While Daniel González and me were fighting with jffs2 tested some code
extracted from Netgear. Here are what we found.
We only tested brcm_wait, broadcom checksum code and the modification in
tlbex.c and nothing strange happened when we flashed it.
Hope this could help for the Broadcom SoCs and maybe others.
diff -urN b/include/asm-mips/checksum.h a/include/asm-mips/checksum.h
--- b/include/asm-mips/checksum.h 2007-06-12 16:13:11.0 +0200
+++ a/include/asm-mips/checksum.h 2010-05-31 03:43:32.0 +0200
@@ -98,6 +98,64 @@
* By Jorge Cwik jo...@laser.satlink.net, adapted for linux by
* Arnt Gulbrandsen.
*/
+
+#if defined(CONFIG_MIPS_BRCM)
+
+/* Brcm version can handle unaligned data. Merged from brcm 2.6.8
kernel.*/
+static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
+{
+ if (((__u32)iph0x3) == 0) {
+ unsigned int *word = (unsigned int *) iph;
+ unsigned int *stop = word + ihl;
+ unsigned int csum;
+ int carry;
+
+ csum = word[0];
+ csum += word[1];
+ carry = (csum word[1]);
+ csum += carry;
+
+ csum += word[2];
+ carry = (csum word[2]);
+ csum += carry;
+
+ csum += word[3];
+ carry = (csum word[3]);
+ csum += carry;
+
+ word += 4;
+ do {
+ csum += *word;
+ carry = (csum *word);
+ csum += carry;
+ word++;
+ } while (word != stop);
+
+ return csum_fold(csum);
+ } else {
+ __u16 * buff = (__u16 *) iph;
+ __u32 sum=0;
+ __u16 i;
+
+ // make 16 bit words out of every two adjacent 8 bit words in
the packet
+ // and add them up
+ for (i=0;iihl*2;i++){
+ sum = sum + (__u32) buff[i];
+ }
+
+ // take only 16 bits out of the 32 bit sum and add up the
carries
+ while (sum16)
+ sum = (sum 0x)+(sum 16);
+
+ // one's complement the result
+ sum = ~sum;
+
+ return ((__sum16) sum);
+ }
+}
+
+#else
+
static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
{
const unsigned int *word = iph;
@@ -129,6 +187,8 @@
return csum_fold(csum);
}
+#endif
+
static inline __wsum csum_tcpudp_nofold(__be32 saddr,
__be32 daddr, unsigned short len, unsigned short proto,
__wsum sum)
--
diff -urN b/drivers/mtd/mtd_blkdevs.c a/drivers/mtd/mtd_blkdevs.c
--- b/drivers/mtd/mtd_blkdevs.c 2007-06-12 16:13:11.0 +0200
+++ a/drivers/mtd/mtd_blkdevs.c 2010-05-31 03:52:56.0 +0200
@@ -21,6 +21,9 @@
#include linux/init.h
#include linux/mutex.h
#include asm/uaccess.h
+#if defined(CONFIG_MIPS_BRCM)
+#include linux/syscalls.h
+#endif
static LIST_HEAD(blktrans_majors);
@@ -80,13 +83,23 @@
struct mtd_blktrans_ops *tr = arg;
struct request_queue *rq = tr-blkcore_priv-rq;
+#if defined(CONFIG_MIPS_BRCM)
+#if defined (CONFIG_PREEMPT_SOFTIRQS)
+ /* mtdblockd needs to run at the same priority as ksoftirqd threads so
loading of applications from flash won't get blocked by network traffic.
+ One bad thing about blocking application loading is that voice
applications can be blocked by network traffic, despite that they have
higher
+ priority than network tasks. This would be a priority inversion
scenario if happens. */
+ struct sched_param param = { .sched_priority =
CONFIG_BRCM_SOFTIRQ_BASE_RT_PRIO };
+ sched_setscheduler(current, SCHED_RR, param);
+#endif
+#endif
+
/* we might get involved when memory gets low, so use PF_MEMALLOC */
current-flags |= PF_MEMALLOC | PF_NOFREEZE;
daemonize(%sd, tr-name);
/* daemonize() doesn't do this for us since some kernel threads
- actually want to deal with signals. We can't just call
+ actually want to deal with signals. We can't just call
exit_sighand() since that'll cause an oops when we finally
do exit. */
spin_lock_irq(current-sighand-siglock);
-
diff -urN b/include/linux/mmzone.h a/include/linux/mmzone.h
--- b/include/linux/mmzone.h2007-06-12 16:13:11.0 +0200
+++ a/include/linux/mmzone.h2010-05-31 03:45:11.0 +0200
@@ -306,7 +306,17 @@
* go. A value of 12 for DEF_PRIORITY implies that we will scan
1/4096th of the
* queues (queue_length 12) during an aging round.
*/
+
+#if defined(CONFIG_MIPS_BRCM)
+/* We normally have only 8M~32M of RAM while desktop systems
