ViperOS/VKernel/Kernel/drivers/input/keyboard/keyboard.vp

import asm
import intr.idt as idt
import drivers.serial.uart.serial as serial
import platform.pch.pic as pic
import string
import t, c


define KBD_DATA    = 0x60
define KBD_STATUS  = 0x64
define KBD_COMMAND = 0x64

define KBD_BUF_SIZE = 1024

define KEY_RELEASED = 0x80

buffer:      [KBD_BUF_SIZE]uint8
buf_head:    static uint32 = 0
buf_tail:    static uint32 = 0
buf_count:   static uint32 = 0
kbd_irq_cnt: static uint64 = 0
# 硬件初始化只做一次（init 有多个调用点，见 init() 内注释）
_kbd_inited: static int = 0

shift_l:   static uint8 = 0
shift_r:   static uint8 = 0
ctrl_l:    static uint8 = 0
alt_l:     static uint8 = 0
caps_lock: static uint8 = 0

scancode_set1: [128]char = [
    '\0', '\x1b', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '-', '=', '\b',
    '\t', 'q', 'w', 'e', 'r', 't', 'y', 'u', 'i', 'o', 'p', '[', ']', '\n',
    '\0', 'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', ';', "'", '`', '\0',
    '\\', 'z', 'x', 'c', 'v', 'b', 'n', 'm', ',', '.', '/', '\0', '\0', '\0', ' ',
    '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '-', '8', '6', '2', '\0',
    '1', '+', '4', '5', '3', '0', '.', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0',
    '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0',
    '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0',
    '\0'
]

scancode_set1_shift: [128]char = [
    '\0', '\x1b', '!', '@', '#', '$', '%', '^', '&', '*', '(', ')', '_', '+', '\b',
    '\t', 'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', 'O', 'P', '{', '}', '\n',
    '\0', 'A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L', ':', '"', '~', '\0',
    '|', 'Z', 'X', 'C', 'V', 'B', 'N', 'M', '<', '>', '?', '\0', '\0', '\0', ' ',
    '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '-', '8', '6', '2', '\0',
    '1', '+', '4', '5', '3', '0', '.', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0',
    '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0',
    '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0',
    '\0'
]

# 清空 8042 输出缓冲（上电自检字节 / 遗留 ACK / 读 CCB 时压入的值）
def _drain_outbuf():
    drain: uint32 = 0
    while (asm.inb(KBD_STATUS) & 0x01) != 0:
        asm.inb(KBD_DATA)
        drain += 1
        if drain > 1000: break

def _wait_read():
    timeout: uint32 = 100000
    while timeout > 0:
        if (asm.inb(KBD_STATUS) & 0x01) != 0: return
        timeout -= 1

def _wait_write():
    timeout: uint32 = 100000
    while timeout > 0:
        if (asm.inb(KBD_STATUS) & 0x02) == 0: return
        timeout -= 1

def irq_handler() -> int:
    global buf_head, buf_tail, buf_count, kbd_irq_cnt
    kbd_irq_cnt += 1
    # 0x60 是键盘/鼠标**共享**的输出缓冲：AUX 位（0x64 bit5）置位表示这是鼠标字节，
    # 不属于键盘 —— 直接读走会让鼠标驱动永远拿不到（本 ISR 只收键盘字节）。
    st: uint8 = asm.inb(KBD_STATUS)
    if (st & 0x20) != 0:
        return 0
    scancode: uint8 = asm.inb(KBD_DATA)
    if buf_count < KBD_BUF_SIZE:
        buffer[buf_tail] = scancode
        buf_tail = buf_tail + 1
        if buf_tail >= KBD_BUF_SIZE:
            buf_tail = 0
        buf_count += 1
    return 0

