80 lines
1.7 KiB
C
Executable file
80 lines
1.7 KiB
C
Executable file
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Based on arch/arm/kernel/atags_proc.c
|
|
*/
|
|
|
|
#include <linux/fs.h>
|
|
#include <linux/init.h>
|
|
#include <linux/printk.h>
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/string.h>
|
|
|
|
#include <asm/bootinfo.h>
|
|
#include <asm/byteorder.h>
|
|
|
|
|
|
static char bootinfo_tmp[1536] __initdata;
|
|
|
|
static void *bootinfo_copy;
|
|
static size_t bootinfo_size;
|
|
|
|
static ssize_t bootinfo_read(struct file *file, char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
return simple_read_from_buffer(buf, count, ppos, bootinfo_copy,
|
|
bootinfo_size);
|
|
}
|
|
|
|
static const struct file_operations bootinfo_fops = {
|
|
.read = bootinfo_read,
|
|
.llseek = default_llseek,
|
|
};
|
|
|
|
void __init save_bootinfo(const struct bi_record *bi)
|
|
{
|
|
const void *start = bi;
|
|
size_t size = sizeof(bi->tag);
|
|
|
|
while (be16_to_cpu(bi->tag) != BI_LAST) {
|
|
uint16_t n = be16_to_cpu(bi->size);
|
|
size += n;
|
|
bi = (struct bi_record *)((unsigned long)bi + n);
|
|
}
|
|
|
|
if (size > sizeof(bootinfo_tmp)) {
|
|
pr_err("Cannot save %zu bytes of bootinfo\n", size);
|
|
return;
|
|
}
|
|
|
|
pr_info("Saving %zu bytes of bootinfo\n", size);
|
|
memcpy(bootinfo_tmp, start, size);
|
|
bootinfo_size = size;
|
|
}
|
|
|
|
static int __init init_bootinfo_procfs(void)
|
|
{
|
|
/*
|
|
* This cannot go into save_bootinfo() because kmalloc and proc don't
|
|
* work yet when it is called.
|
|
*/
|
|
struct proc_dir_entry *pde;
|
|
|
|
if (!bootinfo_size)
|
|
return -EINVAL;
|
|
|
|
bootinfo_copy = kmemdup(bootinfo_tmp, bootinfo_size, GFP_KERNEL);
|
|
if (!bootinfo_copy)
|
|
return -ENOMEM;
|
|
|
|
pde = proc_create_data("bootinfo", 0400, NULL, &bootinfo_fops, NULL);
|
|
if (!pde) {
|
|
kfree(bootinfo_copy);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
arch_initcall(init_bootinfo_procfs);
|