Advanced Operating Systems   COMP9242 2002/S2

UNSW

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Administration               
- Notices
- Course Intro
- Consultations
# On-line Survey (closed)
- Survey Results
 
Work
- Lectures
- Milestone 0
- Project Admin
- Project Spec
- Project FAQ
- Exam
 
Documentation
- ASysT Lab
- L4 source browser
- Sulima ISA Simulator
- R4x00 ISA Summary 
- MIPS R4700 Reference - MIPS R4000 User Manual 
- Network Driver
- GT64111
 
Related Info
- Aurema OS Prize
- OS Hall of Fame
 
History
- 2000
- 1999
- 1998
 
Staff
- Gernot Heiser (LiC)

 

Memory message format

message header

fpage descriptors

by-value data

string dopes

• Fpages are expected only if
  • the -bit is set in the message descriptor, and
  • all register data consists of valid fpages.
• Fpage processing stops if invalid fpage descriptor found.
• Remainder of data (up to size given in header) is simply copied.
• String descriptors (``dopes'') immediately follow in-line data in memory.

Note: present R4k implementation allows no more than 4 fpages
(no fpage descriptors in memory).

This is not a problem in practice.

.