def read_scancode() -> uint8:
    global buf_head, buf_count
    asm.cli()
    if buf_count == 0:
        asm.sti()
        return 0
    code: uint8 = buffer[buf_head]
    buf_head = buf_head + 1
    if buf_head >= KBD_BUF_SIZE:
        buf_head = 0
    buf_count -= 1
    asm.sti()
    return code

def scancode_to_ascii(scancode: uint8) -> char:
    code: uint8 = uint8(scancode & ~uint8(KEY_RELEASED))
    if code >= 128: return '\0'
    shifted: bool = (shift_l or shift_r) != 0
    if caps_lock and code >= 0x10 and code <= 0x32:
        shifted = not shifted
    if shifted:
        return scancode_set1_shift[code]
    return scancode_set1[code]

def has_data() -> int:
    return buf_count

def init():
    global _kbd_inited
    # 幂等：init() 有两个调用点（devfs 注册 /dev/input/keyboard、kbd_svc.start），
    # 硬件初始化只允许做一次。
    if _kbd_inited != 0:
        return
    _kbd_inited = 1

    # 清空控制器输出缓冲（上电自检字节 / 上一次遗留的 ACK 等）
    _drain_outbuf()

    # 读-改-写 CCB（与 mouse.init 同款写法）：
    #   bit0=1 使能键盘 IRQ1；bit6=1 启用 scancode set1 翻译；bit4=0 使能键盘时钟。
    # 这里**不再发 0xAD/0xAE**（禁用 / 启用键盘接口）：QEMU 下 0xAD 之后那次 CCB 回写
    # 经常失败（键盘数据串入 CCB 读取、回读为 0），0xAE 便恢复不了 ⇒ 键盘接口停在
    # 禁用态 ⇒ 之后按键完全不产生任何字节/IRQ1（现场：ki 恒为 2/3、无任何键盘字节）。
    # 鼠标没有这个序列，所以它一直正常 —— 键盘对齐鼠标的写法即可。
    #
    # 全程屏蔽 IRQ1：读 CCB 的 0x20 命令会把 CCB 值放进 0x60 输出缓冲并拉高 IRQ1，
    # IRQ1 handler 一旦运行就会把这个字节当扫描码读走（现场：handler 装上后读到
    # sc=0x47，正是鼠标清 bit5 后的 CCB），这里的 inb(0x60) 便只能拿到残留值 ⇒ 可能把
    # 错误的 CCB 写回。屏蔽期 8259 仍会锁存请求，所以解屏蔽前先清空输出缓冲，
    # 避免解屏蔽瞬间摄入一个陈旧字节。
    pic.setMask(1)

    _wait_write()
    asm.outb(KBD_COMMAND, 0x20)
    _wait_read()
    ccb: uint8 = asm.inb(KBD_DATA)
    ccb = ccb | 0x01
    ccb = ccb | 0x40
    ccb = ccb & 0xEF

    _wait_write()
    asm.outb(KBD_COMMAND, 0x60)
    _wait_write()
    asm.outb(KBD_DATA, ccb)

    # 回读校验：CCB 没写进去 ⇒ 扫描不使能 ⇒ 按键永不产生字节（必须报错，不能静默继续）
    _wait_write()
    asm.outb(KBD_COMMAND, 0x20)
    _wait_read()
    rb: uint8 = asm.inb(KBD_DATA)
    if rb != ccb:
        serial.puts("[kbd] CCB write verify failed\n")
        pic.clearMask(1)
        return

    # 使能键盘扫描（0xF4）：非 0xFA ⇒ 命令没送达键盘
    _wait_write()
    asm.outb(KBD_DATA, 0xF4)
    _wait_read()
    ack: uint8 = asm.inb(KBD_DATA)
    if ack != 0xFA:
        serial.puts("[kbd] scan-enable not ACKed\n")

    _drain_outbuf()
    # 解屏蔽 IRQ1（对齐 mouse.init 的 pic.clearMask(12)），再装 handler
    pic.clearMask(1)
    idt.irqInstallHandler(1, irq_handler, "keyboard")