Logo Search packages:      
Sourcecode: linux-2.6 version File versions

atags.c

#include <linux/slab.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 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;
}

#define BOOT_PARAMS_SIZE 1536
static char __initdata atags_copy[BOOT_PARAMS_SIZE];

void __init save_atags(const struct tag *tags)
{
      memcpy(atags_copy, tags, sizeof(atags_copy));
}

static int __init init_atags_procfs(void)
{
      /*
       * This cannot go into save_atags() because kmalloc and proc don't work
       * yet when it is called.
       */
      struct proc_dir_entry *tags_entry;
      struct tag *tag = (struct tag *)atags_copy;
      struct buffer *b;
      size_t size;

      if (tag->hdr.tag != ATAG_CORE) {
            printk(KERN_INFO "No ATAGs?");
            return -EINVAL;
      }

      for (; tag->hdr.size; tag = tag_next(tag))
            ;

      /* include the terminating ATAG_NONE */
      size = (char *)tag - atags_copy + sizeof(struct tag_header);

      WARN_ON(tag->hdr.tag != ATAG_NONE);

      b = kmalloc(sizeof(*b) + size, GFP_KERNEL);
      if (!b)
            goto nomem;

      b->size = size;
      memcpy(b->data, atags_copy, size);

      tags_entry = create_proc_read_entry("atags", 0400,
                  NULL, read_buffer, b);

      if (!tags_entry)
            goto nomem;

      return 0;

nomem:
      kfree(b);
      printk(KERN_ERR "Exporting ATAGs: not enough memory\n");

      return -ENOMEM;
}
arch_initcall(init_atags_procfs);

Generated by  Doxygen 1.6.0   Back to index