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-rw-r--r--packages/linux/nslu2-kernel/2.6.15/10-mtdpart-redboot-fis-byteswap.patch67
1 files changed, 50 insertions, 17 deletions
diff --git a/packages/linux/nslu2-kernel/2.6.15/10-mtdpart-redboot-fis-byteswap.patch b/packages/linux/nslu2-kernel/2.6.15/10-mtdpart-redboot-fis-byteswap.patch
index edee083e3c..077aa00816 100644
--- a/packages/linux/nslu2-kernel/2.6.15/10-mtdpart-redboot-fis-byteswap.patch
+++ b/packages/linux/nslu2-kernel/2.6.15/10-mtdpart-redboot-fis-byteswap.patch
@@ -1,12 +1,45 @@
-On IXP4XX systems the FIS directory is big endian even with a little
-endian kernel. This patch recognises the FIS directory on such a
-system and byte swaps it to obtain a valid table based on the 'size'
-field of the FIS directory (the size field is know to always match the
-erase block size on such systems, and probably all systems.)
+drivers/mtd/redboot.c: recognise a foreign byte sex partition table
+The RedBoot boot loader writes flash partition tables containing native
+byte sex 32 bit values. When booting an opposite byte sex kernel (e.g. an
+LE kernel from BE RedBoot) the current MTD driver fails to handle the
+partition table and therefore is unable to generate the correct partition
+map for the flash.
+
+The patch recognises that the FIS directory (the partition table) is
+byte-reversed by examining the partition table size, which is known to be
+one erase block (this is an assumption made elsewhere in redboot.c). If
+the size matches the erase block after byte swapping the value then
+byte-reversal is assumed, if not no further action is taken. The patched
+code is fail safe; should redboot.c be changed to support a partition table
+with a modified size field the test will fail and the partition table will
+be assumed to have the host byte sex.
+
+If byte-reversal is detected the patch byte swaps the remainder of the 32
+bit fields in the copy of the table; this copy is then used to set up the
+MTD partition map.
+
+Signed-off-by: John Bowler <jbowler@acm.org>
+Signed-off-by: Andrew Morton <akpm@osdl.org>
+Modified slightly and
+Signed-off-by: David Woodhouse <dwmw2@infradead.org>
+
+Index: drivers/mtd/redboot.c
+===================================================================
+RCS file: /home/cvs/mtd/drivers/mtd/redboot.c,v
+retrieving revision 1.18
+retrieving revision 1.19
+diff -u -p -r1.18 -r1.19
--- linux-2.6.15/drivers/mtd/redboot.c 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.15/drivers/mtd/redboot.c 1970-01-01 00:00:00.000000000 +0000
-@@ -89,8 +89,34 @@
+@@ -1,5 +1,5 @@
+ /*
+- * $Id: redboot.c,v 1.18 2005/11/07 11:14:21 gleixner Exp $
++ * $Id: redboot.c,v 1.19 2005/12/01 10:03:51 dwmw2 Exp $
+ *
+ * Parse RedBoot-style Flash Image System (FIS) tables and
+ * produce a Linux partition array to match.
+@@ -89,8 +89,32 @@ static int parse_redboot_partitions(stru
i = numslots;
break;
}
@@ -14,10 +47,10 @@ erase block size on such systems, and probably all systems.)
+ if (!memcmp(buf[i].name, "FIS directory", 14)) {
+ /* This is apparently the FIS directory entry for the
+ * FIS directory itself. The FIS directory size is
-+ * one erase block, if the buf[i].size field is
++ * one erase block; if the buf[i].size field is
+ * swab32(erasesize) then we know we are looking at
+ * a byte swapped FIS directory - swap all the entries!
-+ * (NOTE: this is 'size' not 'data_length', size is
++ * (NOTE: this is 'size' not 'data_length'; size is
+ * the full size of the entry.)
+ */
+ if (swab32(buf[i].size) == master->erasesize) {
@@ -26,15 +59,13 @@ erase block size on such systems, and probably all systems.)
+ /* The unsigned long fields were written with the
+ * wrong byte sex, name and pad have no byte sex.
+ */
-+# define do_swab32(x) (x) = swab32(x)
-+ do_swab32(buf[j].flash_base);
-+ do_swab32(buf[j].mem_base);
-+ do_swab32(buf[j].size);
-+ do_swab32(buf[j].entry_point);
-+ do_swab32(buf[j].data_length);
-+ do_swab32(buf[j].desc_cksum);
-+ do_swab32(buf[j].file_cksum);
-+# undef do_swab32
++ swab32s(&buf[j].flash_base);
++ swab32s(&buf[j].mem_base);
++ swab32s(&buf[j].size);
++ swab32s(&buf[j].entry_point);
++ swab32s(&buf[j].data_length);
++ swab32s(&buf[j].desc_cksum);
++ swab32s(&buf[j].file_cksum);
+ }
+ }
break;
@@ -42,3 +73,5 @@ erase block size on such systems, and probably all systems.)
}
if (i == numslots) {
/* Didn't find it */
+
+