1 /* 2 * Based on arch/arm/kernel/atags_proc.c 3 */ 4 5 #include <linux/fs.h> 6 #include <linux/init.h> 7 #include <linux/printk.h> 8 #include <linux/proc_fs.h> 9 #include <linux/slab.h> 10 #include <linux/string.h> 11 12 #include <asm/bootinfo.h> 13 #include <asm/byteorder.h> 14 15 16 static char bootinfo_tmp[1536] __initdata; 17 18 static void *bootinfo_copy; 19 static size_t bootinfo_size; 20 21 static ssize_t bootinfo_read(struct file *file, char __user *buf, 22 size_t count, loff_t *ppos) 23 { 24 return simple_read_from_buffer(buf, count, ppos, bootinfo_copy, 25 bootinfo_size); 26 } 27 28 static const struct file_operations bootinfo_fops = { 29 .read = bootinfo_read, 30 .llseek = default_llseek, 31 }; 32 33 void __init save_bootinfo(const struct bi_record *bi) 34 { 35 const void *start = bi; 36 size_t size = sizeof(bi->tag); 37 38 while (be16_to_cpu(bi->tag) != BI_LAST) { 39 uint16_t n = be16_to_cpu(bi->size); 40 size += n; 41 bi = (struct bi_record *)((unsigned long)bi + n); 42 } 43 44 if (size > sizeof(bootinfo_tmp)) { 45 pr_err("Cannot save %zu bytes of bootinfo\n", size); 46 return; 47 } 48 49 pr_info("Saving %zu bytes of bootinfo\n", size); 50 memcpy(bootinfo_tmp, start, size); 51 bootinfo_size = size; 52 } 53 54 static int __init init_bootinfo_procfs(void) 55 { 56 /* 57 * This cannot go into save_bootinfo() because kmalloc and proc don't 58 * work yet when it is called. 59 */ 60 struct proc_dir_entry *pde; 61 62 if (!bootinfo_size) 63 return -EINVAL; 64 65 bootinfo_copy = kmemdup(bootinfo_tmp, bootinfo_size, GFP_KERNEL); 66 if (!bootinfo_copy) 67 return -ENOMEM; 68 69 pde = proc_create_data("bootinfo", 0400, NULL, &bootinfo_fops, NULL); 70 if (!pde) { 71 kfree(bootinfo_copy); 72 return -ENOMEM; 73 } 74 75 return 0; 76 } 77 78 arch_initcall(init_bootinfo_procfs); 79