| #include <linux/slab.h> |
| #include <linux/kexec.h> |
| #include <linux/proc_fs.h> |
| #include <asm/setup.h> |
| #include <asm/types.h> |
| #include <asm/page.h> |
| |
| struct buffer { |
| size_t size; |
| char *data; |
| }; |
| static struct buffer tags_buffer; |
| |
| static int |
| read_buffer(char* page, char** start, off_t off, int count, |
| int* eof, void* data) |
| { |
| struct buffer *buffer = (struct buffer *)data; |
| |
| if (off >= buffer->size) { |
| *eof = 1; |
| return 0; |
| } |
| |
| count = min((int) (buffer->size - off), count); |
| |
| memcpy(page, &buffer->data[off], count); |
| |
| return count; |
| } |
| |
| |
| static int |
| create_proc_entries(void) |
| { |
| struct proc_dir_entry* tags_entry; |
| |
| tags_entry = create_proc_read_entry("atags", 0400, NULL, read_buffer, &tags_buffer); |
| if (!tags_entry) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| |
| |
| static char __initdata atags_copy_buf[KEXEC_BOOT_PARAMS_SIZE]; |
| static char __initdata *atags_copy; |
| |
| void __init save_atags(const struct tag *tags) |
| { |
| atags_copy = atags_copy_buf; |
| memcpy(atags_copy, tags, KEXEC_BOOT_PARAMS_SIZE); |
| } |
| |
| |
| static int __init init_atags_procfs(void) |
| { |
| struct tag *tag; |
| int error; |
| |
| if (!atags_copy) { |
| printk(KERN_WARNING "Exporting ATAGs: No saved tags found\n"); |
| return -EIO; |
| } |
| |
| for (tag = (struct tag *) atags_copy; tag->hdr.size; tag = tag_next(tag)) |
| ; |
| |
| tags_buffer.size = ((char *) tag - atags_copy) + sizeof(tag->hdr); |
| tags_buffer.data = kmalloc(tags_buffer.size, GFP_KERNEL); |
| if (tags_buffer.data == NULL) |
| return -ENOMEM; |
| memcpy(tags_buffer.data, atags_copy, tags_buffer.size); |
| |
| error = create_proc_entries(); |
| if (error) { |
| printk(KERN_ERR "Exporting ATAGs: not enough memory\n"); |
| kfree(tags_buffer.data); |
| tags_buffer.size = 0; |
| tags_buffer.data = NULL; |
| } |
| |
| return error; |
| } |
| |
| arch_initcall(init_atags_procfs); |