1 /* 2 * Copyright 2004-2011, Axel Dörfler, axeld@pinc-software.de. 3 * Distributed under the terms of the MIT License. 4 */ 5 6 7 #include "keyboard.h" 8 #include "bios.h" 9 10 #include <boot/platform.h> 11 12 13 /*! Note, checking for keys doesn't seem to work in graphics 14 mode, at least in Bochs. 15 */ 16 static uint16 17 check_for_key(void) 18 { 19 bios_regs regs; 20 regs.eax = 0x0100; 21 call_bios(0x16, ®s); 22 23 // the zero flag is set when there is no key stroke waiting for us 24 if (regs.flags & ZERO_FLAG) 25 return 0; 26 27 // remove the key from the buffer 28 regs.eax = 0; 29 call_bios(0x16, ®s); 30 31 return regs.eax & 0xffff; 32 } 33 34 35 extern "C" void 36 clear_key_buffer(void) 37 { 38 while (check_for_key() != 0) 39 ; 40 } 41 42 43 extern "C" union key 44 wait_for_key(void) 45 { 46 union key key; 47 do { 48 key.ax = check_for_key(); 49 } while (key.ax == 0); 50 51 return key; 52 } 53 54 55 extern "C" uint32 56 check_for_boot_keys(void) 57 { 58 bios_regs regs; 59 uint32 options = 0; 60 uint32 keycode = 0; 61 regs.eax = 0x0200; 62 call_bios(0x16, ®s); 63 // Read Keyboard flags. bit 0 LShift, bit 1 RShift 64 if ((regs.eax & 0x03) != 0) { 65 // LShift or RShift - option menu 66 options |= BOOT_OPTION_MENU; 67 } else { 68 keycode = boot_key_in_keyboard_buffer(); 69 if (keycode == 0x3920) { 70 // space - option menu 71 options |= BOOT_OPTION_MENU; 72 } else if (keycode == 0x011B) { 73 // ESC - debug output 74 options |= BOOT_OPTION_DEBUG_OUTPUT; 75 } 76 } 77 78 dprintf("options = %d\n", options); 79 return options; 80 } 81 82