1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright IBM Corp. 2017 4 */ 5 6 #include <linux/console.h> 7 #include <linux/kernel.h> 8 #include <linux/init.h> 9 #include <asm/sclp.h> 10 11 static void sclp_early_write(struct console *con, const char *s, unsigned int len) 12 { 13 __sclp_early_printk(s, len, 0); 14 } 15 16 static struct console sclp_early_console = { 17 .name = "earlysclp", 18 .write = sclp_early_write, 19 .flags = CON_PRINTBUFFER | CON_BOOT, 20 .index = -1, 21 }; 22 23 static int __init setup_early_printk(char *buf) 24 { 25 if (early_console) 26 return 0; 27 /* Accept only "earlyprintk" and "earlyprintk=sclp" */ 28 if (buf && strncmp(buf, "sclp", 4)) 29 return 0; 30 if (!sclp.has_linemode && !sclp.has_vt220) 31 return 0; 32 early_console = &sclp_early_console; 33 register_console(early_console); 34 return 0; 35 } 36 early_param("earlyprintk", setup_early_printk); 37