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-rw-r--r--arch/arm/kernel/atags_proc.c83
1 files changed, 83 insertions, 0 deletions
diff --git a/arch/arm/kernel/atags_proc.c b/arch/arm/kernel/atags_proc.c
new file mode 100644
index 00000000000..42a1a1415fa
--- /dev/null
+++ b/arch/arm/kernel/atags_proc.c
@@ -0,0 +1,83 @@
+#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);