1 /* $NetBSD: gatea20.c,v 1.4 2001/05/19 18:15:14 jdolecek Exp $ */ 2 3 /* extracted from freebsd:sys/i386/boot/biosboot/io.c */ 4 5 #include <sys/types.h> 6 #include <machine/pio.h> 7 8 #include <lib/libsa/stand.h> 9 10 #include "libi386.h" 11 #include "biosmca.h" 12 13 #define K_RDWR 0x60 /* keyboard data & cmds (read/write) */ 14 #define K_STATUS 0x64 /* keyboard status */ 15 #define K_CMD 0x64 /* keybd ctlr command (write-only) */ 16 17 #define K_OBUF_FUL 0x01 /* output buffer full */ 18 #define K_IBUF_FUL 0x02 /* input buffer full */ 19 20 #define KC_CMD_WIN 0xd0 /* read output port */ 21 #define KC_CMD_WOUT 0xd1 /* write output port */ 22 #define KB_A20 0x9f /* enable A20, 23 reset (!), 24 enable output buffer full interrupt 25 enable data line 26 disable clock line */ 27 28 /* 29 * Gate A20 for high memory 30 */ 31 static unsigned char x_20 = KB_A20; 32 void gateA20() 33 { 34 __asm("pushfl ; cli"); 35 #ifdef SUPPORT_PS2 36 /* 37 * Check if the machine is PS/2 L40 via biosmca_model, which is 38 * initialized before gateA20() is called. 39 */ 40 if (biosmca_ps2model == 0xf82) 41 outb(0x92, 0x2); 42 else { 43 #endif 44 while (inb(K_STATUS) & K_IBUF_FUL); 45 while (inb(K_STATUS) & K_OBUF_FUL) 46 (void)inb(K_RDWR); 47 48 outb(K_CMD, KC_CMD_WOUT); 49 delay(100); 50 while (inb(K_STATUS) & K_IBUF_FUL); 51 outb(K_RDWR, x_20); 52 delay(100); 53 while (inb(K_STATUS) & K_IBUF_FUL); 54 #ifdef SUPPORT_PS2 55 } 56 #endif 57 __asm("popfl"); 58 } 59