1 /* 2 * memconsole.c 3 * 4 * Architecture-independent parts of the memory based BIOS console. 5 * 6 * Copyright 2017 Google Inc. 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License v2.0 as published by 10 * the Free Software Foundation. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 */ 17 18 #include <linux/init.h> 19 #include <linux/sysfs.h> 20 #include <linux/kobject.h> 21 #include <linux/module.h> 22 23 #include "memconsole.h" 24 25 static ssize_t (*memconsole_read_func)(char *, loff_t, size_t); 26 27 static ssize_t memconsole_read(struct file *filp, struct kobject *kobp, 28 struct bin_attribute *bin_attr, char *buf, 29 loff_t pos, size_t count) 30 { 31 if (WARN_ON_ONCE(!memconsole_read_func)) 32 return -EIO; 33 return memconsole_read_func(buf, pos, count); 34 } 35 36 static struct bin_attribute memconsole_bin_attr = { 37 .attr = {.name = "log", .mode = 0444}, 38 .read = memconsole_read, 39 }; 40 41 void memconsole_setup(ssize_t (*read_func)(char *, loff_t, size_t)) 42 { 43 memconsole_read_func = read_func; 44 } 45 EXPORT_SYMBOL(memconsole_setup); 46 47 int memconsole_sysfs_init(void) 48 { 49 return sysfs_create_bin_file(firmware_kobj, &memconsole_bin_attr); 50 } 51 EXPORT_SYMBOL(memconsole_sysfs_init); 52 53 void memconsole_exit(void) 54 { 55 sysfs_remove_bin_file(firmware_kobj, &memconsole_bin_attr); 56 } 57 EXPORT_SYMBOL(memconsole_exit); 58 59 MODULE_AUTHOR("Google, Inc."); 60 MODULE_LICENSE("GPL"); 61