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
memconsole_read(struct file * filp,struct kobject * kobp,struct bin_attribute * bin_attr,char * buf,loff_t pos,size_t count)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
memconsole_setup(ssize_t (* read_func)(char *,loff_t,size_t))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
memconsole_sysfs_init(void)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
memconsole_exit(void)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
