Thumb 2

Registered by Mounir Bsaibes on 2010-09-21

Ensure proper support for Thumb 2 in the kernel and ship Thumb 2 kernels
Ensure that the kernel compiles with Thumb 2 support (support should be there, but not yet thoroughly tested in kernel)
NO SESSION REQUIRED

Blueprint information

Status:
Complete
Approver:
Paul McKenney
Priority:
Medium
Drafter:
Loïc Minier
Direction:
Approved
Assignee:
Nicolas Pitre
Definition:
Approved
Series goal:
Accepted for 11.05
Implementation:
Implemented
Milestone target:
None
Started by
Mounir Bsaibes on 2011-01-19
Completed by
Mounir Bsaibes on 2011-11-17

Related branches

Sprints

Whiteboard

Specification shared with https://blueprints.launchpad.net/linaro/+spec/hardware-n-kernel-standard-architecture

Rejected: Fix Thumb-2 hardware single step debug emulation in the kernel (for reliable userspace single step in the presence of signals (not currently used; also the existing ARM implementation didn't fully work and has been removed from the kernel in the meantime).

Everything is done except for integrating the memcpy routines (which
was deprioritised) and handling userspace backtraces from the kernel
(which we effectively rejected as infeasible). The Postponed items will not be handled.
dave-martin-arm] Fix kprobes to work with Thumb 2 (DT victim, Tixy helping for 1111): POSTPONE
Work with toolchain group to ensure that the kernel can find user-space unwind tables (Linus/maintainership victim): POSTPONE
Integrate optimized non-NEON memcpy routines from toolchain group (no performance improvement, so not pulled in): POSTPONE

(?)

Work Items

Work items:
[dave-martin-arm] Fix ftrace and dynamic trace to work together on Thumb 2 (no action required): DONE
[dave-martin-arm] Fix SMP on UP to handle Thumb 2: DONE
[aneesh] Build uboot in Thumb 2 mode as experimental effort: DONE
Fix kernel handling of backtraces for Thumb 2 kernel code: DONE
Correctly handle kernel dumping of user-space backtraces: DONE

Dependency tree

* Blueprints in grey have been implemented.

This blueprint contains Public information 
Everyone can see this information.