Elizabeth Liu

US Patent:

56153317, Mar 25, 1997

Filed:

Jun 23, 1994

Appl. No.:

8/265376

Inventors:

Arman Toorians - Santa Clara CA
Elizabeth Q. Liu - San Jose CA

Assignee:

Phoenix Technologies Ltd. - Santa Clara CA

International Classification:

G06F 944

US Classification:

39518207

Abstract:

A system and method for debugging a development computing system is disclosed. The BIOS in the development system includes a debug engine. Interrupt-handling macros in BIOS include an entry macro to direct debug output codes (e. g. , port 80 and beep codes) to the debug engine. A near entry macro is added to BIOS-segment macros (e. g. , F000 segment) which provides the offset of the debug engine. A far entry macro is added to non-BIOS-segment macros which provides the segment and offset of the debug engine. The debug engine sends the output codes to a remote host computer via a communication channel (e. g. , a bi-directional parallel port) on the development system. The debug engine also saves the contents of various registers on the development system to the host computer. Thus, the invention can be used in a stackelss environment. Debug commands (e. g.