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# keyboard scancode table
# ts is not a good way to write a driver lmao
const KBD = " 1234567890-= qwertyuiop[] asdfghjkl;'` \\zxcvbnm,./ "
# same layout, shifted. index 42 (left shift) / 54 (right shift) stay blank
const KBD_SHIFT = " !@#$%^&*()_+ QWERTYUIOP{} ASDFGHJKL:\"~ |ZXCVBNM<>? "
# 8259 pic
fn pic_remap() do
outb(0x20, 0x11) outb(0xa0, 0x11)
outb(0x21, 0x20) outb(0xa1, 0x28)
outb(0x21, 0x04) outb(0xa1, 0x02)
outb(0x21, 0x01) outb(0xa1, 0x01)
outb(0x21, 0xff) outb(0xa1, 0xff)
end
fn pic_unmask(line) outb(0x21, inb(0x21) band (255 bxor (1 shl line)))
# 8253/8254 pit channel 0, mode 3 (square wave)
# divisor 11931 -> ~100 hz (1193182 / 11931)
# the isr just counts ticks
fn pit_init() do
outb(0x43, 0x36)
outb(0x40, 11931 band 0xff)
outb(0x40, (11931 shr 8) band 0xff)
end
# she stroke my keys till i handle
# no fr this is just a key stroke handler
global shell = { line = "", shift = :false }
# decode one scancode to a character string, or :nil for releases / modifiers /
# unmapped keys. this is the only scancode decoder now, used by both the shell
# and the read() syscall
fn decode_key(code) do
if code == 0x2a or code == 0x36 do shell.shift = :true return :nil end # shift down
if code == 0xaa or code == 0xb6 do shell.shift = :false return :nil end # shift up
if code >= 128 return :nil # other releases
if code == 28 return "\n" # enter
if code == 14 return "\x08" # backspace
if code < 2 return :nil
if code >= KBD:len() return :nil
const ch = if shell.shift KBD_SHIFT[code] else KBD[code]
if ch == " " and code != 0x39 return :nil # blank cells = modifiers/unmapped
ch
end
global on_key = fn(code) do
const ch = decode_key(code)
if ch == :nil return :nil
# a process blocked in read() gets first dibs, if it takes the byte, the shell
# doesnt see it (the process echoes its own input via write())
if stdin_deliver(ch:ascii()) return :nil
# otherwise the shells line editor
if ch == "\n" do puts("\n") run(shell.line) shell.line = "" return :nil end
if ch == "\x08" do
if shell.line:len() > 0 do shell.line = shell.line:sub(0, shell.line:len() - 1) puts("\x08 \x08") end
return :nil
end
shell.line ~= ch
puts(ch)
end
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