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authorDavid Woodhouse <dwmw2@infradead.org>2008-05-30 06:57:27 -0400
committerDavid Woodhouse <David.Woodhouse@intel.com>2008-07-10 09:47:36 -0400
commitbacfe09dd7545467965e8d8f1eab20bc62dce00d (patch)
tree1f8b50e22439ef6d65089b3c5f875a6943b9c9df
parent88ecf814c47f577248751ddbe9626d98aeef5783 (diff)
ihex.h: binary representation of ihex records
Some devices need their firmware as a set of {address, len, data...} records in some specific order rather than a simple blob. The normal way of doing this kind of thing is 'ihex', which is a text format and not entirely suitable for use in the kernel. This provides a binary representation which is very similar, but much more compact -- and a helper routine to skip to the next record, because the alignment constraints mean that everybody will screw it up for themselves otherwise. Also a helper function which can verify that a 'struct firmware' contains a valid set of ihex records, and that following them won't run off the end of the loaded data. Signed-off-by: David Woodhouse <dwmw2@infradead.org>
-rw-r--r--include/linux/ihex.h50
1 files changed, 50 insertions, 0 deletions
diff --git a/include/linux/ihex.h b/include/linux/ihex.h
new file mode 100644
index 000000000000..df89edd890ae
--- /dev/null
+++ b/include/linux/ihex.h
@@ -0,0 +1,50 @@
1/*
2 * Compact binary representation of ihex records. Some devices need their
3 * firmware loaded in strange orders rather than a single big blob, but
4 * actually parsing ihex-as-text within the kernel seems silly. Thus,...
5 */
6
7#ifndef __LINUX_IHEX_H__
8#define __LINUX_IHEX_H__
9
10#include <linux/types.h>
11#include <linux/firmware.h>
12
13/* Intel HEX files actually limit the length to 256 bytes, but we have
14 drivers which would benefit from using separate records which are
15 longer than that, so we extend to 16 bits of length */
16struct ihex_binrec {
17 __be32 addr;
18 __be16 len;
19 uint8_t data[0];
20} __attribute__((aligned(4)));
21
22/* Find the next record, taking into account the 4-byte alignment */
23static inline const struct ihex_binrec *
24ihex_next_binrec(const struct ihex_binrec *rec)
25{
26 int next = ((be16_to_cpu(rec->len) + 5) & ~3) - 2;
27 rec = (void *)&rec->data[next];
28
29 return be16_to_cpu(rec->len) ? rec : NULL;
30}
31
32/* Check that ihex_next_binrec() won't take us off the end of the image... */
33static inline int ihex_validate_fw(const struct firmware *fw)
34{
35 const struct ihex_binrec *rec;
36 size_t ofs = 0;
37
38 while (ofs <= fw->size - sizeof(*rec)) {
39 rec = (void *)&fw->data[ofs];
40
41 /* Zero length marks end of records */
42 if (!be16_to_cpu(rec->len))
43 return 0;
44
45 /* Point to next record... */
46 ofs += (sizeof(*rec) + be16_to_cpu(rec->len) + 3) & ~3;
47 }
48 return -EINVAL;
49}
50#endif /* __LINUX_IHEX_H__ */