[GeoffR]

This patch replaces the keyboard's extended Latin characters with Arabic ones:

Spoiler:

<Patch>
patch_name = `Arabic keyboard`
patch_enable = `yes`
# Replace layout sign
replace_bytes = D6C4F8, C3 89 C3 80 C3 87, D8 B9 00 00 00 00
# Change keyboard layout
base_address = D6C418
# Top row
replace_bytes = 0000, C3 A6, D8 B0
replace_bytes = 0030, C5 93, D8 B6
# Second row
replace_bytes = 0004, C3 A0, D8 B5
replace_bytes = 0008, C3 A8, D8 AB
replace_bytes = 000C, C3 AC, D9 82
replace_bytes = 0010, C3 B2, D9 81
replace_bytes = 0014, C3 B9, D8 BA
replace_bytes = 0018, C3 A1, D8 B9
replace_bytes = 001C, C3 A9, D9 87
replace_bytes = 0020, C3 AD, D8 AE
replace_bytes = 0024, C3 B3, D8 AD
replace_bytes = 0028, C3 BA, D8 AC
replace_bytes = 002C, C3 BD, D8 AF
# Third row
replace_bytes = 0034, C3 A2, D8 B4
replace_bytes = 0038, C3 AA, D8 B3
replace_bytes = 003C, C3 AE, D9 8A
replace_bytes = 0040, C3 B4, D8 A8
replace_bytes = 0044, C3 BB, D9 84
replace_bytes = 0048, C3 A4, D8 A7
replace_bytes = 004C, C3 AB, D8 AA
replace_bytes = 0050, C3 AF, D9 86
replace_bytes = 0054, C3 B6, D9 85
replace_bytes = 0058, C3 BC, D9 83
replace_bytes = 005C, C3 BF, D8 B7
# Bottom row
replace_bytes = 0060, C3 A3, D8 A6
replace_bytes = 0064, C3 B1, D8 A1
replace_bytes = 0068, C3 B5, D8 A4
replace_bytes = 006C, C3 A5, D8 B1
replace_bytes = 0070, C3 9F, D9 89
replace_bytes = 0074, C3 A7, D8 A9
replace_bytes = 0078, C4 91, D9 88
replace_bytes = 007C, C3 B8, D8 B2
replace_bytes = 0080, C4 B3, D8 B8
replace_bytes = 0084, C5 82, 2E 00
</Patch>

After a device restart the Arabic glyphs won't display properly until a book has been opened and the font menu (Aa) accessed.

The shift key doesn't do anything to the Arabic keys, is that a fault or doesn't Arabic have upper and lower cases?

Not all of the extended keypad is used, maybe possible to replace some more of the keys on the upper row with Arabic keys?