blob: 34b515a5bfad618f46c9d729ec0b0c8898b506d4 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
|
When invoking an LE kernel from a BE boot loader or vice versa
the ATAG_CMDLINE command line will be byte swapped, other ATAGs
are fine because they are 32 bit values.
This patch adds support for a command line option "swx " - which
must be at the start of the command line - and which is used to
detect a need to byte swap the rest of the command line.
Signed-off-by: John Bowler <jbowler@acm.org>
--- linux-2.6.15/arch/arm/kernel/setup.c 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.15/arch/arm/kernel/setup.c 1970-01-01 00:00:00.000000000 +0000
@@ -659,7 +659,34 @@ __tagtable(ATAG_REVISION, parse_tag_revi
static int __init parse_tag_cmdline(const struct tag *tag)
{
- strlcpy(default_command_line, tag->u.cmdline.cmdline, COMMAND_LINE_SIZE);
+ /* Check the first four bytes for "swx " (swap, but it's
+ * ok) or " xws" (command line is byte swapped)
+ */
+ const char *cmdline = tag->u.cmdline.cmdline;
+ u32 size = tag->hdr.size;
+
+ if (size > 0 && !memcmp(cmdline, " xws", 4)) {
+ cmdline += 4;
+
+ if (--size > 0) {
+ const u32 *from = (const u32*)cmdline;
+ u32 *to = (u32*)default_command_line;
+
+ if (size > COMMAND_LINE_SIZE/4)
+ size = COMMAND_LINE_SIZE/4;
+
+ while (size-- > 0)
+ to[size] = swab32(from[size]);
+
+ default_command_line[COMMAND_LINE_SIZE-1] = 0;
+ return 0;
+ }
+ }
+
+ if (size > 0 && !memcmp(cmdline, "swx ", 4))
+ cmdline += 4;
+
+ strlcpy(default_command_line, cmdline, COMMAND_LINE_SIZE);
return 0;
}
|
