The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 28, 1989
Filed:
Oct. 28, 1985
Applicant:
Inventors:
Michael J Mahon, San Jose, CA (US);
Allen Baum, Palo Alto, CA (US);
William R Bryg, Saratoga, CA (US);
Terrence C Miller, Menlo Park, CA (US);
Assignee:
Hewlett-Packard Company, Palo Alto, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F / ;
U.S. Cl.
CPC ...
364200 ; 178 29 ; 178 37 ;
Abstract
A low overhead way for insuring that only routines of sufficient privilege can execute on a secured page of memory in an hierarchial computer system, and for raising the privilege level of a low privilege process in an orderly and secure way is presented. This is done through the execution of a single 'gateway' branch instruction standing between a procedure call by a lower privileged routine, such as a user program, and an operating system itself.