Experiences with the Universally Live Debugger

Boris Shingarov

Liveness

  • Wonderful world of live Smalltalk objects
  • but...

Optical Scopes

  • First implementation concentrated on simulation
    • Simics
    • GEM5
  • Used to debug TAM, VLS
  • Turns out, useful far outside of simulation

ULD

  • Mother Smalltalk
  • Target Smalltalk
  • GDB RSP

Goals

  • Optical Scope
  • Experimentation, using magic
    • Dealing with incomplete system
    • Early delivery

Demo

  • Example: debug TAM on real MPC5125

Targets

  • PowerPC: real & GEM5
  • MIPS: real & GEM5
  • SPARC: S1 on Virtex-5 & GEM5
  • ARM-A: real & GEM5
  • ARM-M: ← bummer!
  • RISC-V: GEM5 & 32-bit E310 in Artix-7

More Possibilities

  • SPARC-T1 Experiment vs RISC-V OpenOCD JTAG

Going Full Circle: Simulation

  • Obvious: removing HW debug limitations
  • Obvious: Repeatability
  • Obvious: Reversibility
  • Less Obvious: Non-traditional metrics