d8d4
Target 0: (No executable module.) stopped.
(lldb)  register read pc sp x0 x1
      pc = 0xfffffff01703da24
      sp = 0x000000000feebc00
      x0 = 0x000000000fee8000
      x1 = 0x0000000000000000
(lldb) (lldb) thread step-inst
(lldb) (lldb) Process 1 stopped
* thread #2, stop reason = instruction step into
       frame #0: 0xfffffff01703da28 
->  0xfffffff01703da28: and    x0, x16, #0xffffffff
    0xfffffff01703da2c: cmp    x0, #0x0
    0xfffffff01703da30: b.eq   0xfffffff01703d8d4
    0xfffffff01703da34: mov    x8, sp
Target 0: (No executable module.) stopped.
(lldb)  register read pc sp
      pc = 0xfffffff01703da28
      sp = 0x000000000fee8000
(lldb) (lldb) breakpoint delete 1
1 breakpoints deleted; 0 breakpoint locations disabled.
(lldb) (lldb) continue
Process 1 resuming
(lldb) (lldb) Process 1 stopped
* thread #1, stop reason = signal SIGTRAP
       frame #0: 0xfffffff0170842a4 
->  0xfffffff0170842a4: brk    #0x2002
    0xfffffff0170842a8: b      0xfffffff0170842b0
    0xfffffff0170842ac: tenter #0x0
    0xfffffff0170842b0: retab  
Target 0: (No executable module.) stopped.
(lldb)  thread list
Process 1 stopped
* thread #1: tid = 0x0001, 0xfffffff0170842a4, stop reason = signal SIGTRAP
  thread #2: tid = 0x0002, 0xfffffff0170842a4
  thread #3: tid = 0x0003, 0xfffffff0170842a4
  thread #4: tid = 0x0004, 0xfffffff0170842a4
(lldb) (lldb) thread select 4
(lldb) (lldb) * thread #4
       frame #0: 0xfffffff0170842a4 
->  0xfffffff0170842a4: brk    #0x2002
    0xfffffff0170842a8: b      0xfffffff0170842b0
    0xfffffff0170842ac: tenter #0x0
    0xfffffff0170842b0: retab  
(lldb)  register read pc sp tpidr_el1
      pc = 0xfffffff0170842a4
      sp = 0x000000000fef3b60
tpidr_el1 = 0x0000000000000000
(lldb) (lldb) thread select 1
(lldb) (lldb) memory read --size 4 --format x --count 4 $pc
* thread #1, stop reason = signal SIGTRAP
       frame #0: 0xfffffff0170842a4 
->  0xfffffff0170842a4: brk    #0x2002
    0xfffffff0170842a8: b      0xfffffff0170842b0
    0xfffffff0170842ac: tenter #0x0
    0xfffffff0170842b0: retab  
0xfffffff0170842a4: 0xd4240040 0x14000002 0xd4e00000 0xd65f0fff
(lldb) (lldb) disassemble --start-address $pc --count 6
->  0xfffffff0170842a4: brk    #0x2002
    0xfffffff0170842a8: b      0xfffffff0170842b0
    0xfffffff0170842ac: tenter #0x0
    0xfffffff0170842b0: retab  
    0xfffffff0170842b4: pacibsp 
    0xfffffff0170842b8: mov    x16, #0x300000000000000 ; =216172782113783808 
(lldb)