Opened 15 years ago

Last modified 5 years ago

#11 new enhancement

Support PAE on ia32 — at Version 11

Reported by: Jakub Jermář Owned by: Martin Decky
Priority: minor Milestone:
Component: helenos/kernel/ia32 Version: mainline
Keywords: gsoc12, gsoc13, gsoc14, gsoc15, gsoc16, gsoc17, gsoc18 Cc:
Blocker for: Depends on: #3
See also:

Description (last modified by Martin Decky)

Add support for Physical Address Extension to our ia32 port so that more than 4G of physical memory can be addressed.

Details
On all currently supported 32-bit platforms (arm32, ia32, mips32, ppc32), HelenOS assumes 32-bit physical addresses. This allows the system to make use of 4G of physical memory in total. Some of these architectures, however, provide extensions (e.g. PAE on ia32, LPAE on arm32) that make it possible to address more physical memory by using wider physical addresses (e.g. 36-bit or 40-bit).

There are actually two goals for this project. The first is to modify HelenOS to use a dedicated type for representing physical addresses instead of the current uintptr_t or void *, because the assumption that both virtual and physical addresses have the same amount of bits will no longer hold. The second goal is to implement the actual support for PAE in the form of PAE page table format and PAE feature detection and initialization.

What Gains and Benefits will this bring?
By having the PAE support on ia32, HelenOS will be able to utilize more of the installed memory. HelenOS will also become ready to support similar features on other architectures (think LPAE on arm32).
Difficulty
Difficult
Required skills
Kernel programming skills are needed and the applicant should be strong in C and should have the ability to understand the HelenOS memory management subsystem quickly.
Documentation
Possible mentors
HelenOS Core Team, Jakub Jermar

Change History (11)

comment:1 by Martin Decky, 15 years ago

Milestone: 0.5.0

comment:2 by Jiri Svoboda, 15 years ago

Component: kernel/ia32

comment:3 by Jakub Jermář, 13 years ago

Depends on: #3

comment:4 by Jakub Jermář, 13 years ago

Milestone: 0.5.00.5.1

comment:5 by Jakub Jermář, 12 years ago

Keywords: gsoc12 added
Milestone: 0.5.00.5.1

comment:6 by Jakub Jermář, 12 years ago

Keywords: needswork added

comment:7 by Jakub Jermář, 12 years ago

Description: modified (diff)
Keywords: needswork removed

comment:8 by Jakub Jermář, 12 years ago

Description: modified (diff)

comment:9 by Jakub Jermář, 12 years ago

Description: modified (diff)

comment:10 by Jakub Jermář, 12 years ago

Description: modified (diff)

comment:11 by Martin Decky, 12 years ago

Description: modified (diff)
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