Hardware assistance has long been used for logic level and functional unit level hardware debugging, as well as for machine language level software debugging. Such hardware assistance includes probes to detect signals, comparators to identify matches with expected patterns, buffers to record selected events, and independent logic and software to analyze and interpret the observed events. It can also include the ability to generate selected signals to stimulate the object being debugged and the ability to isolate it from normal changes so its state can be examined. Through knowledge of the data structures and algorithms used by the operating systems, and the runtime representation, register usage, and code bursts produced by compilers, it is possible to take advantage of such hardware assistance in high-level debugging. High-level debugging here refers to debugging in terms of abstractions supported by the operating system and programming languages, as well as user defined abstractions built on top of these. This paper discusses design considerations behind a project to build such a hardware assisted high-level debugger.