[GeoffR]

Here is a new Cyrillic keyboard patch that can be used as a template for other languages, to create a custom keypad to replace the extended Latin keypad that appears when you tap the "ÉÀÇ" key.

Note that the keyboard layout on the Aura HD/H2O is different than on other devices:

For the Aura HD/H2O this patch can replace the 34 letters on the second, third and bottom rows, but not the numerals on the top row.

For the Touch/Mini/Glo/Aura the keys that appear at the left of the second and third rows of the Aura HD/H2O keypad have moved to the top row, and there are 7 more keys that can be replaced on the top row, along with a duplicate "ł" key (Latin small letter L with stroke) that appears both on the top and bottom row.

Firmware 3.13.1 (libnickel.so.1.0.0):

Spoiler:

<Patch>
patch_name = `Cyrillic keyboard`
patch_enable = `no`
# Enable uppercase for `ß` key
replace_bytes = 84D690, 00 24, 01 24
# Replace layout sign
replace_string = C16AB4, `ÉÀÇ`, `абв`
# Change keyboard layout
base_address = C169D4
# Second row, left to right:
# (for Touch/Mini/Glo/Aura the first key moves to top row, first column.)
replace_string = 0000, `æ\0`, `й`
replace_string = 0004, `à\0`, `ц`
replace_string = 0008, `è\0`, `у`
replace_string = 000C, `ì\0`, `к`
replace_string = 0010, `ò\0`, `е`
replace_string = 0014, `ù\0`, `н`
replace_string = 0018, `á\0`, `г`
replace_string = 001C, `é\0`, `ш`
replace_string = 0020, `í\0`, `щ`
replace_string = 0024, `ó\0`, `з`
replace_string = 0028, `ú\0`, `х`
replace_string = 002C, `ý\0`, `ъ`
# Third row, left to right:
# (for Touch/Mini/Glo/Aura the first key moves to top row, second column.)
replace_string = 0030, `œ\0`, `ф`
replace_string = 0034, `â\0`, `ы`
replace_string = 0038, `ê\0`, `в`
replace_string = 003C, `î\0`, `а`
replace_string = 0040, `ô\0`, `п`
replace_string = 0044, `û\0`, `р`
replace_string = 0048, `ä\0`, `о`
replace_string = 004C, `ë\0`, `л`
replace_string = 0050, `ï\0`, `д`
replace_string = 0054, `ö\0`, `ж`
replace_string = 0058, `ü\0`, `э`
replace_string = 005C, `ÿ\0`, `ё`
# Bottom row, left to right:
replace_string = 0060, `ã\0`, `я`
replace_string = 0064, `ñ\0`, `ч`
replace_string = 0068, `õ\0`, `с`
replace_string = 006C, `å\0`, `м`
replace_string = 0070, `ß\0`, `и`
replace_string = 0074, `ç\0`, `т`
replace_string = 0078, `đ\0`, `ь`
replace_string = 007C, `ø\0`, `б`
replace_string = 0080, `ij\0`, `ю`
replace_string = 0084, `ł\0`, `.`
#
# Top row: Extra keys for Touch/Mini/Glo/Aura only.
# (This patch cannot change the top row of the AuraHD/H2O keypad.)
base_address = C18C50
# Top row: columns 1-2 (see first key of second/third rows above.)
# Top row: columns 3-5
replace_string = 0004, `þ\0`, `!`
replace_string = 0008, `š\0`, `"`
replace_string = 000C, `ž\0`, `?`
# Top row: column 6 is a duplicate of the last key on the bottom row.
# Top row: columns 7-10
replace_string = 0000, `ƒ\0`, `,`
replace_string = 0010, `μ\0`, `(`
replace_string = 0014, `ª\0`, `)`
replace_string = 0018, `º\0`, `-`
</Patch>