Improved UTF-8 support for the Linux kernel

Note: this site is currently focussing mainly on Linux kernel 2.6.x. I have only backported one of them to 2.4 so far.

Introduction

The Linux kernel has some support for UTF-8 keyboard input, but it has some gaping holes that make it awkward to use, especially when using the console. I have been working on some patches to improve the situation.

My current goal is to have no regressions. That is: I want to be able to do everything in UTF-8 mode that is possible to do in non-Unicode mode. This in itself doesn't give you any incentive to switch to using Unicode. It simply removes the disincentives.

After that, my next goal will be to write a new input method, since the existing input method for extended Latin characters is very 8-bit centric, and is not easily extended to cover the wide range of Unicode characters available.

Patches

• p1_conv_8bit_to_uni.patch: This patch makes the keyboard convert all 8-bit characters into their UTF-8 equivalent when the the keyboard is in unicode mode. It uses the vt's encoding table, so make sure you do a "setfont -m 8859-2" or whatever your favorite 8-bit encoding is.
• p2_selection.patch: This patch allows you to copy and paste UTF-8 when the keyboard is in Unicode mode. Previously, copy and paste would always use an 8-bit encoding.
• p3_extended_utf8.patch: This patch allows you to enter any Unicode value using the Alt-nnnn mechanism. Previously, it was restricted to the BMP, i.e. the first 65536 Unicode characters.
• fbcon.patch: This patch fixes a small problem with the framebuffer console. Previously, incorrect characters were displayed under the selection cursor when the screen is using a 512-character font. (This patch has been submitted to fbdev, and will eventually make its way into the mainstream kernel.)
• ttyutf8.patch: This patch adds a new flag to the TTY to tell its line editor to use UTF-8. This makes the delete key delete a whole character instead of just one byte. (The TTY line editor is what you get when you type "cat" at a shell prompt.) This feature is part of the mainstream kernel as of 2.6.4, so I have removed it from my collection of patches.

Downloads

The patches for the 2.6 kernel can be downloaded in two forms. Take your pick.

• Change Log
• Combined patch for Linux 2.6.4: All the above patches rolled into one.
• Individual patches for Linux 2.6.4: All the above patches provided separately so that you can pick and choose which ones to apply. Note that some of them apply on top of others. For a clean patching experience, apply the patches in alphabetical order.
• sttyutf8 utility: A small Perl script for manipulating the new UTF8 flag in the TTY. Type "sttyutf8 on" to enable UTF-8 mode, "sttyutf8 off" to disable it, or "sttyutf8" by itself to find out the current setting without changing it.
• Patch for Linux 2.4.21: Currently the only patch that I've backported to Linux 2.4 is p1_conv_8bit_to_uni.patch.

Obsolete Downloads

All of the older downloads that were available from this site are archived here.