1 /*
2  * arch/h8300/kernel/sim-console.c
3  *
4  *  Copyright (C) 2015 Yoshinori Sato <ysato@users.sourceforge.jp>
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License.  See the file "COPYING" in the main directory of this archive
8  * for more details.
9  */
10 #include <linux/console.h>
11 #include <linux/init.h>
12 #include <linux/serial_core.h>
13 
sim_write(struct console * con,const char * s,unsigned n)14 static void sim_write(struct console *con, const char *s, unsigned n)
15 {
16 	register const char *_ptr __asm__("er1") = s;
17 	register const unsigned _len __asm__("er2") = n;
18 
19 	__asm__("sub.l er0,er0\n\t"		/* er0 = 1 (stdout) */
20 		"inc.l #1,er0\n\t"
21 		".byte 0x5e,0x00,0x00,0xc7\n\t" /* jsr @0xc7 (sys_write) */
22 		: : "g"(_ptr), "g"(_len):"er0");
23 }
24 
sim_setup(struct earlycon_device * device,const char * opt)25 static int __init sim_setup(struct earlycon_device *device, const char *opt)
26 {
27 	device->con->write = sim_write;
28 	return 0;
29 }
30 
31 EARLYCON_DECLARE(h8sim, sim_setup);
32