《ORANGE’S：一个操作系统的实现》读书笔记（二十四）进程间通信（二）文章代码

#include "type.h" #include "const.h" #include "protect.h" #include "console.h" #include "tty.h" #include "proc.h" #include "proto.h" #include "string.h" #include "global.h" #include "keyboard.h" #include "keymap.h" PRIVATE KB_INPUT kb_in; PRIVATE int code_with_E0; PRIVATE int shift_l; /* l shift state */ PRIVATE int shift_r; /* r shift state */ PRIVATE int alt_l; /* l alt state */ PRIVATE int alt_r; /* r alt state */ PRIVATE int ctrl_l; /* l ctrl state */ PRIVATE int ctrl_r; /* r ctrl state */ PRIVATE int caps_lock; /* Caps Lock */ PRIVATE int num_lock; /* Num Lock */ PRIVATE int scroll_lock; /* Scroll Lock */ PRIVATE int column; PRIVATE int caps_lock; /* Caps Lock */ PRIVATE int num_lock; /* Num Lock */ PRIVATE int scroll_lock; /* Scroll Lock */ PRIVATE u8 get_byte_from_kbuf(); PRIVATE void kb_wait(); PRIVATE void kb_ack(); PRIVATE void set_leds(); PUBLIC void keyboard_handler(int irq) { u8 scan_code = in_byte(KB_DATA); if (kb_in.count < KB_IN_BYTES) { *(kb_in.p_head) = scan_code; kb_in.p_head++; if (kb_in.p_head == kb_in.buf + KB_IN_BYTES) { kb_in.p_head = kb_in.buf; } kb_in.count++; } } PUBLIC void init_keyboard() { kb_in.count = 0; kb_in.p_head = kb_in.p_tail = kb_in.buf; shift_l = shift_r = 0; alt_l = alt_r = 0; ctrl_l = ctrl_r = 0; caps_lock = 0; num_lock = 1; scroll_lock = 0; set_leds(); put_irq_handler(KEYBOARD_IRQ, keyboard_handler); /* 设定键盘中断处理程序 */ enable_irq(KEYBOARD_IRQ); /* 开启键盘中断 */ } PUBLIC void keyboard_read(TTY* p_tty) { u8 scan_code; int make; /* TURE: make; FALSE: break. */ u32 key = 0; /* 用一个整数来表示一个键。比如：如果 Home 被按下，则 key 值将为定义在 keyboard.h 中的 'HOME' */ u32* keyrow; /* 指向 keymap[] 的某一行 */ if (kb_in.count > 0) { code_with_E0 = 0; scan_code = get_byte_from_kbuf(); /* 下面开始解析扫描码 */ if (scan_code == 0xE1) { int i; u8 pausebrk_scode[] = {0xE1, 0x1D, 0x45, 0xE1, 0x9D, 0xC5}; int is_pausebreak = 1; for (i = 1; i < 6; i++) { if (get_byte_from_kbuf() != pausebrk_scode[i]) { is_pausebreak = 0; break; } } if (is_pausebreak) { key = PAUSEBREAK; } } else if (scan_code == 0xE0) { scan_code = get_byte_from_kbuf(); /* PrintScreen 被按下 */ if (scan_code == 0x2A) { if (get_byte_from_kbuf() == 0xE0) { if (get_byte_from_kbuf() == 0x37) { key = PRINTSCREEN; make = 1; } } } /* PrintScreen 被释放 */ if (scan_code == 0xB7) { if (get_byte_from_kbuf() == 0xE0) { if (get_byte_from_kbuf() == 0xAA) { key = PRINTSCREEN; make = 0; } } } /* 不是PrintScreen，此时scan_code为0xE0紧跟的那个值 */ if (key == 0) { code_with_E0 = 1; } } if ((key != PAUSEBREAK) && (key != PRINTSCREEN)) { /* 首先判断是 Make Code 还是 Break Code */ make = (scan_code & FLAG_BREAK ? FALSE : TRUE); /* 先定位到 keymap 中的行 */ keyrow = &keymap[(scan_code & 0x7F) * MAP_COLS]; column = 0; int caps = shift_l || shift_r; if (caps_lock) { if ((keyrow[0] >= 'a') && (keyrow[0] <= 'z')) { caps = !caps; } } if (caps) { column = 1; } if (code_with_E0) { column = 2; } key = keyrow[column]; switch(key) { case SHIFT_L: shift_l = make; break; case SHIFT_R: shift_r = make; break; case CTRL_L: ctrl_l = make; break; case CTRL_R: ctrl_r = make; break; case ALT_L: alt_l = make; break; case ALT_R: alt_r = make; break; case CAPS_LOCK: if (make) { caps_lock = !caps_lock; set_leds(); } break; case NUM_LOCK: if (make) { num_lock = !num_lock; set_leds(); } break; case SCROLL_LOCK: if (make) { scroll_lock = !scroll_lock; set_leds(); } break; default: break; } if (make) { /* 忽略 Break Code */ int pad = 0; /* 首先处理小键盘 */ if ((key >= PAD_SLASH) && (key <= PAD_9)) { pad = 1; switch(key) { case PAD_SLASH: key = '/'; break; case PAD_STAR: key = '*'; break; case PAD_MINUS: key = '-'; break; case PAD_PLUS: key = '+'; break; case PAD_ENTER: key = ENTER; break; default: if (num_lock && (key >= PAD_0) && (key <= PAD_9)) { key = key - PAD_0 + '0'; } else if (num_lock && (key == PAD_DOT)) { key = '.'; } else { switch(key) { case PAD_HOME: key = HOME; break; case PAD_END: key = END; break; case PAD_PAGEUP: key = PAGEUP; break; case PAD_PAGEDOWN: key = PAGEDOWN; break; case PAD_INS: key = INSERT; break; case PAD_UP: key = UP; break; case PAD_DOWN: key = DOWN; break; case PAD_LEFT: key