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 char *memconsole_baseaddr; 26 static size_t memconsole_length; 27 28 static ssize_t memconsole_read(struct file *filp, struct kobject *kobp, 29 struct bin_attribute *bin_attr, char *buf, 30 loff_t pos, size_t count) 31 { 32 return memory_read_from_buffer(buf, count, &pos, memconsole_baseaddr, 33 memconsole_length); 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(void *baseaddr, size_t length) 42 { 43 memconsole_baseaddr = baseaddr; 44 memconsole_length = length; 45 } 46 EXPORT_SYMBOL(memconsole_setup); 47 48 int memconsole_sysfs_init(void) 49 { 50 memconsole_bin_attr.size = memconsole_length; 51 return sysfs_create_bin_file(firmware_kobj, &memconsole_bin_attr); 52 } 53 EXPORT_SYMBOL(memconsole_sysfs_init); 54 55 void memconsole_exit(void) 56 { 57 sysfs_remove_bin_file(firmware_kobj, &memconsole_bin_attr); 58 } 59 EXPORT_SYMBOL(memconsole_exit); 60 61 MODULE_AUTHOR("Google, Inc."); 62 MODULE_LICENSE("GPL"); 63