1 files changed, 86 insertions, 0 deletions
diff --git a/arch/arm/kernel/atags.c b/arch/arm/kernel/atags.c
new file mode 100644
index 00000000000..e2e934c3808
--- /dev/null
+++ b/arch/arm/kernel/atags.c
@@ -0,0 +1,86 @@
+#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, &proc_root, 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);